| The growth and development parameters about early bodyweight of three local goose breeds of large, medium and small type including Shitou goose, Wanxi White goose and Zi goose were analyzed, and the exons and introns of growth hormone(GH) gene and the 5'-regulatory region and exons of prolactin (PRL) gene were cloned and sequenced. Based on the sequence obtained, the single nucleotide polymorphism (SNP) of all these sequence was investigated in Zi goose, Wanxi White goose, Shitou goose, Siji goose and Zhedong White goose with PCR-SSCP method. After Calculated the frequency of genotypes and genes and compared the distribution of genotype frequencies among different goose breeds, the polymorphism of GH and PRL Gene and its relationship with body weight and carcass traits were analyzed. The results were as followed.1. Growth and development regularity and genetic parameters of average week bodyweight of local goose breeds of large, medium and small type from 1 week-old to 11 week-old were fitted with four non-lineared growth models, namely, Logistic model, Gompertz model, Bertalanfy model and Cubics model. The results showed that growth process of three geese could be demonstrated very well by four models, and all indexes of fitness were very high (more than 0.99). But Gompertz model was the best model because of its less bias of feed practice. The inflection age of growth were 5.98 weeks, 5.11 weeks and 6.16 weeks in Shitou goose, Wanxi White goose and Zi goose, respectively, and bodyweight at inflection age were 2115.77g, 1499.08g and 1409.62g, respectively.2. The exons and introns of GH gene were cloned and sequenced, and obtained the coding sequence(cds) of goose, whose length was 651bp. Homologous comparison showed that the identity of cds of GH gene was 91.4% between goose and chicken, the identity of cds of GH gene was 98.5% between goose and duck, and that was 97.6% and 99.9% in amino acid sequences, respectively. Further analysis showed that the identities of cds of goose GH gene with human and mouse were 63.81% and 74.31% and that was 52.51% and 72.81% in amino acid level, respectively. Meanwile, the sequence of four introns were obtained and their length were 1504bp, 664 bp, 362bp and 1144bp, respectively.3. Four SNPs were found in the coding region of GH gene, which are C39T and C74T mutation whith exon 2, and T291C and G297C mutation within exon 4. However, except from the C74T mutation in exon 2, where coding amino acid was changed from alanine to valine, other mutations were slient mutation. The result of polymorphism analysis on exon 2 showed that all kinds of ten genotypes appeared in the populations of Zi goose and Wanxi White goose, seven kinds of genotypes appeared in the populations of Shitou goose and siji goose and eight kinds of genotypes appeared in the population of Zhedong White goose. The allele A was dominant allele in the populations of Zi goose, Siji goose and Wanxi White goose, while allele D was dominant allele in the populations of Shitou goose and Zhedong White goose. The result of polymorphism analysis on exon4 showed that all five populations appeared three kinds of genotypes. The allele A was dominant allele in all populations except for Zi goose. Within all populations the frequencies of alleles in exons fited with Hardy-Weinbery equilibrium (P>0.05). 4. Seven pairs of primers of introns existed polymorphisms. Sequencing results revealed 13 SNPs, which were as follows: A1066G and C1157T amplied by P6 primers, and C548T and T551C amplied by P10 primers from intron 1; five point mutations and deletions caused polymorphism in intron 3 amplied by P13 primers, they were A160G, C167G, T264C and two bases insertion/deletion mutations after position 176 and 231 bp; T130C amplied by P15 primers, G821A and C949T amplied by P18 primers, and T1137C amplied by P15 primers from intron 4.Only fragment amplied by P6 primers of intron 1 existed polymorphism, and the result of polymorphism analysis showed that all kinds of four genotypes appeared in the populations of Zi goose and Wanxi White goose, while three kinds of genotypes appeared in the populations of Shitou goose, siji goose and Zhedong White goose, and the allele A was the dominant allele in all the goose populations. P10 and P11 primers of intron 2 existed polymorphisms and had complete corresponding genotypes, and all the goose populations had all the three genotypes, in which the allele A was the dominant allele except in Zi goose. P13 primers of intron 3 also existed polymorphism, all the three genotypes