Homologies between X and Y chromosomes detected by DNA probes: localisation and evolution.
Homologies between X and Y chromosomes detected by DNA probes: localisation and evolution.
复制标题
DNA 探针检测到的 X 和 Y 染色体之间的同源性：定位和进化。
作者：
M. Koenig;J. Moisan;R. Heilig;J. Mandel
我们已经分离并鉴定了检测X和Y染色体之间同源性的DNA探针。ST25克隆来源于X染色体的Q13-Q22区域，识别Y染色体上98%的同源序列。在5个YQ-个体和分析的7个XX男性个体中，4个个体的DNA中存在Y特异片段。用ST25探针(33%杂合度)检测到X连锁TaqI RFLP，这应该允许建立一个包含该区域其他多态X-Y同源序列的连锁图谱，并将其与Y染色体缺失图谱进行比较。位于Xp223-PTER的探针DXS31在Y染色体上检测到80%的同源序列。后者可以被分配到包含Y特定卫星序列的区域之外的Yq11-QTER。分别存在于X和Y染色体上的肌动蛋白序列Act1和Act2已被克隆。在肌动蛋白序列之外的X和Y衍生片段之间没有检测到同源性。ACT2和对应于DXS31的Y特异序列在一组Y染色体异常中分离在一起，可能是YQ精子发生重要区域的有用标记。对不同的灵长类物种进行了分析，以寻找与这三个探针同源的序列。由ST25和DXS31检测到的序列仅在尾猿科动物的X染色体上发现。ACT2两侧的序列在同一物种中检测到常染色体片段，但没有检测到雄性特有片段。推测在灵长类动物进化过程中，Y染色体在不同时期从X染色体和常染色体获得遗传物质。
We have isolated and characterized DNA probes that detect homologies between the X and Y chromosomes. Clone St25 is derived from the q13-q22 region of the X chromosome and recognizes a 98% homologous sequence on the Y chromosome. Y specific fragments were present in DNAs from 5 Yq-individuals and from 4 out of 7 XX males analysed. An X linked TaqI RFLP is detected with the St25 probe (33% heterozygosity) which should allow one to establish a linkage map including other polymorphic X-Y homologous sequences in this region and to compare it to a Y chromosome deletion map. Probe DXS31 located in Xp223-pter detects a 80% homologous sequence in the Y chromosome. The latter can be assigned to Yq11-qter outside the region which contains the Y specific satellite sequences. ACT1 and ACT2, the actin sequences present on the X and Y chromosomes respectively, have been cloned. No homology was detected between the X and Y derived fragments outside from the actin sequence. ACT2 and the Y specific sequence corresponding to DXS31 segregate together in a panel of Y chromosomes aberrations, and might be useful markers for the region important for spermatogenesis in Yq. Various primate species were analysed for the presence of sequences homologous to the three probes. Sequences detected by St25 and DXS31 are found only on the X chromosome in cercopithecoidae. The sequences which flank ACT2 detect in the same species autosomal fragments but no male specific fragments. It is suggested that the Y chromosome acquired genetic material from the X chromosome and from autosomes at various times during primate evolution.