Transferability of heterologous primers in Brycon falcatus

ABSTRACT The genusBryconcomprises fish species of significant socioeconomic and biological importance in Brazil. Despite that, the genetic knowledge about these species is scarce, especially regardingBrycon falcatus. Thus, the objective of this study was to evaluate the transferability of heterologous microsatellite primers inB. falcatus for the first time. Heterologous primers obtained from B. opalinus, B. hilarii, B. insignis, B. orbignyanus, B. amazonicus, Prochilodus argenteus, Prochilodus lineatus, Piaractus mesopotamicus, and Colossoma macropomum were evaluated. The primers that showed the best amplification patterns were applied to a sample of 22 individuals and the genetic parameters were calculated. Nine primers displayed satisfactory cross-amplification withB. falcatus: BoM5 (Brycon opalinus); Bh8, Bh13 and Bh16 (B. hilarii); Borg59 (B. orbignyanus); Bag22 (B. amazonicus); Par12 and Par80 (P. argenteus), and Cm1A8 (C. macropomum). The genetic parameters (number of alleles, effective alleles, allele richness, and expected and observed heterozygosity) and the polymorphic information content (PIC) confirmed the viability of these primers for population genetics analyses. Our study demonstrates the potential of transferability of microsatellite markers from related species and even different genera to B. falcatus, providing usefull tools for future population genetic studies in this species.

摘要：Brycon属（Brycon）包含在巴西具有重要社会经济与生物学价值的鱼类类群。尽管如此，目前关于该属鱼类的遗传学认知仍较为匮乏，针对镰状脂鲤（Brycon falcatus）的相关研究尤为不足。因此，本研究首次评估了异源微卫星引物（heterologous microsatellite primers）在镰状脂鲤中的跨物种扩增可行性。本研究对源自亮脂鲤（Brycon opalinus）、喜来脂鲤（Brycon hilarii）、饰纹脂鲤（Brycon insignis）、奥氏脂鲤（Brycon orbignyanus）、亚马逊脂鲤（Brycon amazonicus）、银鲮脂鲤（Prochilodus argenteus）、条纹鲮脂鲤（Prochilodus lineatus）、南美肥脂鲤（Piaractus mesopotamicus）以及巨脂鲤（Colossoma macropomum）的异源微卫星引物进行了扩增检测。筛选出扩增效果最优的引物后，对22个个体组成的样本开展扩增实验并计算相关遗传参数。最终有9对引物可在镰状脂鲤中实现良好的跨物种扩增：分别为源自亮脂鲤的BoM5（Brycon opalinus）；源自喜来脂鲤的Bh8、Bh13与Bh16；源自奥氏脂鲤的Borg59；源自亚马逊脂鲤的Bag22；源自银鲮脂鲤的Par12与Par80，以及源自巨脂鲤的Cm1A8（Colossoma macropomum）。相关遗传参数（等位基因数、有效等位基因数、等位基因丰富度、期望杂合度与观测杂合度）以及多态信息含量（PIC）均证实，这批引物可有效应用于该物种的种群遗传学分析（population genetics analyses）。本研究证实了从近缘物种甚至不同属中获取的微卫星标记（microsatellite markers），可跨类群转移应用于镰状脂鲤的遗传学研究，为该物种后续的种群遗传学研究提供了实用的分子工具。