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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.

A study was conducted to estimate the diversity that exists among three rabbit populations adapted to the South-Eastern part of Nigeria. Blood samples were collected from 75 matured, mixedsex, and unrelated three rabbit breeds selected across the zone. Eight microsatellites (Sol30, Sol33, and Sol44, Sat3, Sat7, Sat8, Sat12, and INRA) markers were used for the study. These microsatellites were uniformly distributed among rabbit genomes for genotyping. Subsequently, genetic variability within and between breeds was calculated. Allelic frequencies and Hardy-Weinberg equilibriums as well as Analysis of Molecular Variance, were also estimated using GenAlEX 6.41 software. Discriminant Analysis of Principal Components (DAPC) for the population structure of the rabbit breeds was performed in R v.3.5.0 using the R package adegenet. All the 8 loci amplified in this study were found to be 100% polymorphic, the observed allele sizes and their frequencies for the microsatellite markers in every three breeds showed that the highest frequency was 0.330 for the allele with the size of 470bp at Sol33 locus in New Zealand White (NZW) rabbits. The Nei's genetic identities and distances between Chinchilla (CHI) and Dutch (DUT), CHI and NZW, DUT and NZW obtained in this study were [0.173, 0.185, and 0.189] and [1.753, 1.689, and 1.666] respectively. The dendrogram and biplot revealed that the three breeds were identified at two separate clusters. In addition, the admixture level of an individual rabbit among the three breeds indicated that the breeds were not pure and also the existence of more polymorphism within the breed than among the breed diversity. [ABSTRACT FROM AUTHOR]

The chicken Insulin-like growth factor 1 (IGF1) is a candidate gene for growth, body composition and metabolism, skeletal characteristics and growth of adipose tissue and fat deposition in chickens. It is mapped to 165.95 cM on chromosome 1 and composed of four exons and three introns, spanning more than 50 kb. Genomic DNA was extracted from blood samples collected from the experimental birds using Qiagen DNA extraction kits. Polymersae chain reaction (PCR) was carried out using established primers. The PCR amplicon involving 5'untranslated region were sequenced. The sequences were analysed to identify polymorphisms, their genetic diversities and evolutionary relationships among three strains of Nigerian indigenous chickens [Frizzle Feathered (7), Normal Feathered (19) and Naked Neck (19), and the Arbor Acre broiler chicken (17)]. Nucleotide sequences generated were edited and aligned using Codon Code Aligner. Diversity analysis was done using DnaSp while MEGA6 software was used to plot phylogenetic tree using maximum likelihood method. A total of nineteen single nucleotide polymorphisms (SNPs) were detected from 560 bp portions of the 5'UTR among the four chicken populations studied with none detected in the Frizzle feathered chicken. The Naked neck chicken had the highest number of SNP's (13), haplotypes (6), haplotype diversity (0.778), nucleotide diversity (0.00487), average number of nucleotide differences (2.725), highest number of polymorphic (segregating) sites (13), parsimony informative site (5) and singleton variable site (8). The Naked neck chicken therefore had the highest rate of mutation and degree of allelic variation compared to other chicken strains used in this study. The phylogenetic tree showed that small genetic differentiation exists among the chicken populations studied. Some of the SNPs are newly discovered; hence, association between these alleles and productive traits in Nigerian native chickens is desirable in future studies. [ABSTRACT FROM AUTHOR]