• PMID: 14511788
• Gene Name: CREM
• Condition: Male infertility
• Association: Associated
• Sex: Male
• Infertility type: Male infertility
• Associated genes: CREM
• Other associated phenotypes: Male infertility

Different CREM-isoform gene expression between equine and human normal and impaired spermatogenesis

Blöcher S, Behr R, Weinbauer GF, Bergmann M, Steger K.

Histone-to-protamine exchange causes chromatin condensation ceasing gene expression in elongating spermatids. Gene expression of protamines is regulated by the transcription factor cAMP-responsive element modulator (CREM). Altered CREM expression results in male infertility, as shown by CREM-knock-out mice being sterile due to round spermatid maturation arrest and patients exhibiting round spermatid maturation arrest revealing a lack or substantial reduction of both CREM-mRNA and CREM-protein. Similar defects in histone-to-protamine exchange have been suggested in infertile stallions exhibiting enlarged sperm heads. The CREM-gene consists of 14 exons. Alternative exon splicing results in the production of both activator and repressor proteins. To further clarify the role of different CREM-isoforms for male infertility, the expression pattern of various CREM-isoforms during equine and human normal and impaired spermatogenesis was investigated by RT-PCR. Stallions with normal spermatogenesis expressed six activators and three repressors. In men three activators and seven different repressors were detected. In one stallion and patients with impaired spermatogenesis, only repressors were found. It is concluded that (i). stallion and man reveal a different CREM expression pattern, (ii). the expression of CREM activators is a prerequisite for normal spermatogenesis, and (iii). the lack of CREM activator expression results in male infertility. FAU - Blöcher, Sonja AU - Blöcher S AD - Institute of Veterinary Anatomy, Histology and Embryology, University of Giessen, Frankfurter Strasse 98, Giessen 35392, Germany. FAU - Behr, Rüdiger AU - Behr R FAU - Weinbauer, Gerhard F AU - Weinbauer GF FAU - Bergmann, Martin AU - Bergmann M