Highlighted Text:
Show |
Hide
Full text loading...
Chapter 6 : The Structure, Function, and Composition of the Microsporidian Polar Tube
Authors:
Elaine M. Keohane1,
Louis M. Weiss2
VIEW AFFILIATIONS
HIDE AFFILIATIONS
Affiliations:
1: Department of Clinical Laboratory Sciences, University of Medicine and Dentistry of New Jersey, Newark, NJ 07107;
2: Division of Infectious Diseases and Division of Parasitology, Albert Einstein College of Medicine, Bronx, NY 10461
Content Type: Monograph
Publication Year:
1999
Category: Fungi and Fungal Pathogenesis
Book DOI:
10.1128/9781555818227
Chapter DOI:
10.1128/9781555818227.ch6
MyBook is a cheap paperback edition of the original book and will be sold at uniform, low price.
Preview this chapter:
The Structure, Function, and Composition of the Microsporidian Polar Tube, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555818227/9781555811471_Chap06-1.gif /docserver/preview/fulltext/10.1128/9781555818227/9781555811471_Chap06-2.gif
Abstract:
The spores of microsporidia possess a unique, highly specialized structure, the polar tube, which is used to inject the parasite from the spore into a new host cell. Several theories have been proposed regarding the method by which the sporoplasm exits the spore and on the function of the polar filament or tube in this process. Electron-dense, particulate material fills the center of the filament. Weidner proposed that this material was unpolymerized polar tube protein (PTP). On the basis of ultrastructural observations, the eversion of the polar tube has been likened to a tube sliding within a tube. This chapter presents details on spore activation and discharge. When sporoblasts form, each one contains five to six coils of the preformed polar filament with the anchoring disk positioned at the anterior end. The major amino acids coded by the Encephalitozoon hellem and Encephalitozoon cuniculi PTP genes were proline and glycine. Application of the techniques of modern biology has resulted in the identification of several PTPs although the interactions and functional significance of these proteins remains to be determined.
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
Key Concept Ranking
- Rough Endoplasmic Reticulum
- 0.51159793
- High-Performance Liquid Chromatography
- 0.46051854
- Sodium Dodecyl Sulfate
- 0.46051854
- High-Performance Liquid Chromatography
- 0.46051854
- Transmission Electron Microscopy
- 0.45259506
0.51159793
Figures
The Structure, Function, and Composition of the Microsporidian Polar Tube
[com.pub2web.rdf.cci.facet.ContentItem[id=http://asm.metastore.ingenta.com/content/author/10.1128/9781555818227.chap6-1,webId=/content/author/10.1128/9781555818227.chap6-1,properties={foaf_givenname=Elaine M., foaf_name=Elaine M. Keohane, foaf_surname=Keohane, pub_isAffiliatedWith=[com.pub2web.rdf.cci.facet.ContentItem[id=http://asm.metastore.ingenta.com/content/affiliation/10.1128/9781555818227.chap6-aff1]]}], com.pub2web.rdf.cci.facet.ContentItem[id=http://asm.metastore.ingenta.com/content/author/10.1128/9781555818227.chap6-2,webId=/content/author/10.1128/9781555818227.chap6-2,properties={foaf_givenname=Louis M., foaf_name=Louis M. Weiss, foaf_surname=Weiss, pub_isAffiliatedWith=[com.pub2web.rdf.cci.facet.ContentItem[id=http://asm.metastore.ingenta.com/content/affiliation/10.1128/9781555818227.chap6-aff2]]}]]
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-1
FIGURE 1
Polar tube extrusion. A spore of the microsporidium Thelohania magna after polar tube extrusion by mechanical pressure is shown ( Kudo, 1920 ).
10.1128/9781555818227/fig6-1_thmb.gif
10.1128/9781555818227/fig6-1.gif
FIGURE 1
Polar tube extrusion. A spore of the microsporidium Thelohania magna after polar tube extrusion by mechanical pressure is shown ( Kudo, 1920 ).
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-2
FIGURE 2
Scanning electron micrograph of sporoplasm passage. The micrograph shows an Encephalitozoon intestinalis spore with an extruded polar tube. Arrows indicate sporoplasm passage through the polar tube. (Reprinted with permission from Kock, 1998 .)
10.1128/9781555818227/fig6-2_thmb.gif
10.1128/9781555818227/fig6-2.gif
FIGURE 2
Scanning electron micrograph of sporoplasm passage. The micrograph shows an Encephalitozoon intestinalis spore with an extruded polar tube. Arrows indicate sporoplasm passage through the polar tube. (Reprinted with permission from Kock, 1998 .)
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-3
FIGURE 3
Scanning electron micrograph of a microsporidian infection of a host cell. The micrograph shows an extruded polar tube of a spore of E. intestinalis piercing and infecting Vero E6 green monkey kidney cells in tissue culture. (Reprinted with permission from Kock, 1998 .)
10.1128/9781555818227/fig6-3_thmb.gif
10.1128/9781555818227/fig6-3.gif
FIGURE 3
Scanning electron micrograph of a microsporidian infection of a host cell. The micrograph shows an extruded polar tube of a spore of E. intestinalis piercing and infecting Vero E6 green monkey kidney cells in tissue culture. (Reprinted with permission from Kock, 1998 .)
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-4
FIGURE 4
Diagram of a microsporidian spore. Spores range in size from 1 to 10 μm. The spore coat consists of an electron-dense exospore (Ex), electron-lucent endospore (En), and plasma membrane (Pm). It is thinner at the anterior end of the spore. The sporoplasm (Sp) contains a single nucleus (Nu), the posterior vacuole (PV), and ribosomes. The polar filament is attached to the anterior end of the spore by an anchoring disk (AD) and is divided into two regions: the manubroid or straight portion (M) and the posterior region forming five coils (PT) around the sporoplasm. The manubroid polar filament is surrounded by the lamellar polaroplast (PI) and vesicular polaroplast (VP1). The inset depicts a cross section of the polar tube coils (five coils in this spore), demonstating the various concentric layers of different electron density and electron-dense core present in such cross sections.
