Biology subjects

Muntane, G.

Publications and source records attributed to Muntane, G..

8 recordsLinked to original sources

bioRxiv2026

Convergent Amino-Acid Substitutions Link Primate Longevity to Male-Fertility Genes

Maximum lifespan varies widely among mammals, but the genomic basis of this variation remains incompletely understood. We used body-mass-corrected longevity and a phylogenetically informed phenotype-shift framework to compare 126 primate species, selecting seven long-lived and six short-lived species for convergent amino-acid substitution analysis. Stringent pooling across species identified 1,068 recurrent phenotype-associated positions in 934 genes. These genes showed significant agreement with mammal-wide longevity candidates, with 226 genes shared compared with 120 expected by chance (1.88-fold enrichment; P = 1.16 x 10exp-22). Functional analysis detected 17 significant terms, with the strongest coherent signal involving male infertility and decreased male fertility. Our results show that focused primate sampling recovers a non-random component of the broader mammalian longevity signal and point to male reproductive biology as a promising direction for investigating the evolution of lifespan.

evolutionary biology↗

bioRxiv2026

Mesenchymal predominance in olfactory epithelium-derived cultures limits modeling of neurodevelopmental brain disorders

The human olfactory epithelium (OE) represents a lifelong source of neural progenitor cells and has been proposed as an accessible model to investigate molecular alterations associated with neurodevelopmental disorders in postnatal individuals. Globose basal cells are considered the immediate neuronal progenitors within the OE, and several studies have attempted to culture these cells from nasal exfoliates. However, the actual contribution of neurogenic lineages in these cultures remains largely unquantified. Here, we cultured human nasal explants using an established protocol and characterized the resulting cell populations by immunohistochemistry and single-cell RNA sequencing. Integration with primary in vivo OE datasets revealed that these cultures are predominantly composed of mesenchymal-like cells, with limited representation of globose basal cells and neurons, and low expression of canonical neuronal markers. Using curated gene sets associated with neurodevelopmental disorders and malformations of cortical development, we assessed the extent to which disease-relevant transcriptional programs are captured in OE-derived cultures. While disease-associated genes are enriched in neurogenic lineages in vivo, their representation in mesenchymal cells is reduced. Together, our results challenge the assumption that standard OE culture systems faithfully model neurogenic compartments and suggest that current approaches may need refinement to recover neurogenic lineages.

neuroscience↗

bioRxiv2025

Statistical detection of protein sites associated with continuous traits

Comparative genomic data can be used to look for substitutions in coding sequences that are associated with the variation of a particular phenotypic trait. A few statistical methods have been proposed to do so for phenotypes represented by discrete values. For continuous traits, no such statistical approach has been proposed, and researchers have resorted to sensible but uncharacterized criteria. Here, we investigate a phylogenetic model for coding sequences where amino acid preferences at a site are given by a continuous function of a quantitative trait. This function is inferred from the amino acids and the trait values in extant species and requires inferred point estimates of ancestral values of the trait at internal nodes. For detecting sites whose evolution is associated with this trait, we use a significance test against the hypothesis that amino acid preference does not depend on the trait. This procedure is compared to simpler strategies on simulated alignments. It displays an increased recall for low false positive rates, which is of special importance for performing whole-genome scans. This comes however at a much higher computational cost, and we suggest using a simple test to filter promising candidate sites. We then revisit a dataset of alignments for 62 species of mammals, using longevity as a phenotypic trait. We apply our method to three protein families that have previously been proposed to display sites associated with variation in lifespan in mammals. Using a graphical representation extracted from the detailed phylogenetic analysis of candidate sites, we suggest that the evidence for this in the sequence data alone is weak. The proposed method has been added to our Pelican software. It is available at https://gitlab.in2p3.fr/phoogle/pelican and can now be used with both discrete and continuous phenotypes to search for sites associated with phenotypic variation, on data sets with thousands of alignments.

bioinformatics↗

bioRxiv2022

CAAStools, a toolbox to identify and test Convergent Amino Acid Substitutions.

BackgroundCoincidence of Convergent Amino Acid Substitutions (CAAS) with phenotypic convergences allow pinpointing genes and even individual mutations that are likely to be associated with trait variation within their phylogenetic context. Such findings can provide useful insights into the genetic architecture of complex phenotypes. Here we introduce CAAStools, a set of bioinformatics tools to identify and validate CAAS in orthologous protein alignments for pre-defined groups of species representing the phenotypic values targeted by the user. Implementation and availabilityCAAStools source code is available at http://github.com/linudz/caastools, along with documentation and examples. Supplementary informationSupplementary data are available.

bioinformatics↗

bioRxiv2022

Functional characterization of the Met50Val substitution in SLC30A9 as a novel case of adaptive introgression in humans

