Population-wide genetic analysis of Ovar-DQA1 and DQA2 loci across sheep breeds in India revealed their evolutionary importance and fitness of sheep in a tropical climate.

Genetic variability at the major histocompatibility complex (MHC) is important in any species due to significant role played by MHC for antigen presentation. DQA locus has not been studied for its genetic variability across sheep population in India. In the present study, MHC of sheep at DQA1 and DQA2 loci were evaluated across 17 Indian sheep breeds. Results revealed high degree of heterozygosity (10.34% to 100% for DQA1 and 37.39 to 100% for DQA2). 18 DQA1 alleles and 22 DQA2 alleles were isolated in different breeds. Nucleotide content for DQA region revealed richness of AT content (54.85% for DQA1 and 53.89% for DQA2). DQA1 and DQA2 sequences clustered independently. We could see evidence of divergence of DQA as DQA1 and DQA2 across sheep breeds. Wu-Kabat variability index revealed vast genetic variation across DQA1 and DQA2, specifically at peptide binding sites (PBS) that consisted 21 residues for DQA1 and 17 residues for DQA2. Evolutionary analysis revealed the presence of positive and balancing selection for DQA1 locus, however DQA2 was under purifying selection across sheep breeds. Higher heterozygosity and large diversity at both loci especially at PBS indicated the fitness of the sheep population for evading pathogens and adapt to the harsh tropical climate.

Cross-population genetic analysis revealed genetic variation and selection in the Ovar-DRB1 gene of Indian sheep breeds.

In sheep, MHC variability is studied widely to explore disease association. The aim of the current study was to explore the genetic diversity of Ovar-DRB diversity across sheep breeds of India. Here, Ovar-DRB1 locus was studied across 20 sheep breeds. DRB1 was amplified (301 bp) and sequenced using a PCR-sequence-based typing approach. Results revealed a high degree of heterozygosity across breeds (mean: 73.99%). Overall mean distance for DRB1 was highest in Sangamneri (0.18) and lowest in Madgyal sheep (0.10). There was a higher rate of transition, across breeds. Further, 39 alleles were isolated in different breeds, out of which 10 were new. To allow easy access and use of the immune-polymorphic database, an online database management system was launched (http://www.mhcdbms.in/). Nucleotide content across breeds for the DRB1 region revealed the richness of GC content (59.26%). Wu-Kabat index revealed vast genetic variation across peptide binding sites (PBS) of DRB1. Residues 6, 66, 69, 52, and 81, were polymorphic showing utility for antigen presentation. All breeds were under positive selection for DRB1 locus (dN > dS). Study revealed the importance of DRB locus diversity for beta chain specifically at PBS across sheep breeds of the Indian subcontinent and presented evidence of positive selection for DRB owing to its evolutionary significance.

Quercetin loaded chitosan tripolyphosphate nanoparticles accelerated cutaneous wound healing in Wistar rats.

Previous studies have shown that quercetin on topical application improved cutaneous wound healing in rats, but hydrophobic nature and less skin penetration limits its potential as topical healing agent. Therefore, present study was planned to investigate wound healing potential of chitosan based quercetin nanoparticles. Quercetin loaded nanoparticles were synthesized by ionic gelation method and characterized by various standard techniques. A 2 × 2 cm2 square shaped wound was created on the thoraco-lumbar part of rats. Wounded rats were divided into 6 groups namely, gel (20%), blank nanoparticle (0.16%), bulk quercetin (0.3%), quercetin nanoparticles (0.03%), quercetin nanoparticles (0.1%) and quercetin nanoparticles (0.3%) treated groups. Different formulations of quercetin nanoparticles were applied on the wounds for the duration of study and healing tissues were collected on 7th, 14th and 21st day to study various parameters. Quercetin loaded nanoparticles were 361.16 ± 9.72 nm size and spherical in shape. We observed quercetin nanoparticles (0.03%) treatment caused marked reduction in the tumor necrosis factor-alpha, whereas expressions of interleukin 10, vascular endothelial growth factor and transforming growth factor beta1 was increased significantly with treatment. The granulation tissue of quercetin nanoparticles (0.03%) treated group showed better quality healing and maturity as supported by the increased blood vessels density, decreased inflammatory cells, increased number of myofibroblasts, deposition and arrangement of collagen fibers and re-epithelialization. In conclusion, quercetin nanoparticles (0.03%) treatment significantly improved wound healing by modulation of cytokines and growth factors involved in inflammatory and proliferative phases of wound healing.