鸡脂滴包被蛋白基因内含子6多态性与胴体及脂肪性状的相关性研究

试验采用PCR-RFLP方法检测脂滴包被蛋白(perilipin,PLIN)基因内含子6在济宁百日鸡、莱芜黑鸡等4个地方鸡种和1个培育品系中的遗传多态性,分析了多态位点不同基因型与鸡胴体及脂肪性状的相关性。结果发现,在5个供试群体中检测到1个多态位点,测序证实为新发现的鸡PLIN基因2 467 bp处G→A突变,该突变位点在供试群体中检测到3种基因型:A1A1、A1A2和A2A2,2个等位基因:A1和A2。等位基因A1在所有供试群体中均表现为优势等位基因。关联分析结果表明,PLIN基因2 467 bp位点对鸡部分胴体性状和脂肪性状影响显著(P<0.05)。多重比较结果表明,A1A1基因型个体活体重、屠体重、全净膛重、腹脂重和腹脂率均显著高于A2A2基因型个体(P<0.05)。A1A2基因型个体的胸肌肌内脂肪含量显著高于A1A1和A2A2基因型个体(P<0.05)。研究结果表明,PLIN基因对鸡胴体及脂肪性状有一定影响。     

太行鸡Mx基因抗性位点与体尺和胴体性状的关联分析

采用错配PCR-RFLP对太行鸡Mx基因2032位点多态性进行检测,结果发现太行鸡Mx基因2032位点经RsaⅠ酶切后,检测到AA、AG和GG3种基因型,基因型频率分别为0.185,0.577和0.238,抗性基因A的频率为0.473。χ2适合性检验表明该多态位点上等位基因的分布处于Hardy-Weinberg平衡状态。对3个基因型与太行鸡一些经济性状间的关联性分析,结果表明,发现除胸深、胫围和胫长外,AA基因型个体其他体尺小于或接近AG和GG基因型个体;抗性纯合子AA基因型个体胴体性状均显著小于GG基因型个体。     

秦川牛CEBPA基因遗传变异对体尺和胴体性状的影响

试验以CCAAT增强子结合蛋白A(CEBPA)为候选基因,采用直接测序的方法寻找秦川牛CEBPA基因SNP,筛查到一个新的多态位点T963G,该突变位于基因的编码区。运用PCR-RFLP方法验证并分析该位点在215头秦川牛群体中的多态性。结果表明:在秦川牛群体中分布A、B 2个等位基因,处于中度多态。经过χ2适合性检验,秦川牛群体在该位点达到Hardy-Weinberg平衡状态(P0.05)。将该T963G位点的基因型与体尺、胴体性状进行关联分析,表明该位点与胴体重显著相关(P0.05),BB为有利基因型,B等位基因为有利等位基因,提示该位点有可能作为秦川牛胴体性状标记辅助选择的标记之一。     

朝那鸡MC1R基因G274A和A427G多态位点与羽色性状的关联分析

为了研究宁夏地方品种鸡朝那鸡的黑色素皮质激素1受体(melanocortin 1 receptor, MC1R)基因G274A和A427G多态位点与羽色性状的关联性,试验选择120日龄健康的朝那鸡150只(红羽、黑羽和白羽各50只)为试验对象,采用高分辨熔解曲线(high resolution melting, HRM)分析技术对朝那鸡MC1R基因G274A和A427G位点进行基因型分型检测,并且对基因型和羽色性状进行了关联分析。结果表明：试验朝那鸡群体MC1R基因G274A位点有GG、GA、AA三种基因型,其中AA基因型个体数量最多,等位基因A为优势等位基因,多态信息含量(PIC)为0.286 7,表现为中度多态(0.25≤PIC≤0.50),说明MC1R基因位点为G274A的朝那鸡群体选育潜力较高;A427G位点有AA、AG两种基因型,其中AA基因型个体数量最多,等位基因A为优势等位基因,PIC为0.062 3,表现为低度多态(PIC<0.25),说明MC1R基因位点为A427G的朝那鸡群体选育潜力较低;这两个位点均处于Hardy-Weinberg平衡状态(P>0.05...     

