The murine Fem1 gene family: Homologs of the Caenorhabditis elegans sex-determination protein FEM-1

The pathway controlling sex determination in the nematode Caenorhabditis el egans is a model for the genetic control of cell-fate determination. We rep ort here the cloning and characterization of a new mouse gene family with h omology to FEM-1, a signal-transducing regulator in the C. elegans sex-dete rmination pathway. This gene family consists of two known members, designat ed Fem1a and Fem1b. The highest degree of homology between the two mouse pr oteins and the nematode protein is in a domain that encodes seven sequentia l ANK repeats. The Fem1a gene localizes to chromosome 17 and is highly expr essed in adult heart and skeletal muscle. The Fem1b gene localizes to chrom osome 9 and is highly expressed in adult testis. Both genes are expressed d uring embryogenesis. The existence of FEM-1 homologs in the mouse raises th e possibility that evolutionary conservation of ancient FEM-1 signaling int eractions may play a role in vertebrate cell-fate determination, (C) 1998 A cademic Press.