Characterization of a mouse recA-like gene specifically expressed in testis

Using the sequence information on a class of recA-like genes, which have been isolated from meiosis-specific cDNA libraries of Lilium and budding yeast and identified in various plant cells, a new gene was screened from a mouse testis cDNA library. The putative product of the gene, termed MmLim15, was 37.8 kDa consisting of 340 amino acid residues. The predicted amino acid sequence showed 72-78% similarity to those of Lim15 from Lilium and other meiosis-specific RecA-like proteins. Similarity was also found to another class of recA-like proteins, Rad51 and its homologues, which have been detected in both budding and fission yeasts and various animal cells, but to a lesser extent and the similarity patterns were somewhat different from those for Lim15 type proteins, revealing that the two classes of recA-like genes are phylogenetically separate. Reverse transcription-PCR using poly(A)+ RNAs from various tissues as templates indicated that transcription of MmLim15 occurred specifically in the testis, suggesting that the MmLim15 product participates in meiotic recombination.