Molecular cloning and genomic organization of mouse homologue of Drosophila germ cell-less and its expression in germ lineage cells

Primordial germ cells (PGCs) are founder cells of all gametes. A number of genes which control PG;Cs development have been identified in invertebrates, whereas such genes are by and large unelucidated in mammals. Here we describe cloning, genomic structure and expression of mouse homologue of germ cell-less (gcl) gene which is required for PGCs formation in Drosophila. The mouse gel shows 34% identity compared with Drosophila gel protein and contains BTB/ POZ domain. The gel gene consists of 14 exons and spans more than 50 kb, The CpG islands are found around exon 1 of the gene Putative promoter region contains potential binding sites for various transcription factors. Northern blot analysis showed that its mRNA is highly expressed in adult testis with lower expression in ovary, ES (embryonic stem) cells, and various other organs. In situ hybridization analysis revealed strong expression of the gel gene in the pachytene stage spermatocytes, The expression was also observed in post-migratory PGCs, but was not apparent in migratory and pre-migratory PG;Cs. Further studies including gene disruption analysis would provide an important insight into mammalian germ lineage development. (C) 1999 Academic Press.