Light J E, Harper S E, Johnson K P, Demastes J W, Spradling T A
Department of Wildlife and Fisheries Sciences, Texas A&M University, 534 John Kimbrough Blvd., College Station, Texas 77843.
J Parasitol. 2018 Feb;104(1):89-95. doi: 10.1645/17-130. Epub 2017 Nov 8.
Next-generation sequencing methodologies open the door for evolutionary studies of wildlife parasites. We used 2 next-generation sequencing approaches to discover microsatellite loci in the pocket gopher chewing louse Geomydoecus aurei for use in population genetic studies. In one approach, we sequenced a library enriched for microsatellite loci; in the other approach, we mined microsatellites from genomic sequences. Following microsatellite discovery, promising loci were tested for amplification and polymorphism in 390 louse individuals from 13 pocket gopher hosts. In total, 12 loci were selected for analysis (6 from each methodology), none of which exhibited evidence of null alleles or heterozygote deficiencies. These 12 loci showed adequate genetic diversity for population-level analyses, with 3-9 alleles per locus with an average H per locus ranging from 0.32 to 0.70. Analysis of Molecular Variance (AMOVA) indicated that genetic variation among infrapopulations accounts for a low, but significant, percentage of the overall genetic variation, and individual louse infrapopulations showed F values that were significantly different from zero in the majority of pairwise infrapopulation comparisons, despite all 13 infrapopulations being taken from the same locality. Therefore, these 12 polymorphic markers will be useful at the infrapopulation and population levels for future studies involving G. aurei. This study shows that next-generation sequencing methodologies can successfully be used to efficiently obtain data for a variety of evolutionary questions.
新一代测序方法为野生动物寄生虫的进化研究打开了大门。我们使用了两种新一代测序方法来发现囊鼠嚼虱Geomydoecus aurei中的微卫星位点,以用于群体遗传学研究。在一种方法中,我们对富含微卫星位点的文库进行了测序;在另一种方法中,我们从基因组序列中挖掘微卫星。在发现微卫星后,对来自13只囊鼠宿主的390只虱子个体中的有前景的位点进行了扩增和多态性测试。总共选择了12个位点进行分析(每种方法6个),其中没有一个显示出无效等位基因或杂合子缺陷的证据。这12个位点显示出足够的遗传多样性用于群体水平分析,每个位点有3 - 9个等位基因,每个位点的平均H值在0.32到0.70之间。分子方差分析(AMOVA)表明,群体内的遗传变异占总体遗传变异的比例较低,但具有显著性,并且尽管所有13个群体都来自同一地点,但在大多数成对群体比较中,个体虱子群体的F值显著不同于零。因此,这12个多态性标记在未来涉及Geomydoecus aurei的群体内和群体水平研究中将是有用的。这项研究表明,新一代测序方法可以成功地用于高效获取针对各种进化问题的数据。