Gene targeting of desrt, a novel ARID class DNA-binding protein, causes growth retardation and abnormal development of reproductive organs

We have cloned and characterized a novel murine DNA-binding protein Desrt, with a motif characteristic of the ARID (A-T rich interaction domain) famil y of transcription factors. The Desrt gene encodes an 83-kD protein that is shown to bind DNA and is widely expressed in adult tissues. To examine the in vivo function of Desrt we have generated mice with a targeted mutation in the ARID domain of Desrt. Homozygous mutants have reduced viability, pro nounced growth retardation, and a high incidence of abnormalities of the fe male and male reproductive organs including cryptorchidism. This may thus s erve as a model to dissect the mechanisms involved in the development of th e reproductive tract including testicular descent. Gene-targeted mice also display a reduction in the thickness of the zona reticularis of the adrenal gland and transient aberrations of the T and B cell compartments of primar y lymphoid organs. These data show that this novel DNA-binding protein, Des rt, has a nonredundant function during growth and in the development of the reproductive system.