Department of Biological Sciences and Chemistry; Southern University and Agricultural & Mechanical College; 801 Harding Blvd; Baton Rouge; LA 70807; USA.
Biodiversity and Systematics; Department of Biological Sciences; The University of Alabama; Tuscaloosa; AL 35487-0345; USA.
Zootaxa. 2023 Jun 9;5301(2):182-198. doi: 10.11646/zootaxa.5301.2.2.
The Lake Tana Labeobarbus species flock represents one of the world's most famous examples of lacustrine species radiations. Previous studies of this group have resulted in the description of at least 15 species based on their differences in functional morphology and definition of two clades (lacustrine and riverine spawning clades) based on life history traits. A total of 166 fish representing 14 Labeobarbus species were genotyped using 10 lineage-specific hexaploid microsatellite loci. Six of these loci were developed for this study based on DNA sequence contigs derived from a microsatellite-enriched genomic library of Labeobarbus intermedius from Lake Tana; the remaining four loci were obtained from a previous study. The genotypes of the 10 loci were analyzed to examine genetic diversity and population structure within Lake Tana Labeobarbus. Overall mean allelic richness (NA) was 17.6 alleles per locus and observed (Ho) and expected (He) heterozygosities were 0.84 ± 0.14 and 0.73 ± 0.09, respectively, across all Lake Tana Labeobarbus samples examined. Our analyses reveal that there is little genetic differentiation among species (FST = 0.020-0.099; only 10 of 91 species comparisons were significant), but moderate differentiation (FST = 0.11, p < 0.05) between lacustrine and riverine spawning populations. Relative to previous phylogenetic hypotheses, our phenetic analysis employing the R-based Analysis of Phylogenetics and Evolution (APE) program seems to perform marginally better in revealing lineages within Lake Tana Labeobarbus. Herein, our results are compared to a previous microsatellite-based study of the same populations.
塔纳湖拟腹吸鳅物种群代表了世界上最著名的湖泊物种辐射之一。先前对该群体的研究基于功能形态学差异和基于生活史特征定义的两个分支（湖泊和河流产卵分支），至少描述了 15 个物种。使用 10 个六倍体微卫星基因座对代表 14 个拟腹吸鳅物种的 166 条鱼进行了基因分型。其中 6 个基因座是根据从塔纳湖拟腹吸鳅微卫星富集基因组文库中获得的 DNA 序列连续体开发的；其余 4 个基因座来自先前的研究。分析了这 10 个基因座的基因型，以研究塔纳湖拟腹吸鳅的遗传多样性和种群结构。总体平均等位基因丰富度（NA）为每个基因座 17.6 个等位基因，观察到的（Ho）和预期的（He）杂合度分别为 0.84 ± 0.14 和 0.73 ± 0.09，涵盖了所有检查的塔纳湖拟腹吸鳅样本。我们的分析表明，物种之间的遗传分化很小（FST = 0.020-0.099；只有 10 个物种比较有显著性），但湖泊和河流产卵种群之间存在中度分化（FST = 0.11，p < 0.05）。与先前的系统发育假说相比，我们使用基于 R 的系统发育和进化分析（APE）程序进行的表型分析似乎在揭示塔纳湖拟腹吸鳅内部的谱系方面表现稍好。在此，我们将结果与先前对同一群体进行的基于微卫星的研究进行了比较。
