Cytogenetic analysis of Astylus antis using mitotic and meiotic cells was performed to characterize the haploid and diploid numbers, sex determination system, chromosome morphology, constitutive heterochromatin distribution pattern and chromosomes carrying nucleolus organizer regions (NORs). Analysis of spermatogonial metaphase cells revealed the diploid number 2n = 18, with mostly metacentric ...

The existence of spermatogonial stem cells in the testis offers clinically relevant options for preservation and restoration of male fertility. New approaches based on male germ cell transplantation and testicular tissue grafting can be applied to generate a limited number of sperm cells and could therefore be considered important new avenues for restoration of fertility in oncological patients...

Melatonin has a direct inhibitory effect on the basal and oestradiol-stimulated mitotic activity of primary spermatogonia in the testis of the frog, Rana esculenta. In this study oestradiol was used to induce spermatogonial proliferation to verify the anti-proliferative effect of melatonin. The colchicine metaphase arrest technique was used. The results obtained from in vivo experiments confirm...

Retinoic acid (RA) signaling is critical for spermatogonial differentiation, which is a key step for spermatogenesis. We explored the mechanisms underlying spermatogonial differentiation by targeting expression of a dominant-negative mutant of RA receptor α (RARα) specifically to the germ cells of transgenic mice to subvert the activity of endogenous receptors. Here we show that (i) inhibition ...

BACKGROUND The development of a spermatogonial transplantation technique has provided new possibilities for the treatment of male infertility. Previous studies have shown that spermatogonial stem cells could reinitiate spermatogenesis after cryopreservation and reintroduction into the seminiferous tubules of infertile recipient males, and this raised the possibility of banking frozen stem cells...

BACKGROUND Spermatogonial stem cell (SSC) is a self-renewing population of male adult stem cell. SSCs have a differentiation potential which are similar to embryonic stem cells. These Embryonic stem like (ES-like) cells can be a potential source for pluripotent cells for stem cell-based therapy. OBJECTIVE This study presents an economical and simple co-culture system for pluripotent stem cell...

Germ cell development begins with the characteristics of the primordial germ cells (PGCs) early in human fetal life. PGCs arise from the proximal epiblast and will replace to the extra embryonic mesoderm during the fourth and fifth week of embryonic development. By the finish of the fifth week to early sixth week, PGCs will embark for a second immigration via the dorsal mesenterium of the gut t...