Genome-Wide Association Study for Type 2 Diabetes in Indians Identifies a New Susceptibility Locus at 2q21

Indians undergoing socioeconomic and lifestyle transitions will be maximally affected by epidemic of type 2 diabetes (T2D). We conducted a two-stage genome-wide association study of T2D in 12,535 Indians, a less explored but high-risk group. We identified a new type 2 diabetes–associated locus at 2q21, with the lead signal being rs6723108 (odds ratio 1.31; P = 3.32 3 1029 ). Imputation analysis refined the signal to rs998451 (odds ratio 1.56; P = 6.3 3 10212) within TMEM163 that encodes a probable vesicular transporter in nerve terminals. TMEM163 variants also showed association with decreased fasting plasma insulin and homeostatic model assessment of insulin resistance, indicating a plausible effect through impaired insulin secretion. The 2q21 region also harbors RAB3GAP1 and ACMSD; those are involved in neurologic disorders. Forty-nine of 56 previously reported signals showed consistency in direction with similar effect sizes in Indians and previous studies, and 25 of them were also associated (P , 0.05). Known loci and the newly identified 2q21 locus altogether explained 7.65% variance in the risk of T2D in Indians. Our study suggests that common susceptibility variants for T2D are largely the same across populations, but also reveals a population-specific locus and provides further insights into genetic architecture and etiology of T2D

Preserved lignin structures in early eocene Surat lignites, Cambay Basin, Western India

Lignite samples from Vastan and Tadkeshwar lignite mines, Cambay Basin have been analysed to elucidate lignin precursor using thermochemolysis-gas chromatography-mass spectrometry. The thermochemolysis products of lignites are characterized by monomethoxy-, dimethoxy-, and trimethoxybenzene derivatives originated from -hydroxyphenyl, guaiacyl, and syringyl units of lignin polymer, respectively. The other compounds obtained in thermochemolysates of studied lignites are some resin derived C-15 sesquiterpenoids, with a series of fatty acid methyl esters and -alkanes/alkenes. The methylated guaiacyl and syringyl derivatives originate from the cleavage of beta-O-4 linkages and subsequent methylation of acidic hydroxyl groups of preserved lignin. Gymnosperm lignin is characterized mainly by guaiacyl derivatives whereas angiosperm lignin yields some syringyl-type compounds in addition to guaiacyl-type compounds. By analogy with the lignin structure of modern trees, the abundant occurrences of syringyl derivatives in the thermochemolysis products of Surat lignites clearly demonstrate that the palaeofloral community was dominated by angiosperms during the deposition of these lignites