摘要
二年级作文DGAT是脂肪合成代谢中的关键酶之一，它与脂类在脂肪细胞中的沉积、血浆中三酰甘油的调节、肌肉中能量代谢以及畜禽卵母细胞的形成等有密切的关系。研究证明，DGAT基因是影响畜禽肉质性状、产奶性状和体脂性状的重要候选基因，已成为进行分子标记辅助育种主要因素之一，对筛选和鉴定影响新疆良种驴的肉质、产奶等生产性状，具有重要的理论意义和应用价值。
本实验采用PCR-SSCP技术，对新疆和田和喀什良种驴的DGAT2基因的多态性进行了检测，对不同SSCP带型的DNA片段进行测序，分析了新疆良种驴的遗传多样性及多态性位点与生产性状的关系，为其合理保护、开发和利用提供了科学依据。实验结果如下：
（1）PCR-SSCP技术检测结果
分析检测了新疆和田和喀什良种驴DGAT2基因第3、4、5内含子和第5、6外显子的多态性，仅发现第3内含子存在多态性现象，有两种等位基因分别命名为A和B，存在AA和AB两种基因型，没有检测到BB基因型，其中AA基因型为优势基因型。纯合子AA型有两条带，杂合子AB有四条带。基因型频率AA＞AB，基因型频率为0.6964（0.3036）。测序结果表明：AB型与AA型相比存在A→G的碱基突变。
（2）DGAT2基因第3内含子多态性与体尺性状的相关性分析
DGAT2基因第3内含子多态性与体尺性状有极显著或显著的相关性。和田良种驴AA与AB基因型个体相比，体高和胸围差异极显著（P＜0.01），体长差异显著（P＜0.05），AB型体高、胸围和体长高于AA型。喀什良种驴AA与AB基因型个体相比，体高差异显著（P＜0.05），AB型体高、胸围和体长高于AA型，但体长和胸围差异不显著（P ＞0.05)。实验群体中喀什良种驴在体高、体长和胸围高于和田良种驴，差异极显著（P ＜0.01）。
（3）DGAT2基因第3内含子多态性与屠宰性状的相关性分析
和田良种驴AA和AB基因型个体的体重、胴体重、屠宰率及净肉重差异不显著（P ＞0.05)，只有净肉率差异极显著（P＜0.01），但这几项测定值均是AB型高于AA型。喀什良种驴AA和AB基因型个体的体重、胴体重、屠宰率、净肉重及净肉重差异都不显著（P＞0.05)，但这几项测定值中，除AB型的净肉率高于AA型，其余均是AA型高于AB 型。和田良种驴的屠宰率和净肉率高于喀什良种驴，差异极显著（P＜0.01）。
题竹
（4）DGAT2基因第3内含子多态性与奶产量的相关性分析
环传DGAT2基因内含子3多态性位点与和田和喀什良种驴的奶产量没有显著的相关性，AB基因型平均日产奶量与整个泌乳期的产奶总量高于AA基因型，但是都没有达到显著水平。
关键词：新疆良种驴；DGAT2基因；PCR-SSCP；多态性；生产性状
海南椰子树论文类型：A（基础研究）
ABSTRICT
祝福语大全简短赞美DGAT is an important enzyme in fat metabolism, such a clo relationship with the lipids in the fat cells deposition, plasma triglyceride regulation, energy metabolism in muscle and the formation of animal cytes. Studies have shown that DGAT gene is an important candidate gene that affecting meat quality traits, milk production traits and fatness traits in livestock, have become one of the main factors for the molecular marker-assisted breeding. DGAT gene has important theoretical significance and application value for the screening and identification of varieties in Xinjiang donkey's meat and milk production traits.
In this study, PCR-SSCP technique was ud to detection DGAT2 gene polymorphism of Hotan and Kashgar breeding donkeys in Xinjiang, and the different SSCP band pattern of DNA fragments were quenced, and analyzed the correlations between genetic diversity and polymorphism locus of Xinjiang breeding donkeys with production traits, provide scientific basis for their effective protection, development and utilization .The experiment results as follows:
(1) Detection results of PCR-SSCP technique
Detected and analyzed the polymorphism of DGAT2 gene intron 3,4,5 and exon 5,6 on Hotan and Kashgar breeding donkeys in Xinjiang,only found DGAT2 gene intron 3 has polymorphism,there were two alleles were named A and B, exist two genotypes were AA and AB, have’t find BB genotypes, AA genotype was the dominant genotype. AA-homozygotes have two bands, there were four bands with heterozygous AB. Genotype frequency was AA> AB, genotype frequency was 0.6964 (0.3036). The quencing results showed that: AB-type was compared with AA-type, there was A→G nucleotide mutation occurred.
