Molecular cloning and characterization of Dmc1, a gene involved in gametogenesis, from the whiteleg shrimp Litopenaeus vannamei

In order to gain a better understanding of the developmental processes of shrimp germ cells, the molecular cloning and characterization of a meiosis-related gene, and, was carried out using the whiteleg shrimp Litopenaeus vannamei. The cDNA of the L. vannamei Dmc1 homologue (LvDmc1) was 1,647 bp long and contained a 1,023-bp open reading frame corresponding to 341 amino acid residues. The deduced amino acid sequence contained motifs conserved in the RecA/Rad51 superfamily to which Dmc1 homologues belong and showed high identities with Dmc1 of other animals, including invertebrate and vertebrate species. RT-PCR revealed the presence of transcripts of LvDmc1 in gonads having meiotic genii cells. In situ hybridization analysis showed that LvDmc1 mRNA was abundantly expressed in premeiotic spermatogonia and oogonia, but not in gonadal somatic cells. Lvmc1 is thus a potentially useful indicator of the early stages of germ cell development.