Genetic polymorphisms of the TLR4 gene and their association with susceptibility to type 2 diabetes mellitus in the Chinese population.

Toll-like receptor 4 (TLR4) is potentially an important gene affecting the susceptibility to type 2 diabetes mellitus (T2DM). The objective of this study was to evaluate whether genetic polymorphisms of the TLR4 gene are associated with T2DM susceptibility. This potential association was analyzed in 668 T2DM patients and 672 healthy controls by polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing methods. Two novel genetic polymorphisms (g.12375A>G and g.14367G>A) were investigated, and our data support the idea that the g.14367G>A variant significantly increased susceptibility to T2DM in homozygote comparison (AA vs GG: OR = 2.396, 95%CI = 1.682-3.413, P < 0.0001), heterozygote comparison (GA vs AA: OR = 1.322, 95%CI = 1.050-1.664, P = 0.0175), dominant model (AA/GA vs GG: OR = 1.511, 95%CI = 1.217-1.876, P = 0.0002), recessive model (AA vs GA/GG: OR = 2.093, 95%CI = 1.496-2.927, P < 0.0001), and allele contrast (A vs G: OR = 1.503, 95%CI = 1.279-1.766, P < 0.0001). The allele A of g.14367G>A variants may contribute to the susceptibility to T2DM. However, we failed to detect a similar significantly increased susceptibility to T2DM in the g.12375A>G variant. Our findings suggest that the g.14367G>A genetic polymorphism of the TLR4 gene is associated with the susceptibility to T2DM in the population studied.

Evaluation of cellulolytic activity in insect digestive fluids.

Efficient and low-cost cellulolytic enzymes are urgently needed to degrade recalcitrant plant biomass during the industrial production of lignocellulosic biofuels. Here, the cellulolytic activities in the gut fluids of 54 insect species that belong to 7 different taxonomic orders were determined using 2 different substrates, carboxymethyl cellulose (CMC) (approximating endo-ß-1,4-glucanase) and filter paper (FP) (total cellulolytic activities). The use of CMC as the substrate in the zymogram analysis resulted in the detection of distinct cellulolytic protein bands. The cellulolytic activities in the digestive system of all the collected samples were detected using cellulolytic activity analysis. The highest CMC gut fluid activities were found in Coleoptera and Orthoptera, while FP analysis indicated that higher gut fluid activities were found in several species of Coleoptera and Lepidoptera. In most cases, gut fluid activities were higher with CMC than with FP substrate, except for individual Lepidoptera species. Our data indicate that the origin of cellulolytic enzymes probably reflects the phylogenetic relationship and feeding strategies of different insects.

DNA polymorphisms of the Hu sheep melanocortin-4 receptor gene associated with birth weight and 45-day weaning weight.

The melanocortin-4 receptor (MC4R) has important roles in regulating food intake, energy balance, and body weight in mammals. In pigs and cattle, MC4R mutations have been identified as genetic markers for growth and traits. Compared with abundant research conducted on other livestock species, little is known about mutations of the ovine MC4R gene. We investigated the effect of MC4R polymorphisms on birth weight and on 45-day weaning weight in 144 Hu sheep. Four single nucleotide polymorphisms (SNPs; g.1016 G/A, g.1240 T/C, g.1264 G/A, and g.1325 A/G) were identified in the 3ꞌ-untranslated region of Hu sheep MC4R by PCR-single-strand conformation polymorphism and DNA sequencing. A haplotype block, containing g.1240 T/C, g.1264 G/A, and g.1325 A/G, was constructed within the Hu sheep MC4R gene. Four SNPs were found to be significantly associated with 45-day weaning weight, while the haplotype block was significantly associated with birth weight. Hu sheep with the genotypes GG in g.1016 G/A or with the genotype CCAAGG in the haplotype block, had higher 45-day weaning weights. We conclude that these 4 SNPs of the MC4R gene have potential as genetic markers for early growth traits in Hu sheep.