棕色田鼠遗传多样性研究

Here we describe our comparative studies on two types of X chromosomes, namely XM and XSM, of Microtus mandarinus. By chromosome G- and C-banding analysis, we have found that two different types of X chromosomes exist in mandarin voles. The two types of X chromosomes present two different G- and C-banding: the XM chromosome is a longer metacentric X chromosome which is C-band negative; and the XSM is a shorter submetacentric X chromosome which has one C-band at the centromere and another one at the middle part of the short arm. The XSM has 6 G-bands including one on the kinetochore, one in the middle of the short arm, and four on the long arm. The XM has 7 G-bands including one on the kinetochore, two on the short arm, and four on the long arm. We have further found that female voles can be grouped into three types based on the composition of the X chromosome but the male voles have only one type. The three female groups are: (1) female voles (XMXSM), in which the two X chromosomes are different, the longer one is metacentric and the shorter is submetacentric; (2) female vole (XSMXSM), in which the two X chromosomes are both submetacentric; (3) female vole (XMO), in which there is only one X chromosome that is metacentric. We hypothesize that the XSM chromosome is derived from XM chromosome through its breakage and re-joining. The paper also discuss the formation of XMO female.

棕色田鼠主要分布于我国，是种内遗传多样性、遗传进化研究的理想模式动物。采用细胞遗传学及分子生物学技术，对分布于国内不同地区的棕色田鼠核型等遗传指标的比较、染色体多态形成及机制、XO雌体可育及机制、雌性育性基因定位、检测SRY基因同源序列等研究，锌赡芙沂靖锰厥饨窒蠛蜕郴疲抟删哂兄匾砺垡庖濉