Isolation and expression of DNA repair genes dmc1 and rad51 from the model fish medaka (Oryzias latipes)

Abstract

Homologous recombination (HR) is involved in DNA repair and essential for the development and progression of germ cells through meiosis. A key player in HR is the bacterial RecA which has two true homologs in metazoan: rad51 and dmc1. HR is also widely used for gene targeting in embryonic stem (ES) cells. Here, we isolated putative dmc1 and rad51 cDNAs from the medaka as a vertebrate model. Sequence alignment and phylogenetic analysis show that the medaka Dmc1 is much more closely homologous to the tetrapod Dmc1 (87%) than to Rad51 protein (49%). Gene expression was analyzed in adult tissues by RT-PCR. Recombinant proteins were generated and were used for the production of antibodies. In situ hybridization from mRNA level and immunostaining of oocytes from protein level were carried out. Based on the sequence, structure and expression similarity, we can conclude that we isolated indeed dmc1 and rad51 cDNAs from medaka.