边鸡IGF-ⅠR基因AluⅠ位点多态性及其对生长性状和繁殖性状的遗传效应分析

为了寻找与边鸡生长性状和繁殖性状相关的遗传标记,本试验采用PCR-RFLP技术检测边鸡类胰岛素生长因子Ⅰ受体（insulin-like growth factor Ⅰreceptor,IGF-ⅠR）基因Alu Ⅰ位点的多态性,并分析该多态位点对边鸡生长性状和繁殖性状的遗传效应。结果显示,边鸡IGF-ⅠR基因Alu Ⅰ位点存在多态性,在外显子2的376 bp处有1个G→A突变,产生了GG、GA和AA 3种基因型,基因型频率分别为0.687、0.296和0.017,GG为优势基因型;G等位基因频率为0.835,为优势等位基因。卡方适合性检验结果表明,该基因座位在边鸡群体中处于哈代-温伯格平衡状态（P>0.05）。相关分析结果表明,在8、14、16和18周龄时,GG基因型个体的体重显著高于GA基因型（P<0.05）,GG基因型个体的开产体重极显著高于GA基因型个体（P<0.01）,但并不能说明该位点可以作为影响边鸡繁殖性状的遗传标记。IGF-ⅠR基因外显子2的Alu Ⅰ位点（G→A）可能是影响边鸡生长性状的一个遗传标记。     

延边黄牛PLIN基因多态性及其与胴体和肉质性状的相关性分析

为探究延边黄牛脂滴包被蛋白（perilipin，PLIN）基因遗传多态性及其对胴体和肉质性状的影响，试验选取70头30月龄健康延边黄牛公牛，采集颈静脉血液及其12~13肋间背最长肌以提取延边黄牛DNA样本，并测定胴体与肉质性状，采用直接测序方法检测PLIN基因SNP位点，结合延边黄牛胴体、肉质数据与PLIN基因遗传多态性进行关联分析。结果显示，在延边黄牛PLIN基因外显子3 103与156 bp处存在2个突变位点：g.103 C→T和g.156 T→C，均为错义突变。g.103 C→T位点存在CC、CT两种基因型，CC基因型为优势基因型（0.81），C基因为优势等位基因（0.90），表现为CT基因型个体脂肪含量、宰前重、胴体重、背膘厚均显著高于CC基因型个体（P<0.05）；g.156 T→C位点存在TC、TT两种基因型，TT基因型为优势基因型（0.83），T基因为优势等位基因（0.92），表现为TC基因型个体的宰前重、胴体重及背膘厚均显著高于TT基因型个体（P<0.05）。卡方检验结果表明，延边黄牛在PLIN基因外显子3的2个SNPs位点均达到Hardy-Weinberg平衡（P>0.05），杂合度较低，属于低度多态（PIC<0.25）。综上，PLIN基因g.103 C→T和g.156 T→C位点对延边黄牛部分胴体与肉质性状存在一定影响，该位点可作为延边黄牛胴体、肉质性状的潜在标记，PLIN基因可以作为延边黄牛品种选育的候选基因和潜在分子标记。     

猪HK2基因第17外显子多态与胴体和肉质性状的相关性研究

采用PCR—RFLP技术,分析了HK2基因第17外显子中MspI的酶切突变多态位点（A171G）在6个群体186头猪中的多态性分布及其与胴体性状和肉质性状间的相关性。研究结果表明：3个纯种猪群和3个杂交猪群中A和B等位基因频率分布情况较一致,均为B等位基因占绝对优势;在6个群体中,没有发现AA基因型个体,AB与BB基因型效应与胴体长、肋骨数和眼肌面积的相关性极显著（P〈0．01）,与肩部背膘厚、胸腰椎间背膘厚、三点平均背膘厚、眼肌高度、眼肌宽度、肥肉率、瘦肉率和肌内脂肪等性状的相关显著（P〈0．05）。该位点是否可用作改良猪胴体、肉质性状的标记位点并在标记辅助选择中加以应用还有待进一步的研究。     

