Polymorphism of bone morphogenetic protein 4 gene and its relationship with litter size of Jining Grey goats

Two pairs of primers (P1 and P2) were designed to detect single nucleotide polymorphisms of exon 2 and intron 2 of bone morphogenetic protein 4 (BMP4) gene in both high fecundity breed (Jining Grey goat) and low fecundity breeds (Boer, Angora and Inner Mongolia Cashmere goats) by single strand conformation polymorphism. Results showed that no polymorphism was detected for exon 2 (primer P1) of BMP4 gene in four goat breeds. For intron 2 (primer P2), three genotypes (AA, AB and BB) were detected in Jining Grey and Inner Mongolia Cashmere goats, two genotypes (AB and BB) in Angora goats, and only one genotype (AA) in Boer goats. Sequencing revealed one mutation (2203G>A) of BMP4 gene in the genotype BB in comparison to the genotype AA. The differences of litter size between AA, AB and BB genotypes were not significant (P > 0.05) in Jining Grey goats. A pair of primer (P3) was designed to detect polymorphism in the 3' flanking region of BMP4 gene that contained dinucleotide repeated sequence (CA) in the four goat breeds by microsatellite analysis. For primer P3, three genotypes (CC, CD and DD) were detected in four goat breeds. Sequencing revealed one more CA dinucleotide in genotype DD than in genotype CC. The Jining Grey does with genotype CC had 0.55 (P < 0.05) or 0.72 (P < 0.05) kids more than those with genotype CD or DD. These results preliminarily indicated that allele C of BMP4 gene is a potential DNA marker for improving litter size in goats.     

Single-nucleotide polymorphisms g.151435C>T and g.173057T>C in PRLR gene regulated by bta-miR-302a are associated with litter size in goats

Single-nucleotide polymorphisms (SNPs) located at microRNA-binding sites (miR-SNPs) can affect the expression of genes. This study aimed to identify the miR-SNPs associated with litter size. Guanzhong (n = 321) and Boer (n = 191) goat breeds were used to detect SNPs in the caprine prolactin receptor (PRLR) gene by DNA sequencing, primer-introduced restriction analysis-polymerase chain reaction, and polymerase chain reaction-restriction fragment length polymorphism. Three novel SNPs (g.151435C>T, g.151454A>G, and g.173057T>C) were identified in the caprine PRLR gene. Statistical results indicated that the g.151435C>T and g.173057T>C SNPs were significantly associated with litter size in Guanzhong and Boer goat breeds. Further analysis revealed that combinative genotype C6 (TTAACC) was better than the others for litter size in both goat breeds. Furthermore, the PRLR g.173057T>C polymorphism was predicted to regulate the binding activity of bta-miR-302a. Luciferase reporter gene assay confirmed that 173057C to T substitution disrupted the binding site for bta-miR-302a, resulting in the reduced levels of luciferase. Taken together, these findings suggested that bta-miR-302a can influence the expression of PRLR protein by binding with 3′untranslated region, resulting in that the g.173057T>C SNP had significant effects on litter size.     

Polymorphisms of BMPR-IB gene and their relationship with litter size in goats

The bone morphogenetic protein receptor IB (BMPR-IB) gene was studied as a candidate gene for the prolificacy of goats. According to mRNA sequence of ovine BMPR-IB gene, ten pairs of primers were designed to detect single nucleotide polymorphisms (SNPs) of exon 1, exon 2, exon 6 to exon 10 and 3′ untranslated region (UTR) of the BMPR-IB gene in both high prolificacy breed (Jining Grey goat) and low prolificacy breeds (Wendeng Dairy and Inner Mongolia Cashmere goats) by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) method. Only the products amplified by primers P8 and P10 of the 3′UTR displayed polymorphisms. For primer P8, three genotypes (AA, AB and BB) were detected in Jining Grey and Wendeng Dairy goats, two genotypes (AA and AB) were in Inner Mongolia Cashmere goats. Sequencing revealed one mutation (71C→T) of the BMPR-IB gene in genotype BB compared with AA. The differences of least squares mean (LSM) for litter size between genotypes AA, AB and BB were non-significant (P > 0.05) in Jining Grey goats. For primer P10, three genotypes (CC, CD and DD) were detected in Jining Grey and Wendeng Dairy goats and one genotype (CC) in Inner Mongolia Cashmere goats. Sequencing revealed one mutation (130T→C) of the BMPR-IB gene in genotype DD compared with CC. The differences of LSM for litter size between genotypes CC, CD and DD were non-significant (P > 0.05) in Jining Grey goats. These results preliminarily showed that the detected loci of the BMPR-IB gene had no significant effect on prolificacy of Jining Grey goats.     

