Biology subjects

Cueff, G.

Publications and source records attributed to Cueff, G..

4 recordsLinked to original sources

bioRxiv2024

Generation of diversity in the blue cheese mold Penicillium roqueforti and identification of pleiotropic QTL for key cheese-making phenotypes

Elucidating the genomic architecture of quantitative traits is essential for our understanding of adaptation and for breeding in domesticated organisms. Penicillium roqueforti is the mold used worldwide for the blue cheese maturation, contributing to flavors through proteolytic and lipolytic activities. The two domesticated cheese populations display very little genetic diversity, but are differentiated and carry opposite mating types. We produced haploid F1 progenies from five crosses, using parents belonging to cheese and non-cheese populations. Analyses of high-quality genome assemblies of the parental strains revealed five large translocations, two having occurred via a circular intermediate. Offspring genotyping with genotype-by-sequencing (GBS) revealed several genomic regions with segregation distortion, possibly linked to degeneration in cheese lineages. We found transgressions for several traits relevant for cheese making, with offspring having more extreme trait values than parental strains. We identified quantitative trait loci (QTLs) for colony color, lipolysis, proteolysis, extrolite production, including mycotoxins, but not for growth rates. Some genomic regions appeared rich in QTLs for both lipid and protein metabolism, and other regions for the production of multiple extrolites, indicating that QTLs have pleiotropic impacts. Some QTLs corresponded to known biosynthetic gene clusters, e.g., for the production of melanin or extrolites. F1 hybrids constitute valuable strains for cheese producers, with new traits and genetic diversity, and allowed identifying target genomic regions for traits important in cheese making, paving the way for strain improvement. The findings further contribute to our understanding of the genetic mechanisms underlying rapid adaptation, revealing convergent adaptation targeting major regulators.

evolutionary biology↗

bioRxiv2024

Different metabolite profiles across Penicillium roqueforti populations associated with ecological niche specialisation and domestication

Fungi are known to produce many chemically diversified metabolites, yet their ecological roles are not always fully understood. The blue cheese making fungus Penicillium roqueforti thrives in different ecological niches and is known to produce a wide range of metabolites, including mycotoxins. Three P. roqueforti populations have been domesticated for cheese production and two populations thrive in other anthropized environments, i.e., spoiled food, lumber and silage. Here, we looked for differences in targeted and untargeted metabolite production profiles between populations using HPLC-HR-Q-TOF and UHPLC-Q-TOF-HR-MS/MS. The non-cheese populations produced several fatty acids and different terpenoids, lacking in cheese strains. The Termignon cheese population displayed intermediate metabolite profiles between cheese and non-cheese populations, as previously shown for other traits. The non-Roquefort population, the cheese population with the strongest domestication syndrome, produced the lowest quantities of measured metabolites, including known mycotoxins such as mycophenolic acid (MPA), andrastin A and PR toxin. Its inability to produce MPA was due to a deletion in the mpaC gene, while a premature stop codon in ORF 11 of the PR toxin gene cluster explained its absence and the accumulation of its eremofortin A & B intermediates. In the Roquefort population, we detected no PR toxin nor eremofortins A or B, but found no indel or frameshift mutation, suggesting downregulation. Our results suggest that domesticated cheese populations were selected for lower toxin production while populations from other anthropized environments maintained high metabolite diversity, the bioactivities of these compounds being likely important in these ecological niches.

microbiology↗

bioRxiv2023

A transcriptomic dataset for investigating the Arabidopsis Unfolded Protein Response under chronic, proteotoxic endoplasmic reticulum stress

The Unfolded Protein Response (UPR) is a retrograde, ER-to-nucleus, signalling pathway which is conserved across kingdoms. In plants, it contributes to development, reproduction, immunity and tolerance to abiotic stress. This RNA sequencing dataset was produced from 14-day-old Arabidopsis thaliana seedlings challenged by tunicamycin (Tm), an antibiotic inhibiting Asn-linked glycosylation in the endoplasmic reticulum (ER), causing an ER stress and eventually activating the UPR. Wild-type (WT) and a double mutant deficient for two main actors of the UPR (INOSITOL-REQUIRING ENZYME 1A and INOSITOL-REQUIRING ENZYME 1B) were used as genetic backgrounds in our experimental setup, allowing to distinguish among differentially-expressed genes (DEGs) which ones are dependent on or independent on IRE1s. Also, shoots and roots were harvested separately to determine organ-specific transcriptomic responses to Tm. Library and sequencing were performed using DNBseq technology by the Beijing Genomics Institute. Reads were mapped and quantified against the Arabidopsis genome. Differentially-expressed genes were identified using Rflomics upon filtering and normalization by the Trimmed Mean of M-value (TMM) method. While the genotype effect was weak under mock conditions (with a total of 182 DEGs in shoots and 195 DEGs in roots), the tunicamycin effect on each genotype was characterized by several hundred of DEGs in both shoots and roots. Among these genes, 872 and 563 genes were statistically up- and down-regulated in the shoot tissues of the double mutant when compared to those of WT, respectively. In roots of Tm-challenged seedlings, 425 and 439 genes were significantly up- and down-regulated in mutants with respect to WT. We believe that our dataset could be reused for investigating any biological questions linked to ER homeostasis and its role in plant physiology. SPECIFICATIONS TABLE O_TBL View this table: org.highwire.dtl.DTLVardef@a6de12org.highwire.dtl.DTLVardef@13d7c62org.highwire.dtl.DTLVardef@1b14109org.highwire.dtl.DTLVardef@24dbaborg.highwire.dtl.DTLVardef@1d1c1e1_HPS_FORMAT_FIGEXP M_TBL C_TBL

plant biology↗

bioRxiv2023

Aurora A mediated new phosphorylation of RAD51 is observed in Nuclear Speckles

To maintain its genome integrity, the cell uses complementary and orchestrated processes, among which is the DNA Damage Response. Pre mRNA maturation is an essential step of the DNA damage response that provides an adapted proteome in order to face genotoxic stress. We describe here a new phosphorylation of the RAD51 recombinase, on its Ser97 residue. This new Aurora A mediated RAD51 phosphorylation modulates its in vitro activity evaluated by D-loop and polymerization assays. Using recombinant proteins, we show that RAD51 is an RNA binding protein and that the Ser97 phosphorylation modulates its RNA binding affinity in vitro. Using a specifically generated antibody we revealed that this Ser97 phosphorylation is correlated with RAD51 localization into the RNA maturation membrane less organelles, Nuclear Speckles. We describe here for the first time the presence of RAD51 DNA repair factor within the Nuclear Speckles, raising the hypothesis of a possible role for RAD51 in splicing modulation. This point is of particular interest in the context of splicing profiles modulations associated with radio and/or chemoresistance.

cell biology↗