PLIN基因多态性与秦川牛胴体、肉质性状的相关性研究

旨在研究PLIN基因第3、4外显子多态性与秦川牛部分产肉性状的关系。以相同饲养条件下18~24月龄的405头秦川牛为研究对象,利用PCR-SSCP方法和测序技术,对PLIN基因第3、4外显子进行SNPs位点检测,并将发现的SNPs位点与部分产肉性状进行关联性分析。结果,在第3外显子的156 bp处发生T→C突变,第4外显子的14 bp处发生C→T突变。方差分析表明:AB基因型个体的宰前活体质量、胴体质量、背膘厚和眼肌面积显著高于AA和BB基因型个体(P0.05),而且相对于AA基因型个体达到差异极显著水平(P0.01);DE基因型个体的胴体长、胴体胸深和背膘厚显著高于DD和EE基因型个体(P0.05),DD基因型个体的肌肉嫩度极显著高于EE和DE基因型个体(P0.01)。研究显示,PLIN基因单核苷酸多态性对秦川牛脂肪沉积有一定的影响,可作为影响胴体和肉质的候选基因,指导肉牛的育种工作。     

鸭ApoVLDL-Ⅱ基因的克隆及其多态与肉质和脂肪性状的关联分析

本研究设计6对引物,采用克隆测序和PCR-SSCP技术对鸭ApoVLDL-Ⅱ基因进行克隆测序和单核苷酸多态进行检测,并分析其多态对内质和脂肪性状的遗传效应.结果表明,首次获得鸭ApoVLDL-Ⅱ基因DNA序列3 197 bp(GQ 180104),与番鸭和鸡的同源性分别为94.44%和68.74%;在引物Exon3检测到1910位碱基后插入/缺失2个碱基CC和G2106A突变,产生3种基因型:CC、CD和DD,等位基因D为樱桃谷鸭的优势等位基因,而C则为金定鸭和苏牧麻鸭的优势等位基因,该座位的基因型分布仅苏牧麻鸭符合Hardy-Weinberg平衡(P＞0.05);在引物Exon4检测到T2723C、C2743T和A2944C突变,产生AA、AB和BB 3种基因型,3个鸭群体中的等位基因B均为优势等位基因,基因型分布均处于Hardy-Weinberg平衡(P＞0.05);2个多态座位均表现为中度多态,基因型分布仅苏牧麻鸭与金定鸭之间未达到显著差异(P＞0.05).最小二乘分析显示,AA型个体的UFA和EFA分别极显著低于和高于AB和BB(P＜0.01); AA型个体的胸肌率显著高于AB(P＜0.05),极显著高于BB(P＜0.01),揭示鸭ApoVLDL-Ⅱ基因Exon4座位的突变可能影响鸭胸肌率以及脂肪酸的合成和代谢过程,等位基因A可能是EFA和胸肌率的有利等位基因,等位基因B可能为UFA的有利等位基因.     

延边黄牛脂蛋白脂肪酶基因多态性及其与肉质性状的关联分析

为探究延边黄牛脂蛋白脂肪酶（lipoprteinlipase,LPL）基因遗传多态性及其对肉质性状的影响,本试验以80头健康的30月龄延边黄牛背最长肌作为试验材料,运用PCR直接测序法和高分辨率熔解曲线技术（HRM）对LPL基因的SNP位点进行检测,分析了试验群体的遗传效应,并与延边黄牛的肉质性状数据进行关联分析。PCR直接测序结果表明,延边黄牛LPL基因存在2个多态性位点（g.6215 A>G和g.18341 C>T）,其中g.6215 A>G位点表现为2种基因型：AA与AG,优势等位基因为A;g.18341 C>T位点表现为2种基因型：CC和CT,C为优势等位基因;对文献中2个位点的检测结果表明,g.355427 T>A位点表现为2种基因型：AA与AT,A为优势等位基因;c.322 G>A位点的HRM分型结果显示并未分型。这些多态性位点全部呈中度多态（0.25<PIC<0.5）,并处于Hardy-Weinberg平衡状态。HRM分型结果显示,这3个SNPs位点与延边黄牛肉质性状存在显著相关：g.6215 A>G位点与延边黄牛胴体重及脂肪、蛋白、水分含量有显著关联,表现为AG基因型个体胴体重、脂肪含量显著高于AA基因型个体（P<0.05）,AA基因型个体蛋白及水分含量显著高于AG基因型个体（P<0.05）;g.18341 C>T位点与延边黄牛宰前活重、胴体重及背膘厚有显著关联,表现为CT基因型个体这些性状均显著高于CC基因型个体（P<0.05）;g.355427 T>A位点AT基因型个体宰前活重、背膘厚和脂肪含量均高于AA基因型个体（P<0.05）。综上,LPL基因g.6215 A>G、g.18341 C>T和g.355427 T>A位点对延边黄牛的肉质有显著影响,LPL基因可以作为延边黄牛品种选育改良工作的优势候选基因和有效分子标记。     

