[show abstract][hide abstract] ABSTRACT: The balancers of Drosophila melanogaster are widely used in genetic research. By analyzing the phenotype of offspring from hybridization of chapped wing (L) mating with OR, 982p and e, respectively, we mapped the chapped wing mutation on chromosome 3 for the first time and demonstrated the chapped wing mutation as a new balancer of D. melanogaster with dominant wing nicking phenotype. Finally, we bred a novel gathering line with double balancers of L and Cy in D. melanogaster. The mutant L provided a legible dominant marker for the balancer of chromosome 3, and the cultivation of double balancers chapped-curly wing enriches the balancer stock, which is often used in mapping and screening.
[show abstract][hide abstract] ABSTRACT: The inducible nitric-oxide synthase (iNOS) can be induced by hypoxia to produce NO, which regulates blood flow and improves oxygen delivery to tissues. In present study, SNPs in coding and 5'-flanking regions of iNOS gene were examined in Tibetan chicken and lowland chicken using sequence and PCR-RFLP methods, and the quantitive express of mRNA of iNOS and the enzyme activity were measured in chorioallantoic membrane of chick embryo that was incubated under hypoxic and normal conditions. The results showed that a special SNP (-870C-->T)was found in 5'-flanking region of iNOS gene. Tibetan chicken has higher frequencies in mutation allele T than lowland chicken. In hypoxic incubation, the mRNA expression of iNOS and enzyme activity were higher in Tibetan chicken than that in Dwarf chicken. It was concluded that the mutation of iNOS and hypoxic increase of its expression were important base for adaptability to hypoxia in Tibetan chicken.
[show abstract][hide abstract] ABSTRACT: The purpose of this experiment was to investigate the cardiac physiological characteristics for adaptation to high-altitude hypoxia in chickens.
Tibetan, Dwarf Recessive White and Shouguang chickens were fed at low-and high-altitude, and measurements were made in heart weights, lactic acid (LA), lactate dehydrogenase (LDH), and succinate dehydrogenase (SDH) at the age of 10 weeks.
The results showed that Tibetan chickens at high-altitude had lower heart weight and LA content, and similar LDH activity, and higher SDH activity when compared to Dwarf Recessive White and Shouguang chickens.
It was concluded that the cardiac mechanisms of high-altitude hypoxic adaptation in Tibetan chickens were increasing neither heart weight, nor level of anaerobic metabolism, but the higher SDH activity was significant to the adaptation. The SDH was a symbol enzyme for hypoxic adaptation in Tibetan chicken.
Zhongguo ying yong sheng li xue za zhi = Zhongguo yingyong shenglixue zazhi = Chinese journal of applied physiology 05/2008; 24(2):233-6.
[show abstract][hide abstract] ABSTRACT: Tibet pig is a special Chinese indigenous pig breed, which could survive in high-altitude areas of Tibet. In the present study, the genotypes of ESR, FSHbeta, and PRLR gene, the three known major genes of reproductive traits, were identified in 202 Tibet pig individuals. The results showed that the predominant genotypes of ESR, FSHbeta, and PRLR gene were BB, AB and AA, respectively. The genotype frequencies of the three genes were in Hardy-Weinberg equilibrium. The frequencies of desired alleles of the three genes were higher than those of other alleles, which indicated that Tibet pig had a good potential for improving reproductive traits.
[show abstract][hide abstract] ABSTRACT: Hypoxia inducible factor-1 (HIF-1) is a transcriptional factor first discovered in cancer cells under hypoxic conditions, and was demonstrated to play a key role in the organism's adaptation to changing oxygen tensions. The Tibetan chicken, a breed indigenous to the Tibetan plateau is particularly adaptable to the low oxygen tension and low temperature conditions in the high altitude environment. By comparison, the White Leghorn and ShouGuang chicken are low-altitude chicken breeds. The eggs of these three chicken breeds were incubated in a fitted hatcher that simulated hypoxic condition. The results demonstrated that the hatching rate for Tibetan chicken was significantly higher than the two low altitude breeds, and Tibetan chicken displayed higher endurance in the hypoxia environment. To a certain degree, the hypoxic condition proved fatal to hatching for the low-altitude chickens. Gene expression of HIF-1alpha was detected in brain and skeletal muscle tissues for three chicken varieties using the TaqMan probe FQRT-PCR method. The results showed that HIF-1alpha mRNA displayed tissue specific differential expression, with the highest in the brain. In addition, the expression of HIF-1alpha mRNA in the brain of Tibetan chicken embryos was similar to that of the low-altitude chickens when they were hatched under normal oxygen tensions.
