QTL mapping for berry shape based on a high-density genetic map constructed by whole-genome resequencing in grape

Grape berry shape is an important agricultural trait.Clarifying its genetic basis is significant for cultivating grape varieties that meet market demands.However,the current study by forward genetics has not achieved in-depth results.Here,a high-density map was constructed to identify quantitative trait loci(QTLs)for berry shape.A total of 358709 polymorphic SNPs were obtained using whole-genome resequencing(WGS)based on 208 F2 individuals derived from round grape‘E42-6’and oblong grape‘Rizamat’.The 1635.65 cM high-density map was divided into 19 linkage groups with an average distance of 0.37 cM.Using this map,three significant QTLs for fruit shape index(ShI:ratio of berry length to berry width)identified over three years were mapped onto LG4 and LG5,including one stable QTL on Chr5 with the genomic region of 0.47–1.94 Mb.Combining with gene annotation and expression patterns based on RNA-seq data from two contrasting F2 individuals with round and oblong berry(their average ShI was 1.89 and 1.10,respectively)at four developmental stages,four candidate genes were selected from the above QTLs.They were mainly involved in DNA replication,cell wall modification,and phytohormone biosynthesis.Further analysis of RNA-seq data revealed that several important phytohormone synthesis and metabolic pathways were enriched based on differentially expressed genes(DEGs),which was consistent with the results of QTL mapping for genes related to plant hormone biosynthesis in the F2 population.Furthermore,a comparison of plant hormone content showed that there were significant differences in IAA and tZ content between the two contrasting F2 individuals at different developmental stages.Our findings provide molecular insights into the genetic variation in grape berry shape.Stable QTLs and their tightly linked markers offer the possibility of marker-assisted selection to accelerate berry shape breeding.

A new look at cardiac pathophysiology difference in type 2 diabetic mice by comparative analysis

Objective To clarify the differences in cardiac structure,cardiac function,and myocardial metabolism in type 2 diabetes mellitus mice with obesity or non-obesity and to elucidate the key molecular mechanisms leading to this difference.Methods Db/db mice and low-dose STZ injection combined with HFD-induced diabetes mellitus mice were used in this study as the model of type 2 diabetes mellitus with obesity or non-obesity.

A novel mouse model of PEDF-associated serious liver inflammation,hepatic tumorigenesis and cardiovascular injury mimics human nonalcoholic steatohepatitis

There are no approvedtherapeuticdrugs for nonalcoholic steatohepatitis(NASH)due to the many bottlenecks,including the lack of preclinical animal models that can perfectly mimic human NASH features,such as systemic metabolic disorders,hepatic steatosis,intense liver inflammation and fibrosis,liver tumorigenesis,and cardiovascularcomplications.i,2"Pigment"epitheliumderived factor(PEDF)is a lipid metabolism regulator with high expression in the liver,and its reduced expression in the liver is closely related to the development of nonalcoholic fatty liver disease(NAFLD).