Rattus norvegicus Cryptorchidism Genomic Variation. Rattus norvegicus

Study of what genomic loci confer susceptibility to cryptorchidism, or undescended testis, in a rat substrain with phenotypic similarity to the human disease? Cryptorchidism in the LE/orl rat is associated with a unique combination of homozygous minor alleles at multiple loci, and encoded proteins are co-localized with androgen receptor (AR) in fetal gubernaculum. Prior studies showed aberrant perinatal gubernacular migration, muscle patterning defects and reduced fetal testicular testosterone in the LE/orl strain. In addition, altered expression of androgen-responsive, cytoskeletal and muscle-related transcripts in the LE/orl fetal gubernaculum suggest a role for defective AR signaling in cryptorchidism susceptibility. Study identifies genomic variants from two cryptorchid rat lines: Long Evans orl and Long Evans X Sprague Dawley, as compared to Long Evans wildtype.