10.1128/9781555818227/fig6-4_thmb.gif
10.1128/9781555818227/fig6-4.gif
FIGURE 4
Diagram of a microsporidian spore. Spores range in size from 1 to 10 μm. The spore coat consists of an electron-dense exospore (Ex), electron-lucent endospore (En), and plasma membrane (Pm). It is thinner at the anterior end of the spore. The sporoplasm (Sp) contains a single nucleus (Nu), the posterior vacuole (PV), and ribosomes. The polar filament is attached to the anterior end of the spore by an anchoring disk (AD) and is divided into two regions: the manubroid or straight portion (M) and the posterior region forming five coils (PT) around the sporoplasm. The manubroid polar filament is surrounded by the lamellar polaroplast (PI) and vesicular polaroplast (VP1). The inset depicts a cross section of the polar tube coils (five coils in this spore), demonstating the various concentric layers of different electron density and electron-dense core present in such cross sections.
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-5
FIGURE 5
Transmission electron micrograph of a longitudinal section of a spore of Plistophora hyphessobryconis. The manubroid polar filament (M) is attached to the anterior end of the spore by an anchoring disk (open arrow) and then forms 33 coils (Pt and solid arrow) around the sporoplasm in one to three rows. PI, lamellar polaroplast; e, electron-lucent endospore. Note that the endopsore layer is thinner at the apical end and that the polar tube contains concentric layers of varying electron density with a dense core. The spore measures 2.8 by 4.6 μm. (Reprinted with permission from Lom and Corliss, 1967 .)
10.1128/9781555818227/fig6-5_thmb.gif
10.1128/9781555818227/fig6-5.gif
FIGURE 5
Transmission electron micrograph of a longitudinal section of a spore of Plistophora hyphessobryconis. The manubroid polar filament (M) is attached to the anterior end of the spore by an anchoring disk (open arrow) and then forms 33 coils (Pt and solid arrow) around the sporoplasm in one to three rows. PI, lamellar polaroplast; e, electron-lucent endospore. Note that the endopsore layer is thinner at the apical end and that the polar tube contains concentric layers of varying electron density with a dense core. The spore measures 2.8 by 4.6 μm. (Reprinted with permission from Lom and Corliss, 1967 .)
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-6
FIGURE 6
Morphology of anchoring disk. (A) Electron micrograph of the anterior portion of a longitudinal section of a spore of Nosema algeme showing the mushroom-shaped anchoring disk (a) connected to the manubroid polar filament (p).The polar filament and anchoring disk are surrounded by a limiting membrane. Note the thin endospore area above the anchoring disk. (Reprinted with permission from Peter M.Takvorian.) (B) Electron micrograph of the anterior portion of a longitudinal section of a spore of a Nosema sp. showing polar filament extrusion. Collarlike structures (a) formed from the anchoring disk hold the polar tube (p) in place during extrusion. This figure also demonstrates eversion of the polar tube. Note that the hinge region (dark lines in the anchoring disk) and the anchoring disk have rotated 90° during extrusion of the polar tube. (Reprinted with permission from Lom, 1972 .)
10.1128/9781555818227/fig6-6_thmb.gif
10.1128/9781555818227/fig6-6.gif
FIGURE 6
Morphology of anchoring disk. (A) Electron micrograph of the anterior portion of a longitudinal section of a spore of Nosema algeme showing the mushroom-shaped anchoring disk (a) connected to the manubroid polar filament (p).The polar filament and anchoring disk are surrounded by a limiting membrane. Note the thin endospore area above the anchoring disk. (Reprinted with permission from Peter M.Takvorian.) (B) Electron micrograph of the anterior portion of a longitudinal section of a spore of a Nosema sp. showing polar filament extrusion. Collarlike structures (a) formed from the anchoring disk hold the polar tube (p) in place during extrusion. This figure also demonstrates eversion of the polar tube. Note that the hinge region (dark lines in the anchoring disk) and the anchoring disk have rotated 90° during extrusion of the polar tube. (Reprinted with permission from Lom, 1972 .)
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-7
FIGURE 7
Polar tube solubility. Shown are negative stain transmission electron micrographs of spores of Glugea americanus disrupted with 0.5 μm acid washed glass beads in a Mini Beadbeater (Biospec Products, Bardesville, Okla.). (Panels 1 and 2) Disrupted spores after being extracted five times with 1% SDS and once with 9 M urea. Note broken spores (S) and straight and twisted polar tubes (PT and closed arrows). (Panel 3) Disrupted spores after being washed five times with 1% SDS and once with 9 M urea and incubated 2 h with 2% DTT. Note broken spores (S), lack of spore contents (open arrows), and absence of polar tubes. (Reprinted with permission from Keohane et al., 1996c.)
10.1128/9781555818227/fig6-7_thmb.gif
10.1128/9781555818227/fig6-7.gif
FIGURE 7
Polar tube solubility. Shown are negative stain transmission electron micrographs of spores of Glugea americanus disrupted with 0.5 μm acid washed glass beads in a Mini Beadbeater (Biospec Products, Bardesville, Okla.). (Panels 1 and 2) Disrupted spores after being extracted five times with 1% SDS and once with 9 M urea. Note broken spores (S) and straight and twisted polar tubes (PT and closed arrows). (Panel 3) Disrupted spores after being washed five times with 1% SDS and once with 9 M urea and incubated 2 h with 2% DTT. Note broken spores (S), lack of spore contents (open arrows), and absence of polar tubes. (Reprinted with permission from Keohane et al., 1996c.)
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-8
FIGURE 8
Immunogold electron microscopy of a polar tube-specific monoclonal antibody. Shown is an immunogold electron micrograph of a G. americanus spore with mAb 3C8.23.1 ( Keohane et al., 1994 ), and a secondary antibody labeled with 12-nm colloidal gold, stained with 1% uranyl acetate. (Panels 1 to 3) Note gold localization on longitudinal, transverse, and cross sections of polar tubes (PT). (Panel 4) four polar tube (PT) cross sections, a portion of the lamellar polaroplast (PL), and a sagittal cut through the anterior straight portion (manubroid) of the polar tube (MPT) indicated by arrowheads. Note the localization of the gold on the “sheath” or outer portion, the “dense” core or center, and the medium-dense material of the polar tube. (Reprinted with permission from Keohane etal, 1996c).
10.1128/9781555818227/fig6-8_thmb.gif
10.1128/9781555818227/fig6-8.gif
FIGURE 8
Immunogold electron microscopy of a polar tube-specific monoclonal antibody. Shown is an immunogold electron micrograph of a G. americanus spore with mAb 3C8.23.1 ( Keohane et al., 1994 ), and a secondary antibody labeled with 12-nm colloidal gold, stained with 1% uranyl acetate. (Panels 1 to 3) Note gold localization on longitudinal, transverse, and cross sections of polar tubes (PT). (Panel 4) four polar tube (PT) cross sections, a portion of the lamellar polaroplast (PL), and a sagittal cut through the anterior straight portion (manubroid) of the polar tube (MPT) indicated by arrowheads. Note the localization of the gold on the “sheath” or outer portion, the “dense” core or center, and the medium-dense material of the polar tube. (Reprinted with permission from Keohane etal, 1996c).
