Biomedical subjects

Xiao-Xiang Hu

Publications and source records attributed to Xiao-Xiang Hu.

7 recordsLinked to original sources

PubMed2004

[Identification and analysis of a novel microsatellite marker flanking porcine myostatin gene (MSTN)].

In animal breeding, microsatellite marker plays an important role in constructing genetic maps, QTL mapping and function analysis of structural genes. Myostatin, also known as GDF8, is a negative regulator of skeletal muscle mass and, in swine, it is evidenced to be related to birth weight and average daily gain from 60 kg to 100 kg of body weight. In present study, by subcloning and sequencing,we identified a novel microsatellite marker which is useful for fine QTL mapping for meat traits. A BAC clone containing porcine MSTN was extracted and digested with EcoR I to recover the fragment of > 4 kb for subcloning in pGEM-3zf (+). Sequencing and alignment results showed that this subcloned fragment was not from porcine MSTN, but included a tandem repeat of (TG) 13, which is a novel microsatellite marker (GenBank accession number: AF454400) flanking MSTN. To exclude its vector origin we designed specific primers flanking this marker and successfully amplified this fragment from porcine genome. Through a pedigree analysis of a double-muscled Yorshire strain, we found that it is inherited in a co-dominant manner. We also checked the gene frequencies of this locus in 381 unrelated individuals of 7 pig breeds, namely Laiwu,Landrace, Yorkshire,Duroc, Peterian, Min and Erhualian. Only two alleles were detected, the repeating number of which are 13 (allele A) and 19 (allele B) respectively, which indicated that it is a low poly morphic microsatellite marker. In addition, the frequencies of the two alleles are different between the two types of pig breeds, while allele A is dominant in Chinese local breeds, allele B is dominant in imported breeds. Alignment with AY208121 indicate that this locus is located 42 kb downstream of porcine MSTN. We speculate that this microsatellite DNA is an important marker both in fine QTL mapping for meat traits and in the expression study of porcine MSTN.

Animals↗

PubMed2004

[A new method for phylogenic analysis].

With ESTs from porcine fatty tissue and cDNA sequences from human, bovine and mouse in non-reduncdant database and dbEST in GenBank,we sampled cDNA sequences of 70 function-known genes in four species on the base of randomly sampling method, analyzed the mutation pattern of 70 x 150 bp linking sequences between them, and established an integrated phylogenic analysis method. The results showed that 391 single bases mutations were found in 70 x 150 bp linking sequences alignment among four species. The number of mutation bases between them were greatly exceeded the 1/1000 predicted in the human genome analysis. C/T(T/C) and A/G (G/A) transitions were the major types of single base mutation. The genetic relationship between pig and bovine who are both Artiodactylous is the nearest, the next is human, and the farthest is mouse. The differentiation sequence taken place in four species from the same ancestor is that mouse is the earliest one, and the latter human, and pig and bovine are the latest.

Animals↗

PubMed2004

[Genetic diversity in Tibetan chicken].

Morphological traits and living habit of Tibetan chicken, which is an aboriginal chicken breed on plateau with its own characteristic populational genetic features, are in great common with the Red Jungle Fowl, the assumed ancestry of domestic chicken. To fully exploit this chicken resource, Multiplex PCR with semi-automated polyacrilamide gel electrophoresis (PAGE) using fluorescently labeled microsatellite primers was used to detect the polymorphism at 20 microsatellite loci. At the same time, we randomly test the individual morphology and performance. It showed that numbers of polymorphic alleles were 4 approximately 10, with mean value 7.25 per locus. Polymorphism Information Content (C(PI)) and Heterozygosity (H) had mean values 0.67 and 0.74, respectively. Macrochromosomes had relatively higher polymorphism than microchromosomes(P > 0.05). In all, high polymorphisms at microsatellite loci related to the uneven production performance and morphological discrepancy of population genetic characteristics in Tibetan chicken.

Alleles↗

PubMed2003

[Preliminary analysis on China Agricultural University chicken resource population based on genomic scanning].

