两个封闭群SPF级昆明小鼠遗传背景调查

目的：比较两个封闭群SPF级昆明（ KM）小鼠的遗传差异，调查引进的SPF级KM小鼠封闭繁殖6年后，其遗传构成是否发生变化。方法应用微卫星DNA标记方法对18个位点在两个群体中的遗传差异进行分析，主要包括观察等位基因数（ Na）、有效等位基因数（ Ne）、观察杂合度（ Ho）、期望杂合度（ He）、多态信息含量（PIC ）、Shan-non信息指数、遗传分化系数（ F st）、遗传距离等遗传参数。结果两个封闭群SPF 级KM小鼠在18个微卫星位点共发现67个等位基因，Na为2～8个，平均3．7222个；Ne为1．9459～6．5442，平均2．7966个；Ho为0．4225～1．0000，平均0．8823；He为0．4892～0．8527，平均0．6162；Shannon信息指数0．6792～1．9526，平均1．0598；PIC为0．3680～0．8301，平均0．5317；Fst平均值为0．0159，表明群体间的遗传差异仅1．59％，二者间的遗传距离（DA）为0．0499。结论两个封闭群SPF级KM小鼠遗传结构相似度极高，它们与原引进群体的分化差异极小。

Genetic background of SPF mice from Kunming species in two closed colonies

Objective Compare genetic differences between the SPF KM mice in two closed colonies （ group） and investi-gate whether the SPF KM mice occur significant changes in gene structure after their ’ s reproduction in a certain long time . Method Analysis of the genetic differences of 18 locus in the two groups was carried out by the method of labelling micro-satellite DNA markers, which includes observation of number of alleles （Na）, effective number of alleles （Ne）, observa-tion heterozygosity （Ho）, expected heterozygosity （He）, polymorphic information content （PIC）, Shannon＇s information index, coefficient of genetic differentiation , genetic distance and so on .Result We found 67 allelles in 18 microsatellite loci of SPF KM mice in two closed colonies , Na with 2-8 and mean 3.722 2 at each locus ;Ne is 1.945 9-6.544 2, with an average of 2.796 6;Ho is 0.422 5-1.000 0, with an average of 0.882 3;He is 0.489 2-0.852 7, with an average of 0.616 2;Shannon＇s information index is 0.679 2-1.952 6, average 1.059 8;PIC is 0.368 0-0.830 1, with an average of 0.531 7;the average of FST is 0.015 9, indicating that only 1.59% genetic difference from SPF KM mice in two closed colonies, （a difference of 98.41%from within populations;） genetic distance （DA） between the two groups is 0.049 9. Conclusion The genetic structure of SPF KM mice is in a very high homogenecity in two closed colonies and the veriation is extremely tiny in two closed colonies and the original population .