Watson J M, Graves J A
Department of Genetics and Human Variation, La Trobe University, Bundoora.
Aust J Biol Sci. 1988;41(2):231-7. doi: 10.1071/bi9880231.
In order to extend comparative mapping studies to the monotreme mammals (subclass Prototheria), somatic-cell hybrids were obtained between Chinese-hamster cells deficient in hypoxanthine phosphoribosyltransferase (HPRT) and platypus fibroblasts. The characteristics of these hybrids closely resemble those of metatherian x eutherian hybrids, in that they are recovered at low frequency and they rapidly segregate and fragment platypus chromosomes. Biochemical and cytological studies of the hybrids, their subclones and HPRT-deficient revertants indicate that phosphoglycerate kinase is syntenic with HPRT in the platypus (as it is in other mammals); however, the studies do not permit chromosomal assignment of the syntenic group. The implications of the chromosomal location of this ancient synteny group for the evolution of the mammalian X chromosome are discussed.
为了将比较图谱研究扩展到单孔目哺乳动物（原兽亚纲），在缺乏次黄嘌呤磷酸核糖基转移酶（HPRT）的中国仓鼠细胞与鸭嘴兽成纤维细胞之间获得了体细胞杂种。这些杂种的特征与有袋类与真兽类杂种的特征非常相似，即它们的获得频率很低，并且它们会迅速分离并使鸭嘴兽染色体断裂。对杂种、它们的亚克隆以及HPRT缺陷回复体的生化和细胞学研究表明，磷酸甘油酸激酶在鸭嘴兽中与HPRT同线（就像在其他哺乳动物中一样）；然而，这些研究无法确定该同线群的染色体定位。讨论了这个古老同线群的染色体位置对哺乳动物X染色体进化的影响。