appeared in the populations of Shitou goose, Zi goose and Wanxi White goose, while two kinds of genotypes appeared in the populations of Siji goose and Zhedong White goose, and the allele B was the dominant allele in all the goose populations. Polymorphisms were detected from fragments amplied by P15, P18 and P19 primers of intron 4. Except Siji goose, the other four populations had all the three genotypes, and the allele A was the dominant allele in all populations; The result of polymorphism analysis on P18 showed that all kinds of five genotypes appeared in the populations of Wanxi White goose, Zhedong White goose and siji goose, four kinds of genotypes appeared in the populations of Shitou goose, and three kinds of genotypes appeared in the population of Zi goose. In the all five populations, the allele E was the dominant allele in Shitou goose, the frequency of E allele in Zhedong White goose also showed relative high, while there was no E allele existing in Zi goose. Wanxi White goose, Zhedong White goose, Zi goose and siji goose had all the four genotypes and Shitou goose only had two genotypes in P19, M was the dominant allele in Zi goose and siji goose, while N was the dominant allele in Wanxi White goose, Zhedong White goose and Shitou goose. In P19 polymorphic loci, only Zi goose and siji goose were in Hardy-Weinberg equilibrium (P>0.05); But in the other polymorphic loci in introns, all the goose populations were in Hardy-Weinberg equilibrium (P>0.05).5. Association analysis on polymorphism of GH gene and body weight and carcass traits showed that the polymorphic loci of exon 2,intron 3 and intron 4 of GH gene had significant genotype effect on body weight (the age of 1-10 weeks) and carcass traits. For body weight and carcass traits of goose, the CD and DD genotypes in exon 2 were favorable genotypes, while the allele A which is dominant allele in populations of Shitou goose and Zhedong White goose maybe was the favorable gene.BB genotype was the most favorable genotype for body weight and carcass traits of goose among all genotypes of intron 3, NN genotype was also favorable genotype for growth of goose and allele N maybe was the favorable gene for body weight and carcass traits of goose.6. The the 5'-regulatory region and exons of PRL gene were amplified by some premiers, cloned and sequenced, and then obtained the coding sequence of goose were obtained, the length of which was 690bp. Homologous comparision show that the identity of cds of PRL gene was 92.8% between goose and chicken, the identity of cds of PRL gene was 98.7% between goose and duck, and that was 93.3% and 98.3% in amino acid sequences, respectively. Meanwile, the sequence of 5'-regulatory region was obtained and its length was 836bp.7. Six SNPs were found in the PRL gene, which are C135G, C201T, C278Abp and T827G mutation whith the 5'-regulatory region, and GA InDel in the site of 32bp and 33bp within intron 2, while no polymorphism was detected in the exons of PRL. The result of polymorphism analysis on 5'-regulatory region showed that all kinds of three genotypes appeared in the populations of Zi goose and Wanxi White goose and Shitou goose, two kinds of genotypes appeared in the populations of siji goose and Zhedong White goose, allele A was dominant allele in all five populations. The result of polymorphism analysis on intron 2 showed that all kinds of three genotypes appeared in all populations except for Zhedong White goose and allele B was dominant allele in all five populations. Within all populations the frequencies of 5'-regulatory region and intron 2 fited with Hardy-Weinbery equilibrium (P>0.05).8. Association analysis on polymorphism of PRL gene and body weight and carcass traits showed that the only polymorphic loci of 5'-regulatory region of PRL gene had significant genotype effect on body weight and carcass traits. 6-10 week bodyweight of individuals with AA and AB genotype were significant higher(P<0.05) than the of individuals with BB genotype, but were insignificant difference(P>0.05) in 6-10 week bodyweight between geese with AA and BB genotype. The carcass traits such as live weight, eviscerated weight and semi-eviscerated weight of individuals with AA and AB genotype were also significant higher (P<0.05) than the of individuals with BB genotype, and insignificant difference (P>0.05)in carcass traits between geese with AA and AB genotype. The results indicated that AA and AB was favorable genotype for body weight and carcass traits of goose. |
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