Data from: Laboratory rearing of Anopheles arabiensis: impact on genetic variability and implications for Sterile Insect Technique (SIT) based mosquito control in northern Sudan

Background: Mosquito colony populations often show significant changes in their population genetic make-up compared to the field populations that were used as founding source. Most of the changes that have been reported are indicators of depletion in the overall genetic diversity of the colony populations. The Sterile Insect Techniques programme of mosquito control that is underway in Northern Sudan uses sterilized males produced from a laboratory-maintained colony population. The genetic diversity of an advanced generation of this colony population was quantitatively assessed and compared to the field population from which the colony was derived. Methods: Anopheles arabiensis mosquito samples from the 13th generation of the colony, and from the locality that was the source of the first generation of the colony, were genotyped at 11 microsatellite loci distributed throughout the species’ genome. Standard population genetic analyses were carried out to quantify and compare their population genetic make-up and diversities. Results: The colony samples showed significant reduction in the total number of alleles, the numbers of rare and private alleles, and the fractions of heterozygote individuals at all the loci. The pattern of change is consistent with the expected effect of the use of a small number of mosquitoes when the colony was established. Departure from Hardy–Weinberg equilibrium in the direction of homozygote excess was observed at some loci and attributed to the presence of null-alleles. Conclusions: This study highlights the need for broad sampling when initiating colony populations and for ongoing assessment of the population genetic make-up of colony populations. Previous assessments of survivorship, dispersive behaviour and swarm formation indicate that the inbreeding and reduced genetic variability reported in this study may not have had direct fitness consequences yet. However, noting the lessons learned in other SIT programmes about the impact of colonization on male sexual behaviour and longevity, as well as other inbreeding related adverse effects, a systematic investigation of these potential effects is recommended because they have direct impact on the ultimate success of the programme.背景：与作为建群来源的野外种群相比，蚊虫实验室种群的群体遗传组成往往会发生显著变化。已有研究报道的多数变化，均提示实验室种群的整体遗传多样性出现了损耗。苏丹北部正在推进的蚊虫防控昆虫不育技术（Sterile Insect Techniques, SIT）项目，其使用的绝育雄虫均来自实验室维持的蚊虫种群。本研究对该实验室种群的高世代群体的遗传多样性进行了定量评估，并与其建群来源的野外种群进行了对比。 方法：本研究针对阿拉伯按蚊（Anopheles arabiensis）的实验室种群第13代样本，以及该种群建群初代的来源地野外样本，在分布于该物种全基因组的11个微卫星位点（microsatellite loci）上开展了基因分型实验。研究人员采用标准群体遗传学分析方法，对二者的群体遗传组成与遗传多样性进行了定量分析与比较。 结果：实验室种群样本在所有检测位点上均表现出等位基因总数、稀有等位基因与私有等位基因数量，以及杂合个体占比的显著降低。该变化模式与建群初期使用少量蚊虫所带来的预期效应相符。部分位点出现了向纯合子过量方向偏离的哈迪-温伯格平衡（Hardy–Weinberg equilibrium, HWE）现象，该现象被归因于无效等位基因（null-alleles）的存在。 结论：本研究强调，在建立实验室种群时需进行大范围采样，并需持续评估实验室种群的群体遗传组成。此前针对存活率、扩散行为与群聚行为的评估结果显示，本研究报道的近交与遗传变异降低现象，目前尚未对适合度产生直接影响。然而，鉴于其他昆虫不育技术项目已明确建群过程对雄虫性行为与寿命的影响，以及其他与近交相关的负面效应，本研究建议针对这些潜在影响开展系统性调查——因为它们将直接决定该项目的最终成败。