Department of Animal Science, Iowa State University, IA50010, Ames, USA.
Fast Genetics, IA50010, Ames, USA.
BMC Genet. 2020 Mar 12;21(1):28. doi: 10.1186/s12863-020-0834-9.
Reproductive performance is critical for efficient swine production. Recent results indicated that vulva size (VS) may be predictive of reproductive performance in sows. Study objectives were to estimate genetic parameters, identify genomic regions associated, and estimate genomic prediction accuracies (GPA) for VS traits.
Heritability estimates of VS traits, vulva area (VA), height (VH), and width (VW) measurements, were moderately to highly heritable in Yorkshire, with 0.46 ± 0.10, 0.55 ± 0.10, 0.31 ± 0.09, respectively, whereas these estimates were low to moderate in Landrace, with 0.16 ± 0.09, 0.24 ± 0.11, and 0.08 ± 0.06, respectively. Genetic correlations within VS traits were very high for both breeds, with the lowest of 0.67 ± 0.29 for VH and VW for Landrace. Genome-wide association studies (GWAS) for Landrace, reveled genomic region associated with VS traits on Sus scrofa chromosome (SSC) 2 (154-157 Mb), 7 (107-110 Mb), 8 (4-6 Mb), and 10 (8-19 Mb). For Yorkshire, genomic regions on SSC 1 (87-91 and 282-287 Mb) and 5 (67 Mb) were identified. All regions explained at least 3.4% of the genetic variance. Accuracies of genomic prediction were moderate in Landrace, ranging from 0.30 (VH) to 0.61 (VA), and lower for Yorkshire, with 0.07 (VW) to 0.11 (VH). Between-breed and multi-breed genomic prediction accuracies were low.
Our findings suggest that VS traits are heritable in Landrace and Yorkshire gilts. Genomic analyses show that major QTL control these traits, and they differ between breed. Genomic information can be used to increase genetic gains for these traits in gilts. Additional research must be done to validate the GWAS and genomic prediction results reported in our study.
繁殖性能对高效养猪生产至关重要。最近的研究结果表明，外阴大小（VS）可能可以预测母猪的繁殖性能。本研究的目的是估计遗传参数，鉴定与 VS 性状相关的基因组区域，并估计 VS 性状的基因组预测准确性（GPA）。
约克夏猪的 VS 性状（外阴面积 VA、高度 VH 和宽度 VW）的遗传力估计值在中度到高度范围内，分别为 0.46±0.10、0.55±0.10、0.31±0.09；而在长白猪中，这些估计值则在低到中度范围内，分别为 0.16±0.09、0.24±0.11 和 0.08±0.06。两个品种的 VS 性状之间的遗传相关性非常高，长白猪中 VH 和 VW 的最低遗传相关性为 0.67±0.29。长白猪的全基因组关联研究（GWAS）揭示了 VS 性状与Sus scrofa 染色体（SSC）2（154-157 Mb）、7（107-110 Mb）、8（4-6 Mb）和 10（8-19 Mb）上的基因组区域有关。对于约克夏猪，在 SSC 1（87-91 和 282-287 Mb）和 5（67 Mb）上鉴定到了基因组区域。所有区域至少解释了 3.4%的遗传方差。长白猪的基因组预测准确性中等，范围从 0.30（VH）到 0.61（VA），而约克夏猪的准确性较低，范围从 0.07（VW）到 0.11（VH）。品种间和多品种间的基因组预测准确性较低。
本研究结果表明，VS 性状在长白猪和约克夏后备母猪中具有遗传性。基因组分析表明，主要 QTL 控制这些性状，且在品种间存在差异。基因组信息可用于提高后备母猪中这些性状的遗传增益。需要进一步的研究来验证我们研究中报告的 GWAS 和基因组预测结果。
