Recent advances in understanding genetic variants associated with economically important traits in sheep (Ovis aries) revealed by high-throughput screening technologies

Abstract

Sheep are one of the most economically important domesticated animals for human society. However, genetic improvements for the key traits associated with meat, growth, milk, wool, reproduction, horns and tails progress slowly using conventional crossbreeding methods. With the development and utilization of highthroughput screening technologies over the last decade, a list of functional genes and genetic variants associated with these traits has been identified. This review covers recent genome-wide studies on sheep productive traits using high-throughput screening technologies, including those based on single-nucleotide polymorphisms and copy number variants at the whole-genome level (e.g., genome-wide association studies), transcriptome and DNA methylation sequences. Additionally, comprehensive information on functional genes and genetic variants associated with economically important traits in sheep is provided.

Review on Genomic Regions and Candidate Genes Associated with Economically Important Production and Reproduction Traits in Sheep (Ovies aries)

“…It is preferred due to the power it has to detect causal variants and the ability in defining narrower genomic regions [4]. These approaches have been working on the basis of single-nucleotide polymorphisms in different domestic animals [5]. GWAS is an important approach to identify candidate genes and molecular variants associated with different phenotypic traits.…”

Recent advances in understanding genetic variants associated with growth, carcass and meat productivity traits in sheep (<i>Ovis aries</i>): an update

“…We restricted our search to papers published in English in peer-reviewed journals since 2013. We chose 2013 as the year when the first biggest genome-wide association study (GWAS) (n>200) on growth and meat production traits in sheep was published (Zhang et al, 2013). Keyword combinations included words related to organism (sheep, ovine, Ovis aries), to trait of interest (birth weight, weaning weight, 6-month weight etc.…”

“…Next, we selected the earliest (starting from 2013) and the most relevant papers describing GWAS of growth and meat production traits in sheep (Zhang et al, 2013;Wang et al, 2015;Kominakis et al, 2017). We assume that GWASs that contain information about several relevant associated QTLs and candidate genes potentially have larger citation trees than gene candidate papers.…”

“…We discovered that the words related to organism and trait of interest in the keyword combinations used for the search are more important than the word related to the type of the study. Next, we investigated the citation tree of the paper of Zhang et al (2013) in Google Scholar and related papers on PubMed. We found 16 papers, 9 of which were absent in ST1 (see Table ST2).…”

“…The current QTL sheep database -Sheep QTLdb -contains information on 1658 QTLs for 225 different traits (Hu et al, 2016). Recently, Xu and Li (2017) reviewed information about markers associated with economically important traits in sheep revealed by high-throughput screening technologies. A few genes and markers associated with growth, carcass and meat productivity traits were reported.…”