Ce. Lange et al., HETEROVESICULA-COWANI N-G, N-SP (HETEROVESICULIDAE N FAM), A MICROSPORIDIAN PARASITE OF MORMON CRICKETS, ANABRUS-SIMPLEX HALDEMAN, 1852 (ORTHOPTERA, TETTIGONIIDAE), The Journal of eukaryotic microbiology, 42(5), 1995, pp. 552-558
Heterovesicula cowani, n. g., n. sp., is a dimorphic microsporidium de
scribed from the adipose tissue of the Mormon cricket, Anabrus simplex
Haldeman. Proliferation of the microsporidium is by karyokinesis of u
ninucleate and binucleate cells to form binucleate and tetranucleate c
ells, respectively. These cells will undergo binary fission (merogony)
, Ultimately, the meronts undergo karyokinesis without subsequent cyto
kinesis producing spherical multinucleate plasmodia that are transitio
nal to 2 types of sporogony. Transitional to disporoblastic sporogony,
a fragile interfacial envelope delaminates from the plasmodium with m
orphogenesis to a monfiliform plasmodium consisting of fusiform binucl
eate diplokaryotic sporonts. These undergo karyokinesis to form tetran
ucleate diplokaryotic sporonts that undergo cytokinesis during disinte
gration of the plasmodium into isolated binucleate sporonts. Transitio
nal to octosporoblastic sporogony, multinucleate plasmodia disintegrat
e into short monofiliform plasmodia of diplokaryotic sporonts which th
en segregate while undergoing gradual nuclear dissociation (haplosis b
y nuclear dissociation). These undergo two sequences of karyokinesis a
nd subsequent multiple fission to form eight uninucleate (haploid) spo
roblasts in a fusiform arrangement within a persistent envelope. Binuc
leate spores are ovocylindrical, about 5.4 x 1.7 mu m (flesh), with an
isofilar polar filament singly coiled about 11 turns. Uninucleate spo
res are ovoid to slightly pyriform, 4.0 x 1.7 mu m (fresh), with an is
ofilar filament singly coiled about 9 turns. A new family, Heterovescu
lidae, is proposed for the new genus.