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Browsing Articles by Author "Adefenwa, M.A"

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    GENE FLOW BETWEEN NIGERIAN SHEEP BREEDS AS REVEALED BY MICRO SATELLITE DNA MARKERS
    (Department of Animal Science, Nasarawa State University, Keffi., 2020-02-11) Yakubu, Abdulmojeeb; Agaviezor, B.0; Peters, S.O; Ajayi, F.O; Gunn, Hollingsheed H; Adefenwa, M.A; Adebambo, O.A; Ozoje, M.O; Ikeobi, C.O.N; Wheto, M.; Ajayi, O.O; Amusan, S.A; Ekundayo, J.O; Sanni, Timothy M; Okpeku, M.; Onasanya, Gbolabo O; Donato, Marcos De; Ilori, M.B; Kizilkaya, Kadir; Imumorin, I.G
    The presence and level of gene flow between the four major Nigerian sheep breeds (West African Dwarf (WAD), Yankasa, Balami and Uda) was assessed using microsatellite DNA markers. DNA was extracted from 50~1of whole blood using the ZymoBead™ Genomic DNA Kit The DNA was amplified by PCR in a MyCycler™ Thermal Cycler (Biorad, Hercules, CA) using 15microsatellite markers selected. DNA fragment analysis of microsatellite markers was carried out using the Applied BioSystems 3730xl DNA Analyzer (Applied Biosystems, Carlsbad, CA, USA). The level of gene flow or population structure was assessed by STRUCTURE software and barplots generated by DISTRUCT. At K=2, two clusters was constituted from breeds descending from Balami and Yankasa, both of which are from Northern region in Nigeria. At K=3 and K=4, one more cluster emerged and further analyses did not reveal any additional strong high level substructure, so separating the entire the entire datasets into 3 major clusters was chosen as the final configuration. There are however, several cases of adm ixtures in the genome of some of the individuals that constitute the cluster. Yankasa and Salami breed had more cases of admixtures followed by Udawhile the WAD was the least breed with cases of admixtures
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    Genetic diversity analysis of the mitochondrial D-loop of Nigerian indigenous sheep
    (Department of Animal Science, Nasarawa State University, Keffi., 2012-03-06) Agaviezor, B.O; Adefenwa, M.A; Peters, S.O; Yakubu, Abdulmojeed; Adebambo, O.A; Ozoje, M.O; Ikeobi, C.O.N; Ilori, B.M; Wheto, M.; Ajayi, O.O; Amusan, S.A; Okpeku, M.; Donato, M. De; Imumorin, I.G
    Indigenous livestock resources are strategic in the socio-economics of rural agricultural systems to ensure food security in resourcepoor countries. Therefore, better understanding of genetic variation holds the key to future utilization through conservation. We report the first analysis of genetic diversity of Nigerian sheep based on the D-loop region of the Ovis aries mitochondrial genome using 1 179 bases between sites 15 437 and 16 616 base pairs. A sample of 290 animals made up of Balami, West African Dwarf (WAD), Uda and Yankasa breeds were randomly collected from across Nigeria. Ninety-six haplotypes were observed with a high mean haplotype diversity of 0.899 ± 0.148. Gene diversity was highest in Uda (0.921 ± 0.021) and lowest in WAD (0.852 ± 0.061). Population specific FST indices varied from 0.00133 in Uda to 0.00335 in WAD. Yankasa had the highest number of polymorphic sites (201), while the least was in Uda (96). Analysis of molecular variance revealed that 0.23 percent of the variation is found among populations compared with 99.77 percent variation found within populations. The phylogenetic tree indicates that the mitochondrial lineages of these sheep breeds originated from a common source consistent with first divergence of Yankasa followed by WAD, while Balami and Uda remain more closely related. These results suggest that evolutionary divergence of Nigerian sheep breeds based on mitochondrial DNA D-loop sequence may be coincident with geographical distribution in Nigeria and suggest significant interbreeding. This could have implications for managing improvement and conservation strategies and long-term conservation of Nigerian indigenous sheep.