History and genetic diversity of African sheep: Contrasting phenotypic and genomic diversity.

Domesticated sheep have adapted to contrasting and extreme environments and continue to play important roles in local community-based economies throughout Africa. Here we review the Neolithic migrations of thin-tailed sheep and the later introductions of fat-tailed sheep into eastern Africa. According to contemporary pictorial evidence, the latter occurred in Egypt not before the Ptolemaic period (305-25 BCE).

Refining the genomic profiles of North African sheep breeds through meta-analysis of worldwide genomic SNP data.

Introduction: The development of reproducible tools for the rapid genotyping of thousands of genetic markers (SNPs) has promoted cross border collaboration in the study of sheep genetic diversity on a global scale.

Methods: In this study, we collected a comprehensive dataset of 239 African and Eurasian sheep breeds genotyped at 37,638 filtered SNP markers, with the aim of understanding the genetic structure of 22 North African (NA) sheep breeds within a global context.

Results And Discussion: We revealed asubstantial enrichment of the gene pool between the north and south shores of the Mediterranean Sea, which corroborates the importance of the maritime route in the history of livestock.

Marker-assisted introgression of fecundity mutation into Barbarine sheep breed under low input production system.

Fecundity gene introgression has become an economical method to improve sheep prolificacy in developing countries. The FecX and FecGH mutations are variants of the BMP15 and GDF9 sheep genes, respectively, identified in Tunisian Barbarine sheep prolific line "W-INRAT," created through a prolificacy-based selection program. The first mutation caused increased prolificacy in heterozygous state and sterility in homozygous ewes.

Efficiency of genotyping by sequencing in inferring genomic relatedness and molecular insights into fat tail selection in Tunisian sheep.

In developing countries, the use of simple and cost-efficient molecular technology is crucial for genetic characterization of local animal resources and better development of conservation strategies. The genotyping by sequencing (GBS) technique, also called restriction enzyme- reduced representational sequencing, is an efficient, cost-effective method for simultaneous discovery and genotyping of many markers. In the present study, we applied a two-enzyme GBS protocol (PstI/MspI) to discover and genotype SNP markers among 197 Tunisian sheep samples.

Genome-wide analyses reveal population structure and identify candidate genes associated with tail fatness in local sheep from a semi-arid area.

Under a climate change perspective, the genetic make-up of local livestock breeds showing adaptive traits should be explored and preserved as a priority. We used genotype data from the ovine 50 k Illumina BeadChip for assessing breed autozygosity based on runs of homozygosity (ROH) and fine-scale genetic structure and for detecting genomic regions under selection in 63 Tunisian sheep samples. The average genomic inbreeding coefficients based on ROH were estimated at 0.