RFLP

Molecular markers are indispensable tools for identifying a particular sequence of DNA in a pool of unknown DNA. Use of Molecular markers are generally based on naturally occurring DNA polymorphism, which forms the basis for designing strategies to exploit for various purposes such as species identification, genetic diagnostics, characterization  of  transformants, study  of  genome  organization, germplasm characterization  and phylogenic analysis. There are various types of markers viz. morphological, biochemical and DNA based molecular markers. The molecular markers are selected for their appropriate purpose on the basis of high level of accuracy and reproducibility. The main properties which helps in choosing the most reliable marker are: Genetic abundance, level of polymorphism, locus-specificity, co-dominancy, technical demands, operational costs and many more. The DNA based molecular markers are again divided in to two i.e. hybridization based and PCR based molecular markers. RFLP belongs to the first non PCR based techniques and PCR based technique includes RAPD and AFLP. In this review, we discuss about the molecular markers with their merits and demerits. 

Peroxisome proliferator activated receptor-gamma (PPARγ) is a nuclear receptor encoded on chromosome 3p25 that plays a pivotal role in adipogenesis and insulin signaling. Differential splicing results in two main isoforms, γ1 and γ2. A number of genetic variants in the PPAR-γ gene have been identified. These include a very rare gain-of-function mutation (Pro115Gln) associated with obesity but not insulin resistance, two loss-of-function mutations (Val290Met and Pro467Leu) reported in three individuals with severe insulin resistance but normal body weight, the silent CAC478CAT mutation, and the highly prevalent Pro12Ala polymorphism in PPAR- γ2. Wild allele proline was associated with decreased insulin sensitivity and increased incidence of type II diabetes, where as mutant alanine allele improves insulin sensitivity. Hence, the present study is on studies on screening of the Pro12Ala mutation among Gujarat population and to correlate with type II diabetes.  SNP detection in PPARγ2 gene was carried out from the blood samples of 52 diabetic subjects and 22 controls followed by PCR and RFLP using restriction enzyme Hae III. The 12Ala allele frequency was 0.08 in total population. Of the 74 subjects, 62 had Pro12Pro genotype and 12 had Pro12Ala genotype. The Ala12Ala genotype was not observed. This study also found that as compared to diabetic group, non-diabetic group had significantly higher frequency of 12Ala allele in PPARγ gene (p=0.06).  Our study found higher frequency of Pro12Ala polymorphism in non-diabetic subjects, suggestive of protective role of polymorphism in risk of type II diabetes. Key words: PPARG2, T2D, Pro12Ala, RFLP