[show abstract][hide abstract] ABSTRACT: A Longissimus Dorsi muscle cDNA library of Xiang Pig was constructed, and 131 randomly isolated clones were sequenced in this study. The results of bioinformatics analysis showed that 131 ESTs represented 109 unique clones sequences, of which 99 showed homology to previously identified genes in humans or other mammals, 3 matched other uncharacterized expressed sequence tags (ESTs), and 7 showed no significant matches to sequences already present in DNA databases. No protein matches were found for 10 ESTs. Functional analysis of the ESTs showed that a considerable proportion of them encoded proteins involved in gene/protein expression (45.46%). Other classes included genes involved in metabolism (10.10%), cell structure/motility (10.10%), cell/organism defense (5.05%), cell signaling/communication (2.02%), and cell division (0.0%). Unclassified genes constituted the remaining 27.27%. This study reported the results of the first gene expression profile analysis of Chinese native Xiang Pig skeletal muscle cells, thereby greatly facilitating the functional study of candidate genes involved in muscle growth as well as in the improvement of meat quality in domestic pigs.
[show abstract][hide abstract] ABSTRACT: Curly is a easily distinguishable dominant mutant wing character. The Cy mutation is the most commonly used dominant marker for the second chromosome balancers in Drosophila melanogaster, but little is known about the Cy gene. Based on known genomic and cytogenetic information, a 102 bp deletion which is located between the Genes synaptotagmin (syt) and Activin Like Protein at 23B(Alp23B) on the Drosophila melanogaster genome (release 4) had been found to be commonly contained on Cy chromosome in three different curly strains. Meanwhile, when using the deletion as a DNA marker, the result suggested that Cy homozygote be lethal in embryo period. These results will provide some helpful information to investigate molecular mechanism of curly wings in the further study.
[show abstract][hide abstract] ABSTRACT: The objective was to determine the effects of various methods of oocyte activation and sperm pretreatment on development of porcine embryos derived from in vitro-matured oocytes and intracytoplasmic sperm injection (ICSI). The second polar body was extruded in the majority (>78.4%) of in vitro-matured (IVM) oocytes 4h after electrical pulse activation. In embryos generated by ICSI and sham-ICSI, a combination of an electrical pulse, with various chemical activators 4 h later, improved (P < 0.05) blastocyst formation rate compared to activation only with a pulse. Treatment with 6-dimethylaminopurine (DMAP) after electrical activation significantly increased the oocyte activation rate. The effects of exposure of sperm to repeated freeze-thaw cycles (without cryoprotectant) on oocyte activation and the effects of sperm pre-incubated with dithiothreitol (DTT) or Triton X-100 on early embryo development were also examined. Blastocyst formation rates after ICSI did not differ between motile sperm and those rendered immotile by one-time freezing and thawing without cryoprotectant. However, sperm rendered immotile by three cycles of freezing/thawing without cryoprotectant had a significantly lower blastocyst formation rate. Although oocytes injected with sperm pre-incubated with Triton X-100 had a higher normal fertilization rate than those pre-incubated with DTT or one-time frozen/thawed sperm, rates of blastocyst formation and cell numbers were similar among the three groups. In conclusion, various methods of oocyte activation and sperm preparation significantly affected the developmental capacity of early porcine embryos derived from IVM and ICSI.
[show abstract][hide abstract] ABSTRACT: Tibetan chickens were crossed reciprocally with White Leghorn and Shou-Guang chicken respectively, and inter se matings in F1 were carried out to generate the F2 population. Feather color and shank color appearance and segregation ratio in F1 and F2 were observed. Results indicate that white feather of White Leghorn chicken and black feather of Shou-Guang chicken exhibit complete dominant heredity to hemp feather of Tibetan chicken. Hemp feather is determined by two or more alleles. Only when these two or more alleles are concurrently present, will hemp feather then be displayed. The Id/id allele that determines shank color demonstrates sex-linked inheritance, and the recessive id is expressed gradually in the homozygotes. We confirm that genotype of shank color in White Leghorn rooster used in this study is the dominant homozygote.
[show abstract][hide abstract] ABSTRACT: For the first time, a 16 kb fragment of the porcine Ob gene, namely intron1, exon1, 5' region of Ob gene, was restrictively analyzed and sequenced by the primers designed in the portion of the swine Ob sequence. The first small 38 bp untranslated exon1 is located 11.1 kb upstream of the initiator ATG codon, and two novel microsatellites SW200 and SW160 are found in intron1. Promoter analysis of several putative binding sites revealed that this 300 bp promoter located at -1 to -300, including C/EBP and two Sp1, may be as effective as the longer promoter in directing leptin transcription. To examine microsatellites association with important economic traits, we statistically analyzed genotypes and alleles of the two microsatellites. Statistical analysis carried out by SAS 8.2 revealed significant positive correlation between the two microsatellites genotypes and the litter size in first parity of Erhualian.