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-9
FIGURE 9
HPLC purification of G. amerkanus polar tube components. Reverse-phase HPLC of the DTT-solubilized PTPs of G. ameriamus obtained from SDS-urea extracted spores was performed. Spores of G. americanus were disrupted by glass beads and sequentially extracted according to a previously published protocol ( Keohane et al., 1994 , 1996c ). The proteins were subjected to reductive alkylation by 4-vinylpyridine, followed by reverse-phase HPLC with a linear gradient of H2O and acetonitrile containing 0.1% trifluoroacetic acid ( Keohane et al., 1996a ). (Inset, lane A) SDS-PAGE (10% polyacrylamide) silver stain of the major ultraviolet-absorbing peak, demonstrating a 43-kDa protein. Peaks corresponding to the previously reported 23- and 34-kDa proteins in the DTT-solubilized material were also identified. (Inset, lane B) The purified 43-kDa PTP demonstrated strong immunoblot activity with polar tube specific mAb 3C8.23.1. (Inset, lane C) A polyclonal mouse antiserum to this 43-kDa protein (anti-Ga PTP43) reacted with a 43-kDa antigen in G. americanus spore lysate. Anti-Ga PTP43 also reacted with extruded and intrasporal polar tubes of G. americanus spores by immunogold electron microscopy. (Reprinted with permission from Keohane et al., 1996c .)
10.1128/9781555818227/fig6-9_thmb.gif
10.1128/9781555818227/fig6-9.gif
FIGURE 9
HPLC purification of G. amerkanus polar tube components. Reverse-phase HPLC of the DTT-solubilized PTPs of G. ameriamus obtained from SDS-urea extracted spores was performed. Spores of G. americanus were disrupted by glass beads and sequentially extracted according to a previously published protocol ( Keohane et al., 1994 , 1996c ). The proteins were subjected to reductive alkylation by 4-vinylpyridine, followed by reverse-phase HPLC with a linear gradient of H2O and acetonitrile containing 0.1% trifluoroacetic acid ( Keohane et al., 1996a ). (Inset, lane A) SDS-PAGE (10% polyacrylamide) silver stain of the major ultraviolet-absorbing peak, demonstrating a 43-kDa protein. Peaks corresponding to the previously reported 23- and 34-kDa proteins in the DTT-solubilized material were also identified. (Inset, lane B) The purified 43-kDa PTP demonstrated strong immunoblot activity with polar tube specific mAb 3C8.23.1. (Inset, lane C) A polyclonal mouse antiserum to this 43-kDa protein (anti-Ga PTP43) reacted with a 43-kDa antigen in G. americanus spore lysate. Anti-Ga PTP43 also reacted with extruded and intrasporal polar tubes of G. americanus spores by immunogold electron microscopy. (Reprinted with permission from Keohane et al., 1996c .)
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-10
FIGURE 10
Comparison of G. americanus and E. intestinalis PTPs. Reverse-phase HPLC of the major DTT-solubilized PTP of G. americanus and E. intestinalis was performed. The method of purification is the same as that shown in Fig. 9 . Note the similarity in the retention times of the PTPs of these two microsporidia.
10.1128/9781555818227/fig6-10_thmb.gif
10.1128/9781555818227/fig6-10.gif
FIGURE 10
Comparison of G. americanus and E. intestinalis PTPs. Reverse-phase HPLC of the major DTT-solubilized PTP of G. americanus and E. intestinalis was performed. The method of purification is the same as that shown in Fig. 9 . Note the similarity in the retention times of the PTPs of these two microsporidia.
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-11
FIGURE 11
Transmission electron micrographs of polar tube discharge. Electron micrographs of anterior portion of longitudinal sections of the spores of N. algerae are shown. (Panel 1) Swelling of the anterior end of the spore and disruption of the anchoring disk. Note protein filaments already present above the anterior end of the spore. (Panel 2) Eversion of polar tube membrane (arrow) and release of material (presumably PTP) from the polar tube (p). (Panel 3) Further formation of the polar tube (p). Note polar tube membrane and deposition of PTP coat on the outside of the membrane (arrow). (Reprinted with permission from Peter M.Takvorian.)
10.1128/9781555818227/fig6-11_thmb.gif
10.1128/9781555818227/fig6-11.gif
FIGURE 11
Transmission electron micrographs of polar tube discharge. Electron micrographs of anterior portion of longitudinal sections of the spores of N. algerae are shown. (Panel 1) Swelling of the anterior end of the spore and disruption of the anchoring disk. Note protein filaments already present above the anterior end of the spore. (Panel 2) Eversion of polar tube membrane (arrow) and release of material (presumably PTP) from the polar tube (p). (Panel 3) Further formation of the polar tube (p). Note polar tube membrane and deposition of PTP coat on the outside of the membrane (arrow). (Reprinted with permission from Peter M.Takvorian.)
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-12
FIGURE 12
Model of polar tube discharge. (A) A resting spore. (B) Initial eversion of the polar filament. Note that the anchoring disk has everted or rotated to form a collar and that the polaroplast membranes have swollen. Unpolymerized PTP is released from the polar tube core and polymerizes on the outside of the membrane scaffolding as it is being everted. AD, anchoring disk, PI, polaroplast membranes: Ex, exospore; En, endospore; PT, polar tube; PTP, polar tube protein(s).
10.1128/9781555818227/fig6-12_thmb.gif
10.1128/9781555818227/fig6-12.gif
FIGURE 12
Model of polar tube discharge. (A) A resting spore. (B) Initial eversion of the polar filament. Note that the anchoring disk has everted or rotated to form a collar and that the polaroplast membranes have swollen. Unpolymerized PTP is released from the polar tube core and polymerizes on the outside of the membrane scaffolding as it is being everted. AD, anchoring disk, PI, polaroplast membranes: Ex, exospore; En, endospore; PT, polar tube; PTP, polar tube protein(s).
