几种优良养殖对虾杂合性的比较研究

应用聚丙烯酰胺凝胶电泳技术研究了南美白对虾（Penaeus vannamei)，日本对虾（Penaeus japonicus)，斑节对虾（Penaeus monodon)，新对虾（Metapenaeus ensis)养殖群体杂合体缺乏及过量。结果表明南美白对虾在Est-2(F=0.705),Aat-2(F=1.000)，两个位点上存在杂合子缺乏，在Adh-3(F=-1.000),Sdh-2(F=-1.000),Mdh-4(F=-1.000)三个位点上存在杂合子过量；日本对虾在Est-1(F=0.258),Sod-1(F=0.467)两个位点上存在杂合子缺乏；斑节对虾在Est-1(F=0.254),Sdh-3(F=1.000)两个位点上存在杂合子缺乏；新对虾在Aat-1(F=1.000)位点上存在杂合子缺乏，在Est-1(F=-0.158),Sod-1(F=-1.000),Me-4(-F=1.000)三个位点上存在杂合子过量。导致杂合子缺乏的主要原因可能是自然选择，近交，Wahland效应等。杂合子缺乏会导致某些基因从基因库中消失，造成种群遗传多样性的降低，从而降低物种适应环境的能力。

THE COMPARISON STUDY ON HETEROZYGOSITY IN FOUR SPECIES OF SHRIMPS

Heterozygosity was investigated using the assay of vertical slab polyacrylamide gel electrophoresis in4species of shrimps:Penaeus japonicus,Penaeus monodon,Penaeus vannamei and Metapenaeus ensis.The results showed that there is heterozygote deficiency in Est-2(F=0.705),Aat-2(F=1.000),and heterozygote excess in Adh-3(F=-1.000),Sdh-2(F=-1.000),Mdh-4(F=-1.000)in P.vannamei;there is heterozygote deficiency in Est-1(F=0.258),Sod-1(F=0.467)in P.japonicus;there is heterozygote deficiency in Est-1(F=0.254),Sdh-3(F=1.000)in P.monodon;and there was heterozygote deficiency in Aat-1(F=1.000),and heterozygote excess in Est-1(F=-0.158),Sod-1(F=-1.000),Me-4(-F=1.000)in M.ensis.The main causes of heterozygote defi-ciency were nature selection incross Wahland effect and so on.The heterozygote deficiency would result in allele disappear,the lower genetic diversity and the lower ability of adaptation.