Thepa - Tyasi: Relationships between myostatin gene single nucleotide polymorphisms and growth traits in goats: a systematic review - 2401 - APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 22(3):2401-2410. http://www.aloki.hu ● ISSN 1589 1623 (Print) ● ISSN 1785 0037 (Online) DOI: http://dx.doi.org/10.15666/aeer/2203_24012410 © 2024, ALÖKI Kft., Budapest, Hungary RELATIONSHIPS BETWEEN MYOSTATIN GENE SINGLE NUCLEOTIDE POLYMORPHISMS AND GROWTH TRAITS IN GOATS: A SYSTEMATIC REVIEW THEPA, T. L. P. – TYASI, T. L. * School of Agricultural and Environmental Sciences, Department of Agricultural Economics and Animal Production, University of Limpopo, Private Bag X1106, Sovenga, Limpopo 0727, South Africa *Corresponding author e-mail: louis.tyasi@ul.ac.za; phone: +27-15-268-2803 (Received 11 th May 2023; accepted 19 th Jul 2023) Abstract. A member of the transforming growth factor-β superfamily, myostatin (MSTN) functions in the regulation and growth of muscle mass in animals. The MSTN gene’s single nucleotide polymorphisms (SNPs) are implicit in their relationship with growth traits in multiple agricultural species, although the research has been limited with regards to goats. As such, the objective of the paper was to conduct a systematic review of the relationship between the SNPs of the MSTN gene and growth traits in goats. 4 databases were systematically evaluated, and 6 studies were found to be eligible. The 6 included articles observed 24 SNPs of the MSTN gene across several breeds, and 5 articles identified 7 SNPs with a significant association to at least one growth trait. All identified SNPs were unique to the studies, except 368A>C of exon 1 which was identified in 2 articles and can potentially be used as a candidate genetic marker. The systematic review concludes that there is an existing relationship between the MSTN gene’s SNPs and growth traits in goats and further studies need to be done to confirm the validity of the identified MSTN gene SNPs so that they might be used as potential genetic markers in goats. Keywords: genetic variation, genetic marker, marker-assisted selection, breeding, PCR Introduction Growth traits are significant as they influence the economic viability and profitability of industry-related enterprises (Khani et al., 2017). The complexity of growth traits is made evident in their control and ability of a trait to be influenced by multiple genes and their concurrent epistasis, as such many genes have been implicated in their effect on growth traits, one of which is the Myostatin (MSTN) gene (Khani et al., 2017). The myostatin protein, which is encoded by the MSTN gene, a constituent of the transforming growth factor β superfamily, expresses itself phenotypically to limit skeletal muscle accumulation through its regulatory role of muscle fiber numbers and growth (An et al., 2011). The type of genetic variation that occurs the most frequently in the genome is that of single nucleotide polymorphisms (SNPs) and variations of the MSTN gene can limit gene expression, or produce a Myostatin protein that is non-functional, resulting in considerable muscle development or the “double muscling” phenomenon observed in multiple species of livestock having significant associations with growth and related traits, however, studies of such a nature have been limited in goats (Zhang et al., 2012; Khani et al., 2017; Ahad et al., 2017). Multiple MSTN gene variants have been discovered in goats that have phenotypic consequences amongst multiple breeds, but there is the minimal occurrence of studies that associate SNPs with growth traits (An et al., 2011). The generation of DNA markers through partial sequencing using restriction enzymes to target specific identified genomic regions of importance is a viable method