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-13
FIGURE 13
Model of sporoplasm exit from microsporidian spores. (A) As the polar tube (PT) continues to form with polymerization of the polar tube protein(s) (PTP), the polaroplast membrane begins to enter the hollow portion of the tube. The posterior vacuole (PV) starts to enlarge. (B) Sporoplasm (SP) and nucleus (Nu) flow into the tube surrounded by the polaroplast membrane (PI), leaving behind the plasma membrane (Pm) (still attached to the spore coat [Ex and En]).The polar tube has penetrated a host cell, and the posterior vacuole (PV) has swollen and fills the space vacated by the sporoplasm. The swelling of the posterior vacuole generates the osmotic pressure driving the extrusion of the contents of the spore. (C) After the polar tube has pierced the host cell membrane, the sporoplasm and nucleus now surrounded by the polaroplast membrane emerge from the tip of the hollow polar tube inside the host cell. The spore contains the plasma membrane (Pm), posterior vacuole (PV), and spore coat (exospore [Ex] and endospore [En]) which are left behind. The limiting membrane of the sporoplasm in the host cell is provided by the polaroplast membranes (PI).
10.1128/9781555818227/fig6-13_thmb.gif
10.1128/9781555818227/fig6-13.gif
FIGURE 13
Model of sporoplasm exit from microsporidian spores. (A) As the polar tube (PT) continues to form with polymerization of the polar tube protein(s) (PTP), the polaroplast membrane begins to enter the hollow portion of the tube. The posterior vacuole (PV) starts to enlarge. (B) Sporoplasm (SP) and nucleus (Nu) flow into the tube surrounded by the polaroplast membrane (PI), leaving behind the plasma membrane (Pm) (still attached to the spore coat [Ex and En]).The polar tube has penetrated a host cell, and the posterior vacuole (PV) has swollen and fills the space vacated by the sporoplasm. The swelling of the posterior vacuole generates the osmotic pressure driving the extrusion of the contents of the spore. (C) After the polar tube has pierced the host cell membrane, the sporoplasm and nucleus now surrounded by the polaroplast membrane emerge from the tip of the hollow polar tube inside the host cell. The spore contains the plasma membrane (Pm), posterior vacuole (PV), and spore coat (exospore [Ex] and endospore [En]) which are left behind. The limiting membrane of the sporoplasm in the host cell is provided by the polaroplast membranes (PI).
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-14
FIGURE 14
Extruded polar tube, demonstrating membranes and polar tube protein coat. A transmission electron micrograph of an extruded polar tube of N. algerae demonstrating a polar tube membrane (curved arrow) and the coating of PTP over the membrane (straight arrow) is shown. (Reprinted with permission from Peter M. Takvorian.)
10.1128/9781555818227/fig6-14_thmb.gif
10.1128/9781555818227/fig6-14.gif
FIGURE 14
Extruded polar tube, demonstrating membranes and polar tube protein coat. A transmission electron micrograph of an extruded polar tube of N. algerae demonstrating a polar tube membrane (curved arrow) and the coating of PTP over the membrane (straight arrow) is shown. (Reprinted with permission from Peter M. Takvorian.)
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.fig6-15
FIGURE 15
Micrograph of sporoplasm passage through the polar tube. A negative stain of transmission electron microscopy of discharged spores of Nosema michaelis (A. mkhaelis) shows extruded polar tubes. Arrows indicate appearance of sporoplasm at the end of the discharged polar tube. (Reprinted with permission from Weidner, 1972 .)
10.1128/9781555818227/fig6-15_thmb.gif
10.1128/9781555818227/fig6-15.gif
FIGURE 15
Micrograph of sporoplasm passage through the polar tube. A negative stain of transmission electron microscopy of discharged spores of Nosema michaelis (A. mkhaelis) shows extruded polar tubes. Arrows indicate appearance of sporoplasm at the end of the discharged polar tube. (Reprinted with permission from Weidner, 1972 .)
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
References
/content/book/10.1128/9781555818227.chap6
1.
Bailey, L. 1955. The infection of the ventriculus of the adult honeybee by Nosema apis Zander. Parasitology 45: 86– 94.
2.
Bardehle, G.,, A. Jepp-Libutzki,, D. Linder,, K. Moehnle,, H. H. Schott,, H. Zahner,, U. Zahringer,, and S. Stirm. 1992. Chemical composition of Litomosoides carinii microfilarial sheaths. Acta Trop. 50: 237– 247.
3.
Beckers, P. J. A.,, G. J. M. M. Derks,, T. van Gool,, E. J. R. Rietveld,, and R. W. Sauerwien. 1996. Encephalitozoon intestinalis-specific monoclonal antibodies for laboratory diagnosis of microsporidiosis. J. Clin. Microbiol. 34: 282– 285.
4.
Biderre, C.,, M. Pages,, G. Metenier,, E. U. Canning,, and C. P. Vivares. 1995. Evidence for the smallest nuclear genome (2.9 Mb) in the microsporidium Encephalitozoon cuniculi. Mol. Biochem. Parasitol. 74: 229– 231.
5.
Cali, A.,, and R. L. Owen,. 1988. Microsporidiosis, p. 929– 950. In A. Ballows,, W. J. Hausler Jr.,, M. Ohashi,, and H. Turano (eds.), Laboratory Diagnosis of Infectious Diseases: Principles and Practice, vol. 1. Springer-Verlag, New York.
6.
Cali, A.,, and R. L. Owen. 1990. Intracellular development of Enterocytozoon, a unique microsporidian found in the intestine of AIDS patients. J. Protozool, 37: 145– 155.
7.
Canning, E. U.,, and J. Lorn. 1986. The Microsporidia of Vertebrates, p. 1– 16. Academic Press, New York.
8.
Chilmonczyk, S.,, W. T. Cox,, and R. P. Hedrick. 1991. Enterocytozoon salmonis n. sp.: an intranuclear microsporidium from salmonid fish. J. Protozool. 38: 264– 269.
9.
Chioralia, G.,, T. Trammer,, W. A. Maier,, and H. M. Seitz. 1998. Morphologic changes in Nosema algerae (Microspora) during extrusion. Parasitol. Res. 84: 123– 131.
10.
Connet, A. 1932. Le cycle évolutif du Plistophora chironomi. Cellule 41: 181– 202.
11.
Connor, R. M. 1970. Disruption of microsporidian spores for serologic studies. J. Invertebr. Pathol. 15: 138.
12.
Dall, D. J. 1983. A theory for the mechanism of polar filament extrusion in the Microspora. J. Theor. Biol. 105: 647– 659.