Analysis on DNA sequence of goat RFRP gene and its possible association with average daily sunshine duration

Goat RFRP gene was cloned and its mutations were detected in thirteen goat breeds whose reproductive seasonality and litter size were different. Then sequence characteristics were analyzed and association analyses were performed to reveal the relationships between mutations of RFRP gene and average daily sunshine duration, reproductive seasonality as well as litter size in goats. A 4,862 bp DNA fragment of goat RFRP gene was obtained and the complete CDS of 591 bp encodes 196 amino acids, having high homology with that of other mammals. The protein was predicted to be a secreted protein with a signal peptide of 21 amino acids. Moreover, two mutations (A712G, T1493C) in 5' regulatory region and one mutation (A3438T) in exon 2 were detected. The test of genotype distribution in six selective goat breeds showed that there was no uniform significant association between the three polymorphisms and seasonal reproduction. The association just existed in some goat breeds for each locus. Interestingly, however, there was a strong positive correlation (r = 0.830, P = 0.003) between the G allele frequency of the A712G locus and average daily sunshine duration in ten local goat breeds, suggesting that RFRP gene has undergone a selective pressure in sunshine duration and may have indirect relationship with reproductive seasonality in goats. Additionally, no significant difference was found in litter size between genotypes in prolific Jining Grey goats.     

Polymorphisms of caprine <Emphasis Type="Italic">POU1F1</Emphasis> gene and their association with litter size in Jining Grey goats

Seven pairs of primers were designed to amplify 5′ promoter region, six exons and partial introns and to detect the polymorphisms of POU1F1 gene in five goat breeds with different prolificacy. The results showed that six mutations were identified in caprine POU1F1 gene including C256T in exon 3, C53T and T123G in intron 3, and G682T (A228S), T723G and C837T in exon 6. The former four mutations were novel SNPs in goat POU1F1 gene. The 53 and 123 loci were in complete linkage disequilibrium in five caprine breeds. Regarding the 256 locus, the Jining Grey goat does with genotype CT had 0.66 kids more than those with genotype CC (P < 0.05), while does with genotype GT had 0.63 (P < 0.05) kids more than those with genotype GG at the 682 locus. The present study preliminarily showed an association between allele T at the 256 and 682 loci of POU1F1 gene and high litter size in Jining Grey goats. Totally 16 haplotypes and 50 genotypes were identified at the above six loci in POU1F1 gene of five goat breeds. Three common haplotypes (hap2, hap3 and hap4) were identified in five goat breeds joined. Four specific haplotypes (hap7, hap9, hap11 and hap13) were detected in Jining Grey goats. The predominant haplotype was hap1 (35.29% and 48.25%) in both Jining Grey and Guizhou White goats, while hap4 (50%) in Boer goats, and hap2 (42.86% and 38.75%) in both Wendeng Dairy and Liaoning Cashmere goats. The most frequent genotypes at six loci in the above five goat breeds were hap1/hap2 (14.38%) and hap1/hap4 (14.38%), hap1/hap2 (38.60%), hap4/hap4 (40.91%), hap2/hap4 (26.53%), hap2/hap5 (20.00%), respectively. The Jining Grey goat does with nine genotypes analyzed of POU1F1 gene showed no obvious difference in litter size.     

