Mutations in inhibin alpha gene and their association with litter size in Kalahari Red and Nigerian goats

Association between INHA gene polymorphisms and litter size in Hainan black goats

Background

The inhibin alpha (INHA) gene is one of the important genes affecting the reproductive traits of animals. Hainan black goats are the main goat breed in Hainan Island (China), whose development is limited by low reproductive performance. However, the relationship between INHA gene and the reproductive performance of Hainan black goats is still unclear. Therefore, the purpose of this work was to explore the effect of INHA gene polymorphisms on the litter size of Hainan black goats.

Methods

Single nucleotide polymorphisms (SNPs) of INHA were detected, and the genetic parameters and haplotype frequency of these SNPs were calculated and association analysis was performed for these SNPs with the litter size. Finally, the SNP with significant correlations to litter size was analyzed by Bioinformatics tools.

Results

The results showed that the litter size of individuals with the AC genotype at loci g.28317663A>C of INHA gene was significantly higher than those with the AA genotype. This SNP changed the amino acid sequence, which may affect the function of INHA protein by affecting its structure. Our results suggest that g.28317663A>C loci may serve as a potential molecular marker for improving the reproductive traits in Hainan black goats.

Characterization of gonadotropin releasing hormone receptor gene in Sokoto and Kalahari Red goats

The objective of this study was to characterize GnRHR gene in Sokoto (n = 70) and Kalahari Red (n = 70) goats. Three SNPs, (g.-29T > G, g.48 G > A and g.209 T > G), were detected in Sokoto Red (SR) and one (g.48 G > A) in Kalahari Red (KR) goats. All the mutations occurred within the 5'UTR and Exon one of the gene and the g.209 T > G was non-synonymous and, therefore, resulted in an amino acid change from methionine to arginine at Position 70 of the GnRHR polypeptide. The homozygous mutant genotypes at the three SNP loci were not detected in both breeds but minor allele frequencies were ≥ 0.1 for the three SNP loci in SR goats. Frequency of the T allele, however, was 0.93 at the only SNP locus detected in KR goats. There was a strong linkage disequilibrium (LD; r²>0.98) among the detected mutations in SR goats resulting in two haplotypes (T-G-T and G-A-G) with a frequency of 86% and 13%, respectively. There was no significant association between genotypes at the polymorphic loci and litter size (P > 0.05) in the two breeds. The non-synonymous mutation (g.209T>G) appears to have changed the nucleotide binding region and area spanning exposed/buried regions on the predicted secondary structure of the two variants of the receptor. This change led to variation in the tertiary structure between the two variants of the receptor and can influence the function of the transmembrane receptor. Comparison of the GnRH receptor domains for goats, sheep, cattle and swine confirmed that the seven transmembrane domains of the receptor are conserved in all the farm animals considered.

Polymorphism in inhibin alpha (INHA) gene is not associated with litter size in Markhoz goats

The present study was aimed to survey the polymorphisms in 2 loci (exon 2) of inhibin alpha (INHA) gene in Markhoz goats. Blood samples collected from 150 female goats were used for extraction of genomic DNA; and 2 fragments related to exon 2 with 332 bp (G567A, P1 locus) and 478 bp (T911C, P2 locus) in length were amplified using polymerase chain reaction (PCR). PCR products were subjected to digestion using Bsp143II endonuclease. The results showed that 2 alleles (G and A) with the frequency of 0.526 and 0.473, and 3 genotypes (GG, GA and AA) with the frequency of 0.138, 0.085 and 0.773 were identified for P1 locus in Markhoz goats but P2 locus was monomorphic. Investigation on effect of genotypes in P1 locus on litter size trait showed that P1 locus genotypes had no association with litter size in Markhoz goats. The results demonstrated, for the first time, that polymorphism in a locus in exon 2 of the INHA gene had no significant association with litter size in Markhoz goats.

Leveraging Available Resources and Stakeholder Involvement for Improved Productivity of African Livestock in the Era of Genomic Breeding

The African continent is home to diverse populations of livestock breeds adapted to harsh environmental conditions with more than 70% under traditional systems of management. Animal productivity is less than optimal in most cases and is faced with numerous challenges including limited access to adequate nutrition and disease management, poor institutional capacities and lack of adequate government policies and funding to develop the livestock sector. Africa is home to about 1.3 billion people and with increasing demand for animal proteins by an ever growing human population, the current state of livestock productivity creates a significant yield gap for animal products. Although a greater section of the population, especially those living in rural areas depend largely on livestock for their livelihoods; the potential of the sector remains underutilized and therefore unable to contribute significantly to economic development and social wellbeing of the people. With current advances in livestock management practices, breeding technologies and health management, and with inclusion of all stakeholders, African livestock populations can be sustainably developed to close the animal protein gap that exists in the continent. In particular, advances in gene technologies, and application of genomic breeding in many Western countries has resulted in tremendous gains in traits like milk production with the potential that, implementation of genomic selection and other improved practices (nutrition, healthcare, etc.) can lead to rapid improvement in traits of economic importance in African livestock populations. The African livestock populations in the context of this review are limited to cattle, goat, pig, poultry, and sheep, which are mainly exploited for meat, milk, and eggs. This review examines the current state of livestock productivity in Africa, the main challenges faced by the sector, the role of various stakeholders and discusses in-depth strategies that can enable the application of genomic technologies for rapid improvement of livestock traits of economic importance.