<b>Genetic diversity of sheep breeds in the Maghreb using Microsatellite Markers: A systematic review</b>

Sheep are one of the most important domestic farm animals for agriculture and food production in North Africa, with a wide diversity of indigenous breeds threatened with extinction. According to FAO, approximately 17% of sheep breeds worldwide are at risk of extinction, including at least five native North African breeds: Rembi, Sidahou, D’men, Hamra, and Berber. To date, few large-scale genomic studies have been devoted to investigating the structure of the sheep population in this region. The objective of this study was to provide a detailed assessment of the current state of the genetic structure and admixture patterns of different sheep populations in the Maghreb, based on recent work using microsatellite markers. Following the PRISMA guidelines, four databases were searched, resulting in the inclusion of 17 eligible articles in this systematic review. Our findings indicate significant gaps in research efforts, as several breeds in several regions have received limited scientific attention, with studies per breed ranging from 1 to 12. Most of the studies investigated the four main breeds of the region. Regarding the number of microsatellites used, most studies followed the FAO guidelines. However, the sample size remained relatively small in most articles compared to the 40 animals recommended by FAO/ISAG. Greater within-population variation than between-population variation was reported, with most having a mean number of alleles greater than 10 and expected and observed-heterozygosity, and polymorphism-information-content greater than 0.5. This study provides useful information for the future development of conservation programs for the various endangered breeds in the Maghreb.