Identification and characterization of a novel spermatogenesis related gene LM23 in rat testis

The aim of this study is to screen the novel gene related to the spermatogenesis. A novel rat testis-specific gene LM23 was identified and characterized by differential display PCR with total RNA from rat type A spermatogonia, pachytene spermatocytes, and round spermatids. LM23 cDNA consists of 1896 base pairs (bp) with a complete open reading frame of 936 bp, and encodes a putative protein including 312 amino acids, which shares no significant homology with any known gene. The sequence of LM23 was submitted to GenBank and the Accession No. was AF492385. Multitissue Northern blot and RT-PCR analysis showed LM23 was specific expression in testis, while its expression was not detected in other tissues. Real-time PCR analysis showed that the expression level of LM23 was highest in spermatocytes and very low in spermatogonia. In situ hybridization revealed strong cytoplasmic positive signal in spermatocytes and weak signal in spermatids and spermatogonia. These results indicated LM23 possessed the testis-specific and stage-specific expression characteristics, and possibly involved in rat spermatogenesis.