Laboratory of Diversity, Management and Conservation of Biological Systems, LR18ES06, Faculty of Sciences of Tunis, University of Tunis El Manar, El Manar II Tunis 2092, Tunisia.
Department of Agronomy, Animal, Food, Natural Resources and Environment, University of Padova, 35020 Legnaro Padova, Italy.
Genes (Basel). 2022 Feb 5;13(2):304. doi: 10.3390/genes13020304.
This study analyzed the genetic variability, inbreeding and population structure of the Tunisian-North African dairy sheep breed, the Sicilo-Sarde (SS), created by crossing the Sarda and Comisana dairy breeds. The level of variability in the SS, considered as an endangered breed after a dramatic decrease, was assessed using 17 microsatellite markers by analyzing the two breed populations sampled from their respective cradles: SS of Beja (SS, = 27) and SS of Mateur (SS, = 25). High levels of genetic diversity in SS were revealed, with a total of 212 alleles, a high mean number of alleles (12.47 ± 4.17) and a high average polymorphism information content (PIC) (0.81 ± 0.10). The observed heterozygosity was considerable in SS and SS (0.795 and 0.785, respectively). The inbreeding level measured by the population inbreeding coefficient is higher in the SS population (0.121) than in the SS population (0.090). The higher genetic diversity level detected in SS reflected the effect of new Italian Sarda genes introduced by intra-uterine artificial insemination recently practiced in this population. The Wilcoxon test and the mode-shift distribution indicated that the SS breed is a non-bottlenecked population. The structural analysis reflected the historical miscegenation practiced during the breed creation and highlighted further ancient miscegenation, which could date back to the first waves of sheep introduction to the western Mediterranean region. Microsatellite markers were successfully applied in the assessment of the genetic variability of SS and should be used in monitoring this variability during the application of conservation strategies.
本研究分析了突尼斯-北非乳用绵羊品种西西里-撒丁（SS）的遗传变异、近交和种群结构，该品种是通过杂交萨达和科米萨纳乳用品种创建的。在经历了急剧减少后，被认为是濒危品种的 SS 的变异程度，通过分析从各自发源地采集的两个品种群体（贝贾的 SS [SS，n=27]和马图尔的 SS [SS，n=25]）的 17 个微卫星标记进行评估。SS 中存在高水平的遗传多样性，共发现 212 个等位基因，平均等位基因数高（12.47±4.17），平均多态信息含量（PIC）高（0.81±0.10）。SS 和 SS 的观察杂合度都相当高（分别为 0.795 和 0.785）。由群体近交系数测量的近交水平在 SS 群体中较高（0.121），而在 SS 群体中较低（0.090）。在 SS 中检测到的较高遗传多样性水平反映了最近在该群体中实施的宫内人工授精引入的新意大利萨达基因的影响。Wilcoxon 检验和模式转移分布表明，SS 品种是非瓶颈种群。结构分析反映了在品种创建过程中进行的历史混合，并且强调了进一步的古代混合，这可以追溯到第一次将绵羊引入到西地中海地区。微卫星标记成功应用于 SS 遗传变异性的评估，并且应该在应用保护策略期间用于监测这种变异性。