GnRHR gene polymorphisms and their effects on reproductive performance in Chinese goats

In this study, polymorphisms in the goat GnRHR gene exon 1 were detected by PCR-SSCP and DNA sequencing methods in 786 individuals from two different goat breeds. Two haplotypes (A and B), two observed genotypes (AA and AB), and two single nucleotide polymorphisms (SNPs) were detected, which resulted in five amino acid substitutions. The frequencies of haplotypes A and B in the two goat breeds were 0.78–0.83 and 0.17–0.22, respectively. The SNP locus was in Hardy–Weinberg disequilibrium in the two goat breeds (P < 0.05). Polymorphisms of the GnRHR gene were shown to be associated with litter size in the two goat breeds. The SNPs in the goat GnRHR gene had significant effects on litter size (P < 0.05). Therefore, these results suggest that the GnRHR gene is a strong candidate gene that affects litter size in goat.     

猪整合素β1基因CRS-PCR多态性与产仔数的关联性分析

文章采用CRS-RFLP技术对长白猪、大白猪和杜洛克猪3个品种的整合素β1基因第5外显子T32207C位点及第7外显子A35230G位点进行单核苷酸多态性分析,并将基因多态性与猪的产仔数进行关联分析。结果表明:32207多态位点的基因型效应对3个品种的总产仔数(TNB)和产活仔数(NBA)影响均不显著;35230多态位点的基因型效应对大白猪和长白猪头胎、二胎及所有胎次的TNB和NBA的影响达到显著(P<0.05)或者极显著水平(P<0.01),基因型GG、AG与AA对产仔数的影响存在差异,其效应为GG,AG>AA。可见整合素β1基因35230位点的G等位基因对大白猪和长白猪的产仔数性状有显著影响。     

Genotyping of Novel SNPs in BMPR1B,BMP15, and GDF9 Genes for Association with Prolificacy in Seven Indian Goat Breeds

Goats form the backbone of rural livelihood and financial security systems in India but their population is showing decreasing trend. Improvement of reproductive traits such as prolificacy offers a solution to stabilize the decreasing goat population and to meet the nutritional needs of growing human population. In the present study, six novel SNPs in three candidate genes for prolificacy (BMPR1B, BMP15, and GDF9) were genotyped in seven breeds of Indian goats to evaluate their association with litter size. Tetra primer ARMS-PCR and PCR-RFLP based protocols were developed for genotyping six novel SNPs, namely, T(-242)C in BMPR1B; G735A and C808G in BMP15; and C818T, A959C, and G1189A in GDF9 gene. The effect of breed was highly significant (p ≤ 0.01) on litter size but the effect of genotype was nonsignificant. The effect of parity on litter size was also significant in the prolific Black Bengal breed. The litter size differences observed between breeds are attributed to breed differences. Novel mutations observed at different loci in GDF9, BMP15, and BMPR1B genes do not contribute to the reproductive capability of the investigated breeds. Further studies with more number of breeds and animals exploring association of these novel SNPs with reproductive traits may be fruitful.     

Polymorphisms in BMP-2 gene and their associations with growth traits in goats

BMPs plays an important role in skeletal development. In this study, PCR-SSCP and DNA sequencing methods were employed to screen the genetic variation of caprine BMP-2 gene in 299 goats from three breeds (Boer goat, Chinese Xuhuai white goat and Chinese Haimen goat). Three fragments of BMP-2 gene were investigated, only 3′ flanking region of BMP-2 gene showed polymorphism. The alignment between nucleotide sequences of AY714781.1 in GenBank and the sequencing results of three PCR products with different patterns revealed that there was one mutation (AY714781.1: g.A172G) in 3′ flanking region of BMP-2 gene, which constructed three genotypes (AA, AB, BB). The frequencies of allele A and genotype AA were dominant in all three breeds. Frequency of allele B in Haimen goat breed was significantly lower than that of the other two breeds. The genotype distributions were in good agreement with Hardy-Weinberg equilibrium (P>0.05) in each breed. The PIC (Polymorphism Information Content) values in three populations were 0.3261, 0.2558, 0.1663 for Boer goat, Xuhuai White goat and Haimen goat respectively. It was indicated that individuals of Boer goats with genotype BB were significantly higher than those of individuals with genotype AA in body trunk index (P<0.01). No polymorphism was detected in the exon3.     

