Nayar Jai K, Knight J W, Munstermann L E
Florida Medical Entomology laboratory, IFAS/University of Florida, 200 9th Street, S.E. Vero Beach, Florida, 32962, USA.
J Med Entomol. 2002 Nov;39(6):854-60. doi: 10.1603/0022-2585-39.6.854.
A field population of Culex (Culex) nigripalpus Theobald from Vero Beach, FL sampled monthly over a period of 24 mo, a colony sample and 10 geographic samples were analyzed for genetic variation at 14 enzyme loci using polyacrylamide gel electrophoresis. The Cx. nigripalpus colony sample showed significantly lower genetic variation than the field-collected samples, measured by mean number of alleles per locus (colony 1.4 +/- 0.1 versus field 2.1 +/- 0.22), percentage of polymorphic loci (colony 35.7% versus field 54.8 +/- 7.7%), but mean observed heterozygosity (Ho = colony 0.16 +/- 0.07 versus field 0.17 +/- 0.03) and mean Hardy-Weinberg expected heterozygosity (He = colony 0.14 +/- 0.06 versus field 0.18 +/- 0.02) did not differ significantly. Three of the 14 loci (Aldox, Gpd, and Gpi) from the Vero Beach field samples showed distinct temporal patterns in the frequency of the most common allele. Higher mean observed heterozygosity (Ho) occurred during months following high rainfall in the Vero Beach field samples than during months following low rainfall. The average Nm value of 3.6 indicated high gene flow among the temporally distributed samples of the Vero Beach population. Genetic variability values between geographic samples from Panhandle, FL and south Florida were not significant. Gene flow estimates based on F(ST) = 0.039 provided a Nm of 6.2 indicating high levels of gene flow among the geographic samples of Cx. nigripalpus. The average Nei's and modified Rogers' genetic distances among the 10 populations were 0.009 +/- 0.001 and 0.081 +/- 0.004, respectively. The cluster analysis did not suggest geographic clustering, Because Cx. nigripalpus is the vector of St. Louis encephalitis (SLE) in Florida, temporal and geographic genetic variation in this species is discussed in relation to the seasonal and geographic SLE virus activity in Florida.
对来自佛罗里达州维罗海滩的尖音库蚊（库蚊属）黑须亚种野外种群进行了为期24个月的月度采样，同时分析了一个群体样本和10个地理样本在14个酶位点的遗传变异情况，采用聚丙烯酰胺凝胶电泳法。尖音库蚊群体样本的遗传变异显著低于野外采集样本，以每个位点的平均等位基因数衡量（群体为1.4±0.1，野外为2.1±0.22），多态位点百分比（群体为35.7%，野外为54.8±7.7%），但平均观察杂合度（Ho =群体为0.16±0.07，野外为0.17±0.03）和平均哈迪-温伯格期望杂合度（He =群体为0.14±0.06，野外为0.18±0.02）差异不显著。维罗海滩野外样本的14个位点中有3个（Aldox、Gpd和Gpi）在最常见等位基因频率上呈现出明显的时间模式。维罗海滩野外样本中，高降雨量后的月份比低降雨量后的月份平均观察杂合度（Ho）更高。平均Nm值为3.6，表明维罗海滩种群在时间上分布的样本间基因流动较高。来自佛罗里达州狭长地带和佛罗里达州南部的地理样本间的遗传变异性值不显著。基于F(ST)=0.039的基因流估计得出Nm为6.2，表明尖音库蚊地理样本间基因流动水平较高。10个种群间平均奈氏遗传距离和修正罗杰斯遗传距离分别为0.009±0.001和0.081±0.004。聚类分析未显示出地理聚类现象。由于尖音库蚊是佛罗里达州圣路易斯脑炎（SLE）的传播媒介，因此讨论了该物种的时间和地理遗传变异与佛罗里达州季节性和地理性SLE病毒活动的关系。
