CRYPTORCHIDISM AND HOMEOTIC TRANSFORMATIONS OF SPINAL NERVES AND VERTEBRAE IN HOXA-10 MUTANT MICE

Homozygous mice mutated by homologous recombination for the AbdB-relat ed Hoxa-10 gene are viable but display homeotic transformations of ver tebrae and lumbar spinal nerves. Mutant males exhibit unilateral or bi lateral criptorchidism due to developmental abnormalities of the guber naculum, resulting in abnormal spermatogenesis and sterility, These re sults reveal an important role of Hoxa-10 in patterning posterior body regions and suggest that Hox genes are involved in specifying regiona l identity of both segmented and nonovertly segmented structures of th e developing body.