利用微卫星进行凉山半细毛羊毛性状的QTL定位研究
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摘要
本研究利用绵羊基因组中第3条染色体上的11个微卫星(Microsatellite)标记，采用父系半同胞家系群体对控制凉山半细毛羊毛性状的数量性状座位(QTL)进行研究。性状的表型值包括育成毛纤维直径(WFD1)、成年毛纤维直径(WFD2)、断乳毛长(SL1)、育成毛长(SL2)和成年毛长(SL3)均来自此群体的鉴定记录及实验室测定。群体在这11个微卫星标记座位上的等位基因频率、微卫星的多态信息含量(PIC)、群体的杂合度(Heterozygosity)以及毛性状QTL进行了分析。
群体性状表型值分析结果显示：WFD1为32.15±2.16μm；WFD2为35.02±2.61μm；SL1为6.49±2.29cm；SL2为14.04±1.69cm；SL3为16.15±1.84cm。分析结果与以前研究结果一致，说明整体水平上基本达到了使性状趋于一致的育种目标。各家系的毛性状表型值分析结果表明，各家系间存在差异，但差异不大。家系内表现有所不同，这正是利用父系半同胞家系进行QTL定位的基础。
所选择的11个微卫星标记在凉山半细毛羊群体中表现出较好的多态性。微卫星标记平均检测到7.8个等位基因(5～11个)，平均多态信息含量(PIC)为0.6038(0.3125～0.8410)，平均杂合度为0.6423(0.3232～0.8179)。微卫星的多态性和Genbank中的结果存在差异，其原因可能是试验群体和群体大小的差异引起的。
用覆盖3号染色体上的11个微卫星标记(标记区间平均为29.3cM)对绵羊7个家系的5个毛性状进行QTL检测。MultiQTL程序的分析结果显示：在家系H1G4003中，断乳毛长(SL1)和成年毛长(SL3)在99％置信区间时均表明在RM150-ILSTS22(66.3～90.0cM)标记区间有显著的QTL；在家系H1G4035中存在一连续显著的QTLs，有两个分离的峰，一个位于标记BMS1953(204cM)处，另一个位于BMC1009-OARCP43(229.4～253.5cM)标记之间，BMC1009与QTL的重组率为8.6％。本次试验结果显示BMC1009标记与影响毛长的QTL存在连锁，这与已报道的结果(Allain，D.et al.,1996)相一致。所有家系中没有检测到育成毛纤维直径，成年毛纤维直径显著的QTL，也没有发现育成毛长存在显著的QTL，可能是因为资源参考家系少，家系小和标记密度小等原因，也可能是毛纤维直径QTL与羊毛长度QTL在3号染色体上没有相关性存在。
通过文献检索，未发现绵羊第3条染色体RM150-ILSTS022记区间有影响羊毛长度的QTL的报道，我们将通过增加样本量和缩小标记区间的方法进一步加以验证。
Eleven microsatellites from the sheep linkage map were used to search for Quantitative Trait Loci (QTL) for wool traits using an experimental population comprising 7 paternal families of half-sibs/sire of Liangshan semi-fine wool sheep. Various phenotypes including wool fibre diameter (WFD) and staple length (SL) were measured in the flock, phenotypic correlations between wool traits using SAS program are presented. Allele frequencies of 11 microsatellites were estimated based on genotype measured using Genscan 2.0. Polymorphism information content (PIC) and heterozygosity were calculated based on allele frequencies and QTL analysis for wool traits using multiQTL program.
Phenotype values and phenotypic correlations of wool fibre diameter at 18 months, 30 months and staple length at weaning, 18 months, 30months were estimated. Results in this paper were found generally agreed with those in the previous references.
Every microsatellite loci analyzed were polymorphic in this flock with an average number of alleles per locus ,the average information content(PIC) and average heterozygosity are 7.8(from 5 to 11), 0.6179(from 0.3125 to 0.8410) and 0.6629 (from 0.3232 to 0.8179) respectively. Polymorphism of every microsatellite in this flock is different with the results in the Genbank. These differences were probably result from microsatellite primer for multiple PCR reaction and experimental population different from the results in the Genbank.
