Browsing by Author "Amusan, Samuel A"

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    Genetic Diversity in Exon 2 of the Major Histocompatibility Complex Class II DQB1 Locus in Nigerian Goats
    (Department of Animal Science, Nasarawa State University, Keffi., 2013-04-12) Yakubu, Abdulmojeed; Salako, Adebowale E.; Donato, Marcos De; Takeet, Michael I.; Peters, S.O; Adefenwa, Mufliat A; Okpeku, Moses; Wheto, Mathew; Agaviezor, Brilliant O.; Sanni, Timothy M; Ajayi, Oyeyemi O.; Onasanya, Gbolabo O; Ekundayo, Oludotun J; Ilori, Babatunde M; Amusan, Samuel A; Imumorin, I.G
    The DQB1 locus is located in the major histocompatibility complex (MHC) class II region and involved in immune response. We identified 20 polymorphic sites in a 228 bp fragment of exon 2, one of the most critical regions of the MHC DQB1 gene, in 60 Nigerian goats. Four sites are located in the peptide binding region, and 10 amino acid substitutions are peculiar to Nigerian goats, compared with published sequences. A significantly higher ratio of nonsynonymous/synonymous substitutions (dN/dS) suggests that allelic sequence evolution is driven by balancing selection (P\0.01). In silico functional analysis using PANTHER predicted that substitution P56R, with a subPSEC score of -4.00629 (Pdeleterious = 0.73229), is harmful to protein function. The phylogenetic tree from consensus sequences placed the two northern breeds closer to each other than either was to the southern goats. This first report of sequence diversity at the DQB1 locus for any African goat breed may be useful in the search for disease-resistant genotypes
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    A Novel TaqI Polymorphism in the Coding Region of the Ovine TNXB Gene in the MHC Class III Region: Morphostructural and Physiological Influences
    (Department of Animal Science, Nasarawa State University, Keffi., 2013-07-23) Ajayi, O.O; Yakubu, Abdulmojeed; Adefenwa, Mufliat A; Agaviezor, Brilliant O.; Ikeobi, Christian O. N.; Wheto, Matthew; Okpeku, Moses; Amusan, Samuel A; Donato, Marcos De; Peters, Sunday O.; Imumorin, Ikhide G.
    Abstract The tenascin-XB (TNXB) gene has antiadhesive effects, functions in matrix maturation in connective tissues, and localizes to the major histocompatibility complex class III region. We hypothesized that it may influence adaptive physiological response through an effect on blood vessel function. We identified a novel g.1324 A?G polymorphism at a TaqI recognition site in a 454 bp fragment of ovine TNXB and genotyped it in 150 Nigerian sheep using PCR-RFLP. The missense Electronic supplementary material The online version of this article (doi:10.1007/s10528-013-9622-9) contains supplementary material, which is available to authorized users. O. O. Ajayi B. O. Agaviezor C. O. N. Ikeobi M. Wheto S. A. Amusan S. O. Peters Department of Animal Breeding and Genetics, University of Agriculture, Abeokuta, Nigeria O. O. Ajayi M. A. Adefenwa B. O. Agaviezor A. Yakubu M. De Donato S. O. Peters I. G. Imumorin (&) Department of Animal Science, Cornell University, 267 Morrison Hall, Ithaca, NY 14853, USA e-mail: igi2@cornell.edu M. A. Adefenwa Department of Cell Biology and Genetics, University of Lagos, Lagos, Nigeria B. O. Agaviezor Department of Animal Science and Fisheries, University of Port Harcourt, Port-Harcourt, Nigeria M. Okpeku Department of Livestock Production, Niger Delta University, Amassoma, Nigeria A. Yakubu Department of Animal Science, Nasarawa State University, Lafia, Nigeria M. De Donato Department of Biomedicine, Universidad de Oriente, Cumana´, Venezuela S. O. Peters Department of Animal Science, Berry College, Mount Berry, GA 30149, USA 123 mutation changes glutamic acid (GAA) to glycine (GGA). Among SNP genotypes, significant differences (P\0.05) were observed in body weight and fore cannon bone length. Interaction effects of breed, SNP genotype, and geographic location had a significant effect (P\0.05) on chest girth. The SNP genotype was significantly (P\0.05) associated with physiological traits of pulse rate and skin temperature. The observed effect of this novel polymorphism may be mediated through its role in connective tissue biology, requiring further association and functional studies.