The genomics of fat and fertility in pigs

二十多年来，商业猪群的选择压力以脂肪积累为代价提高了蛋白质沉积的效率。 体脂减少伴随着青春期推迟、窝仔数减少和仔猪断奶后恢复发情期的时间延长。 这一建议已被开发来测试的假设，主要或专门在猪的脂肪组织中表达的基因作为多态性的遗传标记的繁殖性状和调节繁殖过程。我们的总体目标是确定脂肪相关基因和基因产物对猪繁殖性能的影响和机制。 这些结果将为遗传选择提供标记，以提高生育能力，沿着深入了解脂肪在生殖调节中的作用。 我们将确定脂肪组织中的基因组标记，预测生殖性状，包括青春期，窝仔数和断奶发情间隔。 我们将筛选来自>3000头已知繁殖表型的猪的多代DNA库，以获得可用于遗传选择的多态性。 我们将用已知的脂肪基因、从我们以前的基因发现工作中获得的未知基因以及来自与生殖性状相关的染色体区域的基因进行筛选。 我们将进一步比较高生育力（>16/窝）和低生育力（<9/窝）的猪群，以确定脂肪和生殖组织中已知和新候选基因的生殖特征和表达谱。 我们将通过对卵巢、子宫和胚胎的研究来确定变异生育力的基础。 我们将研究皮下和内脏脂肪库中的基因表达，以寻找脂肪与多产性的相关性。 进一步的目标是确定皮下和内脏脂肪基因产物对猪繁殖性状的影响。 这些研究将采用重要的终点，包括指示排卵的卵巢变化、胚胎发育至胚泡阶段以及胚胎附着于子宫。 这个多方面的项目将产生新的信息的遗传学和功能基因组学的猪繁殖有价值的养猪业和加拿大。

Over two decades, selection pressure in commercial pig populations has improved the efficiency of protein deposition at the expense of fat accumulation.   Reduction in body fat has been accompanied by later puberty, reduced litter size and a longer period for return to estrus after piglets are weaned.  This proposal has been developed to test the hypothesis that genes expressed predominantly or exclusively in adipose tissue in the pig serve as polymorphic genetic markers of reproductive traits and regulate reproductive processes. Our overall objective is to determine the influence and the mechanisms of adipose-associated genes and gene products on reproductive performance in swine.  The results will provide markers for genetic selection to improve fertility, along with insight into the role of fat in modulation of reproduction.   We will identify genomic markers in adipose tissue that predict reproductive traits, including puberty, litter size and weaning to estrus interval.  A multigenerational DNA bank derived from >3000 pigs of known reproductive phenotype will we screened for polymorphisms useful for genetic selection.  We will screen with known adipose genes, with unknown genes derived from our previous gene discovery efforts, and with genes from regions of chromosomes associated with reproductive traits.   We will further compare populations of pigs of elevated fertility (>16/litter) with subfertile populations (<9/litter) to establish reproductive characteristics and expression profiles of known and novel candidate genes in adipose and reproductive tissues.  We will determine the bases for variant fertility by studies of the ovary, uterus and embryo.  We will examine gene expression in subcutaneous and visceral fat depots to seek adipose correlates to prolificity.  A further goal is to determine the effects of subcutaneous and visceral adipose gene products on pig reproductive traits.  These studies will employ important endpoints including ovarian changes indicative of ovulation, embryo development to the blastocyst stage, and attachment of the embryo to the uterus.   This multifaceted project will yield new information on the genetics and functional genomics of pig reproduction valuable to the pig industry and to Canada.