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Munoz-Guzman, F.

Publications and source records attributed to Munoz-Guzman, F..

2 recordsLinked to original sources

Domestication signatures in the non-conventional yeast Lachancea cidri

Evaluating domestication signatures beyond model organisms is essential for thoroughly understanding the genotype-phenotype relationship in wild and human-related environments. Structural variations (SVs) can significantly impact phenotypes playing an important role in the physiological adaptation of species to different niches, including during domestication. A detailed characterization of the fitness consequences of these genomic rearrangements, however, is still limited in non-model systems, largely due to the paucity of direct comparisons between domesticated and wild isolates. Here, we used a combination of sequencing strategies to explore major genomic rearrangements in a Lachancea cidri yeast strain isolated from cider (CBS2950) and compared them to those in eight wild isolates from primary forests. Genomic analysis revealed dozens of SVs, including a large reciprocal translocation ([~]16 kb and 500 kb) present in the cider strain, but absent from all wild strains. Interestingly, the number of SVs was higher relative to single-nucleotide polymorphisms in the cider strain, suggesting a significant role on the strains phenotypic variation. The set of SVs identified directly impacts dozens of genes, and likely underpins the greater fermentation performance in the L. cidri CBS2950. Additionally, the large reciprocal translocation affects a proline permease (PUT4) regulatory region, resulting in higher PUT4 transcript levels, which agrees with higher ethanol tolerance, improved cell growth when using proline, and higher amino acid consumption during fermentation. These results suggest that SVs are responsible for the rapid physiological adaptation of yeast to an anthropogenic habitat and demonstrate the key contribution of SVs in adaptive fermentative traits in non-model species. ImportanceThe exploration of domestication signatures associated with anthropogenic niches has predominantly focused on studies conducted on model organisms, such as Saccharomyces cerevisiae, overlooking the potential for comparisons across other non-Saccharomyces species. In our research, employing a combination of long- and short-read data, we found domestication signatures in L. cidri, a non-model species recently isolated from fermentative environments in cider in France. The significance of our study lies in the identification of large array of major genomic rearrangements in a cider strain compared to wild isolates, which underly several fermentative traits. These domestication hallmarks result from structural variants, which are likely responsible for the phenotypic differences between strains, providing a rapid path of adaptation to human-related environments.

genetics↗

Developing a temperature-inducible transcriptional rheostat in Neurospora crassa

Heat shock protein (hsp) encoding genes, part of the highly conserved Heat Shock Response (HSR), are known to be induced by thermal stress in several organisms. In Neurospora crassa, three hsp genes, hsp30, hsp70, and hsp80, have been characterized; however, the role of defined cis-elements in their response to discrete changes in temperature remains largely unexplored. To fill this gap, while also aiming to obtain a reliable fungal heat-shock inducible system, we analyzed different sections of each hsp promoter, by assessing the expression of real-time transcriptional reporters. Whereas all three promoters, and their resected versions, were acutely induced by high temperatures, only hsp30 displayed a broad range of expression and high tunability amply exciding other inducible promoter systems existing in Neurospora, such as Quinic acid- or light-inducible ones. As proof of concept, we employed one of these promoters to control the expression of clr-2, which encodes for the master regulator of Neurospora cellulolytic capabilities. The resulting strain fails to grow on cellulose at 25{degrees}C, whereas it robustly grows if heat shock pulses are delivered daily. Additionally, we designed two hsp30 synthetic promoters and characterized these, as well as the native promoters, to a gradient of high temperatures, yielding a wide range of responses to thermal stimuli. Thus, Neurospora hsp30-based promoters represent a new set of modular elements that can be used as a transcriptional rheostat to adjust the expression of a gene of interest or for the implementation of regulated circuitries for synthetic biology and biotechnological strategies. ImportanceTimely and dynamic response to strong temperature rises is paramount for organismal biology. At the same time, inducible promoters are a powerful tool for fungal biotechnological and synthetic biology endeavors. In this work, we analyzed the activity of several N. crassa heat shock protein (hsp) promoters upon a wide range of temperatures, observing that hsp30 exhibits remarkable sensitivity and dynamic range of expression as we chartered the response of this promoter to subtle increases in temperature, while also building synthetic promoters based on hsp30 cis-elements. As proof of concept, we analyzed the ability of hsp30 to provide tight control of a central process such as cellulose degradation. While this study provides an unprecedented description of the regulation of the N. crassa hsp genes it also contributes with a noteworthy addition to the molecular toolset of transcriptional controllers in filamentous fungi.

molecular biology↗