Ultrastructure of the lesion nematode, Pratylenchus penetrans (Nemata: Pratylenchidae)

TLDR: Spermatozo a with irregular clumps of nonmembrane-boun d chromati n surrounded by mitochondri a as well as residual fibrous bodies were found in seminal vesicles and vas deferens of males and in spermatheca e of female gonads.

Abstract: Various stages of a lesion nematode , Pratylenchus penetrans (Cobb, 1917) Sher and Allen, 1953, were observed with transmission electron microscopy and low-temperatur e scanning electron microscopy (LTSEM) to elucidate the structural anatomy of the esophagus , intestine, and reproductive system. The lumen of the esophagu s is circular through the procorpus and triradiate in the metacorpus where it is part of the metacorpus pump valve. A pair of esophagea l lumen branches terminate as quadriradiat e valves in the subventral gland ampullae. The central lumen extends posteriad to become part of the esophago-intestina l valve. The enlarged intestinal lumen is delineated by scattered evaginated membrane s of the epithelial cells. The lumen may be occluded during nonfeeding periods or when the intestine becomes compresse d by the reproductive organs. The testis contains spermatocyte s with membrane-boun d nuclei that transform into amoeboi d spermatids with electron-opaque , nonmembrane-boun d nuclei surrounded by fibrous bodies. Spermatozo a with irregular clumps of nonmembrane-boun d chromati n surrounded by mitochondri a as well as residual fibrous bodies were found in seminal vesicles and vas deferens of males and in spermatheca e of female gonads. The ultrastructur e of the male and female reproductive organs is compared to similar features observed with light microscopy and