Genetics in the Third Millennium
Volume:12 Issue: 3, 2014

Obese people are at risk of a number of diseases which can lead to further morbidity and mortality. The resistin hormone is secreted from the adipose tissue and the elevated levels of this hormone have been linked to obesity and insulin resistance. Thus, the resistin gene represents a potential candidate for the etiology of insulin resistance and obesity. In this study, we analyzed the possible association of -420 C/G resistin gene polymorphisms with overweight and obesity risk in Iranian population. This case-control study was done on 289 subjects divided into control (BMI<25) and obese (BMI≥25) groups based on the body mass index. Resistin -420 C/G gene polymorphism was analyzed using the PCR-RFLP method. The GG genotype frequency was 15% and 85% in control and obese groups, respectively. There was a significant association between GG genotype and susceptibility to obesity after adjusting for sex and age (OR: 3.9, 95%CI: 1.7-8.7, P: 0.001). In conclusion, Resistin -420 C/G gene polymorphism was associated to susceptibility to obesity.

This research aim was to identify, isolate, and clone ND1 gene of native chicken genome of Khorasan and compare it with other genomes and protein sequences of this gene in order to examine the possible mutations. For this purpose, genomic DNA was extracted from the blood sample of Khorasan native chickens and after designing specific primers of this gene using reference nucleotide sequence and carrying out polymerase chain reaction (PCR) for gene amplification, the product of reaction was electrophoresed on the agarose gel. The resulting bands were cloned and sequenced into E. coli using the pTZ57R/T linear vector. The comparison between the sequenced fragment of nucleotide and the reference genome revealed three mutations and a 99%/100% similarity was found in length with complete mitochondrial genome sequence of Gallus gallus in the recorded poultry mitochondria with accession number X52392.1 (reference genome), GU261719.1, GU261715.1, GU261712.1, AP003318.1, KF826490.1 and HQ857210.1. The protein comparison showed that the resulted sequence was similar to the protein sequences related to gene ND1 of the poultry mitochondriain the database so that the most similarity (100%/100%) in length belonged to gene ND1 in Gallus gallus spadiceus with accession number NP 006515.1 and the least similarity belonged to species and genera of Criniferpiscator, Nyctiousgrandis, Cursoriustemminckii and Aceroswaldeni with 78%/100% similarity. The comparison of the sequence with the reference genome was also 99%/100% similar in length. The nucleotide comparison showed mutation in three places of which two primary mutations occurred in the tRNA area which were not entered in the ND1 translation. After changing the obtained nucleotide sequences to amino acid sequences, it was compared with the reference protein sequences. The result of this comparison showed the difference in placing of one amino acid. In amino acid 173, alanine, which is a polar amino acid, changed to threonin polar amino acid.

Genetic epidemiology, as a relatively new science, investigates the independent role of genetic and environmental factors in the occurrence and progression of diseases. Genetic epidemiology studies, depending on the objectives, encompass the most preliminary surveys such as looking for family history of diseases to the most advanced surveys including specific strategies in prevention of genetic diseases using clinical trials. Various goals require special methods and study designs in genetic epidemiology studies. In the present study, main designs including familial aggregation, heritability, segregation, linkage and association have been studied and the purpose of each study design and the used tests are briefly discussed. Knowledge of different study designs and related tests is the main and necessary issue in accurate implementation of the studies and is also a guide to the shortest possible ways for reaching the goals.