Construction of the chromosome map of hamster and Suncus by FISH using human and mouse cDNA clones

比较染色体图谱的构建是鉴定不同动物物种间染色体重排和染色体同源性的有效方法之一。本研究利用小鼠和大鼠的cDNA克隆，采用直接r带荧光原位杂交（FISH）技术，构建了叙利亚仓鼠和中国仓鼠与小鼠和大鼠的比较图谱。我们在叙利亚和中国仓鼠中分别鉴定出26个和13个染色体区域与小鼠具有保守的连锁同源性。通过对小鼠-大鼠和小鼠-叙利亚仓鼠染色体比较图的比较，我们的结果表明小鼠和叙利亚仓鼠染色体之间的染色体重排可能多于小鼠和大鼠染色体之间的染色体重排。为了了解啮齿目动物X染色体重排的过程，我们构建了家鼠（M.m. domesticus）、大鼠、叙利亚仓鼠、中国仓鼠和印度棘鼠（m.p platythrix） X染色体的细胞遗传学图谱，其中有26个功能基因已在人类X染色体上定位。基因序列的比较表明，小鼠和大鼠X染色体之间存在4个具有保守连锁同源性的染色体片段。大鼠、叙利亚仓鼠、中国仓鼠和印度棘鼠的X染色体基因顺序除2个基因外，其余基因顺序相同。这些物种的基因顺序与人类的X染色体相似。这些结果表明，小鼠体内积累了大量的X染色体重排，印度棘鼠的X染色体与祖先哺乳动物的X染色体密切相关。与小鼠和人类的X染色体比较，我们发现鼠尾鼠的染色体片段具有不同的基因顺序。

The construction of comparative chromosome map is one of useful approaches for identifiing chromosome rearrangements and chromosomal homology between different animal species.In this study, we constructed comparative maps of Syrian hamster and Chinese hamster to mouse and rat by the direct R-banding fluorescence in situ hybridization (FISH) using mouse and rat cDNA clones. We identified twenty-six and thirteen chromosomal regions with conserved linkage homology to mouse in Syrian and Chinese hamsters, respectively. In comparison between mouse-rat and mouse-Syrian hamster comparative chromosome maps, our results indicated a possibility that there are more chromosome rearrangements between mouse and Syrian hamster chromosomes than between mouse and rat chromosomes.To estimate the process of X chromosome rearrangements in Rodentia animals, we constructed cytogenetic maps of mouse (M.m. domesticus), rat, Syrian hamster, Chinese hamster and Indian spiny mouse (M.platythrix) X chromosomes with twenty-six functional genes, which have been mapped on human X chromosome. The comparison of the gene orders indicated the presence of four chromosome segments with conserved linkage homology between mouse and rat X chromosomes. However, the gene orders were the same among rat, Syrian hamster, Chinese hamster and Indian spiny mouse X chromosomes with the exception of two genes. The gene orders in these species were similar to that of human X chromosome. These results suggested that numerous X chromosome rearrangements accumulated in mouse, and that Indian spiny mouse X chromosome is closely related to the ancestral mammalian X chromosome. We found several chromosome segments with different gene orders in Suncus murinus compared with mouse and human X chromosomes.