The ultrastructure of the male reproductive system of Didymocystis wedli was studied for the first time, demonstrating spermiogenesis and spermatogenesis at different cell stages. The spermatozoa morphology was compared with that of other Digenea species. It was observed that the different cells of the spermatogenesis process follow the classic pattern reported for the majority of the parasitic...

Small pieces of the sperm sacs of Lumbricus herculeus were fixed for 4 hours in chrome-osmium, embedded in methacrylate, sectioned with a Porter-Blum microtome, and studied with a R.C.A. EMU-2C electron microscope. Each spermatid of a group developing synchronously is attached by a cytoplasmic strand to a common nutrient protoplasmic mass. This mass contains mitochondria and yolk bodies but is ...

The CCCTC-binding factor (CTCF) is an architectural protein that governs chromatin organization and gene expression in somatic cells. Here, we show that CTCF regulates chromatin compaction necessary for packaging of the paternal genome into mature sperm. Inactivation of Ctcf in male germ cells in mice (Ctcf-cKO mice) resulted in impaired spermiogenesis and infertility. Residual spermatozoa in C...

The effects of colchicine on spermiogenesis in the mouse were examined. Mice were injected intratesticularly with colchicine in concentrations of 10(-4) M to 10(-6) M for various periods of time. The ultrastructure of the testes was examined and abnormal sperm in the epididymis were scored. Colchicine degraded microtubules in the testis and the treatment caused abnormalities of the head and acr...

Background: Nanosilver (NS) contains silver nanoparticles to control infections delivered from bacteria. The NS compounds as well as being toxic to prokaryotes are highly toxic to mammalian cells. The present study was evaluated the effect of colloidal NS on leydig cells glucose transporter type I (GLUT I) expression, serum level of testosterone, germinal cells RNA damage and spermiogenesis pro...

Spermiogenesis in Cancer crabs was studied by light and electron microscopy. The sperm are aflagellate, and when mature consist primarily of a spherical acrosome surrounded by the nucleus with its short radiating arms. The acrosome forms by a coalescence of periodic acid-Schiff-positive (PAS-positive) vesicles. During spermiogenesis one edge of the acrosomal vesicle invaginates to form a PAS-ne...