Disteche C M, Zacksenhaus E, Adler D A, Bressler S L, Keitz B T, Chapman V M
Department of Pathology, University of Washington, Seattle 98195.
Mamm Genome. 1992;3(3):156-61. doi: 10.1007/BF00352460.
The nucleotide sequence of the human cDNA encoding ubiquitin-activating enzyme E1 is more than 99% identical with the human A1S9T cDNA, a gene that has been shown to complement the temperature-sensitive mutant mouse cell line, tsA1S9. The amino acid sequences of the proteins encoded by these two cDNA sequences are identical, and both cDNAs were previously shown to be located in the same region of the human X chromosome; thus, ubiquitin-activating enzyme E1 and A1S9T appear to be the same gene, designated UBE1. By in situ hybridization to metaphase chromosomes from male mice and by Southern blot analysis of male and female mouse DNA, we show that, in the mouse, a human UBE1 cDNA probe identified both X- and Y-linked loci. Ube1 is located at band A2 of the mouse X Chromosome (Chr) and Ube2 on the short arm of the Y Chr. This is in contrast to the situation in the human, where there is no evidence for Y-linked sequences related to UBE1. Mapping of the Ube1 gene in interspecific backcrosses between Mus spretus and C57BL/6 shows that the Ube1 locus maps close to Timp, in a conserved region of the mouse and human X Chrs that include Otc, Cybb, Syn1, Timp, and Araf. Expression of Ube1 on the inactive X Chr was examined to determine whether this gene is subject to X-Chr inactivation in the mouse, as there is previous evidence that the human UBE1 gene escapes, at least partially, X inactivation. Sequencing of reverse transcriptase polymerase chain reaction (RT-PCR) products from M. spretus, C57BL/6J, and T(X;16)16H x M. spretus F1 female mice indicates that the mouse Ube1 gene is subject to X-Chr inactivation in vivo. This represents a new example of differences between the sex chromosomes of mouse and human.
编码泛素激活酶E1的人类cDNA的核苷酸序列与人类A1S9T cDNA的相似度超过99%，A1S9T是一个已被证明可互补温度敏感突变小鼠细胞系tsA1S9的基因。这两个cDNA序列编码的蛋白质的氨基酸序列相同，并且先前已证明这两个cDNA都位于人类X染色体的同一区域；因此，泛素激活酶E1和A1S9T似乎是同一个基因，命名为UBE1。通过对雄性小鼠中期染色体的原位杂交以及对雄性和雌性小鼠DNA的Southern印迹分析，我们发现，在小鼠中，人类UBE1 cDNA探针可识别X和Y连锁基因座。Ube1位于小鼠X染色体（Chr）的A2带，Ube2位于Y Chr的短臂上。这与人类的情况形成对比，在人类中没有证据表明存在与UBE1相关的Y连锁序列。在小家鼠和C57BL/6之间的种间回交中对Ube1基因进行定位，结果表明Ube1基因座靠近Timp，位于小鼠和人类X Chrs的一个保守区域，该区域包括Otc、Cybb、Syn1、Timp和Araf。检测了Ube1在失活X Chr上的表达，以确定该基因在小鼠中是否会发生X Chr失活，因为之前有证据表明人类UBE1基因至少部分逃避了X失活。对来自小家鼠、C57BL/6J和T(X;16)16H×小家鼠F1雌性小鼠的逆转录酶聚合酶链反应（RT-PCR）产物进行测序表明，小鼠Ube1基因在体内会发生X Chr失活。这代表了小鼠和人类性染色体之间差异的一个新例子。
