چكيده انگليسي :
A meta-analysis of genome-wide association studies (GWAS) was conducted to identify genes
and chromosomal regions associated with reproductive performance traits in sheep. Using Persian
and English keywords such as gene, chromosome, SNP, GWAS, chromosomal regions, sheep,
performance traits, and reproductive traits, relevant articles were retrieved from English databases
including PubMed, Scopus, Web of Science, and Google Scholar, as well as Persian databases
such as Irandoc, SID, Magiran, and Civilica. After removing duplicates and irrelevant articles, a
total of 35 studies were included in R version 4.4.1. The metafor and qqman packages were used
to analyze the data. The results showed that for weight traits, the highest number of SNPs was
located on chromosome 6, followed by chromosome X and then chromosome 3, with the lowest
number of SNPs observed on chromosome 24. For reproductive traits, the highest number of
SNPs was located on chromosomes 1, 2, and 3, with the lowest number on chromosome 16. For
lactation traits, the highest number of SNPs was located on chromosomes 2, 1, and 3, with the
lowest number on chromosome 23. Manhattan plots for birth weight identified four significant
SNPs: OAR2_51716542.1, OAR12_20575087.1, OAR17_29260298.1, and s03219.1, located on
chromosomes 2, 12, 17, and 18, respectively. For weaning weight, two significant SNPs were
identified: rs421690996 and rs409558668, located on chromosomes 22 and 16, respectively. For
average daily gain before weaning, SNP OAR10_91128145.1 on chromosome 10 was significant,
but no significant SNPs were found for average daily gain after weaning. For average daily gain
and body weight, SNPs rs414911966 and s45224.1, located on chromosomes 20 and 1,
respectively, were significant. For yearling weight, SNPs OAR6_27552838.1,
OAR8_39977285.1, OAR5_84496122_X.1, oar3_OAR9_42035112, oar3_OAR20_22070146,
and s12060.1, located on chromosomes 6, 8, 5, 9, 20, and 1, respectively, were significant. For
the reproductive trait of lamb birth weight, SNP s50067.1 on chromosome 2 was significant, and
for the trait of twinning, SNP OAR3_233748114.1 on chromosome 3 was significant. No
significant SNPs were found for milk production traits and milk components, except for milk fat
percentage, where two SNPs, rs425417915 and OAR3_147028849, located on chromosomes 7
and 3, respectively, were significant.