13.
de Graaf, D. C.,, G. Masschelein,, F. Vandergeynst,, H. E. De Brabander,, and F. J. Jacobs. 1993. In vitro germination of Nosema apis (Microspora: Nosematidae) spores and its effect on their α-trehalose/d-glucose ratio. J. Invertebr. Pathol. 62: 220– 225.
14.
Delbac, F.,, F. Duffieux,, D. David,, G. Metenier,, and C. P. Vivares. 1998a. Immunocytochemical identification of spore proteins in two microsporidia, with emphasis on extrusion apparatus. J. Eukaryot. Microbiol. 45: 224– 231.
15.
Delbac, F.,, F. Duffieux,, P. Peyret,, D. David,, G. Metenier,, and C. Vivares. 1996. Identification of sporal proteins in two microsporidian species: an immunoblotting and immunocytochemical study. J. Eukaryot. Microbiol. 43: 101S.
16.
Delbac, F.,, P. Peyret,, G. Metenier,, D. David,, A. Danchin,, and C. P. Vivares. 1998b. On proteins of the microsporidian invasion apparatus: complete sequence of a polar tube protein in Encephalitozoon cuniculi. Mol. Microbiol. 29: 825– 834.
17.
Desportes-Livage, I.,, S. Chilmonczyk,, R. Hedrick,, C. Ombrouck,, D. Monge,, I. Maiga,, and M. Gentilini. 1996. Comparative development of two microsporidian species: Enterocytozoon bieneusi and Enterocytozoon salmonis, reported in AIDS patients and salmonid fish, respectively. J. Eukaryot. Microbiol. 43: 49– 60.
18.
Dissanaike, A. S. 1955. Emergence of the sporoplasm in Nosema helminthorum. Nature 174: 1002– 1003.
19.
Dissanaike, A. S.,, and E. U. Canning. 1957. The mode of emergence of the sporoplasm in Microsporidia and its relation to the structure of the spore. Parasitology 47: 92– 99.
20.
Erickson, B.W., Jr.,, S. H. Vernick,, and V. Sprague. 1968. Electron microscope study of the everted polar filament of Glugea weissenbergi (Microsporida, Nosematidae). J. Protozool. 15: 758– 761.
21.
Fantham, H. B.,, and A. Porter. 1914. The morphology, biology, and economic importance of Nosema bombi n. sp. parasitic in various bumblebees ( Bombus spp.) Ann. Trop. Med. Parasitol. 8: 623– 638.
22.
Frixione, E.,, L. Ruiz,, J. Cerbon,, and A. H. Undeen. 1997. Germination of Nosema algerae (Microspora) spores: conditional inhibition by D 2O, ethanol and Hg 2+ suggests dependence of water influx upon membrane hydration and specific transmembrane pathways. J. Eukaryot. Microbiol. 44: 109– 116.
23.
Frixione, E.,, L. Ruiz,, M. Santillan,, L.V. de Vargas,, J. M. Tejero,, and A. H. Undeen. 1992. Dynamics of polar filament discharge and sporoplasm expulsion by microsporidian spores. Cell Motil. Cytoskeleton 22: 38– 50.
24.
Frixione, E.,, L. Ruiz,, and A. H. Undeen. 1994. Monovalent cations induce microsporidian spore germination in vitro. J. Eukaryot. Microbiol. 41: 464– 468.
25.
Gibbs, A. J. 1953. Gurleya sp. (Microsporidia) found in the gut tissue of Trachea secalis (Lepidoptera). Parasitology 43: 143– 147.
26.
Hall, I. M. 1952. A new species of Microsporidia from the fawn-colored lawn moth, Crambus bonifatellus (Hulst) Lepidoptera, Crambidae. J. Parasitol. 38: 487– 491.
27.
Hashimoto, K.,, Y. Sasaki,, and K. Takinami. 1976. Conditions for extrusion of the polar filament of the spore of Plistophora anguillarum, a microsporidian parasite in Anguilla japonica. Bull. Jpn. Soc. Sci. Fish. 42: 837– 845.
28.
He, Q.,, G. J. Leitch,, G. S. Visvesvara,, and S. Wallace. 1996. Effects of nifedipine, metronidazole and nitric oxide donors on spore germination and cell culture infection of the microsporidia Encephalitozoon hellem and Encephalitozoon intestinalis. Antimicrob. Agents Chemother. 40: 179– 185.
29.
Huger, A. 1960. Electron microscope study on the cytology of a microsporidian spore by means of ultrathin sectioning. J. Insect Pathol. 2: 84– 105.
30.
Ishihara, R. 1967. Stimuli causing extrusion of polar filaments of Glugea fumiferanae spores. Can. J. Microbiol. 13: 1321– 1332.
31.
Ishihara, R. 1968. Some observations on the fine structure of sporoplasm discharged from spores of a microsporidian, Nosema bombycis. J. Invertebr. Pathol. 12: 245– 258.
32.
Iwano, H.,, and R. Ishihara. 1989. Intracellular germination of spores of a Nosema sp. immediately after their formation in cultured cell. J. Invertebr. Pathol. 54: 125– 127.
33.
Jensen, H. M.,, and S. R. Wellings. 1972. Development of the polar filament-polaroplast complex in a microsporidian parasite. J. Protozool. 19: 297– 305.
34.
Keohane, E. M.,, G. A. Orr,, R. M. Takvorian,, A. Cali,, H. B. Tanowitz,, M. Wittner,, and L. M. Weiss. 1996a. Purification and characterization of a microsporidian polar tube protein. Mol. Biochem. Parasitol. 79: 255– 259.
35.
Keohane, E. M.,, G. A. Orr,, R. M. Takvorian,, A. Cali,, H. B. Tanowitz,, M. Wittner,, and L. M. Weiss. 1996b. Purification and characterization of human microsporidian polar tube proteins. J. Eukaryot. Microbiol. 43: 100S.
36.
Keohane, E. M.,, G. A. Orr,, H. S. Zhang,, R. M. Takvorian,, A. Cali,, H. B. Tanowitz,, M. Wittner,, and L. M. Weiss. 1998. The molecular characterization of the major polar tube protein gene from Encephalitozoon hellem, a microsporidian parasite of humans. Mol. Biochem. Parasitol 94: 227– 236.
37.
Keohane, E.,, R. M. Takvorian,, A. Cali,, H. B. Tanowitz,, M. Wittner,, and L. M. Weiss. 1994. The identification and characterization of a polar tube reactive monoclonal antibody. J. Eukaryot. Microbiol. 41: 48S.