猪IGF2基因的遗传多态性及其遗传效应分析

采用PCR-SSCP方法检测胰岛素样生长因子2 (insulin-like growth factor 2, IGF2)基因外显子7, 8, 9的多态性, 并分析其对初生重、断奶重、6月龄重和6月龄背膘厚的遗传效应。根据猪IGF2基因的DNA序列(AY044828)设计3对引物, 结果在Ex8引物对扩增的片段上发现了多态性, 并对纯合子进行测序, 发现exon8的53位存在C→T转换, 且检测到3种基因型(AA、AB、BB)。统计结果表明, 3种基因型在各品种中的分布不一致, 长白猪与大白猪比较, 莱芜猪与大薄莲猪比较, 沂蒙黑猪和里岔黑猪比较差异不显著(P > 0.05); 其他猪种间基因型分布的差异均显著(P < 0.01)。固定效应模型分析结果表明, 初生重和6月龄背膘厚基因型间差异显著(P < 0.05), 而断奶重和6月龄重基因型间差异不显著(P > 0.05)。最小二乘分析结果表明, BB基因型个体同AA和AB基因型个体比较初生重的差异显著(P < 0.05), 3种基因型在初生重的大小排列顺序为AB > AA > BB; AA基因型个体同AB和BB基因型个体比较6月龄背膘厚的差异显著(P < 0.05), 3种基因型在6月龄背膘厚的大小排列顺序为BB > AB > AA。因此, 推测IGF2基因对个体的初生重和胴体瘦肉率存在一定的影响, 将IGF2基因应用于猪育种过程中的标记辅助选择可以加快猪的育种进程。     

Polymorphism identification in the goat KITLG gene and association analysis with litter size

This study reported the analysis of KIT ligand (KITLG) gene polymorphisms in 681 goats of three breeds: Xinong Saanen (SN), Guanzhong (GZ), and Boer (BG). In addition, the study identified three allelic variants: g.769T>C and g.817G>T in SN and GZ breeds, and g.9760G>C in the three goat breeds. The g.769T>C and g.817G>T loci were closely linked (r² > 0.33). All the single nucleotide polymorphism loci were in Hardy–Weinberg disequilibrium (P < 0.05). Significant associations were found for litter size with all three loci. Therefore, these results suggest that the KITLG gene is a strong candidate gene affecting litter size in goats.     

高山美利奴羊INHA基因多态性生物信息学分析及与产羔数关联分析

本研究旨在研究高山美利奴羊INHA基因外显子多态性及其与产羔数的相关性。本实验通过比对高山美利奴羊全基因组测序结果中不同个体INHA外显子,分析高山美利奴羊INHA基因的单核苷酸多态性,应用生物信息学软件分析高山美利奴羊INHA基因突变前后不同等位基因的m RNA二级结构、蛋白质的二级结构及三级结构。通过上述分析,将引起高山美利奴羊INHA编码氨基酸变化的位点作为该基因的特异性候选位点,通过直接测序法分析高山美利奴羊特异性候选位点INHA基因多态性,并分析其与产羔数的相关性。结果发现,高山美利奴羊INHA基因外显子区域存在3个SNPs,分别为T206A (Met→Lys)、T387A(Thr→Thr)、G900A (Pro→Pro);INHA基因3个SNPS都改变了RNA的最小自由能以及二级结构,错义突变T206A (Met→Lys)引起蛋白质二级结构和三级结构的改变;高山美利奴羊INHA基因T206A突变表现出3种基因型分别命名为TT、TA、AA,基因型与产羔数关联分析发现TT、TA基因型个体的产羔数极显著高于TT基因型个体(p<0.01)。本研究初步表明INHA基因是影响高山美利奴羊产羔数的一个主效基因。     