The results of QTL analysis for wool traits using 11 microsatellites located on chromosome 3 hi the Liangshan semi-fine wool sheep revealed that a marker interval(RM150-ILSTS022) had a significant effect on staple length at weaning(SLl) (p<0.01) and staple length at 30months(SL3)(p<0.01) in the H1G4003 family using MultiQTL program indicating their potential linkage to QTLs. However, more markers between RM150 and ILSTS022 will be required to continue to locate the QTL more clearly. Two QTLs for staple length at weaning (SL1) were observed located on BMS1953 marker and in the marker interval(BMC1009-OARCP43). The result that BMC 1009 marker(Chr. 3) had a significant within sire effect on
SL(P<0.01) are in agreement with that of QTL reported earlier by Allain, D. et al.(1996). However, more markers between the two peaks will be required to dissect the QTLs more clearly.
In conclusion, we have detected a new QTL in this study for wool traits in the Liangshan semi-fine wool sheep which could result from the use of a different population from those used in other studies, sample size and marker density.
群体性状表型值分析结果显示：WFD1为32.15±2.16μm；WFD2为35.02±2.61μm；SL1为6.49±2.29cm；SL2为14.04±1.69cm；SL3为16.15±1.84cm。分析结果与以前研究结果一致，说明整体水平上基本达到了使性状趋于一致的育种目标。各家系的毛性状表型值分析结果表明，各家系间存在差异，但差异不大。家系内表现有所不同，这正是利用父系半同胞家系进行QTL定位的基础。
所选择的11个微卫星标记在凉山半细毛羊群体中表现出较好的多态性。微卫星标记平均检测到7.8个等位基因(5～11个)，平均多态信息含量(PIC)为0.6038(0.3125～0.8410)，平均杂合度为0.6423(0.3232～0.8179)。微卫星的多态性和Genbank中的结果存在差异，其原因可能是试验群体和群体大小的差异引起的。
用覆盖3号染色体上的11个微卫星标记(标记区间平均为29.3cM)对绵羊7个家系的5个毛性状进行QTL检测。MultiQTL程序的分析结果显示：在家系H1G4003中，断乳毛长(SL1)和成年毛长(SL3)在99％置信区间时均表明在RM150-ILSTS22(66.3～90.0cM)标记区间有显著的QTL；在家系H1G4035中存在一连续显著的QTLs，有两个分离的峰，一个位于标记BMS1953(204cM)处，另一个位于BMC1009-OARCP43(229.4～253.5cM)标记之间，BMC1009与QTL的重组率为8.6％。本次试验结果显示BMC1009标记与影响毛长的QTL存在连锁，这与已报道的结果(Allain，D.et al.,1996)相一致。所有家系中没有检测到育成毛纤维直径，成年毛纤维直径显著的QTL，也没有发现育成毛长存在显著的QTL，可能是因为资源参考家系少，家系小和标记密度小等原因，也可能是毛纤维直径QTL与羊毛长度QTL在3号染色体上没有相关性存在。
通过文献检索，未发现绵羊第3条染色体RM150-ILSTS022记区间有影响羊毛长度的QTL的报道，我们将通过增加样本量和缩小标记区间的方法进一步加以验证。
Eleven microsatellites from the sheep linkage map were used to search for Quantitative Trait Loci (QTL) for wool traits using an experimental population comprising 7 paternal families of half-sibs/sire of Liangshan semi-fine wool sheep. Various phenotypes including wool fibre diameter (WFD) and staple length (SL) were measured in the flock, phenotypic correlations between wool traits using SAS program are presented. Allele frequencies of 11 microsatellites were estimated based on genotype measured using Genscan 2.0. Polymorphism information content (PIC) and heterozygosity were calculated based on allele frequencies and QTL analysis for wool traits using multiQTL program.