38.
Keohane, E. M.,, P. M. Takvorian,, A. Cali,, H. B. Tanowitz,, M. Wittner,, and L. M. Weiss. 1996c. Identification of a microsporidian polar tube protein reactive monoclonal antibody. J. Eukaryot. Microbiol. 43: 26– 31.
39.
Keohane, E. M.,, and L. M. Weiss. 1998. Characterization and function of the microsporidian polar tube: a review. Folia Parasitol. 45: 117– 127.
40.
Kock, N. P. 1998. Diagnosis of human pathogen microsporidia. Ph.D. thesis. Bernard Nocht Institute for Tropical Medicine, Hamburg, Germany.
41.
Korke, V. T. 1916. On a Nosema (Nosema pulicis n.s.) parasitic in the dog flea ( Ctenocephalus felis). Ind. J. Med. Res. 3: 725– 730.
42.
Kramer, J. P. 1960. Observations on the emergence of the microsporidian sporoplasm. J. Insect Pathol. 2: 433– 439.
43.
Kudo, R. 1916. Contributions to the study of parasitic protozoa. I. On the structure and life history of Nosema bombycis Naegeli. Bull. Imp. Seric. Exp. Stn. Jpn. 1: 31– 51.
44.
Kudo, R. 1918. Experiments on the extrusion of polar filaments of cnidosporidian spores. J. Parasitol. 4: 141– 147.
45.
Kudo, R. 1920. On the structure of some microsporidian spores. J. Parasitol. 6: 178– 182.
46.
Kudo, R. 1921. On the nature of structures characteristic of cnidosporidian spores. Trans. Am. Microsc. Soc. 40: 59– 74.
47.
Kudo, R. R.,, and E. W. Daniels. 1963. An electron microscope study of the spore of a microsporidian, Thelohania californica. J. Protozool. 10: 112– 120.
48.
Langley, R. C., Jr.,, A. Cali,, and E. W. Somberg. 1987. Two-dimensional electrophoretic analysis of spore proteins of microsporidia. J. Parasitol. 73: 910– 918.
49.
Leger, L.,, and E. Hesse. 1916. Sur la structure de la spore des Microsporidies. C.R. Soc. Biol. 79: 1049– 1053.
50.
Leitch, G.J.,, Q. He,, S. Wallace,, and G. S. Visvesvara. 1993. Inhibition of spore polar filament extrusion of the microsporidium, Encephalitozoon hellem, isolated from an AIDS patient. J. Eukaryot. Microbiol. 40: 711– 717.
51.
Liu, T. P.,, and D. M. Davies. 1973. Ultrastructural architecture and organization of the spore envelope during development in Tlielohania bracteata (Strickland, 1913) after freeze-etching. J. Protozool. 20: 622– 630.
52.
Lom, J. 1972. On the structure of the extruded microsporidian polar filament. Z. Parasitenk. 38: 200– 213.
53.
Lom, J.,, and J. O. Corliss. 1967. Ultrastructural observations on the development of the microsporidian protozoon, Plistophora hyphessobryconis Schaperclaus. J. Protozool. 14: 141– 152.
54.
Lom, J.,, and J. Vávra. 1963. The mode of sporoplasm extrusion in microsporidian spores. Ada Protozool. 1: 81– 92.
55.
Malone, L. A. 1984. Factors controlling in vitro hatching of Vairimorpha plodiae (Microspora) spores and their infectivity to Plodia interpunctella, Heliothis virescens and Pieris brassicae. J. Invertebr. Pathol. 44: 192– 197.
56.
Malone, L. A. 1990. In vitro spore hatching of two microsporidia, Nosema costelytrae and Vávraia oncoperae from New Zealand pasture insects. J. Invertebr. Pathol. 55: 441– 443.
57.
Olsen, P. E.,, W. A. Rice,, and T. P Liu. 1986. In vitro germination of Nosema apis spores under conditions favorable for the generation and maintenance of sporoplasms. J. Invertebr. Pathol. 47: 65– 73.
58.
Oshima, K. 1927. A preliminary note on the structure of the polar filament of Nosema bombycis and its functional significance. Annot. Zool. Jpn. 11: 235– 243.
59.
Oshima, K. 1937. On the function of the polar filament of Nosema bombycis. Parasitology 29: 220– 224.
60.
Oshima, K. 1964a. Effect of potassium ion on filament evagination of spores of Nosema bombycis as studied by neutralization method. Annot. Zool. Jpn. 37: 102– 103.
61.
Oshima, K. 1964b. Stimulative or inhibitive substance to evaginate the filament Nosema bombycis Nageli: I. The case of artificial buffer solution. Jpn. J. Zool. 14: 209– 229.
62.
Oshima, K. 1966. Emergence mechanism of sporoplasm from the spore of Nosema bombycis and the action of filament during evagination. Jpn. J. Zool. 15: 203– 220.
63.
Pleshinger, J.,, and E. Weidner. 1985. The microsporidian spore invasion tube. IV. Discharge activation begins with pH-triggered Ca 2+ influx. J. Cell Biol. 100: 1834– 1838.
64.
Scarborough-Bull, A.,, and E. Weidner. 1985. Some properties of discharged Glugea hertwigi (Microsporida) sporoplasms. J. Protozool. 32: 284– 289.
65.
Schuberg, A. 1910. Ueber Mikrosporidien aus dem Hoden der barbe und durch sie verursachte Hypertrophie der Kerne. Arb. Kais. Gesundh. 33: 401– 434.
66.
Schwartz, D. A.,, G. S. Visvesvara,, G. J. Leitch,, L. Tashjian,, M. Pollack,, J. Holden,, and R.T. Bryan. 1993. Pathology of symptomatic microsporal ( Encephalitozoon hellem) bronchiolitis in the acquired immunodeficiency syndrome: a new respiratory pathogen diagnosed from lung biopsy, brochoalveolar lavage, sputum and tissue culture. Hum. Pathol. 24: 937– 943.
67.
Sinden, R. E.,, and E. U. Canning. 1974. The ultra-structure of the spore of Nosema algerae (Protozoa, Microsporida) in relation to the hatching mechanism of microsporidian spores. J. Gen. Microbiol. 85: 350– 357.
68.
Sprague, V.,, and S. H. Vernick. 1969. Light and electron microscope observations on Nosema nelsoni Sprague, 1950 (Microsporida, Nosematidae) with particular reference to its Golgi complex. J. Protozool. 16: 264– 271.
