جستجوی مقالات مرتبط با کلیدواژه "indigenous chicken" در نشریات گروه "دامپزشکی"

The growth hormone of chickens affects the growth and development of chickens, egg production, body type, appetite control, reproduction, and response of body immune system. Several studies have shown that the growth hormone gene is a candidate gene for chicken economic traits. The polymorphisms of this gene can be used to improve of production, phylogenetic analysis and marker assisted selection programs. In this study, allelic polymorphism in intron 1 of growth hormone (cGH) gene in the Marandi indigenous chicken examined using PCR-RFLP technique. A total of 100 birds were selected and for detection of mutation in intron 1 of cGH gene (776 bp), the PCR products were digested by MspI restriction enzyme. The results showed that the five genotypes and three of the A1, A2 and A3 alleles with frequency of 24, 4 and 73 percent respectively, identified. The A3A3 genotype had the highest (0.50) and the lowest (0.02) frequency was found for A1A1 and A1A2 genotypes. In the total population, Shannon's information index and Fixation index 0.69 and -0.16 respectively, calculated. According to the Chi-square test, the Marandi indigenous chickens had a Hardy-Weinberg equilibrium for this locus. Considering the high polymorphism of this locus in Marandi indigenous chickens can after determining the genotype and the performance of each genotype in the production of economic traits be used as a marker in genetic selection and breeding programs to improve the economic traits associated with growth hormone.

Prolactin gene plays a key role in the initiation and continuation of broodiness in chickens. Dopamine in the pituitary gland reduces the effect of prolactin. This research was conducted to investigate the allelic polymorphism of dopamine D1 receptor gene (DRD1) using PCR-RFLP method in Marandi and Mazandarani indigenous chickens. In this study, blood samples were collected randomly from 200 chickens and genomic DNA was extracted using salting out method. Amplification of the desired locus with 283 bp was performed using specific primers and the CfrI enzyme was used to identify the mutation in the desired locus. After digestion, for DRD1 marker site, three genotypes AA, AG and GG, and two alleles of A (with on band of 283 bp) and G (with two bands of 183 and 100 bp) were identified. Indigenous chicken masses were in the Hardy-Weinberg equilibrium. For Marandi and Mazandarani indigenous chicken masses, the Shannon information index in DRD1 marker site was 0.59 and 0.67, respectively, the fixation index was -0.09 and -0.19, respectively and the observed heterozygosity index was 0.44 and 0.58, respectively. Regarding the presence of polymorphism and mutation in the studied locus and by studying the traits of related to the observed genotypes, it is suggested that this locus can be used as an appropriate marker for breeding programs.

In this study, allelic polymorphism in candidate genes of Mx and SLC11A1 involved in the immune system in some Iranian Common, West Azarbaijani, Marandi, Mazandarani indigenous and commercial chicken strains examined using PCR-RFLP technique. A total of 300 birds were selected and for detection of mutation in Mx and SLC11A1 genes the PCR products were digested by Hyp81 and SacI restriction enzymes, respectively. For the Mx gene, one fragment with length of 299 bp and two fragments with the length of 200 and 99 bp were identified for the A and G alleles respectively. One fragment with the length of 801 bp for T allele and two fragments with the length of 722 and 79 bp for C allele were identified in SLC11A1 gene. Between different groups of chickens, in the Mx and SLC11A1 genes, the most frequency of susceptible to disease alleles (G and C) were in the indigenous chicken strains and meat commercial chicken strain. In the Mx loci, Shannon's information index was in different groups of chicken from 0.1347 to 0.6641 and in the SLC11A1 loci was from 0.3669 to 0.6769. In the Mx loci, fixation index was positive for indigenous chickens group and in the SLC11A1 loci was negative for different groups of chickens. The results of this study indicate that these genes loci can be used as marker for genetic breeding to reduce the diseases of indigenous and commercial chicken strains.

Indigenous chickens could serve as precious genetic resources that should be considered in conservation and breeding programs. The Major Histocompatibility Complex (MHC) has a strong association to disease resistance/susceptibility, production and reproduction traits in chicken. Therefore, identifying its polymorphism in populations under selective breeding could be used for selection of disease resistant and higher productive breeds. MHC association with quantitative traits could be a result of its linkage with causative genes controlling these traits. Insulin-like growth factor 1 (IGF1) is a candidate marker for phenotypic traits in chicken which are associated with important production and reproduction features.
Based on this hypothesis, MHC polymorphism and its association to IGF1 gene (as a marker for production traits) were investigated in Khorasan indigenous chicken.
In total, 313 DNA samples that belonged to the Khorasan indigenous chicken were analyzed. LEI0258 microsatellite marker and fragment analysis method was used for MHC genotyping. Single nucleotide polymorphism (SNP) of the IGF1 5’-UTR was detected by restriction fragment length polymorphism (PCR-RFLP) and PstI restriction endonuclease enzyme. Linkage disequilibrium between MHC and IGF1 loci were also determined using SAS/Genetics software and likelihood ratio test.
Collectively, 25 different alleles (185-493 bp) and 76 genotypes of LEI0258 microsatellite were identified in Khorasan population. Two alleles, A (PstI -) and B (PstI ) and three genotypes (AA, AB and BB) were identified for IGF1 gene. Significant linkage disequilibrium (p=0.0083) was observed between LEI0258 and IGF1 loci in this population.
These results indicate a high MHC genetic diversity in Khorasan indigenous chicken as a valuable genetic resource. Results from MHC/IGF1 linkage study confirm the hypothesis that MHC association with production traits could be as a result of MHC linkage with causative genes controlling the traits.

Major histocompatibility complex (MHC) in chicken has profound influence on resistance/susceptibility to disease, and production and reproduction traits. Microsatellite marker LEI0258 is a genetic indicator for MHC haplotypes. Recognizing diversity of MHC haplotypes in selectively bred populations will be helpful for selecting population resistant to disease and development of effective vaccines. The purpose of the present study was to evaluate polymorphism at MHC in two populations of Khorasan indigenous chickens and commercial Leghorn breed using microsatellite marker LEI0258 and to investigate its segregation and heredity. A total of 335 blood samples from Khorasan Razavi indigenous chickens and commercial Leghorn population including parents (P) and offspring (F1), were analyzed. The MHC genotypes were determined using LEI0258 microsatellite. The study of allele heredity from P to F1 and Hardy-Weinberg equilibrium were conducted using Chi-square and Likelihood Ratio tests. In Khorasan indigenous chickens 20 different alleles were identified for LEI0258 microsatellite. The allele 321 bp had the highest (22.88%) and the allele 182 bp had the lowest (0.16%) frequency. In the commercial population (Leghorn breed) 3 alleles were found for this marker of which the allele 261 bp had the highest (50%) and alleles 487 bp had the lowest (6 %) frequency. In allele heredity analysis and Hardy-Weinberg equilibrium of Khorasan population, no significant differences were observed between P and F1 progenies. These results indicate a higher genetic variation in indigenous chickens compared to commercial breed. There was no preference for a particular allele in indigenous chickens. The higher frequency of some alleles in F1 population is due to the high frequency of the same alleles in parent population which their gametes make the population gene pool.