Johannesen Jes, Fabritzek Armin G, Ebner Bettina, Bikar Sven-Ernö
Institute of Organismic and Molecular Evolution, Mainz University, Mainz, Germany.
StarSEQ GmbH, Mainz, Germany.
PeerJ. 2017 Aug 14;5:e3582. doi: 10.7717/peerj.3582. eCollection 2017.
Phylogeographic analyses of the gall fly have in earlier studies based on allozymes and mtDNA identified small-scale, parapatrically diverged populations within an expanding Western Palearctic population. However, the low polymorphism of these markers prohibited an accurate delimitation of the evolutionary origin of the parapatric divergence. from the Western Palearctic have been introduced into Canada as biological control agents of the host plant . Here, we characterise 12 microsatellite loci with hexa-, penta- and tetra-nucleotide repeat motifs and report a genotyping-by-sequencing SNP protocol. We test the markers for genetic variation among three parapatric populations. Microsatellite variability ( = 59 individuals) was high: expected heterozygosity/locus/population (0.60-0.90), allele number/locus/population (5-21). One locus was alternatively sex-linked in males or females. Cross-species amplification in the sister species was successful or partially successful for seven loci. For genotyping-by-sequencing ( = 18 individuals), different DNA extraction methods did not affect data quality. Depending on sequence sorting criteria, 1,177-2,347 unlinked SNPs and 1,750-4,469 parsimony informative sites were found in 3,514-5,767 loci recovered after paralog filtering. Both marker systems quantified the same population partitions with high probabilities. Many and highly differentiated loci in both marker systems indicate genome-wide diversification and genetically distinct populations.
在早期基于等位酶和线粒体DNA的研究中，瘿蚊的系统发育地理学分析在一个不断扩张的西古北区种群中识别出了小规模的、邻域分化的种群。然而，这些标记的低多态性阻碍了对邻域分化进化起源的准确界定。来自西古北区的瘿蚊已作为宿主植物的生物防治剂被引入加拿大。在此，我们鉴定了12个具有六核苷酸、五核苷酸和四核苷酸重复基序的微卫星位点，并报告了一种通过测序进行基因分型的单核苷酸多态性方案。我们测试了这些标记在三个邻域种群间的遗传变异情况。微卫星变异性（n = 59个个体）很高：预期杂合度/位点/种群（0.60 - 0.90），等位基因数/位点/种群（5 - 21）。一个位点在雄性或雌性中呈交替性连锁。在姐妹物种中的跨物种扩增对7个位点成功或部分成功。对于通过测序进行基因分型（n = 18个个体），不同的DNA提取方法不影响数据质量。根据序列分类标准，在经过旁系同源物过滤后回收的3514 - 5767个位点中，发现了1177 - 2347个不连锁的单核苷酸多态性和1750 - 4469个简约信息位点。两种标记系统都以高概率量化了相同的种群划分。两种标记系统中许多高度分化的位点表明了全基因组的多样化和遗传上不同的种群。