Polymorphism of FecB gene in nine sheep breeds or strains and its effects on litter size, lamb growth and development

Nine sheep breeds or strains, including 615 individuals were screened with forced PCR RFLP method for the FecB gene to study the polymorphism and its effects on litter sizes, body weights and body sizes. Results show that the polymorphism frequencies of FecB gene are significantly imbalanced in these breeds or strains. The Hu sheep were all homozygous carriers (BB). In the Chinese Merino prolific meat strain, the genotype frequencies of BB, B+ and ++ are 51%, 30% and 19%, respectively, whereas all the other flocks had only the wild-type (++) genotype. Results within Chinese Merino prolific meat strain showed that mean litter sizes of ewes with genotype BB and B+ are 2.8 (+/-0.74) and 2.3 (+/-0.63) (P > 0.05), whereas ++ ewes had a litter size of only 1.2 (+/-0.68) (P < 0.01). At 90 days after birth, the body weights of BB/B+ lambs were higher than that of ++ lambs (18.6 +/- 3.70 kg, 18.0 +/- 3.71 kg versus 15.6 +/- 2.22 kg, P < 0.05). In addition, the heart girth and chest width of BB/B+ lambs were significantly longer than ++ lambs (P < 0.05). No significant differences were observed in either body weight or body size at day 120. Litter size at first lambing from Hu at Natural Source Conservative Region was found to be significantly higher than that from the other two regions sampled (P < 0.05). In addition to the additive effect on litter size, these findings show for the first time that the FecB gene had a positive effect on early postnatal body growth.     

Polymorphism in exon 3 of follicle stimulating hormone beta (FSHB) subunit gene and its association with litter traits and superovulation in the goat

The polymorphism in follicle stimulating hormone beta (FSHB) subunit gene was detected by PCR-SSCP and PCR-RFLP methods in 780 does from four goat breeds including Boer, Matou, Black and Boer-Matou crossbred (BM). The associations of FSHB genotypes with litter size (LS), litter weight at birth (LWB) and gestation length (GL) as well as superovulation performances were analyzed in relatively lower-prolific Boer and higher-prolific Matou breeds. A 1514 bp linear DNA sequence of goat FSHB gene covering the complete 3 exons was cloned by four pairs of primer. A new mutation (A2645G, GenBank Accession no: S64745) locating in exon 3 causing an amino acid change from glutamine (Gln) to arginine (Arg) at residue 115 was identified, which resulted in three genotypes named AA, AB and BB. The three genotypes were detected in the four studied goat breeds. The higher-prolific Matou breed had the highest frequency of genotype AA. Association analysis showed that Boer and Matou does with AA genotype have the largest LS both in average and in parities from first to fourth (P < 0.05). Furthermore, Boer does with AA genotype had the heaviest LWB compared to other two genotypes (P < 0.05). Matou does with AA genotype have more numbers of ova harvested, large follicles and corpus lutea on ovaries after superovulation than those with BB genotype (P < 0.05). Therefore, these results suggest that the FSHB gene is a candidate gene that affects reproduction traits in goats.     

