猪产仔数分子标记及其效应的研究

【作者】 张淑君；

【导师】 曾凡同； 邱祥聘； 熊远著； 邓昌彦；

【作者基本信息】 四川农业大学 ， 动物遗传育种与繁殖， 2001， 博士

【摘要】 借助分子生物学技术寻找、检测数量性状基因的方法，目前主要有候选基因法、基因组扫描法。本文以ESR、PRLR、RYR1、FSHR四个基因作为候选基因，以及八号染色体上的9个微卫星进行猪产仔数分子标记研究。 1．初步确定了三个新的猪产仔数分子标记：雌激素受体基因ESR的第八外显子处的ESRB酶切位点、促卵泡生长激素受体基因的第七外显子的FSHRB酶切位点和猪八号染色体上微卫星SWR1101位点。 2．筛选出了较优的分子标记：进行多个分子标记效应比较研究，确定了有利于产仔数提高和不利于产仔数提高的分子标记。 有利于母猪产仔数提高而又不影响仔猪生长的分子标记有五个：ESR酶切位点的基因型BB、FSHRB酶切位点的基因型BB、PRLR基因位点的基因型AA、ESR基因酶切位点ESRB的基因型AA、RYR1基因位点的基因型BB。可提高猪每窝产仔数2.2头。 不利于母猪产仔数提高的分子标记，即用于淘汰母猪的分子标记有五个：ESR酶切位点的基因型AA、PRLR基因位点的基因型BB、FSHRB酶切位点的基因型AA、ESR基因酶切位点ESRB的基因型BB、微卫星SWR1101 基因型BD。 3．产仔数分子标记对仔猪生长不存在负效应：进行了分子标记产仔数与约17000头仔猪初生重和断奶重相关性研究，结果表明：产仔数分子标记不显著地影响仔猪生长性能，即对仔猪生长不产生负效应。 4．从分子遗传和解剖角度证实了“母猪子宫大产仔多”的传统观念：屠宰了参考家系F₂代103头成年母猪，测定了卵巢重量、子宫重量、子宫容积、输卵管长度、子宫角长度，并比较分析了子宫卵巢大小、产仔数与基因多态的相关性。母猪携带高产仔数基因，其子宫卵巢较大，也证实了产仔数分子标记的可能性和合理性。 5．寻找到二个分子标记同时检测的简便快速有效的新方法：筛选出 了H个产仔数分子标记（RYRI与ESR、RYRI与ESRB）同时PCR－RFLPS 检测，这既降低了检测成本，又提高了检测的准确性和可靠性。它适用于 育种和生产中大规模检测。 6．猪产仔数分子标记在生产上得到了验证和应用：将这些产仔数分 子标记在长大母猪中进行辅助选择，其结果与大白母猪、二花脸母猪的情 况很相似。它们可用于产仟数的辅助选择。 7．八号染色体上 9个微工星位点（SW205、50086、SW709、SW268、 SW905、SWRI 101． SW1070、SW444、OPN）的等位基因频率、杂合度、 多态信息含量在长大母猪、二花脸母猪、大白母猪、参考家系FZ代（大 白x梅山）母猪中存在较大的差异。 兄基因位点O、FSHRA)在四个母猪群中不存在的PCRSSCP 多态性。基因酶切位点（ESR、ESM、ESRB、PRLR、RYRI、FSHRB） 的PCWotMys多态性在不同母猪群中存在，其等位基因频率差异较大。 本文从基因变异中筛选出猪产仔数分子标记，比较多个分子标记的效 应和基因间互作，从而确定有利于和不利于产仔数提高的分子标记。而且， 开展了在生产中验证分子标记的稳定性和可靠性、从分子遗传学和解剖学 角度证实产仔数分子标记存在的可能性和合理性、在方法上完善分于标记 分析技术等一系列完整的研究，为探讨猪产仔数分子标记辅助选择、影响 产仔数的遗传机理打下基础，同时为人类生育研究提供动物模型。更多还原

【Abstract】 Two important methods to identify markers of QTLs(quantitative traits loci) are genome scan and the candidate gene approach. in this study the Estrogen Receptor, Prolactin Receptor, Ryanodine Receptor, Follicle Stimulating Hormone Receptor as candidate genes and nine microsatellites on chromosome 8 were investigated for genetic markers of lifter size in pigs. 1. Three new genetic molecular markers of litter size in pigs were primarily confirmed: ESRB in Exon 8 of Estrogen Receptor gene, FSHRB in Exon 7 of Follicle Stimulating Hormone Receptor gene and microsatellite SWR1 101 on chromosome 8. 2. Effective genetic molecular markers were selected: advantageous and disadvantageous genetic markers of litter size in pig were determined after comparing several genetic molecular makers. Advantageous genetic molecular markers which could increase litter size and no negative effect on pig growth. including the genotype BB on the loci of ESR.% FSHRB and RYR1 and the genotype AA on the loci of ESRB and PRLR. There were five disadvantageous genetic markers that had disadvantageous effect on reproductive ability of sows. They were genotype AA on the loci of ESR~ FSHRB , BB on the loci of PRLR, ESRB and BD of microsatellite SWRI 101. 3. Genetic molecular markers of litter size in pigs could not adversely affect growth traits: About 17000 piglets were analyzed to determined whether genetic molecular markers influenced birth weight and weaning weight, no significant effect was fonud. 4.The traditional idea was verified from molecular genetics and anatomy that the sows with big ovum and uterus could get more total number bom(TNB) and number born alive(NBA): 103 F2 mature sows of a reference family (Large white X Meishan) were slaughtered and sow’s weight of two ova~ uterus, volumn of uterus, the length of oviduct and womb horn were measured, meanwhile, 145 the relationships between the size of ovum and womb litter size and polymorphisms of genes were analyzed. The results show that The sows?size of ova and uterus were also bigger if sows carried the favorable lifter size gene, It also proved it was possible and reasonable for genetic molecular markers of litter size to be applied as markers. 5.Two fast effective1 simple new methods for investigating two genetic markers at the same time were developed, the two genetic markers (RYR1SL RYR1SRB) could be detected by PCR-RFLPs at the same time, it could not only reduce cost ,but also increase accuracy and reliability. 6. Genetic molecular markers of litter size were verified and applied in pigs production. Genetic markers were used to analyze total number bom(TNB) and number born alive(NBA) in sows of Landrace X Large white, The results were quite similar with those obtained conclusion of Large White and Erhualian. These markers could be used in marker assisted selection for litter size in pigs. 7. Allele frequencies, Heterozygote and polymorphism information content of nine Microsatellites (SW205 S0086 SW790 SW268 SW905 SWR11OU. SW444 SW1O7O OPN) on chromosome 8 were significantly different in these of ErhualianL, Large white, Landrace X Large white and reference family F2 sows. 8. No polymorphism in PRLR1 and FSHRA loci was found by PCR-SSCP. but polymorphisms of ESR ESRBI ESRA RYR1 PRLR and FSHRB were found by PCR-RFLPs, Allele更多还原