MC4R、POU1F1基因对京海黄鸡生长性能的遗传效应

以MC4R和POU1F1基因为候选基因, 采用PCR-SSCP和DNA测序技术检测两个候选基因在京海黄鸡群体中的单核苷酸多态性(SNPs), 同时对候选基因与京海黄鸡生长性能的相关性进行了研究。结果表明, MC4R基因编码区第662 bp位置有G→C碱基的点突变, 在京海黄鸡中检测到AA、AB、BB 3种基因型, A等位基因频率为0.929, B等位基因频率为0.071; 在POU1F1基因exon3在序列的第5 231 bp位置有一个A→T碱基的点突变, 检测到CC、CD、DD 3种基因型, C等位基因频率为0.500, D等位基因频率为0.500。采用GLM模型分析基因型对生长性能的遗传效应, 结果表明, MC4R基因AA基因型个体的4、8、12周龄体重显著地高于BB型个体(P<0.05), 16周龄体重差异极显著(P<0.01); POU1F1基因CD基因型个体体重极显著高于CC型和DD型(P<0.01)。因此推测MC4R和POU1F1基因可能是影响鸡生长性状的主效基因或与主效基因紧密连锁的标记基因, 能够在分子标记辅助选择中用于对鸡生长性状的遗传改良。     

Absent or delayed adrenarche in Pit-1/POU1F1 deficiency

Mutations of the PIT1/POU1F1 gene are responsible for a rare variant of anterior hypopituitarism, including deficiency of growth hormone, prolactin and thyrotropin. In 8 ethnically diverse POU1F1-deficient patients (4 different mutations) with normal circulating levels of cortisol and adrenocorticotropic hormone, and with spontaneous onset and progression of puberty, we observed an absence or delay of adrenarche (median circulating dehydroepiandrosterone-sulfate -6.2 SD); in each of the 4 postmenarcheal females, pubarche (i.e. appearance of pubic hair) was also absent or delayed. The absence/delay of adrenarche in POU1F1-deficient patients and the absence/delay of pubarche in POU1F1-deficient females suggest that a POU1F1-dependent factor contributes to the normal development of adrenarche and female pubarche.     

Analysis of associations of PIT1 genotypes with growth,meat quality and carcass composition traits in pigs

PIT1 was chosen as a candidate gene to investigate its associations with growth, meat quality and carcass composition traits in the pig. PIT1 is known as the pituitary-specific activator of the growth hormone in several mammals. Furthermore, PIT1 is a positive regulatory factor of prolactin and thyroid-stimulating hormone beta. PIT1 is a member of the POU-domain family of genes and is located on porcine chromosome 13. Two informative three-generation families of the University of Hohenheim were used for the presented investigations. The families were based on crosses of the European Wild boar (W) x Pietrain (P) and Meishan (M) x Pietrain (P). Each family included 310 F(2) animals. A RsaI (PCR) RFLP described by Yu et al. (1994) was used for genotyping the animals. Altogether over 50 parameters of growth, meat quality, carcass composition and stress susceptibility were evaluated concerning their associations with RsaI PCR-RFLP. The statistical model of association analyses was used including fixed effects of sex, family, PIT1 genotypes and covariate age at slaughter. Taking the significance level of p < 0.05 as the basis, fourteen traits of growth and carcass composition were associated with PIT1 genotypes in family W x P. Results from this study suggest that there are contributions of PIT1 gene to variations in the analysed performance traits in pigs. The influence of PIT1 genotypes could not be confirmed under the supposition of a genome-wide test limit.     

Effects of single and combined genotypes of MC4R and POU1F1 genes on two production traits in Langshan chicken

The objective of this study was to analyze the effects of single and combined genotypes of MC4R and POU1F1 genes in Chinese well-known indigenous chicken (Langshan chicken) population. Genetic variants within MC4R gene and POU1F1 gene were screened through PCR-SSCP and DNA sequencing methods. A C/T mutation at nt 944 in MC4R gene (NC_006089.2:g. 944C>T) and a G/A mutation at nt 3109 in POU1F1 gene (NC_006088.2:g. 3109 G>A) were identified. Associations between the mutations of the two genes with two production traits were analyzed. The results showed that, at MC4R locus, individuals with BB and AB genotypes had highly significantly higher body weight at 16 weeks (p < 0.01) than did those with the AA genotype. And, individuals within AA and AB genotypes had significantly higher egg numbers at 300 days (p < 0.05). At POU1F1 locus, individuals with CD genotype had higher body weight at 16 weeks and egg numbers at 300 days (p < 0.05). Furthermore, combined genotypes from these two loci were found to be associated with egg numbers at 300 days (p < 0.05). The individuals within combined genotype AB/CD had higher egg production. Therefore, variations identified within the MC4R and POU1F1genes are suitable for future use in identifying chickens with the genetic potential of higher body weight and reproductive traits, at least in the population of Langshan chickens.     

Polymorphisms and expression of the chicken POU1F1 gene associated with carcass traits

POU1F1 is an essential factor that regulates the development and reproduction of animal. The objective of the current research was to screen for polymorphism, expression of POU1F1 and their association with carcass quality traits. A total of 126 Erlang mountainous chickens from two strains (SD02 and SD03) were employed for testing. Seventeen single nucleotide polymorphisms (SNPs) were detected, but only two SNPs (g.96217999 T > C and g.96219442 C > T) were associated with carcass quality traits. In SD03 chicken, g.96217999 T > C genotypes were significantly associated with body weight (BW), carcass weight (CW), eviscerated weight (EW), and semi-eviscerated weight (SEW; P < 0.05), and was highly significantly associated with breast muscle weight (BMW) and abdominal fat weight (AW; P < 0.01). g.96219442 C > T was significantly associated with BW, EW, SEW (P < 0.05). However, these two SNPs were not significantly associated with any carcass traits in SD02 chicken. Diplotypes showed that in SD03 chicken, the haplotype [C: C] was the most favorable haplotype because it was associated with higher BW, CW, SEW, EW, BMW, and AW (P < 0.05). On the contrary, haplotype [T: T] was associated with lower carcass quality traits (P < 0.01). In addition, qRT-PCR revealed that at 13 weeks, the POU1F1 mRNA expression was significantly higher in breast muscle of cock compared to that of hens (P < 0.05), whereas there was no significant correlation between POU1F1 expression and carcass traits. These results suggested that POU1F1 could be a potential candidate gene for carcass traits in chicken.     

POU1F1基因的遗传变异对南阳牛生长发育性状的影响

利用PCR-RFLP技术首次研究了南阳牛群体100个个体POU1F1基因多态性及其与体重、体尺等生长性状指标之间的相关性。结果表明,南阳牛群体POU1F1基因座的451bp的PCR产物被限制性酶Hinf Ⅰ消化后表现多态性,它们的等位基因A／B频率为：0．465／0．535,且处于Hardy-Weinberg平衡状态。同时,南阳牛群体POU1F1-Hinf Ⅰ基因座不同基因型与体重、体尺等生长性状指标相关分析的结果表明：南阳牛群体内BB与AB基因型个体在初生重、断奶前平均日增重、六月龄体重、体斜长和胸围以及十二月龄的体重、体高、体斜长和胸围指标上有显著差异,且BB〉AB（P〈0．05）;群体内BB型个体在十二月龄体重指标上显著高于群体的AA型个体,即BB〉AA（P〈0.05）,在其他各年龄段的各项体重和体尺指标上同样呈现出B等位基因高于A等位基因的一种趋势。初步认为BB基因型为优势基因型,相应地B为优势等位基因,对选择有正向效应,提示POU1F1基因的占等位基因可能与高生长发育性状有关。