(2) Correlations between DGAT2 gene intron 3 polymorphism and body size traits
There was highly significant or significant correlation in DGAT2 gene intron 3 polymorphism and body size traits were. AA genotype compared with AB genotype of Hotan breeding donkeys, body height and chest circumference were significantly different (P<0.01), body length was significantly different (P<0.05), body height, chest circumference and body length of AB-type was higher than the AA. AA genotype compared with AB genotype of Kashgar breeding donkeys, body height was significantly different (P<0.05), body height, chest circumference and length of AB-type was higher than AA, but the body length and chest circumference was no significant (P>0.05). Body height, body length and chest circumference of Kashgar breeding donkeys was higher than Hotan breeding
donkeys in experimental groups,the difference was significant (P<0.01).
(3) Correlations between DGAT2 gene intron 3 polymorphism and carcass traits
The difference in weight, carcass weight, slaughter rate and net meat weight of Hotan donkey's AA and AB genotype were not significant (P>0.05), only lean percentage was significantly different (P<0.01), but this veral measured values was AB type higher than AA type. Body weight, carcass weight, slaughter rate, net meat weight and net meat weight of Kashgar breeding donkey's AA and AB genotype were not significantly different (P>0.05), but a number of measured values, except for AB-type lean percentage was higher than AA-type, the rest was AA-type higher than were AB-type. Hotan donkey's slaughter rate and lean percentage were higher than Kashgar donkey's, the difference was significant (P<0.01).
(4) Correlations between DGAT2 gene intron 3 polymorphism and milk production
There was no significant correlation of DGAT2 gene intron 3 polymorphism locus with Hotan and Kashgar donkey's milk production, average daily milk yield and milk throughout the lactation period of AB gene type were higher than AA gene type, but did not reach significant level.
Key words: Xinjiang excellent donkeys; DGAT2 gene; PCR-SSCP; Polymorphism; production traits
Type of paper: A (theory rearch)
中英文对照表
节约用水的一段话缩略语英文中文
QTL Quantitative trait locus数量性状基因座位DGAT1Diacylgycerol Acyltransfera 1二酰甘油酰基转移酶1 DGAT2Diacylgycerol Acyltransfera 2二酰甘油酰基转移酶2 SSCP Single-strand conformation polymorphism单链构象多态
TAG Triacylglycerol三酰甘油
PCR Polymera Chain Reaction聚合酶链反应
Tris Tris(hydroxymethy1) aminomethane三羟基甲基氨基甲烷PBS Phosphate buffered solution磷酸盐缓冲溶液Proteina K Proteina K 蛋白酶K
DNA Deoxy ribonuclea tetrahydrochloride脱氧核糖核酸Genebank Genebank核苷酸序列资料库PAGE polyacrylamide gel electrophoresis聚丙烯酰胺凝胶电泳Acr Acrylamide丙烯酰胺
AP Ammonium Persulfate过硫酸铵
幼儿园安全第一课
Bis Bis-acrlylamdie甲叉双丙烯酰胺EDTA Ethylenediamine Tetra-acetic Acid乙二胺四乙酸TEMED N,N,N',N'-Teteramethylthylenediamine四甲基乙二胺RNAa ribonucleic acid enzyme Taq RNA polymera 核糖核酸酶
最大的素数Taq DNA Taq DNA polymera聚合酶
dNTP Deoxyribo nucleoside trephosphate脱氧核苷三磷酸
bp ba pair碱基对
kb lokba pairs in duplex nucleic acid 千碱基对
ACD anticoagulant抗凝血剂
TE tris-EDTA buffer tris-EDTA缓冲液SDS Sodium dodecyl sulfate十二烷基磺酸钠
TBE Tris/Boric acid/EDTA buffer Tris硼酸缓冲液
EB ethidium bromide 溴化乙锭
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