SLC30A9 encodes a ubiquitously zinc transporter (ZnT9) and has been consistently suggested as a candidate for positive selection in humans. However, no direct adaptive molecular phenotype has been demonstrated. Our results provide evidence for directional selection operating in two major complementary haplotypes in Africa and East Asia. These haplotypes are associated with differential gene expression but also differ in the Met50Val substitution (rs1047626) in ZnT9, which we show is found in homozygosis in the Denisovan genome and displays accompanying signatures suggestive of archaic introgression. Although we found no significant differences in systemic zinc content between individuals with different rs1047626 genotypes, we demonstrate that the expression of the derived isoform (ZnT9 50Val) in HEK293 cells shows a gain of function when compared with the ancestral (ZnT9 50Met) variant. Notably, the ZnT9 50Val variant was found associated with differences in zinc handling by the mitochondria and endoplasmic reticulum, with an impact on mitochondrial metabolism. Given the essential role of the mitochondria in skeletal muscle and since the derived allele at rs1047626 is known to be associated with greater susceptibility to several neuropsychiatric traits, we propose that adaptation to cold may have driven this selection event, while also impacting predisposition to neuropsychiatric disorders in modern humans. Author SummaryContrasting continental signatures of positive natural selection have been previously found in the human SLC30A9 gene encoding the protein ZnT9, which transports zinc across cell membranes. Here we investigate the genetic variants that have been targeted by natural selection in the surrounding region of this gene and which molecular and whole-body changes may have brought about. We found that two major SLC30A9 variant combinations (haplotypes) that are extremely frequent in Africa and East Asia, respectively, are expressed differentially. These two haplotypes also differ at one site that creates an amino acid difference at ZnT9; the version most often found outside Africa avoiding zinc overload in the endoplasmic reticulum and mitochondria and directly influencing mitochondrial activity. Moreover, we found that this substitution, which is known to be associated with greater susceptibility to several neuropsychiatric disorders, is present in the Denisova and displays accompanying patterns of variation that could be suggestive of adaptive introgression. Since mitochondria play an important role in skeletal muscle energy metabolism, we speculate that adaptation to cold may have driven this selection event outside Africa, while also impacting predisposition to neuropsychiatric disorders in modern humans.

evolutionary biology↗

bioRxiv2021

Comparative analysis of mammal genomes unveils key genomic variability for human lifespan.

Mammals vary 100-fold in their maximum lifespan. This enormous variation is the result of the adaptations of each species to their own biological trade-offs and ecological conditions. Comparative genomics studies have demonstrated that the genomic factors underlying the lifespans of species and the longevity of individuals are shared across the tree of life. Here, we set out to compare protein-coding regions across the mammalian phylogeny, aiming to detect individual amino acid changes shared by the most long-lived mammal species and genes whose rates of protein evolution correlate with longevity. We discovered a total of 2,737 amino acid changes in 2,004 genes that distinguish long- and short-lived mammals, significantly more than expected by chance (p=0.003). The detected genes belong to pathways involved in regulating lifespan, such as inflammatory response and hemostasis. Among them, a total 1,157 amino acids, located in 996 different genes, showed a significant association with maximum lifespan in a phylogenetically controlled test. Interestingly, most of the detected amino acids positions do not vary in extant human populations (>81.2%) or have allele frequencies below 1% (99.78%), Consequently, almost none could have been detected by Genome-Wide Association Studies (GWAS). Additionally, we identified four more genes whose rate of protein evolution correlated with longevity in mammals. Crucially, SNPs located in the detected genes explain a larger fraction of human lifespan heritability than expected by chance, successfully demonstrating for the first time that comparative genomics can be used to enhance the interpretation of human GWAS. Finally, we show that the human longevity-associated proteins coded by the detected genes are significantly more stable than the orthologous proteins from short-lived mammals, strongly suggesting that general protein stability is linked to increased lifespan.

genomics↗

bioRxiv2020

Evolutionary phenome-genome analysis of cranial suture closure in mammals

Cranial sutures are growth and stress diffusion sites that connect the bones protecting the brain. The closure of cranial suture is a key feature of mammalian late development and evolution, which can also lead to head malformations when it occurs prematurely (craniosynostosis). To unveil the phenotypic and genetic causes of suture closure in evolution, we examined 48 mammalian species searching for (i) causal links between suture patency, brain size, and diet using phylogenetic path analysis; and (ii) instances of genome-phenome convergence amino acid substitutions. Here we show that brain size and the anteroposterior order of ossification of the skull are the two main causes of sutures patency in evolution. We also identified three novel candidate genes for suture closure in evolution (HRNR, KIAA1549, and TTN), which have never been reported in clinical studies of craniosynostosis. Our results suggest that different genetic pathways underlie cranial suture closure in evolution and disease.

evolutionary biology↗

bioRxiv2018

Genome-wide study identifies 611 loci associated with risk tolerance and risky behaviors

Humans vary substantially in their willingness to take risks. In a combined sample of over one million individuals, we conducted genome-wide association studies (GWAS) of general risk tolerance, adventurousness, and risky behaviors in the driving, drinking, smoking, and sexual domains. We identified 611 approximately independent genetic loci associated with at least one of our phenotypes, including 124 with general risk tolerance. We report evidence of substantial shared genetic influences across general risk tolerance and risky behaviors: 72 of the 124 general risk tolerance loci contain a lead SNP for at least one of our other GWAS, and general risk tolerance is moderately to strongly genetically correlated ([Formula] to 0.50) with a range of risky behaviors. Bioinformatics analyses imply that genes near general-risk-tolerance-associated SNPs are highly expressed in brain tissues and point to a role for glutamatergic and GABAergic neurotransmission. We find no evidence of enrichment for genes previously hypothesized to relate to risk tolerance.

genetics↗