Biology subjects

Bertolucci, C.

Publications and source records attributed to Bertolucci, C..

4 recordsLinked to original sources

bioRxiv2024

miR-210 is essential to retinal homeostasis in fruit flies and mice

miR-210 is one of the most evolutionarily conserved microRNAs. Recent studies in Drosophila melanogaster have unveiled that the absence of miR-210 leads to a progressive retinal degeneration characterized by the accumulation of lipid droplets and disruptions in lipid metabolism. Further investigation into lipid anabolism and catabolism revealed significant alterations in gene expression within these pathways. We provide the first morphological characterization of miR-210 KO mice retinas, highlighting a significant photoreceptor degeneration. While exploring potential parallels between miR-210 KO models in flies and mice, we examined mice lipid metabolism, circadian behaviour, and retinal transcriptome yet found no resemblances, suggesting divergent mechanisms of retinal degeneration between the two species. Simultaneously, analysis of the transcriptome in the brains of miR-210 KO flies revealed the potential existence of a shared upstream mechanism contributing to retinal degeneration in both fruit flies and mammals.

genetics↗

bioRxiv2023

Hagfish genome illuminates vertebrate whole genome duplications and their evolutionary consequences

Whole genome duplications (WGDs) are major events that drastically reshape genome architecture and are causally associated with organismal innovations and radiations1. The 2R Hypothesis suggests that two WGD events (1R and 2R) occurred during early vertebrate evolution2, 3. However, the veracity and timing of the 2R event relative to the divergence of gnathostomes (jawed vertebrates) and cyclostomes (jawless hagfishes and lampreys) is unresolved4-6 and whether these WGD events underlie vertebrate phenotypic diversification remains elusive7. Here we present the genome of the inshore hagfish, Eptatretus burgeri. Through comparative analysis with lamprey and gnathostome genomes, we reconstruct the early events in cyclostome genome evolution, leveraging insights into the ancestral vertebrate genome. Genome-wide synteny and phylogenetic analyses support a scenario in which 1R occurred in the vertebrate stem-lineage during the early Cambrian, and the 2R event occurred in the gnathostome stem-lineage in the late Cambrian after its divergence from cyclostomes. We find that the genome of stem-cyclostomes experienced two additional, independent genome duplications (herein CR1 and CR2). Functional genomic and morphospace analyses demonstrate that WGD events generally contribute to developmental evolution with similar changes in the regulatory genome of both vertebrate groups. However, appreciable morphological diversification occurred only after the 2R event, questioning the general expectation that WGDs lead to leaps of morphological complexity7.

genomics↗

bioRxiv2021

The most comprehensive annotation of the Krill transcriptome provides new insights for the study of physiological processes and environmental adaptation

The krill species Euphausia superba plays a critical role in the food chain of the Antarctic ecosystem, as the abundance of its biomass affects trophic levels both below it and above. Major changes in climate conditions observed in the Antarctic Peninsula region in the last decades have already altered the distribution of the krill population and its reproductive dynamics. A deeper understanding of the adaptation capabilities of this species, and of the molecular mechanisms behind it are urgently needed. The availability of a large body of RNA-seq assays gave us the opportunity to extend the current knowledge of the krill transcriptome, considerably reducing errors and redundancies. Our study covered the entire developmental process, from larval stages to adult individuals, providing information of central relevance for ecological studies. Here we describe the KrillDB2 database, a resource combining the latest annotation of the krill transcriptome with a series of analyses specifically targeting genes and molecular processes relevant to krill physiology. KrillDB2 provides in a single resource the most complete collection of experimental data and bioinformatic annotations: it includes an extended catalog of krill genes; an atlas of their expression profiles over all RNA-seq datasets publicly available; a study of differential expression across multiple conditions such as developmental stages, geographical regions, seasons, and sexes. Finally, it provides initial indications about non-coding RNAs, a class of molecules whose contribute to krill physiology has never been reported before.

ecology↗

bioRxiv2019

Fisheries-induced evolution of the circadian system and collective personality traits

Intensive and trait-selective harvesting of fish and wildlife can cause evolutionary changes in a range of life-history and behavioural traits. These changes might in turn alter the circadian system both at behavioral and molecular levels, with knock-on effects on daily physiological processes and behavioural outputs. We examined the evolutionary impact of size-selective mortality on collective risk-taking behavior and the circadian system in a model fish species. We exposed zebrafish (Danio rerio) to either large or small size-selective mortality relative to a control over five generations, followed by eight generations during which harvesting halted to remove maternal effects. Large size-selective mortality typical of many fisheries and specialized predators targeting larger size classes decreased collective risk-taking behavior compared to controls. The opposite occurred in response to small size-selective mortality typical of specialized fisheries and most gape-limited predators. The evolutionary changes in risk-taking behavior were linked to daily activity rhythms in response to small size-selective mortality, while no changes were observed in response to large size-selective mortality. We also found changes in the molecular circadian core clockwork in response to both size selective mortality treatments. These changes disappeared in the clock output pathway, resulting in similar transcription profiles of both size-selected lines. The results suggest a switch downstream to the molecular circadian core clockwork, leading to overall similar daily activity patterns across selection lines. Our experimental harvest left an evolutionary legacy in collective risktaking behavior and relatedly in the circadian system, both at behavioral and molecular levels. Changes to risk-sensitive behavior of exploited organisms can have far-reaching consequences for how space and time is used and may also affect catchability and natural predation.

evolutionary biology↗