Morphological and microsatellite DNA diversity of Nigerian indigenous sheep

Abstract

BackgroundSheep is important in the socio-economic lives of people around the world. It is estimated that more than half of our once common livestock breeds are now endangered. Since genetic characterization of Nigerian sheep is still lacking, we analyzed ten morphological traits on 402 animals and 15 microsatellite DNA markers in 384 animals of the 4 Nigerian sheep breeds to better understand genetic diversity for breeding management and germplasm conservation.ResultsMorphological traits of Uda and Balami were significantly (P < 0.05) higher than Yankasa, which were both higher than West African Dwarf (WAD) sheep. Stepwise discriminant analysis showed tail length, rump height, chest girth, ear length and chest depth as the most discriminating variables for classification. Mahalanobis distances show the least differentiation between Uda and Balami and the largest between WAD and Balami sheep. While 93.3% of WAD sheep were correctly assigned to their source genetic group, 63.9% of Yankasa, 61.2% of Balami and 45.2% of Uda were classified correctly by nearest neighbour discriminant analysis. The overall high Polymorphism Information Content (PIC) of all microsatellite markers ranged from 0.751 to 0.927 supporting their use in genetic characterization. Expected heterozygosity was high for all loci (0.783 to 0.93). Mean heterozygote deficiency across all populations (0.171 to 0.534) possibly indicate significant inbreeding (P < 0.05). Mean values for FST, FIT and FIS statistics across all loci were 0.088, 0.394 and 0.336 respectively. Yankasa and Balami are the most closely related breeds (DA = 0.184) while WAD and Balami are the farthest apart breeds (DA = 0.665), which is coincident with distance based on morphological analysis and population structure assessed by STRUCTURE.ConclusionsThese results suggest that within-breed genetic variation in Nigerian sheep is higher than between-breeds and may be a valuable tool for genetic improvement and conservation. The higher genetic variability in Yankasa suggests the presence of unique ancestral alleles reflecting the presence of certain functional genes which may result in better adaptability in more agro-ecological zones of Nigeria. These genetic characteristics are potentially useful in planning improvement and conservation strategies in Nigerian indigenous sheep.

New genetic identification and characterisation of 12 Algerian sheep breeds by microsatellite markers

“…Although the G ST values in the present study were lower when compared to Swiss sheep breeds (Stahlberger-Saitbekova et al 2001), Nigerian native sheep breeds (Agaviezor et al 2012) and Native Turkish sheep breeds (Yilmaz et al 2014) were in fact higher than Albanian sheep breeds (Hoda & Marsan 2012). The average G ST value obtained from overall loci pointed out that 1.9% of total genetic variation resulted from the differences between the populations.…”

Single-nucleotide polymorphism-based genetic diversity analysis of the Kilakarsal and Vembur sheep breeds

“…The global F IS observed in the present study is much lower than the previous reports in European sheep (0.123) [15], Nigerian sheep (0.335) [16], and Bulgarian sheep (0.288) [17]. In contrast, much lower F IS value of 0.024 has been reported in indigenous sheep breeds of China [18].…”

The Origin of African Sheep: Archaeological and Genetic Perspectives

“…Finally, several country-or region-specific microsatellite studies have been now performed on African sheep (Muigai 2003;Muigai et al 2009;Agaviezor et al 2012b;Soma et al 2012). Though restricted in their geographic scope, these studies indicate close relationships and high levels of admixture among sheep populations from the same geographic area.…”