69.
Stempell, W. 1909. Über Nosema bombycis Naegeli nebst Bemerkungen über Mikrophotographie mit gewõhnlichem und ultraviolettem Licht. Arch. Protistenk. 16: 281– 358.
70.
Strickland, E. H. 1913. Further observations on the parasites of Simulium larvae. J. Morph. 24: 43– 102.
71.
Takvorian, P. M.,, and A. Cali. 1986. The ultrastructure of spores (Protozoa: Microsporida) from Lophius americanus, the angler fish. J. Protozool. 33: 570– 575.
72.
Takvorian, P. ML, and A. Cali. 1994. Enzyme histochemical identification of the golgi apparatus in the microsporidian, Glugea stephani. J. Eukaryot. Microbiol. 41: 63S– 64S.
73.
Takvorian, P. M.,, and A. Cali. 1996. Polar tube formation and nucleoside diphosphatase activitiy in the microsporidian, Glugea stephani. J. Eukaryot. Microbiol. 43: 102S– 103S.
74.
Thelohan, P. 1892. Observations sur les Myxosporidies et essai de classification de ces organismes. Bull. Soc. Philom. 4: 165– 172.
75.
Thelohan, P. 1894. Sur la présence d'une capsule à filament dans les spores des microsporidies. C. R. Acad. Sci. 118: 1425– 1427.
76.
Toguebaye, B. S.,, and B. Marchand. 1987. Intracellular emergence of the microsporidian sporoplasm as revealed by electron microscopy in Nosema couilloudi (Microspora, Nosematidae) Arch. Protistenk. 134: 397– 407.
77.
Trager, W. 1937. The hatching of spores of Nosema bombycis Nageli and the partial development of the organism in tissue cultures. J. Parasitol. 23: 226– 227.
78.
Undeen, A. H. 1976. In vivo germination and host specificity of Nosema algerae in mosquitos. J. Inverted. Pathol. 27: 343– 347.
79.
Undeen, A. H., 1978. Spore hatching processes in some Nosema species with particular reference to N. algerae (Vavra and Undeen), p. 29– 49. In W. M. Brooks (ed.), Selected Topics on the Genus Nosema ( Microsporida). Entomological Society of America, College Park, Md.
80.
Undeen, A. H. 1983. The germination of Vávraia culicis. J. Protozool. 30: 274– 277.
81.
Undeen, A. H. 1990. A proposed mechanism for the germination of microsporidian (Protozoa: Microspora) spores. J. Theor. Biol. 142: 223– 235.
82.
Undeen, A. H.,, and S.W. Avery. 1984. Germination of experimentally nontransmissible microsporidia. J. Invertebr. Pathol. 43: 299– 301.
83.
Undeen, A. H.,, and S.W. Avery. 1988a. Effect of anions on the germination of Nosema algerae (Microspora: Nosematidae) spores. J. Invertebr. Pathol. 52: 84– 89.
84.
Undeen, A.H.,,and S.W. Avery. 1988b. Spectrophotometric measurement of Nosema algerae (Microspora: Nosematidae) spore germination rate. J. Invertebr. Pathol. 52: 253– 258.
85.
Undeen, A.H.,,and S.W. Avery. 1988c. Ammonium chloride inhibition of the germination of spores of Nosema algerae (Microspora: Nosematidae). J. Invertebr. Pathol. 52: 326– 334.
86.
Undeen, A. H.,, L. M. El Gazzar,, R. K. Vander Meer,, and S. Narang. 1987. Trehalose levels and trehalase activity in germinated and ungerminated spores of Nosema algerae (Microspora: Nosematidae). J. Invertebr. Pathol. 50: 230– 237.
87.
Undeen, A. H.,, and N. D. Epsky. 1990. In vitro and in vivo germination of Nosema locustae (Microspora: Nosematidae) spores. J. Invertebr. Pathol. 56: 371– 379.
88.
Undeen, A. H.,, and E. Frixione. 1990. The role of osmotic pressure in the germination of Nosema algerae spores. J. Protozool. 37: 561– 567.
89.
Undeen, A. H.,, and E. Frixione. 1991. Structural alteration of the plasma membrane in spores of the microsporidium Nosema algerae on germination. J. Protozool. 38: 511– 518.
90.
Undeen, A. H.,, and R. K. Vander Meer. 1990T he effect of ultraviolet radiation on the germination of Nosema algerae Vavra and Undeen (Microsporida: Nosematidae) spores. J. Protozool. 37: 194– 199.
91.
Undeen, A. H.,, and R. K. Vander Meer. 1994. Conversion of intrasporal trehalose into reducing sugars during germination of Nosema algerae (Protista: Microspora) spores: a quantitative study. J. Eukaryot. Microbiol. 41: 129– 132.
92.
Undeen, A. H.,, R. K. Vander Meer,, B. J. Smittle,, and S.W. Avery. 1984. The effect of gamma radiation on Nosema algerae (Microspora: Nosematidae) spore viability, germination and carbohydrates. J. Protozool. 31: 479– 482.
93.
Vandermeer, J., W, and T. A. Gochnauer. 1971. Trehalase activity associated with spores of Nosema apis. J. Invertebr. Pathol. 17: 38– 41.
94.
Van Gool, T.,, J. C. M. Vetter,, B. Weinmayr,, A. Van Dam,, F. Derouin,, and J. Dankert. 1997. High seroprevalence of Encephalitozoon species in immunocompetent subjects. J. Infect. Dis. 175: 1020– 1024.
95.
Vávra, J., 1976. Structure of microsporidia, p. 1– 86. In L. A. Bulk, and T C. Cheng (ed.), Comparative Pathobiology, vol. 1. Plenum Press, New York.
96.
Vávra, J.,, L. Joyon, and R de Puytorac. 1966. Observation sur l'ultrastructure du filament polaire des microsporidies. Protistologica 2: 109– 112.
97.
Vávra, J.,, and A. H. Undeen. 1970. Nosema algerae n.sp. (Cnidospora, Microsporida), a pathogen in a laboratory colony of Anopheles stephensi Liston (Diptera,Culicidae). J. Protozool 17: 240– 249.
98.
Vávra, J.,, D. Vinckier,, G. Torpier,, E. Porchet,, and E. Vivier. 1986. A freeze-fracture study of microsporidia I (Protozoa: Microspora). The sporophorous vesicle, the spore wall and the spore plasma membrane. Protistologica 22: 143– 154.
