Protozoa Guide review

Pyrsonympha Leidy

genus / OXYMONADIDA / PYRSONYMPHIDAE

Description

Flagellates with a spirally twisted and contractile cell body of 20-150 ~m depending of the species (Figs. 8,9). The 4 or 8 flagella are wrapped around the cell body and have a posterior trailing OXYMONADIDA A Fig. ?A. Saccinobaculus ambloaxostylus from Cryptocercus punctulatus (after Cleveland, 1950a). Bar=1 0 iJm. Fig . ?B . Notila proteus from Cryptocercus punctulatus (after Cleveland , 1950b). Bar=1 0 iJm. A B lucifugus. A. Motile "Dinenympha" form . B. Attached "Pyrsonympha" form. Bar=1 0 iJm. (G. Brugerolle) portion. The small and ribbon-like cells ( 1 2-3 0 1-Jm), also called "Dinenympha" forms, have 4 flagella and swim in the intestinal fluid. The large and pyriform cells (150-200 1-1m), the "Pyrsonympha" forms, have 8 flagella and are generally attached by a holdfast to the intestinal 11 91 adhering flagella, several rod-shaped bacteria , and the posterior axostyle protrusion . Bar=1 0 iJm . (G. Brugerolle) wall of the termite. Electron microscopy has permitted the recognition of the oxymonad characters (Fig. 3) . The basal bodies are separated into 2 pairs and linked to the preaxostylar lamina . The axostyle, originating close to the preaxostylar lamina, is composed of parallel rows (up to 50) of microtubules, which enroll at the posterior end , where the axostyle is surrounded by a sheath . The central axostyle is contractile and undulates in the cytoplasm. The flagella rest on gutters and adhere to the cell membrane forming undulating membranes (Fig. 9). The axoneme of the flagella present additional paraxonemal striated fibers alongside the 4 external triplets (Fig . 4f) . All cells have an anterior holdfast, which is filled with longitudinal microfibrils originating from a dense centrosomal zone in contact with one pair of basal bodies. The multifid holdfast serves to attach the cell to the intestinal intima of the termite but does not reach the epithelial cells . Paraxostylar microtubules (Fig. 3) arising from the centrosomal zone form a non-organized bundle , which parallels the central crytalline axostyle . The cell surface is covered by a microfibrillar coat and by salpingoid and dendroid scales (Smith and Arnot, 1 9 7 3) . Flagellates phagocytize and digest wood and bacteria and also feed by pinocytosis. They live in the rectal pouch of the Rhinotermitidae of the genus Reticulitermes. During their life cycle young forms (Dinenympha) with 4 flagella transform to large fixed forms (Pyrsonympha) with 8 flagella OXYMONADIDA by incomplete divisions while they increase their nuclear plo'idy (32 times) by successive endomitosis (Hollande eand Carruette-Valentin , 197Gb). When the termite molts Pyrsonympha cells detach and divide several times restoring their normal plo'idy. Synaptonemal complexes occur in the first mitosis of the series and seem not related to a sexual process. The nuclear division is of the closed type with an intra-nuclear spindle (Cleveland , 1938, Hollande and Carruette- Valentin, 197Gb}. No cyst has been described ; after the molt, the termite is reinfected by proctodea! feeding . Light microscopy of the 2 species is found in Grasse, 1952; Koidzumi , 1921; Powells, 1928 ; Cleveland, 1938; and electron microscopy by Brugerolle, 197G, Hollande and Carruette- Valentin, 197Ga,b; Smith and Arnot , 1973 ; Bloodgood et al., 1974; Cochrane et al. , 1979.

Type species

Figures

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Raw text

Flagellates with a spirally twisted and contractile
cell body of 20-150 ~m depending of the species
(Figs. 8,9). The 4 or 8 flagella are wrapped
around the cell body and have a posterior trailing
OXYMONADIDA
A
Fig. ?A. Saccinobaculus ambloaxostylus from
Cryptocercus punctulatus (after Cleveland, 1950a).
Bar=1 0 iJm. Fig . ?B . Notila proteus from Cryptocercus
punctulatus (after Cleveland , 1950b). Bar=1 0 iJm.
A B
lucifugus. A. Motile "Dinenympha" form . B. Attached
"Pyrsonympha" form. Bar=1 0 iJm. (G. Brugerolle)
portion. The small and ribbon-like cells ( 1 2-3 0
1-Jm), also called "Dinenympha" forms, have 4
flagella and swim in the intestinal fluid. The large
and pyriform cells (150-200 1-1m), the
"Pyrsonympha" forms, have 8 flagella and are
generally attached by a holdfast to the intestinal
11 91
adhering flagella, several rod-shaped bacteria , and the
posterior axostyle protrusion . Bar=1 0 iJm . (G.
Brugerolle)
wall of the termite. Electron microscopy has
permitted the recognition of the oxymonad
characters (Fig. 3) . The basal bodies are separated
into 2 pairs and linked to the preaxostylar lamina .
The axostyle, originating close to the preaxostylar
lamina, is composed of parallel rows (up to 50) of
microtubules, which enroll at the posterior end ,
where the axostyle is surrounded by a sheath . The
central axostyle is contractile and undulates in the
cytoplasm. The flagella rest on gutters and adhere
to the cell membrane forming undulating
membranes (Fig. 9). The axoneme of the flagella
present additional paraxonemal striated fibers
alongside the 4 external triplets (Fig . 4f) . All cells
have an anterior holdfast, which is filled with
longitudinal microfibrils originating from a dense
centrosomal zone in contact with one pair of basal
bodies. The multifid holdfast serves to attach the
cell to the intestinal intima of the termite but does
not reach the epithelial cells . Paraxostylar
microtubules (Fig. 3) arising from the centrosomal
zone form a non-organized bundle , which parallels
the central crytalline axostyle . The cell surface is
covered by a microfibrillar coat and by salpingoid
and dendroid scales (Smith and Arnot, 1 9 7 3) .
Flagellates phagocytize and digest wood and bacteria
and also feed by pinocytosis. They live in the rectal
pouch of the Rhinotermitidae of the genus
Reticulitermes. During their life cycle young
forms (Dinenympha) with 4 flagella transform to
large fixed forms (Pyrsonympha) with 8 flagella
OXYMONADIDA
by incomplete divisions while they increase their
nuclear plo'idy (32 times) by successive
endomitosis (Hollande eand Carruette-Valentin ,
197Gb). When the termite molts Pyrsonympha
cells detach and divide several times restoring their
normal plo'idy. Synaptonemal complexes occur in
the first mitosis of the series and seem not related
to a sexual process. The nuclear division is of the
closed type with an intra-nuclear spindle
(Cleveland , 1938, Hollande and Carruette-
Valentin, 197Gb}. No cyst has been described ; after
the molt, the termite is reinfected by proctodea!
feeding . Light microscopy of the 2 species is found
in Grasse, 1952; Koidzumi , 1921; Powells, 1928 ;
Cleveland, 1938; and electron microscopy by
Brugerolle, 197G, Hollande and Carruette-
Valentin, 197Ga,b; Smith and Arnot , 1973 ;
Bloodgood et al., 1974; Cochrane et al. , 1979.