Production of Sterile Mouse Model for Human and Domestic Animal

在小鼠种间或亚种间杂种不育中，由杂种不育（Hst）基因诱导的实验小鼠与野生小鼠交配时，偶尔会发现杂种不育。其中Hst 3基因控制实验小鼠与西班牙野生小鼠种间杂种的不育性，它与X-Y染色体分离有关，伴随着中期Ⅰ（MI）后精子发生的破坏。为了详细分析Hst 3引起的杂种不育，建立了C57 BL/6同源小鼠，携带Spretus来源的Hst 3，至生后12天，两种类型的睾丸中精子发生进展相对正常。第14天，正常睾丸粗线期早期精母细胞出现，不育睾丸精母细胞出现大量变性。第20天，正常睾丸中出现大量圆形精子细胞，而不育睾丸中未见圆形精子细胞。性成熟60天时，正常睾丸中各种生殖细胞均参与， ...更多信息 根据正常睾丸和不育睾丸的形态学差异，采用同源小鼠睾丸cDNA差减法，对正常和不育睾丸的精子发生相关基因进行分析。北方印迹分析表明，部分消减cDNA克隆在正常睾丸中的表达高于不育睾丸。其中克隆F77在正常睾丸中的表达量显著高于不育睾丸。除睾丸外，其它器官均未检测到该转录本。北方印迹分析表明，F77基因只在正常成年睾丸中表达，而在长形精子细胞和部分圆形精子细胞中均有表达。cDNA克隆F77定位于小鼠8号染色体Mt-1和Ctrb之间，其中未检测到相关基因Less

In mice, the interspecific or intersubspecific hybrid sterility has been occasionally found in matings between laboratory mice and wild mice induced by Hybrid sterility (Hst) genes. One of them, Hst3, which controls the sterility of interspecific hybrids between laboratory mice and Mus spretus originated from Spanish wild mouse, is associated with X-Y chromosome dissociation accompanied by spermatogenic breakdown after metaphase I (MI). For detaild analysis of hybrid sterility caused by Hst3, C57BL/6 congenic mice, carring Hst3 derived from spretus, were created.Up to postnatal day 12, spermatogenesis progressed relatively normal in both type testis. At day 14, when early pachytene spermatocytes appeared in nomal testis, many degenerations weredetected on these cells in sterile testis. At day 20, many round spermatids appeared in nomal testis, while no round spermatids were found in stertile testis. At day 60 of sexually matured age, nomal testis involved in all kinds of germ cells, ho … More wever it was noted that few spermatids and spermatozoa were found in sterile testis throughout the histological sections.According to morphologial differeces between normal and sterile testis, the subtraction method between normal and sterile testis cDNA was performed using congenic mouse testis to analyze the normal spermatogenesis-associated genes. Transcripts of some subtracted cDNA clones were expressed higher in normal testis than in sterile testis by northern blot analysis. One of them, clone F77, showing significant unmatchies with entries in the demonstrated remarkable expression of apporoximately 4kb transcript in nomal testis, compared to those in sterile testis. Additionaly the transcript was not detected at any other organs except testis. Northern blot analysis using developing normal testis and germ cell-defficient W/Wv mutant testis, show that the transcript of cDNA clone F77 was expressed only in normal adult testis, in which it was detected in elongated spermatids and partially round spermatids by in situ hybridization. cDNA clone F77 was mapped at position between Mt-1 and Ctrb on mouse chromosome 8, in which no related genes were detected Less