Biology subjects

Okpeku, M.

Publications and source records attributed to Okpeku, M..

3 recordsLinked to original sources

bioRxiv2023

Development of selection strategies for genetic improvement in production traits of Mecheri sheep based on a Bayesian multi trait evaluation

The progression of genetic selection techniques to enhance farm animal performance traits is guided by the present level of genetic variation and maternal impact in each trait, as well as the genetic association between traits. This study was conducted on a population of Mecheri sheep maintained from 1980 to 2018 at Mecheri Sheep Research Station, Pottaneri, India, to determine variance and covariance components, as well as genetic parameters for various production performance traits. The production traits of Mecheri sheep assessed include: birth weight (BW), weaning weight (WW), six-month weight (SMW), nine-month weight (NMW) and yearling weight (YW). The Bayesian approach using the Gibbs sampler analyzed six animal models with different combinations of additive direct and maternal additive effects was used. Direct genetics, maternal genetics and residual effects models were the major significantly contributors to total phenotypic variation for all the production traits studied. Direct heritability estimates of birth weight, WW, SMW, NMW and YW were 0.25, 0.20, 0.12, 0.14 and 0.13, respectively. The maternal heritability estimated for BW, WW, SMW, NMW and YW were 0.17, 0.10, 0.12, 0.14 and 0.14, respectively. The maternal effects had a major impact on the pre-weaning production traits. The genetic correlations estimated between different pairs of production traits studied ranged from 0.19 to 0.93. The body weight at birth exhibited higher genetic relationship with weaning weight than post-weaning growth characteristics, and the genetic correlation between weaning weight and post-weaning attributes was moderate to high (0.52 to 0.72). Based on the additive genetic variance in weaning weight and the correlation estimates of weaning weight with post-weaning traits, the weaning weight was proposed as a selection criterion for improving growth traits in Mecheri sheep.

genetics↗

bioRxiv2020

The origin of domestication genes in goats

Goat domestication was critical for agriculture and civilization, but its underlying genetic changes and selection regimes remain unclear. Here we analyze the genomes of worldwide domestic goats, wild caprid species and historical remains, providing evidence of an ancient introgression event from a West Caucasian tur-like species to the ancestor of domestic goats. One introgressed locus with a strong signature of selection harbors the MUC6 gene which encodes a gastrointestinally secreted mucin. Experiments revealed that the nearly fixed introgressed haplotype confers enhanced immune resistance to gastrointestinal pathogens. Another locus with a strong signal of selection may be related to behavior. The selected alleles at these two loci emerged in domestic goats at least 7,200 and 8,100 years ago, respectively, and increased to high frequencies concurrent with the expansion of the ubiquitous modern mitochondrial haplogroup A. Tracking these archaeologically cryptic evolutionary transformations provides new insights into the mechanism of animal domestication. One Sentence SummaryGoat domestication mainly focused on immune and neural genes, with adaptive leaps driven by introgression and selection.

genomics↗

bioRxiv2018

qRT-PCR/High Resolution Melting Analyses detected polymorphisms of HSP-70 gene in Zebu cattle

Concerns over environmental heat stress have increased in recent years with the realization of global warming effects on environment and subsequently on animal production. Heat stress indicators help to monitor adaptability and survivability of livestock to thermal assault; a consequent effect of global warming. Heat shock proteins (HSPs) are highly conserved and are classified into six groups. Heat shock protein (HSP) 70 gene is a member of molecular chaperone, known to be highly expressed under stressful environmental and physiological conditions. In this study, we used a one-step qReal-Time PCR, followed by high-resolution melting analyses (HRMA) for detection and identification of polymorphism of HSP-70 gene in four extant cattle breeds of (White Fulani, Sokoto Gudali, Red Bororo and Ambala). qRT-PCR/HRMA-based assay detected twelve (12) genetic variant groups of HSP-70 gene. Ambala breed of Nigerian Zebu cattle had the highest number (7) of genetic variants of HSP-70 gene followed by Red Bororo breed (6 genetic variants), Sokoto Gudali breed had 5 genetic variants while White Fulani breed had the least (4 genetic variants) number of genetic variants in the population of Nigerian Zebu cattle breeds examined. We therefore hypothesize that the detected variant groups can be interrogated for their possible effects on thermo-tolerance performance of zebu cattle bred under thermal assaults of tropical conditions.

genetics↗