Spermatogenesis is composed of three distinctive phases, which include self-renewal of spermatogonia via mitosis, spermatocytes undergoing meiosis I/II and post-meiotic development of haploid spermatids via spermiogenesis. Spermatogenesis also involves condensation of chromatin in the spermatid head before transformation of spermatids to spermatozoa. Epigenetic regulation refers to changes of h...

Pachytene piRNAs are a class of Piwi-interacting small RNAs abundant in spermatids of the adult mouse testis. They are processed from piRNA primary transcripts by a poorly understood mechanism and, unlike fetal transposon-derived piRNAs, lack complementary targets in the spermatid transcriptome. We report that immunopurified complexes of a conserved piRNA pathway protein Maelstrom (MAEL) are en...

During mammalian spermatogenesis, meiosis is followed by a brief period of high transcriptional activity. At this time a large amount of mRNA is stored as messenger ribonucleoprotein (mRNP) particles. All subsequent processes of sperm maturation occur in the complete absence of transcription, primarily using proteins which are newly synthesized from these stored mRNAs. By expressing transgene m...

The chromatoid body (CB) is a germ granule in the cytoplasm of postmeiotic haploid round spermatids that is loaded with RNA and RNA-binding proteins. Following the discovery of small non-coding RNA-mediated gene regulation and the identification of PIWI-interacting RNAs (piRNAs) that have crucial roles in germ line development, the function of the CB has slowly begun to be revealed. Male germ c...

Cyclic AMP (cAMP) and its action by way of cAMP-dependent protein kinase is important for sperm motility. Previous studies on germ cells have demonstrated a selective decrease in the amount of type I cAMP-dependent protein kinase during spermatid development, and that type II was the major form present in elongating spermatids and in mature sperm. This would indicate activation of a gene in hap...

Spermiogenesis Germ cells differentiate and function to transmit the parental genome to descendant generations. All of the attributes of germ cells that distinguish them from somatic cell lines are related to this prime function. Germ cells differentiate by either oogenesis or spermatogenesis to form eggs and sperm, respectively. Meiosis occurs exclusively in the formation of eggs and sperm and...

Spermatogenesis consists broadly of three phases: proliferation of diploid germ cells, meiosis, and finally extensive differentiation of the haploid cells into effective delivery vehicles for the paternal genome. Despite detailed characterization of many haploid developmental steps leading to sperm, only fragmentary information exists on the control of gene expression underlying these processes...

Transcription regulation in male germ cells can involve specialised mechanisms and testis-specific paralogues of the general transcription machinery. Here we describe TAF7L, a germ-cell-specific paralogue of the TFIID subunit TAF7. TAF7L is expressed through most of the male germ-cell differentiation programme, but its intracellular localisation is dynamically regulated from cytoplasmic in sper...

Department of Urology, Renji Hospital, Shanghai Human Sperm Bank, Shanghai Jiao Tong University School of Medicine, Shanghai 200135, China; State Key Laboratory of Oncogenes and Related Genes, Stem Cell Research Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China; Shanghai Key Laboratory of Reproductive Medicine, Shanghai 200025, China; Shanghai Key...