Bayés M, Prieto I, Noguchi J, Barbero J L, Pérez Jurado L A
Genetics Unit, Dept. Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain.
Mol Reprod Dev. 2001 Nov;60(3):414-7. doi: 10.1002/mrd.1104.
Affected males (as/as) from the mutant TT rat strain are sterile due to spermatogenesis impairment with meiotic arrest at the pachytene stage. The as locus is on rat chromosome 12, in a region that shows conserved synteny to cM 74-94 on mouse chromosome 5. Stag3, a new member of the stromalin protein family, is expressed specifically in testis and associates to the synaptonemal complex. Mouse Stag3 gene has been assigned to cM 78 on chromosome 5. In this study, we have characterized the rat Stag3 gene and examined it as a candidate for male infertility in as/as rats. The rat Stag3 cDNA is 4181 nucleotides long, contains a highly polymorphic hexanucleotide repeat in the coding region, and encodes a 1256 amino acid protein with 93 and 77% sequence identity to mouse and human Stag3 proteins, respectively. No mutations or differences in size or abundance of Stag3 mRNA were detected between as/as and control rats, suggesting that Stag3 is not responsible for the aspermic phenotype. In addition, immunohistochemistry with antibodies against SCP1 and SPC3 proteins suggest that the synaptonemal complex structures are not primarily affected in these rats.
来自突变型TT大鼠品系的患病雄性（as/as）由于精子发生受损且减数分裂停滞在粗线期而不育。as基因座位于大鼠12号染色体上，该区域与小鼠5号染色体上74-94 cM的区域显示出保守的同线性。Stag3是基质蛋白家族的一个新成员，在睾丸中特异性表达并与联会复合体相关联。小鼠Stag3基因已被定位到5号染色体上的78 cM处。在本研究中，我们对大鼠Stag3基因进行了表征，并将其作为as/as大鼠雄性不育的候选基因进行了研究。大鼠Stag3 cDNA长4181个核苷酸，在编码区含有一个高度多态的六核苷酸重复序列，并编码一种1256个氨基酸的蛋白质，与小鼠和人类Stag3蛋白的序列同一性分别为93%和77%。在as/as大鼠和对照大鼠之间未检测到Stag3 mRNA的突变、大小或丰度差异，这表明Stag3与无精子表型无关。此外，用针对SCP1和SPC3蛋白的抗体进行免疫组织化学分析表明，这些大鼠的联会复合体结构并未受到主要影响。