99.
Walters, V. A. 1958. Structure, hatching and size variation of the spores in a species of Nosema (Microsporidia) found in Hyalophora cecropsia (Lepidoptera). Parasitology 48: 113– 120.
100.
Weidner, E. 1970. Ultrastructural study of microsporidian development. Z. Zellforsch. 105: 33– 54.
101.
Weidner, E. 1972. Ultrastructural study of microsporidian invasion into cells. Z. Parasitenkd. 40: 227– 242.
102.
Weidner, E. 1976. The microsporidian spore invasion tube: the ultrastructure, isolation, and characterization of the protein comprising the tube. J. Cell Biol. 71: 23– 34.
103.
Weidner, E. 1982a. The microsporidian spore invasion tube. III. Tube extrusion and assembly. J. Cell Biol. 93: 976– 979.
104.
Weidner, E. 1992. Cytoskeletal proteins expressed by microsporidian parasites. Subcell. Biochem. 18: 385– 399.
105.
Weidner, E.,, and W. Byrd. 1982. The microsporidian spore invasion tube. II. Role of calcium in the activation of invasion tube discharge. J. Cell Biol. 93: 970– 975.
106.
Weidner, E.,, W. Byrd,, A. Scarborough,, J. Pleshinger,, and D. Sibley. 1984. Microsporidian spore discharge and the transfer of polaroplast organelle membrane into plasma membrane. J. Protozool. 31: 195– 198.
107.
Weidner, E.,, S. B. Manale,, S. K. Halonen,, and J. W. Lynn. 1994. Microsporidian spore invasion tubes as revealed by fluorescent probes. Biol. Bull. 187: 255– 256.
108.
Weidner, E.,, S. B. Manale,, S. K. Halonen,, and J. W. Lynn. 1995. Protein-membrane interaction is essential to normal assembly of the microsporidian spore invasion tube. Biol. Bull. 188: 128– 135.
109.
Weiser, J. 1958. Nosema laphygmae n.sp. and the internal structure of microsporidian spore. J. Insect Pathol. 1: 52– 59.
110.
Weiss, L. M. Unpublished data.
111.
Weiss, L. M.,, and C. R. Vossbrinck. 1998. Microsporidiosis: molecular and diagnostic aspects. Adv. Parasitol. 40: 351– 395.
112.
West, A. E., Jr. 1960. The biology of a species of Nosema (Sporozoa, Microsporidia) parasitic in the flour beetle Tribolium confusum. J. Parasitol. 46: 747– 753.
113.
Whitlock, V. H.,, and S. Johnson. 1990. Stimuli for the in vitro germination and inhibition of Nosema locusta (Microspora: Nosematidae) spores. J. Inverted. Pathol. 56: 57– 62.
114.
Wood, P. J.,, I. R. Siddiqui,, J. W. Vandermeer,, and T. A. Gochnauer. 1970. Carbohydrates of Nosema apis spores. Carbohydr. Res. 15: 154– 158.
115.
Zahner, H.,, G. Hobom,, and S. Stirm. 1995. The microfilarial sheath and its proteins. Parasitol. Today 11: 116– 120.
116.
Zierdt, C. H.,, V. J. Gill,, and W. S. Zierdt. 1993. Detection of microsporidian spores in clinical samples by indirect fluorescent-antibody assay using whole-cell antisera to Encephalitozoon cuniculi and Encephalitozon hellem. J. Clin. Microbiol. 31: 3071– 3074.
117.
Zwolfer, W. 1926. Pleistophora blochmanni, eine neue Microsporidie aus Gammarus pulex L. Arch. Protistenkd. 54: 261– 340.
Tables
The Structure, Function, and Composition of the Microsporidian Polar Tube
[com.pub2web.rdf.cci.facet.ContentItem[id=http://asm.metastore.ingenta.com/content/author/10.1128/9781555818227.chap6-1,webId=/content/author/10.1128/9781555818227.chap6-1,properties={foaf_givenname=Elaine M., foaf_name=Elaine M. Keohane, foaf_surname=Keohane, pub_isAffiliatedWith=[com.pub2web.rdf.cci.facet.ContentItem[id=http://asm.metastore.ingenta.com/content/affiliation/10.1128/9781555818227.chap6-aff1]]}], com.pub2web.rdf.cci.facet.ContentItem[id=http://asm.metastore.ingenta.com/content/author/10.1128/9781555818227.chap6-2,webId=/content/author/10.1128/9781555818227.chap6-2,properties={foaf_givenname=Louis M., foaf_name=Louis M. Weiss, foaf_surname=Weiss, pub_isAffiliatedWith=[com.pub2web.rdf.cci.facet.ContentItem[id=http://asm.metastore.ingenta.com/content/affiliation/10.1128/9781555818227.chap6-aff2]]}]]
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.tab6-1
TABLE 1
Polar tube proteins
a Cloned gene ( Delbac et al., 1998b ).
b Cloned gene ( Keohane et al., 1998a ).
10.1128/9781555818227/tab6-1_thmb.gif
10.1128/9781555818227/tab6-1.gif
TABLE 1
Polar tube proteins
a Cloned gene ( Delbac et al., 1998b ).
b Cloned gene ( Keohane et al., 1998a ).
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.tab6-2
TABLE 2
Comparison of PTP genes and predicted proteins
a Underlined amino acids in E. hellem PTP are an alternating motif. Amino acids in a boldface type are substitutions in the repeat sequences.
10.1128/9781555818227/tab6-2_thmb.gif
10.1128/9781555818227/tab6-2.gif
TABLE 2
Comparison of PTP genes and predicted proteins
a Underlined amino acids in E. hellem PTP are an alternating motif. Amino acids in a boldface type are substitutions in the repeat sequences.
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6
/content/10.1128/9781555818227.chap6.tab6-3
TABLE 3
Reported conditions for activation and discharge of polar tubes
a Also known as Glugea americanus.
10.1128/9781555818227/tab6-3_thmb.gif
10.1128/9781555818227/tab6-3.gif
TABLE 3
Reported conditions for activation and discharge of polar tubes
a Also known as Glugea americanus.
Citation:
Keohane E, Weiss L.
1999.
The Structure, Function, and Composition of the Microsporidian Polar Tube,
p 196-224.
In
Wittner M, Weiss L (ed),
The Microsporidia and Microsporidiosis.
ASM Press, Washington, DC.
doi: 10.1128/9781555818227.ch6