RESUMO
Promotion of spermatogonial stem cell (SSC) differentiation into functional sperms under in vitro conditions is a great challenge for reproductive physiologists. In this study, we observed that melatonin (10(-7) M) supplementation significantly enhanced the cultured SSCs differentiation into haploid germ cells. This was confirmed by the expression of sperm special protein, acrosin. The rate of SSCs differentiation into sperm with melatonin supplementation was 11.85 ± 0.93% which was twofold higher than that in the control. The level of testosterone, the transcriptions of luteinizing hormone receptor (LHR), and the steroidogenic acute regulatory protein (StAR) were upregulated with melatonin treatment. At the early stage of SSCs culture, melatonin suppressed the level of cAMP, while at the later stage, it promoted cAMP production. The similar pattern was observed in testosterone content. Expressions for marker genes of meiosis anaphase, Dnmt3a, and Bcl-2 were upregulated by melatonin. In contrast, Bax expression was downregulated. Importantly, the in vitro-generated sperms were functional and they were capable to fertilize oocytes. These fertilized oocytes have successfully developed to the blastula stage.
Assuntos
Antioxidantes/farmacologia , Diferenciação Celular/efeitos dos fármacos , Melatonina/farmacologia , Espermatogênese/efeitos dos fármacos , Espermatozoides/citologia , Espermatozoides/efeitos dos fármacos , Animais , Western Blotting , Células Cultivadas , Feminino , Citometria de Fluxo , Imuno-Histoquímica , Técnicas In Vitro , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Ovinos , Injeções de Esperma Intracitoplásmicas/efeitos dos fármacos , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacosRESUMO
In this viewpoint, the usages of terms for progenitor cells to meiosis and gametogenesis are discussed. Terms for 2 types of germ cells, i.e. "diploid germ cells" and "haploid germ cells" were suggested to replace "archesporial cells" and "generative cells," respectively, in plant developmental research. This suggestion was based on 2 newly proposed concepts, the "sexual reproduction cycle" for eukaryotes, and a "double-ring mode" of plant developmental program.