Probing the potentiality of the defoliator Cricula trifenestrata Helfer silk: a revisit

BACKGROUND

Transformation of pest to valuable product is considered to be a noteworthy innovation. This article explores the potentiality of wild silkworm Cricula trifenestrata Helfer for sustainable development towards human livelihoods.

RESULTS

The innate characteristics of this silkworm with robust rearing capacity have bestowed various aspects of biomaterials with special context to diversification of wild silk products. Views on challenges, prospects and the enigma of converting a pest to beneficial product are also unraveled. Exploration on utmost utilization of raw silk, scope for varied byproduct from silk waste may contribute a ray of hope for income generation to the rural population.

CONCLUSION

With suitable plantation and congenial climatic conditions for rearing Cricula trifenestrata may serve as an alternative wild silk in contributing to the country's wild raw silk production.

Glutathione S-transferase M1 and T1 null genotype frequency distribution among four tribal populations of western India

Glutathione S transferase (GST) family is a key contributor in the detoxification mechanism of our body.Deletion of the genes within this family has been reported in the failure of detoxification system, to some extent leading to various types of cancers and other life threatening diseases. The existing data and reports on the association of null genotype of both GSTM1 and GSTT1 genes for various diseases are inconsistent. But knowledge of the polymorphic distributions of genotypes in different populations is important for investigating the risk factors in different epidemiological studies. The present study thus aims to determine thefrequency of GSTM1 and GSTT1 null genotype frequency among four tribal groups, i.e. Mina, Garasia, Damor and Saharia of western India. A comparative analysis with different tribal as well as world population has also been undertaken to have a view of its worldwide frequency distribution. Our results reveal a frequency distribution varying from 22.6% to 66.9% with respect to GSTM1gene polymorphism and from 19.1% to 33.0% with respect to GSTT1 gene in the studied populations. To the best of our knowledge this is the first report on the GSTM1and GSTT1frequency distribution among the tribal population of western India and our study shows that the Mina tribal population has the highest frequency of GSTM1.

Association of angiotensinogen gene SNPs and haplotypes with risk of hypertension in eastern Indian population

BACKGROUND

Angiotensinogen (AGT) enzyme comprises a vital module of RAAS system that effectively controls the blood pressure and related cardiovascular functions. Ample association studies have reported the importance of AGT variants in cardiovascular and non-cardiovascular adversities. But lately, owing to the complexity of the many anomalies, the haplotype based examination of genetic variation that facilitates the identification of polymorphic sites which are located in the vicinity of the causative polymorphic site, gets greater appreciation.

METHODS

In the present study, we have done genotype and haplotype analysis of AGT gene in reference to hypertension to confirm the association of the two in an Indian population. To accomplish this, we performed candidate SNPs analysis and construct possible haplotypes across the AGT promoter and gene region in 414 subjects (256 Hypertensive cases and 158 controls).

RESULTS

We found four SNPs (rs11568020: A-152G and rs5050: A-20C in promoter; rs4762 and rs699 in exon2) and 3 haplotypes (H4, H7 and H8) that showed a stronger positive association with hypertension. The haplotype H2 was showing protective association with hypertension.

CONCLUSION

The results of the present study confirmed and reestablished the role of AGT gene variants and their haplotypes in the causation of hypertension in Indian population and showed that haplotypes can provide stronger evidence of association.

Approaches in type 1 diabetes research: A status report

Type 1 diabetes is a multifactorial disease with an early age of onset, in which the insulin producing beta cell of the pancreas are destroyed because of autoimmunity. It is the second most common chronic disease in children and account for 5% to 10% of all diagnosed cases of diabetes. India is having an incidence of 10.6 cases/year/100,000, and recent studies indicate that the prevalence of type 1 diabetes in India is increasing. However in view of poor health care network, there is no monitoring system in the country. Of the 18 genomic intervals implicated for the risk to develop type 1 diabetes, the major histocompatibility complex (MHC) region on chromosome 6p21.31 has been the major contributor estimated to account for 40-50%, followed by 10% frequency of INS-VNTR at 5' flanking region of the insulin gene on chromosome 11p15.5. However, population studies suggest that > 95% of type 1 diabetes have HLA-DR3 or DR4, or both, and in family studies, sibling pairs affected with type 1 diabetes have a non-random distribution of shared HLA haplotypes. As predisposing genetic factors such as HLA alleles are known, immunological interventions to prevent type 1 diabetes are of great interest. In the present study we have reviewed the status of molecular genetics of the disease and the approaches that need to be adopted in terms of developing patient and suitable control cohorts in the country.

