Meyers-Wallen V N, Palmer V L, Acland G M, Hershfield B
Department of Anatomy, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
Mol Reprod Dev. 1995 Jul;41(3):300-5. doi: 10.1002/mrd.1080410304.
The Sry gene product serves an important function in male sex determination through testis induction. However, testicular development has been reported in SRY-negative XX sex reversed humans. XX sex reversal of the American cocker spaniel, inherited as an autosomal recessive trait, may be a homolog of this disorder. The purpose of this study was to determine whether the Sry high mobility group (HMG) box is present in genomic DNA of affected dogs. Conserved Sry HMG box and hypoxanthine phosphoribosyltransferase (HPRT) sequences were used as primers in polymerase chain reactions. A 167 bp Y-specific canine Sry HMG box sequence was cloned from genomic DNA of normal male dogs. Internal primers generated a 104 bp Sry HMG box product from normal males, but not from females or XX sex reversed dogs. Parallel reactions generated an HPRT product from all dogs. Results indicate that the Sry HMG box is absent in genomic DNA of XX sex reversed dogs. We speculate that activation of the testis differentiation cascade in the absence of Sry in this model is due to a mutant autosomal gene.
Sry基因产物通过诱导睾丸形成在雄性性别决定中发挥重要作用。然而，在SRY阴性的XX性反转人类中也有睾丸发育的报道。美国可卡犬的XX性反转作为一种常染色体隐性性状遗传，可能是这种疾病的同源病症。本研究的目的是确定受影响犬只的基因组DNA中是否存在Sry高迁移率族（HMG）框。在聚合酶链反应中，使用保守的Sry HMG框和次黄嘌呤磷酸核糖转移酶（HPRT）序列作为引物。从正常雄性犬只的基因组DNA中克隆出一段167 bp的Y特异性犬Sry HMG框序列。内部引物从正常雄性犬只中扩增出104 bp的Sry HMG框产物，但从雌性犬只或XX性反转犬只中未扩增出该产物。平行反应从所有犬只中扩增出HPRT产物。结果表明，XX性反转犬只的基因组DNA中不存在Sry HMG框。我们推测，在该模型中，在没有Sry的情况下睾丸分化级联的激活是由于一个突变的常染色体基因所致。
