Mutations in inhibin alpha gene and their association with litter size in Kalahari Red and Nigerian goats
Introduction
High kidding rate is an important reproduction trait in goats (Ling et al., 2014) because herd profitability depends largely on litter size (Abraham and Thomas, 2012). Goats are prolific small ruminant livestock species that are also resilient to infectious diseases (Devendra, 1999) and represent a principal animal genetic resource of the developing world (Qureshi et al., 2014). West African Dwarf (WAD) and Red Sokoto (RS) goats are two major goat breeds in Nigeria and are genetically unimproved. Litter size in these breeds showed within breed variation and was reported to be influenced by parity and season of kidding (Awemu et al., 1999, Odubote, 1996). Kalahari Red on the other hand is one of the three commercial meat-breeds of South Africa (Kotze et al., 2004) and was introduced to Nigeria in 2011 (Bemji et al., 2014). Although the three breeds were characterized using genetic markers (Awotunde et al., 2015, Okpeku et al., 2011, Pieters et al., 2009), no previous study has characterized inhibin alpha (INHA) gene for sequence variations and their possible associations with reproductive traits.
Inhibin is a glycoprotein hormone of gonadal origin which selectively inhibits the synthesis and release of follicle stimulating hormone (FSH) (Bhardwaj et al., 2012). Its major action is negative feedback control of pituitary FSH secretion (Yang, 1988). Inhibin is under control of three genes which are INHA, inhibin Beta A and inhibin Beta B. Inhibin alpha sub-unit is associated with normal oocyte and follicular development which makes INHA a candidate gene for reproductive traits. Strong association of its mutations with litter size was established in Chinese goat breeds (Hou et al., 2012, Wu et al., 2009). In view of the fact that no similar work has been reported for the Nigerian goat breeds, this study was designed to identify mutations in the coding and regulatory regions of INHA gene in WAD, RS and KR goats and investigate association of its SNPs with litter size in the populations.
Section snippets
Animals, management and sampling
This experiment involved three breeds of goats, WAD (n = 225), RS (n = 70) and 70 KR (n=70), respectively managed at Ipokia Local Government area of Ogun State, National Animal Production Research Institute (NAPRI), Shika-Zaria and Institute of Food Security, Environmental Resources and Agricultural Research of the Federal University of Agriculture, Abeokuta, Nigeria. Animals from the three breeds were semi-intensively managed. Phenotypic data taken include litter size at birth with parity
Polymorphisms identified in INHA gene and genetic diversity of the populations
Sequencing of INHA gene revealed four mutations including one transversion (g.−65C > G, rs643347356) within the 5’UTR, three transitions, one each within exon 2 (g.2518G > A), exon 3 (g.3041A > G, rs641311609) and 3’UTR (g.3234C > T, rs670889338). Two of the SNPs (g.−65C > G and g.2518G > A) were only detected in KR population. The exonic SNPs were both synonymous (p.Pro217 and p.Glu249) (Table 2).
Individuals with homozygous CC genotype at g.−65C > G and GG at g.2518G > A loci were predominant
Discussion
In the present study, we found a novel variant (g.2518A > G in exon 2 of INHA gene in KR goat. Exonic SNPs {g.2518G > A (exon 2) and g.3041A > G (exon 3)} did not cause amino acid change. Similar studies on INHA gene revealed several polymorphisms in Chinese goats (Wu et al., 2009, Yang et al., 2014). Wu et al. (2009) reported 12 variants including three identified in the present study. At variance with the findings of this study, two of the 12 mutations reported by Wu et al. (2009) were non
Conclusions
A total of four SNPs including one novel mutation (g.2518G > A) in exon 2 of INHA gene and three others: g.−65C > G in 5’UTR, g.3041A > G in exon 3 and g.3234C > T in 3’UTR were identified in the current study. The novel mutation and g.−65C > G were only detected in KR population while other mutations were present in all the populations. At g.3234C > T locus in WAD population, contrast between alternative genotypes revealed that heterozygous (CT) does had significantly (P = 0.01) higher litter
Contribution of authors
MNB and AMI designed the work. MNB, AMI, MW and TJW carried out the field work. MNB, MW, AMI did the laboratory work. EMIA advised on the laboratory work. AMI and MNB did the statistical and bioinformatics analyses. AMI and MNB drafted the manuscript. EMIA proof read the drafted manuscript. All authors read and approved the final manuscript.
Conflict of interest statement
I wish to clearly state that this article titled “Mutations in inhibin alpha gene and their association with litter size in Kalahari Red and Nigerian goats” has received substantive contributions from the following authors (A.M. Isa, M.N. Bemji, M. Wheto, T.J. Williams and E.M. Ibeagha-Awemu) with no conflict of interest.
Acknowledgement
This study was made possible through provision of experimental animals by the Managements of National Animal Production Research Institute, Ahmadu Bello University, Zaria, Nigeria and the Institute of Food Security, Environmental Resources and Agricultural Research of Federal University of Agriculture, Abeokuta for which the authors remain grateful.
References (21)
- et al.
Environmental influences on pre weaning and reproductive performance of Red Sokoto does
Small Rumin. Res.
(1999) - et al.
Role of fecundity genes in prolificacy of small ruminants
J. Indian Vet. Assoc. Kerala
(2012) - et al.
Mitochondrial DNA sequence analyses and phylogenetic relationships among two Nigerian Goat Breeds and the South African Kalahari Red
Anim. Biotechnol.
(2015) - Bemji, M.N., Awotunde, E.O., Olowofeso, O., Adebambo, A.O., 2014. Phylogenetic relationships among two Nigerian goat...
- et al.
Inhibin: a Role for fecundity augmentation in farm animals
Asian J. Anim. Vet. Advan.
(2012) - et al.
PCR-SSCP polymorphism of inhibin βA gene in some sheep breeds
Asian-Aust. J. Anim. Sci.
(2007) Goats: challenges for increased productivity and improved livelihoods
Outlook Agric.
(1999)- et al.
Potential etiologic and functional implications of genome-wide association loci for human diseases and traits
Proc. Natl. Acad. Sci. USA
(2009) - et al.
Exploring polymorphisms and their effects on reproductive traits of the INHA and INHBA genes in three goat breeds
Anim. Sci. Journ.
(2012) - et al.
Associations between variants of FADS genes and omega-3 and omega-6 milk fatty acids of Canadian Holstein cows
BMC Genet.
(2014)
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