cCAMP response element modulator (CREM): an essential factor for spermatogenesis in primates?

CREM is a cAMP-related transcription factor and alternate promotor usage an d splicing generate repressor and activator transcripts of CREM within the testis. CREM activators are highly expressed in post-meiotic haploid germ c ells and are essential for spermatid maturation in the mouse model as revea led by gene-targeting studies. Analysis of testicular CREM expression in ro dent and monkey species, and in men yielded a highly comparable pattern thu s suggesting that CREM is of general importance for spermatid development i n the mammalian testis. Also, many CREM target genes have been identified i n haploid germ cells. Studies in men with spermatogenic disturbance and spe rmatid maturation arrest demonstrated abnormal CREM expression and altered splicing events. Collectively, the data strongly argue for an essential rol e of CREM during spermatid maturation in primates.