Novel polymorphisms of goat growth hormone and growth hormone receptor genes and their effects on growth traits

In this study, the polymorphisms of growth hormone (GH) gene 5' promoter region and intron 8, exons 4 and 10 of growth hormone receptor (GHR) gene were analyzed in Xinong Saanen goats (SG) and Boer goats (BG). Two alleles (A and B) and three genotypes (AA, AB and BB) were detected at P1 locus of GH gene, and two alleles (G and T) and two genotypes (GG and GT) were detected at P4 locus of GHR gene by PCR-SSCP analysis. In addition, two single nucleotide polymorphisms (SNPs)-A73C (P1 locus) and G114T (P4 locus), were identified by DNA sequencing. The frequencies of alleles A and B in the two goat breeds were 0.61-0.62, and 0.39-0.38, respectively, and the frequencies of alleles G and T in the two goat breeds were 0.82-0.86, and 0.18-0.14, respectively. The SNP loci were in Hardy-Weinberg disequilibrium in both goat breeds (P<0.05). Polymorphisms of GH and GHR genes were shown to be associated with growth traits in BG breed. AA and GG genotypes were associated with superior growth traits in 1-, 2- and 3-month old individuals. Hence, AA and GG genotypes are suggested to be a molecular marker for superior growth traits in BG breed.     

Two mutations in the 5′‐flanking region of the KITLG gene are associated with litter size of dairy goats

In this study, Xinong Saanen (SN) and Guanzhong (GZ) dairy goat breeds were used to detect single nucleotide polymorphisms (SNPs) in the 5′‐flanking region of the KITLG gene by DNA sequencing and primer‐introduced restriction analysis–polymerase chain reaction. Two novel SNPs (g.13090G>T and g.13664C>A) were identified (GenBank Accession no. KM658964). Furthermore, g.13090G>T and g.13664C>A loci were closely linked in SN and GZ breeds (r² > 0.33). Association analysis results showed that g.13090G>T and g.13664C>A SNPs significantly affected litter size (P < 0.05). The litter size of individuals with the combined genotype GG/CC from both dairy goat breeds was greater than that of individuals with TT/AA in average parity (P < 0.05). Known biochemical and physiological functions, along with our results, indicated that GG/CC could be used in marker‐assisted selection to choose individuals with greater litter size from both breeds. These results extend the spectrum of genetic variation in the caprine KITLG gene and may contribute to genetic resources and breeding of goats.     

Molecular Cloning of Porcine SUN5 Gene and Association between a SNP with Litter Size Trait

SUN domain-containing protein 5 (SUN5) is an important reproduction related gene. In this study, we cloned the full-length coding sequence of porcine SUN5 gene through RT-PCR. Sequence analysis of this gene revealed that the pig SUN5 gene encodes a protein of 383?amino acids that has high homology with the SUN5 protein of eight species: wild Bactrian camel (95%), alpaca (95%), Yangtze River dolphin (94%), sperm whale (94%), sheep (93%), black flying fox (93%), goat (92%), and horse (91%). This gene is structured into 13 exons and 12 introns as revealed by computer-assisted analysis. The prediction of transmembrane helices showed that pig SUN5 protein might be a transmembrane protein. PCR-Taq I-RFLP was established to detect the GU475008:c.138 G>A substitution of porcine SUN5 gene coding sequence and eight pig breeds displayed obvious genotype and allele frequency differences at this mutation locus. Association of this SNP with litter size traits was assessed in Large White (n?=?200) and Landrace (n?=?200) pig populations, and the results demonstrated that this polymorphic locus was significantly associated with the litter size of all parities in Large White and Landrace sows (P?相似文献   