Phenotype values and phenotypic correlations of wool fibre diameter at 18 months, 30 months and staple length at weaning, 18 months, 30months were estimated. Results in this paper were found generally agreed with those in the previous references.
Every microsatellite loci analyzed were polymorphic in this flock with an average number of alleles per locus ,the average information content(PIC) and average heterozygosity are 7.8(from 5 to 11), 0.6179(from 0.3125 to 0.8410) and 0.6629 (from 0.3232 to 0.8179) respectively. Polymorphism of every microsatellite in this flock is different with the results in the Genbank. These differences were probably result from microsatellite primer for multiple PCR reaction and experimental population different from the results in the Genbank.
The results of QTL analysis for wool traits using 11 microsatellites located on chromosome 3 hi the Liangshan semi-fine wool sheep revealed that a marker interval(RM150-ILSTS022) had a significant effect on staple length at weaning(SLl) (p<0.01) and staple length at 30months(SL3)(p<0.01) in the H1G4003 family using MultiQTL program indicating their potential linkage to QTLs. However, more markers between RM150 and ILSTS022 will be required to continue to locate the QTL more clearly. Two QTLs for staple length at weaning (SL1) were observed located on BMS1953 marker and in the marker interval(BMC1009-OARCP43). The result that BMC 1009 marker(Chr. 3) had a significant within sire effect on
SL(P<0.01) are in agreement with that of QTL reported earlier by Allain, D. et al.(1996). However, more markers between the two peaks will be required to dissect the QTLs more clearly.
In conclusion, we have detected a new QTL in this study for wool traits in the Liangshan semi-fine wool sheep which could result from the use of a different population from those used in other studies, sample size and marker density.
引文
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2 陈圣偶，等．凉山半细毛羊种质特性的研究总结报告．2000
3 高用明，朱军．植物QTL定位方法的研究进展．遗传，2000，22(3)：175～179
4 何小红，等，数量性状基因作图精度的主要影响因子．“全国动、植物数量遗传与育种”学术研讨会文．75～81
5 洪琼花，等．云南半细毛羊皮肤毛囊结构与产毛性能相关性的研究．草食家畜，2001，1：24～27
6 姜勋平，等．凉山半细毛羊横交群重要经济性状遗传率及其相关分析．四川畜牧兽医，1996，4(1)9～10
7 李祥龙，等．凉山 48-50 支半细毛羊母羊预期表型值综合选择指数的研究．四川农业大学学报，1996，14(2)：276～279
8 刘鹏渊，等．标记辅助选择改良数量性状的研究进展，遗传，2001，23(4)：375～380
9 刘欣，等．羊毛品质检验与绵羊育种和毛纺产品质量，草食家畜，2000，(1)：15～18
10 山西农业大学主编．养羊学(第二版)．农业出版社，1992
11 盛志廉，陈瑶生编著．现代遗传学丛书—数量遗传学，北京：科学出版社，1999
12 宋九洲，等．分子遗传标记和数量性状位点(QTL)间的连锁分析(综述)．农业生物技术学报，1994，12(2)：17～24
13 陶生策，等．PCR技术研究进展．生物工程进展，2001，04：26～29
14 徐宁迎，等．两个基因位点之间的常用连锁分析法—LOD值法．浙江畜牧兽医，1999，3：43～44
15 徐宁迎，等．德系黑白花奶牛数量性状基因定位研究初报．浙江农业大学学报，1999，25(1)：107～110
16 徐宁迎，等．利用微卫星进行奶牛数量性状基因位点定位的研究．遗传学报，2000．27(9)：772～776
17 吴登俊，等．家畜基因组遗传多态标记—微卫星标记研究进展(上)．国外畜牧科技，1999，26(1)：33～35
18 吴登俊，等．家畜基因组遗传多态标记—微卫星标记研究进展(下)．国外畜牧科技，1999．26(2)：37～40
19 姚树清，等．杂交优势对产毛性状和羊毛品种的影响．中国养羊，1995，15(2)，40～43
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