Reconstructing Indian-Australian phylogenetic link

Background

An early dispersal of biologically and behaviorally modern humans from their African origins to Australia, by at least 45 thousand years via southern Asia has been suggested by studies based on morphology, archaeology and genetics. However, mtDNA lineages sampled so far from south Asia, eastern Asia and Australasia show non-overlapping distributions of haplogroups within pan Eurasian M and N macrohaplogroups. Likewise, support from the archaeology is still ambiguous.

Results

In our completely sequenced 966-mitochondrial genomes from 26 relic tribes of India, we have identified seven genomes, which share two synonymous polymorphisms with the M42 haplogroup, which is specific to Australian Aborigines.

Conclusion

Our results showing a shared mtDNA lineage between Indians and Australian Aborigines provides direct genetic evidence of an early colonization of Australia through south Asia, following the "southern route".

Detailed mtDNA genotypes permit a reassessment of the settlement and population structure of the Andaman Islands

The population genetics of the Indian subcontinent is central to understanding early human prehistory due to its strategic location on the proposed corridor of human movement from Africa to Australia during the late Pleistocene. Previous genetic research using mtDNA has emphasized the relative isolation of the late Pleistocene colonizers, and the physically isolated Andaman Island populations of Island South-East Asia remain the source of claims supporting an early split between the populations that formed the patchy settlement pattern along the coast of the Indian Ocean. Using whole-genome sequencing, combined with multiplexed SNP typing, this study investigates the deep structure of mtDNA haplogroups M31 and M32 in India and the Andaman Islands. The identification of a so far unnoticed rare polymorphism shared between these two lineages suggests that they are actually sister groups within a single haplogroup, M31'32. The enhanced resolution of M31 allows for the inference of a more recent colonization of the Andaman Islands than previously suggested, but cannot reject the very early peopling scenario. We further demonstrate a widespread overlap of mtDNA and cultural markers between the two major language groups of the Andaman archipelago. Given the "completeness" of the genealogy based on whole genome sequences, and the multiple scenarios for the peopling of the Andaman Islands sustained by this inferred genealogy, our study hints that further mtDNA based phylogeographic studies are unlikely to unequivocally support any one of these possibilities.

Deciphering diversity in populations of various linguistic and ethnic affiliations of different geographical regions of India: Analysis based on 15 microsatellite markers

The extent of genetic polymorphism at fifteen autosomal microsatellite markers in 54 ethnically, linguistically and geographically diverse human populations of India was studied to decipher intrapopulation diversity. The parameters used to quantify intrapopulation diversity were average allele diversity, average heterozygosity, allele range (base pairs), and number of alleles. Multilocus genotype frequencies calculated for selected populations were utilized for testing conformity with the assumption of Hardy-Weinberg equilibrium. The exact test values, after Bonferroni correction, showed significant deviation amongst Gowda (vWA, Penta E); Dhangar, Satnami and Gounder (D8S1179); Hmar (FGA); Kuki and Balti (vWA) groups. Relatively low number of alleles and allelic diversity (base-pairs size) had been observed in populations of central India as compared with southern and northern regions of the country. The communities of Indo-Caucasoid ethnic origin and Indo-European linguistic family (Kshatriya of Uttar Pradesh) showed highest allelic diversity, as well as rare alleles, not reported in any other Indian populations. Analysis based on average heterozygosity was also found to be lowest among the populations of central India (0.729) and highest among the populations from north (0.777) and west (0.784) regions of the country, having Indo-Caucasoid ethnic origin and Austro-Asiatic linguistic affiliation. The maximum power of discrimination (85%-89%) had been observed at loci FGA, Penta E, D18S51 and D21S11, suggested high intrapopulation diversity in India. Genetic diversity revealed by STR markers was consistent with the known demographic histories of populations. Thus, the present study clearly demonstrated that the intrapopulation diversity is not only present at the national level, but also within smaller geographical regions of the country. This is the first attempt to understand the extent of diversity within populations of India at such a large scale at genomic level.