Intertryp, IRD, Cirad, Univ Montpellier, Montpellier, France.
University of Dédougou, Dédougou B.P. 176, Burkina Faso.
Infect Genet Evol. 2020 Nov;85:104515. doi: 10.1016/j.meegid.2020.104515. Epub 2020 Aug 28.
Microsatellite loci still represent valuable resources for the study of the population biology of non-model organisms. Discovering or adapting new suitable microsatellite markers in species of interest still represents a useful task, especially so for non-model organisms as tsetse flies (genus Glossina), which remain a serious threat to the health of humans and animals in sub-Saharan Africa. In this paper, we present the development of new microsatellite loci for four species of Glossina: two from the Morsitans group, G. morsitans morsitans (Gmm) from Zimbabwe, G. pallidipes (Gpalli) from Tanzania; and the other two from the Palpalis group, G. fuscipes fuscipes (Gff) from Chad, and G. palpalis gambiensis (Gpg) from Guinea. We found frequent short allele dominance and null alleles. Stuttering could also be found and amended when possible. Cryptic species seemed to occur frequently in all taxa but Gff. This explains why it may be difficult finding ecumenical primers, which thus need adaptation according to each taxonomic and geographic context. Amplification problems occurred more often in published old markers, and Gmm and Gpg were the most affected (stronger heterozygote deficits). Trinucleotide markers displayed selection signature in some instances (Gmm). Combining old and new loci, for Gmm, eight loci can be safely used (with correction for null alleles); and five seem particularly promising; for Gpalli, only five to three loci worked well, depending on the clade, which means that the use of loci from other species (four morsitans loci seemed to work well), or other new primers will need to be used; for Gff, 14 loci behaved well, but with null alleles, seven of which worked very well; and for G. palpalis sl, only four loci, needing null allele and stuttering corrections seem to work well, and other loci from the literature are thus needed, including X-linked markers, five of which seem to work rather well (in females only), but new markers will probably be needed. Finally, the high proportion of X-linked markers (around 30%) was explained by the non-Y DNA quantity and chromosome structure of tsetse flies studied so far.
微卫星位点仍然是研究非模式生物种群生物学的有价值资源。在感兴趣的物种中发现或适应新的合适微卫星标记仍然是一项有用的任务，尤其是对于采采蝇（ Glossina 属）等非模式生物来说，它们仍然是撒哈拉以南非洲人类和动物健康的严重威胁。在本文中，我们为四种 Glossina 物种开发了新的微卫星位点：两种来自 Morsitans 组，津巴布韦的 Glossina morsitans morsitans (Gmm)和坦桑尼亚的 Glossina pallidipes (Gpalli)；另外两种来自 Palpalis 组，乍得的 Glossina fuscipes fuscipes (Gff)和几内亚的 Glossina palpalis gambiensis (Gpg)。我们发现了频繁的短等位基因优势和无效等位基因。如果可能，也可以发现和修正口吃。似乎所有分类群中都经常出现隐种，但 Gff 除外。这解释了为什么很难找到普适性引物，因此需要根据每个分类和地理背景进行适应。在已发表的旧标记中，扩增问题更为常见，受影响最严重的是 Gmm 和 Gpg（更强的杂合子缺失）。在某些情况下，三核苷酸标记显示出选择特征（Gmm）。将新旧位点结合起来，对于 Gmm，可以安全使用 8 个位点（需要无效等位基因校正）；其中 5 个似乎特别有希望；对于 Gpalli，只有 5 到 3 个位点在不同的分支中效果良好，这意味着需要使用其他物种的位点（4 个 morsitans 位点似乎效果良好）或其他新引物；对于 Gff，14 个位点表现良好，但存在无效等位基因，其中 7 个位点效果非常好；对于 G. palpalis sl，只有 4 个需要无效等位基因和口吃校正的位点效果良好，因此需要其他文献中的位点，包括 5 个似乎效果相当好的 X 连锁标记（仅在雌性中），但可能需要新的标记。最后，高比例的 X 连锁标记（约 30%）可以用迄今为止研究的采采蝇的非 Y 染色体数量和染色体结构来解释。
