Search

The flowering time (FT), which determines when fruits or seeds can be harvested, is subject to phenotypic plasticity, i.e. the ability of a genotype to display different phenotypes in response to environmental variations. Here, we investigated how the environment affects the genetic architecture of FT in cultivated strawberry (Fragaria ×ananassa) and modifies its QTL effects. To this end, we used a bi-parental segregating population grown for two years at widely divergent latitudes (5 European countries) and combined climatic variables with genomic data (Affymetrix® SNP array). Examination, using different phenological models, of the response of FT to photoperiod, temperature and global radiation, indicated that temperature is the main driver of FT in strawberry. We next characterized in the segregating population the phenotypic plasticity of FT by using three statistical approaches that generated plasticity parameters including reaction norm parameters. We detected 25 FT QTL summarized into 10 unique QTL. Mean values and plasticity parameters QTL were co-localized in three of them, including the major 6D_M QTL whose effect is strongly modulated by temperature. The design and validation of a genetic marker for the 6D_M QTL offers great potential for breeding programs, for example for selecting early-flowering strawberry varieties well adapted to different environmental conditions., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology.)

As burden of chronic respiratory diseases is constantly increasing, improving in vitro lung models is essential in order to reproduce as closely as possible the complex pulmonary architecture, responsible for oxygen uptake and carbon dioxide clearance. The study of diseases that affect the respiratory system has benefited from in vitro reconstructions of the respiratory epithelium with inserts in air/liquid interface (2D) or in organoids able to mimic up to the arborescence of the respiratory tree (3D). Recent development in the fields of pluripotent stem cells-derived organoids and genome editing technologies has provided new insights to better understand pulmonary diseases and to find new therapeutic perspectives., (© 2020 médecine/sciences – Inserm.)

Extending the period of fruit production is a way to substantially increase crop yield in many fruit or ornamental species. In the cultivated octoploid strawberry (Fragaria × ananassa), the most consumed small fruit worldwide, fruit production season can be extended by selecting the perpetual flowering (PF) cultivars. This trait is of considerable interest to growers and to the food industry. Four homoeologous loci controlling a single trait can be expected in such a complex octoploid species. However, we recently showed that the PF trait is under the control of the single dominant FaPFRU locus (J. Exp. Bot., 2013, 64, 1837), making it potentially amenable to marker-assisted selection (MAS). Here, we report the successful use of a strategy, based on a selective mapping using a reduced sample of individuals, to identify nine markers in close linkage to the FaPFRU allelic variant. Thus, this strategy can be used to fine map the target homoeologous loci in other complex polyploid crop species. Recombinant analysis further enabled us to reduce the locus to a region flanked by two markers, Bx083_206 and Bx215_131, corresponding to a 1.1 Mb region in the diploid F. vesca reference genome. This region comprises 234 genes, including 15 flowering associated genes. Among these, the FLOWERING LOCUS T (FT) is known to be a key activator of flowering. The close association between the PF trait and the FaPFRU flanking markers was validated using an additional segregating population and genetic resources. This study lays the foundation for effective and rapid breeding of PF strawberry cultivars by MAS., (© 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.)

Impaired airway homeostasis in chronic obstructive pulmonary disease (COPD) could be partly related to club cell secretory protein (CCSP) deficiency. We hypothesize that CCSP G38A polymorphism is involved and aim to examine the influence of the CCSP G38A polymorphism on CCSP transcription levels and its regulatory mechanisms. CCSP genotype and CCSP levels in serum and sputum were assessed in 66 subjects with stable COPD included in a 1-yr observational study. Forty-nine of them had an exacerbation. In an in vitro study, the impact on the CCSP promoter of 38G wild-type or 38A variant was assessed. BEAS-2B cells were transfected by either the 38G or 38A construct, in the presence/absence of cigarette smoke extract (CSE) or lipopolysaccharides (LPS). Cotransfections with modulating transcription factors, p53 and Nkx2.1, identified by in silico analysis by using ConSite and TFSEARCH were conducted. A allele carrier COPD patients had lower serum and sputum CCSP levels, especially among active smokers, and a decreased body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) score. In vitro, baseline CCSP transcription levels were similar between the wild and variant constructs. CSE decreased more profoundly the CCSP transcription level of 38A transfected cells. The opposite effect was observed with p53 cotransfection. LPS stimulation induced CCSP repression in 38A promoter transfected cells. Cotransfection with Nkx2.1 significantly activated the CCSP promoters irrespective of the polymorphism. Circulating CCSP levels are associated with smoking and the CCSP G38A polymorphism. CSE, LPS, and the Nkx2.1 and p53 transcription factors modulated the CCSP promoter efficiency. The 38A polymorphism exaggerated the CCSP repression in response to p53 and CSE., (Copyright © 2016 the American Physiological Society.)