The cAMP-responsive element modulator (CREM) is involved in regulating gene expression in haploid spermatids. Transcriptional activity of the CREM protein is thought to be regulated by activator of CREM in the testis (ACT). Applying RT-PCR and in situ hybridization, cell-specific gene expression of ACT was demonstrated in man, cynomolgus monkey and mouse. During normal spermatogenesis, RT-PCR r...

INTRODUCTION In mammals, spermatogenesis is a multistep processes, comprising mitotic proliferation of spermatogonia, meiotic division of spermatocytes and maturation of haploid spermatids (Nakanishi and Shiratsuchi, 2004). As spermatids undergo terminal differentiation into spermatozoa, the bulk cytoplasmic contents are segregated into the residual body, which is sloughed off, phagocytosed and...

Numerous genes are expressed preferentially in spermatids, the haploid germ cells of the testis. Although some have defined, spermatid-specific roles, the expression and function of the products of most of these genes are not restricted to spermatids [1]. Examples include transcription factors that have defined functions elsewhere, kinases, metabolic enzymes, and so on. Recently, another group ...

Spermiogenesis in the mammalian testis is the most critical post-meiotic developmental event occurring during spermatogenesis in which haploid spermatids undergo extensive cellular, molecular and morphological changes to form spermatozoa. Spermatozoa are then released from the seminiferous epithelium at spermiation. At the same time, the BTB (blood-testis barrier) undergoes restructuring to fac...

BACKGROUND The RNase III endonuclease Dicer is an important regulator of gene expression that processes microRNAs (miRNAs) and small interfering RNAs (siRNAs). The best-characterized function of miRNAs is gene repression at the post-transcriptional level through the pairing with mRNAs of protein-encoding genes. Small RNAs can also act at the transcriptional level by controlling the epigenetic s...

The nuclear lamina takes centre stage during spermiogenesis, the post-meiotic phase of spermatogenesis, when haploid round spermatids differentiate into spermatozoa: the acrosome and flagellum develop at opposite nuclear poles, the nucleus elongates and, as the nuclear histones are replaced with protamines, the chromatin condenses, to produce the highly compacted pyriform nucleus of the mature ...

During spermatogenesis, spermiation takes place at the adluminal edge of the seminiferous epithelium at stage VIII of the epithelial cycle during which fully developed spermatids (i.e. spermatozoa) detach from the epithelium in adult rat testes. This event coincides with the migration of preleptotene/leptotene spermatocytes across the blood-testis barrier from the basal to the apical (or adlumi...

OBJECTIVE To assess the effectiveness of the three-dimensional culture of spermatogenic cells in a collagen gel matrix from nonobstructive azoospermic patients and examine the relation between the success rate of in vitro spermatogenesis and serum FSH level as a diagnostic prediction. DESIGN Prospective study using radioimmunoassay, immunocytochemistry, and flow cytometry with primary culture...