Polymorphism in PLIN Gene Intron 6 and its Association with Carcass and Fatness Traits in Chicken

The genetic polymorphisms in PLIN gene were detected by PCR-RFLP method in four Chinese local chickens including Jining Bairi chicken,Laiwu Black chicken et al.,and one breeding strain.The correlations between the SNP and the carcass and fatness traits were analyzed.As a result,a novel G→A mutation at 2 467 bp in PLIN gene was identified in the five populations.Three genotypes (A1A1,A1A2 and A2A2) were detected,and allele A1 was predominant in all the five experimental populations.The statistical analysis showed that the 2 467 bp polymorphism locus was significant association with some carcass and fatness traits (P<0.05).The living body weight,carcass weight,eviscerated weight,abdominal fat weight and percentage of abdominal fat of A1A1 genotype was higher than A2A2 genotype in chickens (P<0.05).The breast intramuscular fat of A1A2 genotype was higher than that of A1A1 and A2A2 genotypes in chickens (P<0.05).The results showed that PLIN gene had effect on carcass and fatness traits in chickens.     

边鸡MSTN基因C.234位点对生长性状的遗传效应分析

采用PCR-RFLP技术检测连续2个世代边鸡群体肌肉生长抑制素基因外显子1的多态性,分析了多态位点对边鸡生长性状的遗传效应。结果表明,边鸡MSTN基因的C.234位点存在多态性,在外显子1编码区的234bp处发生G→A的碱基突变,产生了GG、GA和AA 3种基因型。关联分析表明,无论是一世代还是二世代的边鸡群体,在6~16周龄时,AA和GA基因型边鸡的体质量均显著或极显著的高于GG基因型（P〈0.05或P〈0.01）。结果提示,MSTN基因外显子1的C.234位点突变对边鸡的生长性状具有显著的遗传效应,初步推断该位点可用于边鸡生长性状的标记辅助选择。     

中国环颈雉A-FABP基因SNPs及其与屠宰性状和肌内脂肪含量的相关性分析

以中国环颈雉为材料,利用PCR-SSCP结合测序技术对A-FABP基因序列多态性位点进行研究,并分析与屠宰性状和肌内脂肪含量的相关性。结果表明,在中国环颈雉群体A-FABP基因上检测到多态性位点,为中度多态,在1106 bp处存在碱基A缺失,AA、AB基因型个体在活体重和屠体重上显著高于BB基因型个体,与肌内脂肪含量差异不显著。初步推测AA为中国环颈雉体重增长的优势基因型,A为优势等位基因。     

鸡CAPN1基因3′-UTR多态性及其与肉质性状的关联分析

试验利用PCR-SSCP技术对寿光鸡CAPN1基因3′-UTR的多态性进行了检测,并进一步分析了其与肉质性状的相关性。结果显示,在寿光鸡群体中检测到AA、AB 2种基因型,基因型频率分别为0.43、0.57,AB为优势基因型;A、B等位基因频率分别为0.715、0.285,A为优势等位基因;群体中未检测到BB基因型个体。经χ2检验,群体处于Hardy-Weinberg非平衡状态(P0.05)。CAPN1基因3′-UTR的多态性对胸肌pHu、腿肌pHu、肌内脂肪含量和胸肌剪切力有显著性影响(P0.05);对腿肌剪切力、失水率、胸肌蒸煮损失和腿肌蒸煮损失无显著性影响(P0.05)。     

A novel 86-bp indel of the motilin receptor gene is significantly associated with growth and carcass traits in Gushi-Anka F2 reciprocal cross chickens

ABSTRACT

1. A previous whole-genome association analysis has identified the motilin receptor gene (MLNR), which regulates gastrointestinal motility and gastric emptying, as a candidate gene related to chicken growth.

2. MLNR mRNA was expressed in all tissues tested, and the expression level in digestive tissues was greater than in other tissues. Expression levels in the pancreas, duodenum and glandular stomach at day old and one, two and three weeks of age indicated a possible correlation with the digestive system. This suggested that the MLNR gene plays a central role in gastrointestinal tract function and affects the growth and development of chickens. Moreover, there was a significant difference in expression in the glandular stomach tissue between Ross 308 and Gushi chickens at six weeks of age.

