Novel insights into drought-induced regulation of ribosomal genes through DNA methylation in chickpea.

Modifications within the epigenome of an organism in response to external environmental conditions allow it to withstand the hostile stress factors. Drought in chickpea is a severely limiting abiotic stress factor which is known to cause huge yield loss. To analyse the methylome of chickpea in response to drought stress conditions and how it affects gene expression, we performed whole-genome bisulfite sequencing (WGBS) and RNA-seq of two chickpea genotypes which contrast for drought tolerance. It was observed that the mCHH was most variable under drought stress and the drought tolerant (DT) genotype exhibited substantial genome-wide hypomethylation as compared to the drought sensitive (DS) genotype. Specifically, there was substantial difference in gene expression and methylation for the ribosomal genes for the tolerant and sensitive genotypes. The differential expression of these genes was in complete agreement with earlier reported transcriptomes in chickpea. Many of these genes were hypomethylated (q < 0.01) and downregulated under drought stress (p < 0.01) in the sensitive genotype. The gene RPS6 (ribosomal protein small subunit) was found to be downregulated and hypomethylated in the drought sensitive genotype which could possibly lead to reduced ribosomal biosynthesis. This study provides novel insights into regulation of drought-responsive genes in chickpea.

Bilateral variation in the branching pattern of the subclavian artery: an unusual finding with clinical implications / Variação bilateral no padrão de ramificação da artéria subclávia: um achado incomum com implicações clínicas

Abstract The subclavian artery is a significant branch of the aortic arch. We present a rare case of a bilateral variation in the branching pattern of the subclavian artery, observed in an adult male cadaver aged 70 years. On both the sides of the neck, all the branches of the subclavian artery took their origin from its first part. There was a rare occurrence of a cervicodorsoscapular trunk, which gave rise to superficial cervical, suprascapular, and dorsal scapular arteries. The same branching pattern was observed on the left side of the neck, with the presence of another cervicodorsoscapular trunk. Thyrocervical trunk and transverse cervical artery were both absent from the cervical region bilaterally. The inferior thyroid artery was a direct branch from the subclavian artery. Knowledge regarding variations of the subclavian artery is very important as lateral cervical region arteries are important for flap harvesting in plastic and reconstruction surgery. Preoperative radiologic evaluation of pedicles might help in choosing the optimal flap design, prevent ischemic complications, and help to improve overall treatment outcomes.

Resumo A artéria subclávia é um ramo significativo do arco da aorta. Apresentamos um caso raro de variação bilateral do padrão de ramificação da artéria subclávia, observada em um cadáver adulto do sexo masculino de 70 anos. Em ambos os lados do pescoço, todos os ramos da artéria subclávia originavam-se de sua primeira parte. Houve rara ocorrência de tronco escapular cervical dorsal, que deu origem às artérias cervical superficial, supraescapular e escapular dorsal. O mesmo padrão de ramificação foi observado no lado esquerdo do pescoço, com a presença de tronco escapular cervical dorsal. O tronco tireocervical e a artéria cervical transversa estavam ausentes em ambas as regiões cervicais direita e esquerda. A artéria tireóidea inferior consistia em um ramo direto da artéria subclávia. O conhecimento das variações da artéria subclávia é fundamental, pois as artérias da região cervical lateral são importantes para a obtenção de retalhos em cirurgias plásticas e reconstrutivas. A avaliação radiológica pré-operatória dos pedículos pode ajudar na escolha do desenho ideal do retalho, prevenir complicações isquêmicas e ajudar a melhorar o resultado geral do tratamento.