鸭脂联素基因单核苷酸多态性检测及群体遗传分析

以昆山麻鸭、樱桃谷鸭、高邮鸭、荆江麻鸭、金定鸭, 山麻鸭、龙白鸭和白羽番鸭8个鸭品种为实验材料, 根据鸭脂联素基因开放阅读框序列设计5对引物, 用PCR-SSCP方法进行单核苷酸多态性分析,并对不同品种群体进行群体遗传学分析。结果发现引物4扩增片段上共存有7个单碱基突变, 第430、457、523处的G-A 、A-G、T-C单碱基突变导致第144、153、175个氨基酸分别由丙氨酸（A）变为苏氨酸（T）、异亮氨酸（I）变为缬氨酸(V)、酪氨酸(Y)变为组氨酸(H); 而C507T, T540C, C576T和C597T 4个单碱基突变为沉默突变。鸭群中表现出AA、AB、AC、BB、BC、CC、DD、DE 8种基因型。8种基因型在8个鸭品种间分布存在极显著的差异(P<0.01)。除金定鸭外, 其他品种均处于Hardy-Weinberg平衡状态。群体遗传分析表明金定鸭的纯合度最高, 高邮鸭最低, 其他各群体的纯合度较相近; 金定鸭为低度多态, 高邮鸭为高度多态, 其他品种为中度多态。表明鸭脂联素基因不同品种中具有丰富的单核苷酸多态性, 可以进一步作为候选基因来分析其与脂肪性状的相关性。     

Analysis on DNA sequence of KiSS-1 gene and its association with litter size in goats

Three pairs of primers were designed to clone the goat KiSS-1 and scan polymorphisms and four pairs to detect polymorphisms in sexual precocious and sexual late-maturing goat breeds. A 4118 bp DNA fragment was obtained, which contains an ORF of 408 bp and encodes 135 amino acids, having a high homology with other mammals. The protein was predicted containing a signal peptide of 17 amino acids. There are two mutations (G3433A [A86T] and C3688A) in exon 3, three mutations (G296C, G454T and T505A) in intron 1 and a 18 bp deletion (?)/insertion (+) (1960–1977) in intron 2 and no mutations in exon 2. The genotype distribution didn’t show obvious difference between sexual precocious and sexual late-maturing goat breeds and no consistency within the sexual late-maturing breeds. For the 296 locus, the Jining Grey goats with genotype CC had 0.80 (P < 0.01) or 0.77 (P < 0.01) kids more than those with genotype GG or GC, respectively. No significant difference (P > 0.05) was found in litter size between GG and GC. For the 1960–1977 locus, the Jining Grey goat does with genotype ?/? had 0.77 (P < 0.01) or 0.73 (P < 0.01) kids more than those with +/+ or +/?, respectively. No significant difference (P > 0.05) was found in litter size between +/+ and +/? genotypes. For the other four loci, no significant difference (P > 0.05) was found in litter size between different genotypes in Jining Grey goats. The present study preliminarily indicated an association between allele C of the 296 locus and allele (?) of the 1960–1977 locus in KiSS-1 and high litter size in Jining Grey goats.     

猪MyoG基因内含子1的一个遗传多态性及其遗传效应分析

以长白猪(73),大白猪(68),沂蒙黑猪(57)和莱芜猪(83)为研究对象,采用PCR-SSCP方法 对猪MyoG基因遗传多态性进行分析,并研究基因型与初生重、日增重、肌肉嫩度和背膘厚的相关性.根据猪MyoG 基因的DNA序列（M14331）设计引物,结果在内含子1扩增的片段上发现了一个多态性,检测到2个等位基因(A、B),3种基因型（AA、AB、BB）,并对纯合子进行测序,发现2　943位G→C突变.基因型在不同猪种分布的多重比较,结果表明,大白猪与长白猪、沂蒙黑猪和莱芜猪比较差异显著（P<0.05）,莱芜猪与长白猪和沂蒙黑猪比较差异显著（P<0.05）,长白猪与沂蒙黑猪比较差异不显著（P>0.05）.固定效应模型分析结果表明,初生重及嫩度基因型间差异显著（P<0.01）,而日增重及背膘厚基因型间差异不显著（P>0.05）.最小二乘分析结果表明,BB基因型个体与AA基因型个体比较肌肉嫩度的差异显著（P<0.05）,AA基因型个体与AB和BB基因型个体比较背膘厚的差异显著（P<0.05）.因此,推测MyoG基因对猪肉品质、生长速度及背膘厚存在一定的影响,将 MyoG基因应用于猪育种过程中的标记辅助选择将可以改善猪肉品质,提高生长速度,加快猪的育种进程.