尼罗罗非鱼(♀)×萨罗罗非鱼(♂)F_1家系亲权关系微卫星分析

Analysis of paternity and relatedness in Oreochromis niloticus(♀) × Sarotherodon melanotheron(♂) hybrid F_1 families by microsatellite markers

利用尼罗罗非鱼（Oreochromis niloticus）第2代遗传连锁图谱标记，对3组不同尼罗罗非鱼（♀）×萨罗罗非鱼（Sarotherodon melanotheron）（♂）杂交F1家系内亲权关系进行分析。结果显示，86个微卫星位点中共筛选出20个在尼罗罗非鱼、萨罗罗非鱼中存在差异的扩增位点，含13个种间特异性和7个共享带差异位点。尼萨杂交F1中，平均等位基因2.90，平均多态信息含量0.439，位点多态性较高。3个尼萨杂交F1家系组间遗传距离0.362~0.504，组内个体间遗传距离0.245~0.316，组内遗传距离明显小于组间。利用3个种间特异位点组合，可对3个不同家系组父、母本个体进行鉴别。通过对各组亲本与子代位点基因型分析，家系A、B和C组分别使用4、8和12个特异位点组合进行亲权鉴定，累积排除概率分别为99.99%、99.99%、99.91%，家系A、B组分别含3个半同胞家系，家系C组含2对非同胞或4个半同胞家系。

We conducted an analysis of paternity and relutedness in 3 family groups of Oreochromis niloticus（♀）× Sarotherodon melanotheron（ ♂ ） hybrids F1with different parental information and different sizes by microsatellite markers form the 2nd genetic linkage map of Nile tilapia. The results show there were 20 loci with different-sized alleles in O.niloticus and S.melanotheron detected in 86 pairs of microsatellites, including 13 specific loci and 7 shared allelic loci. The average number of alleles in F1 was 2.90 and of polymorphism information was 0.439. The genetic distance among the 3 family groups was 0.362~0.504, and within each group was 0.245 ~ 0.316. Thes individual parents in the 3 different family groups were effectively identified by 3 completely higher polymorphic markers combinations. Using genotypic information, 4, 8 and 12 loci were needed for accurate paternity identification in family group A, B and C with high parent exclusion probability of 99.99%, 99.99% and 99.91%, respectively. Groups A and B contained 3 half-sib families, while group C contained 2 pairs of non-sib families or 4 half-sib families.