Discrimination of hybrid classes using cross-species amplification of microsatellite loci: methodological challenges and solutions in Daphnia

Microsatellite markers are important tools in population, conservation and forensic studies and are frequently used for species delineation, the detection of hybridization and introgression. Therefore, marker sets that amplify variable DNA regions in two species are required; however, cross-species amplification is often difficult, as genotyping errors such as null alleles may occur. In order to estimate the level of potential misidentifications based on genotyping errors, we compared the occurrence of parental alleles in laboratory and natural Daphnia hybrids (Daphnia longispina group). We tested a set of twelve microsatellite loci with regard to their suitability for unambiguous species and hybrid class identification using F1 hybrids bred in the laboratory. Further, a large set of 44 natural populations of D. cucullata, D. galeata and D. longispina (1715 individuals) as well as their interspecific hybrids were genotyped to validate the discriminatory power of different marker combina...

微卫星标记（microsatellite markers）是种群、保护及法医研究中的重要工具，被广泛应用于物种界定、杂交检测与基因渐渗分析。因此，亟需可扩增两个物种可变DNA区域的标记集；但跨物种扩增往往难度较高，易出现无效等位基因等基因分型错误。为评估基于基因分型错误的潜在误判风险，我们对比了实验室培育与自然环境中的溞属（Daphnia）长棘溞类群（Daphnia longispina group）杂交种的亲本等位基因出现情况。我们利用实验室培育的F1杂交种，对12个微卫星位点的适用性进行了测试，以验证其能否实现无歧义的物种与杂交类群鉴定。此外，我们还对钩状溞（D. cucullata）、 Galeata溞（D. galeata）与长棘溞（D. longispina）的44个自然种群（共计1715个个体）及其种间杂交种进行了基因分型，以验证不同标记组合的区分能力。