MAPPING OF THE MOUSE TDGF1 GENE AND TDGF PSEUDOGENES

Teratocarcinoma-derived growth factor-1 (Tdgf1), a member of the ''EGF family'' of growth factors, is expressed during mouse gastrulation in the forming mesoderm and later in the truncus arteriosus of the devel oping heart. In humans, TDGF1 is highly expressed in germ cell tumors and in colon and mammary carcinomas. In mouse, one gene (Tdgf1) and tw o pseudogenes (Tdgf1-ps1 and Tdgf1-ps2) have been isolated and charact erized. Tdgf1 corresponds to the gene expressed in F9 teratocarcinoma cells. Tdgf1-ps1 and Tdgf1-ps2 are two intronless sequences with all t he characteristics of retroposons. In the present paper, we assign the chromosomal location for Tdgf1, Tdgf1-ps1, and Tdgf1-ps2 sequences to Chromosomes (Chrs) 9, 16, and 17, respectively. Two previously descri bed mouse mutants, scant hair (sch) and fur deficient (fd), map near t he Tdgf1 gene. Analysis of their DNA coding region provided no evidenc e that Tdgf1 could be the responsible gene for these phenotypes. Final ly, analysis of the DNA from several Mus musculus strains and from Mus spretus mice revealed a highly variable restriction pattern and the a bsence of the Tdgf1-ps1 genomic sequence from the Mus spretus genome.