Biology subjects

Monte, A.

Publications and source records attributed to Monte, A..

3 recordsLinked to original sources

bioRxiv2024

Convergent and lineage-specific genomic changes contribute to adaptations in sugar-consuming birds

High-sugar diets cause human metabolic diseases, yet several bird lineages convergently adapted to feeding on sugar-rich nectar or fruits. We investigated the underlying molecular mechanisms in hummingbirds, parrots, honeyeaters, and sunbirds by generating nine new genomes and 90 tissue-specific transcriptomes. Comparative screens revealed an excess of repeated selection in both protein-coding and regulatory sequences in sugar-feeding birds, suggesting reuse of genetic elements. Sequence or expression changes in sugar-feeders affect genes involved in blood pressure regulation, lipid, amino acid and carbohydrate metabolism, with experiments showing functional changes in honeyeater hexokinase 3. MLXIPL, a key regulator of sugar and lipid homeostasis, showed convergent sequence and regulatory changes across all sugar-feeding clades; experiments revealed enhanced sugar-induced transcriptional activity of hummingbird MLXIPL, highlighting its adaptive role in high-sugar diets. Summary Figure: Our comparative screens across four independent sugar-feeding bird groups identified both repeated and lineage-specific targets of selection O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=65 SRC="FIGDIR/small/610474v2_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@148f5c8org.highwire.dtl.DTLVardef@1005dbaorg.highwire.dtl.DTLVardef@1097facorg.highwire.dtl.DTLVardef@9d365c_HPS_FORMAT_FIGEXP M_FIG C_FIG

evolutionary biology↗

bioRxiv2023

Genome analysis of Legionella pneumophila ST901 an Italian endemic strain.

Legionella pneumophila typing, based on SBT analysis, has been allowing to identify sequence types (ST) responsible for many Legionnaires disease cases. ST901 has so far been identified only in a town of the northern Italy, where it caused numerous travel-associated Legionnaires disease cases over a 32-year period. In this study, ST901 were analyzed by whole genome sequencing in looking for both differences and similarities inside this ST and with other unrelated Legionella strains. To this aim core genome multi locus sequence type, single nucleotide polymorphisms and pangenome analyses were performed. ST901 resulted highly similar each other, characterized by I-C CRISPR-cas system, located on the chromosome and by a putative plasmid, highly similar to that found in Lp strain Lens, which contains I-F CRISPR-cas system. Accessory genomic islands, either already described or specifically found in ST901, were also shown. In conclusion ST901 has been quite preserved over the time. The co-occurrence of two phage resistance systems and genomic islands of virulence could have made the ST901 enough virulent to cause such a high number of cases. Summary blurbST901 appears as endemic of the Northern Italy, with virulence traits similar to those in Alcoy and Corby, and with two CRISPR-cas systems which probably preserved them in their environmental niche.

genomics↗

bioRxiv2020

Morphological facilitators for vocal learning explored through the syrinx anatomy of a basal hummingbird

Vocal learning is a rare evolutionary trait that evolved independently in three avian clades: songbirds, parrots, and hummingbirds. Although the anatomy and mechanisms of sound production in songbirds are well understood, little is known about the hummingbirds vocal anatomy. We use high-resolution micro-computed tomography (CT) and microdissection to reveal the three-dimensional structure of the syrinx, the vocal organ of the black jacobin (Florisuga fusca), a phylogenetically basal hummingbird species. We identify three unique features of the black jacobins syrinx: (i) a shift in the position of the syrinx to the outside of the thoracic cavity and the related loss of the sterno-tracheal muscle, (ii) complex intrinsic musculature, oriented dorso-ventrally, and (iii) ossicles embedded in the medial vibratory membranes. Their syrinx morphology allows vibratory decoupling, precise control of complex acoustic parameters, and a large redundant acoustic space that may be key biomechanical factors facilitating the occurrence of vocal production learning.

evolutionary biology↗