[show abstract][hide abstract] ABSTRACT: Mutations of the melanocortin-4 receptor (MC4R) are associated with hyperphagia, obesity, and accelerated longitudinal growth in pig, mice and human. However, little is known about the functions of this gene in chicken. To map the MC4R gene in Chicken chromosome, we used a 6000 rads chicken-hamster radiation hybrid panel (ChikenRH6). PCR of samples from the ChikenRH6 revealed the location of the MC4R gene to be nearby markers MCW0062, BCL2 and OVY on chromosome 2q12. Five markers were placed into a single linkage group based on two-point analysis with a LOD score of greater than 5. At the same time, the MC4R gene was selected as marker to compare DNA sequence between chicken and human chromosome. The result shows there are the same homologous regions between chicken chromosome 2 (GGA2) and human chromosome 18 (HSA18), and we found that the genes BCL2 and obesity are located in the near regions of MC4R on human chromosome 18. So we can reduce that the chicken MC4R gene maybe there are the same functions with the human MC4R gene. Overall, this work reveals widespread chromosome rearrangements of MC4R between chicken and human genomes, and mappings the chicken MC4R gene on 2q12 by a RH panel.
[show abstract][hide abstract] ABSTRACT: 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.
[show abstract][hide abstract] ABSTRACT: The study of the molecular regulation mechanism of melanin synthesis during animal development has become a new focus recently . The synthesis and production of melanin during animal development are regulated by many genes. This paper summarized the molecular function mechanism of melanocortin-1-receptor (MC1R) gene and the relationship between the consequences of polymorphic variation of the gene and melanin traits, in addition to summarized the identification and mutation of MC1R gene in birds. Furthermore, the melanin synthesis mechanism in birds is also discussed here.
[show abstract][hide abstract] ABSTRACT: We constructed the first microsatellite-enriched library of yak according to the strong affinity between biotin and streptavidin. The method included ligation of 300 approximately 1 000 bp enzyme-digested fragments and adaptors, affinity capture of microsatellite repeat using biotinylated oligoprobe ((CA)12, (CCG) 8, (CAG)8, (TTTC) 8) attached to streptavidin-coated magnetic beads, PCR amplification using the 21-mer adaptor oligonucleotide as primer to obtain double-stranded targeted fragments, religated into pMD18-T vector and transformed to DH5alpha. The results of sequencing showed that 37 of 48 readable sequences contained microsatellites indicating a high degree of microsatellite enrichment. The new polymorphic microsatellite markers we have identified and characterized will contribute to the yak genetic linkage mapping, molecular evolution and phylogenetic studies, marker assistant selection and QTLs location of yak main economic traits.
[show abstract][hide abstract] ABSTRACT: 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.
[show abstract][hide abstract] ABSTRACT: 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.
[show abstract][hide abstract] ABSTRACT: SSCP analysis was commanded on the whole sequence of porcine LHbeta gene except the upstream control region. No polymorphic site was found in the 3 exons and 3' control region. But there were 2 polymorphic sites in the 1367 site of intron 1 and 1823 site of intron 2. The gene frequencies of the 2 sites in the Erhualian,Yorkshire and Landrace populations were analyzed.
[show abstract][hide abstract] ABSTRACT: As the molecular biology has been applied in animal genetics and breeding,it is important that we research major genes on quantitative traits for animal breeding by transgenic technology. In this paper,the research advance of FABP genes, obese gene, leptin gene, MCRs genes, LPL gene, HSL gene affecting meat quality in animals are reviewed.
[show abstract][hide abstract] ABSTRACT: The recognizing sequence of restriction enzyme includes palindrome and nonpalindromic, and DNA is double helix complementary strands. So the recognizing sequences of palindrome enzyme in two strands of DNA were identical,and can be considered of one sequence. But for nonpalindromic restriction enzyme,the recognizing sequences of two strands of DNA were not identical. Therefore the true recognizing sequences are not only one. In this experiment,an enzyme cleavage reaction was carried out which confirmed that the true recognizing sites/sequences of nonpalindromic enzyme are two instead of one.
[show abstract][hide abstract] ABSTRACT: Using Longissimus Dorsi muscle as material and Lambda ZAP II as Vector, Xiang Pig Longissimus Dorsi muscle cDNA library has been constructed in our study. The results showed that the titration of the library was 3.4 x 10(7) pfu/ml, the recombinant percentage was 94%, and the fragment length of inserted average cDNA were 1.5 kb. The study pointed out that the more than 30 T insertion is the major factor for low percentage if sequencing the 3'-end.