Search

Abstract: Vascular endothelial growth factor (VEGF) is known to influence the testis function. To establish the role of VEGF in the testis of a variety of species, we analyzed the expression of VEGF transcript using human gene-specific primers by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis in the testes of 18 vertebrates, including a few endangered species. An amplicon of 566 bp representing VEGF165 was identified in testis of all species in this study. Sequence analysis of these amplicons revealed 84 to 96% homology to available human VEGF sequence and to the VEGF sequences of other species in GenBank. Immunohistochemical analysis revealed expression of VEGF protein, primarily in Sertoli and Leydig cells and occasionally in the germ cells of the testis sections. It can be concluded from this study that expression of VEGF transcript is conserved in the testis of several vertebrates and may have a role in the process of spermatogenesis. [Copyright &y& Elsevier]

Abstract: Numerous wild bovids are facing threat of extinction owing to the loss of habitat and various other reasons. Spermatogonial stem cells (SSCs) represent the only germline stem cells in adult body that are capable of self-renewal and that can undergo differentiation to produce haploid germ cells. SSCs can, therefore, serve as a useful resource for preservation of germplasm of threatened and endangered mammals. The Indian black buck (Antilope cervicapra L.) is a small Indian antelope that is listed as endangered by the Indian Wildlife Protection Act, 1972. Immunohistochemical analysis of testes tissues of black buck revealed the presence of spermatogonia that were specifically stained by lectin-Dolichos biflorus agglutinin (DBA). The expression of pluripotent cell-specific markers, NANOG and stage-specific embryonic antigen-1 (SSEA-1), was detected in spermatogonia. Interestingly, the expression of POU5F1 (OCT3/4) was absent from spermatogonia, however, it was detected in differentiating cells such as spermatocytes and round spermatids but not in elongated spermatids. The expression of NANOG protein was also present in spermatocytes but absent in round and elongated spermatids. Using the testis transplantation assay, stem cell potential of black buck spermatogonia was confirmed as indicated by the presence of colonized DBA-stained cells in the basal membrane of seminiferous tubules of xenotransplanted mice testis. The findings from this study suggest the presence of SSCs in the testis of an endangered bovid for the first time and open new possibility to explore the use of SSCs in conservation. [Copyright &y& Elsevier]

Abstract: Buffalo is an economically important livestock species in Asia. Little is known about male germ line technology owing to lack of sufficient understanding regarding expression of germ- and somatic-cell specific-proteins in the testis. In this study, we identified UCHL-1 (PGP 9.5) and lectin- Dolichos biflorus agglutinin (DBA) as specific markers for spermatogonia in buffalo testis. Expression of germ-cell and pluripotency-specific proteins such as DDX4 (VASA) and POU5F1 (OCT3/4) were also present in spermatogonia. Interestingly, the expression of somatic cell-specific proteins such as VIMENTIN and GATA4 were also detected in germ cells. Using two-step enzymatic digestion followed by differential plating and Percoll density-gradient centrifugation, an approximately 55% spermatogonia-enriched cell population could be obtained from the prepubertal buffalo testis. Isolated spermatogonia could survive and proliferate in vitro in DMEM/F12 medium containing 10% fetal bovine serum in the absence of any specific growth factors for a week. Cultured spermatogonia showed DBA affinity and expressed DDX4 and POU5F1. These results may help to establish a long-term culture system for buffalo spermatogonia. [Copyright &y& Elsevier]