Nonneman D, Lents C, Rohrer G, Rempel L, Vallet J
USDA-ARS, U.S. Meat Animal Research Center, Clay Center, NE, 68933-0166, USA.
Anim Genet. 2014 Feb;45(1):130-2. doi: 10.1111/age.12087. Epub 2013 Aug 26.
An improvement in the proportion of gilts entering the herd that farrow a litter would increase overall herd performance and profitability. A significant proportion (10-30%) of gilts that enter the herd never farrow a litter; reproductive reasons account for approximately a third of gilt removals, with anestrous and failure to conceive the most common reasons for culling. Tools to select gilts for reproductive longevity through genomics or alternative phenotypes would be of great benefit to the producer. Ninety-one gilts that failed to display behavioral estrus by 240 days (cases) and 127 pubertal littermates (controls) were genotyped with the Illumina Porcine SNP60 Beadchip. One hundred and seventy-four SNPs with the most significant associations were genotyped in an additional 86 cases and 103 controls. Twelve of these associations were significant in the final analysis. The most significant (P < 1.5 × 10(-14) ) region associated with failure to attain puberty was on chromosome 4 surrounding the NHLH2 gene. Delayed pubertal development and age at first estrus have been associated with NHLH2 in mice. Because attainment of puberty is a complex trait, identifying genes that affect pubertal age would greatly contribute to our knowledge of reproductive development as well as overall fertility.
进入猪群的后备母猪中分娩一窝仔猪的比例提高，将提升整个猪群的生产性能和盈利能力。进入猪群的后备母猪中有很大比例（10% - 30%）从未分娩过仔猪；繁殖相关原因约占后备母猪淘汰的三分之一，其中发情期缺失和未能受孕是最常见的淘汰原因。通过基因组学或其他表型特征选择具有较长繁殖寿命的后备母猪的工具，将对养殖者大有裨益。对91头240日龄时未表现出行为性发情的后备母猪（病例组）和127头青春期同窝仔猪（对照组），使用Illumina猪SNP60芯片进行基因分型。在另外86例病例和103例对照中，对174个关联性最显著的单核苷酸多态性（SNP）进行基因分型。最终分析中有12个此类关联具有显著性。与未达到青春期关联性最显著（P < 1.5×10⁻¹⁴）的区域位于4号染色体上NHLH2基因周围。在小鼠中，青春期发育延迟和初情期年龄与NHLH2有关。由于达到青春期是一个复杂的性状，鉴定影响青春期年龄的基因将极大地有助于我们对生殖发育以及整体繁殖力的了解。