Combining the technique of multiplex-PCR and the fluorescent semi-automated detection, a large-scale genome scanning was performed for 440 chickens, which was derived from China Agricultural University chicken resource families, within three generations. Fifty-five microsatellite markers were analyzed for this study. Those 55 microsatellite loci accorded with the characters of Mendelian co-inheritance. The heterozygosities ranged from zero to 0.89, with 72% of loci having a heterozygosity of more than 0.60. The polymorphism information content (PIC) ranged from 0 to 0.85, in which 70% of those loci had a PIC of more than 0.50 but their distribution varied in line A and line C. The allele frequency was significantly different between line A and line C at most loci (P < 0.01). At the same time, gene accordance inclination was found in line C. The Nei population resemble coefficient and standard genetic distance were 0.1002 and 0.8928.

Animals↗

PubMed2003

[The factors affecting the efficiency of mutiplex PCR].

In the research,the outputs of different cycle parameters, PCR buffer and reaction volumes are compared. The results indicated that the annealing temperature, annealing time, elongated time and ingredient of PCR buffer affected mutiplex PCR, but the reaction volume and cycle number had few effect on it.

English Abstract↗

PubMed2002

[Single nucleotide polymorphism analysis in chicken insulin-like growth factor-II gene and its associations with growth and carcass traits].

In this experiment, F2 chicken derived from Broilers crossing with Silky was used to study the effect of insulin-like growth factor-II gene on growth and carcass traits. The partial gene was amplified by two pairs of primers, and single nucleotide polymorphism (SNPs) was detected by the technique of restriction fragment length polymorphism (RFLP), and then confirmed by DNA sequencing. The mutation was found in the exon-2 of the gene, and can be clarified by cutting of restriction enzyme Aci-I. The result of least square analysis showed the gene was significantly related with growth and carcass traits. It implied that the insulin-like growth factor-II gene could be a genetic locus or linked to a major gene affecting greatly the growth and carcass traits in chicken.

Animals↗

PubMed2002

[Polymorphism analysis of the exon 2 of SLA-DQB gene in Xiao Meishan, Zhong Meishan and Yorkshire pigs with PCR-RFLP].

SLA is an important genetic region which influences disease resistance in pigs, and the gene family is one of important candidates for disease resistance and susceptibility. In present research the exon 2 of SLA-DQB gene was amplified and a uniform fragment of 273 bp was obtained in Xiao Meishan, Zhong Meishan and Yorkshire Pigs. The 273 bp PCR product was digested with restriction endonuclease Rsa I and genetic Polymorphism was investigated with PCR-RFLP (restriction fragment length polymorphism). Polymorphic sites were detected at base position 11, 94 and 124 of the exon 2 of SLA-DQB gene. There were two kinds of genotypes in Xiao Meishan pigs, 246 bp/27 bp(AA) and 132 bp/84 bp/30 bp/27 bp(BB), the frequencies of genotype AA and BB are 0.571, and 0.439 respectively. Four kinds of genotypes were found in Zhong Meishan pigs, 246 bp/27 bp (AA), 132 bp/84 bp/30 bp/27 bp(BB), 132 bp/114 bp/27 bp(CC) and 246 bp/132 bp/84 bp/30 bp/27 bp(AB), their frequencies are 0.037, 0.593, 0.037 and 0.333 respectively. Five kinds of genotypes were found in Yorkshire pigs, 246 bp/27 bp(AA), 246 bp/132 bp/114 bp/27 bp(AC), 132 bp/114 bp/27 bp(CC), 246 bp/132 bp/84 bp/30 bp/27 bp(AB) and 273 bp/246 bp/27 bp(AD), the frequencies of five genotypes are 0.467, 0.300, 0.100, 0.100 and 0.033 respectively. Statistical results indicated that there is no favorable allele in Xiao Meishan pig breed; B is the favorable allele in Zhong Meishan and its gene frequency is 0.759; while in Yorkshire pigs A is the favorable allele and its gene frequency is 0.683. Four alleles (A, B, C and D) were found in SLA-DQB locus among three pig breeds; The results of chi 2 showed that four alleles of this locus fit with Hardy-Weinberg equilibrium. The research showed that conservation of Chinese local pig breeds is necessary in order to protect our rich genetic resources and make use of them in the future.

Alleles↗