3. Re-sequencing revealed an 86-bp insertion/deletion polymorphism in the downstream region of the MLNR gene. The mutation locus was genotyped in 2,261 individuals from nine different chicken breeds. MLNR expression levels in the glandular stomach of chickens with DD genotypes were greater than those in chickens with the ID and II genotypes. The DD genotype was the most dominant genotype in commercial broiler's (Ross 308 and Arbor Acres broilers), and the D allele frequency in these breeds exceeded 91%. The deletion mutation tended towards fixation in commercial broilers.

4. Association with growth and carcass traits analysed in a Gushi-Anka F₂ intercrossed population, showed that the DD genotype was significantly associated with the greatest growth and carcass trait values, whereas values associated with the II genotype were the lowest in the F₂ reciprocal cross chickens.

5. The results suggest that the mutation is strongly associated with growth related traits and it is likely to be useful for marker-assisted selection of chickens.     

An 8bp indel in exon 1 of Ghrelin gene associated with chicken growth

Ghrelin, acts as the endogenous ligand for growth hormone secretagogues receptor (GHS-R), is a novel growth hormone (GH) releasing peptide with reported effects on food intake in chickens. In this study, an 8 bp indel polymorphism in exon 1 of the chicken Ghrelin (cGHRL) gene was genotyped in a F(2) designed full-sib population to analyze its associations with chicken growth and carcass traits. Later, mRNA level in the proventriculus was determined by real-time PCR to reveal the expression feature of cGHRL gene. Result showed that this 8 bp indel was significantly associated with body weight at the age of 28 days (BW28) and 56 days (BW56), eviscerated weight (EW) and leg muscle weight (LMW) (P<0.05), highly significantly associated with hatch weight (HW), BW14, 21, 35, 42, 49, 90 and body length (BL), dressed weight (DW), eviscerated weight with giblet (EWG), wing weight (WW), breast muscle weight (BMW) and head and neck weight (HNW) (P<0.01). Meanwhile, A allele (with 'CTAACCTG') was positive for chicken growth as individuals with AA genotype had the highest value of all traits. Analysis on cGhrelin mRNA level revealed that it differed significantly among individuals with three genotypes (P<0.05). Individuals with AB genotype had the highest mRNA level, whereas that of AA had the lowest one. It was concluded that this 8 bp indel of cGHRL gene was significantly associated with most body weight and body composition traits, and negative effect of endogenous Ghrelin on chicken growth were indicated by this study.     

Polymorphism of PLIN Gene and Its Associaton with Carcass and Meat Quality Traits in Yanbian Yellow Cattle

This experiment was conducted to explore the association between perilipin (PLIN) gene and carcass and meat quality traits in Yanbian Yellow cattle.In this study,70 30-month-old healthy Yanbian Yellow cattle were used as experimental materials,the blood of jugular vein and its 12-13 intercostal longissimus muscle dorsi were collected to extract DNA samples of Yanbian Yellow cattle,and determine the carcass and meat quality characteristics.The SNP of PLIN gene was detected by direct sequencing,and the correlation analysis was conducted based on the carcass and meat quality data of Yanbian Yellow cattle and the genetic polymorphism of PLIN gene.The results showed that there were 2 SNPs of PLIN gene exon 3 in Yanbian Yellow cattle:g.103 C→T and g.156 T→C,both of them were missense mutations.g.103 C→T contained two genotypes:CC and CT,CC genotype was the dominant genotype,the genotype frequency was 0.81,C was the dominant allele,the gene frequency was 0.90.The intramuscular fat,pre slaughter weight,carcass weight and back fat thickness of CT genotype was significantly higher than those of CC genotype(P<0.05).g.156 T→C contained two genotypes:TT and TC,TT genotype was the dominant genotype,the genotype frequency was 0.83,T was the dominant allele,the gene frequency was 0.92.The pre slaughter weight,carcass weight and back fat thickness of TC genotype were significantly higher than those of TT genotype (P<0.05).Chi square test showed that the two SNPs of PLIN gene in Yanbian Yellow cattle reached Hardy-Weinberg equilibrium (P>0.05),and belonged to low polymorphism (PIC<0.25).In conclusion,g.103 C→T and g.156 T→C of PLIN gene had potential effect on carcass and meat quality traits in Yanbian Yellow cattle,and could be used as a candidate gene and potential molecular marker of Yanbian Yellow cattle.