Biology subjects

Gutierrez-Pinto, N.

Publications and source records attributed to Gutierrez-Pinto, N..

3 recordsLinked to original sources

bioRxiv2021

Genetic variation in haemoglobin regulates breathing in high-altitude deer mice

Physiological systems often have emergent properties but the effects of genetic variation on physiology are often unknown, which presents a major challenge to understanding the mechanisms of phenotypic evolution. We investigated the in vivo effects on respiratory physiology of genetic variants in haemoglobin (Hb) that contribute to hypoxia adaptation in high-altitude deer mice (Peromyscus maniculatus). We created F2 inter-population hybrids of highland and lowland deer mice to test the phenotypic effects of - and {beta}-globin variants on a mixed genetic background. High-altitude genotypes were associated with breathing phenotypes that enhance O2 uptake in hypoxia, including a deeper more effective breathing pattern and an augmented hypoxic ventilatory response. These effects could not be explained by erythrocyte Hb-O2 affinity or globin gene expression in the brainstem. Therefore, adaptive variation in haemoglobin can have unexpected effects on physiology that are distinct from the canonical function of this protein in circulatory O2 transport.

evolutionary biology↗

bioRxiv2020

A test of altitude-related variation in aerobic metabolism of Andean birds

Endotherms at high altitude face the combined challenges of cold and hypoxia. Cold increases thermoregulatory costs, and hypoxia may limit both thermogenesis and aerobic exercise capacity. Consequently, in comparisons between closely related highland and lowland taxa, we might expect to observe consistent differences in basal metabolism (BMR), maximal metabolism (MMR), and aerobic scope. Broad-scale comparative studies of birds reveal no association between BMR and native elevation, and altitude effects on MMR have not been investigated. We tested for altitude-related variation in aerobic metabolism in 10 Andean passerines representing five pairs of closely related species with contrasting elevational ranges. Mass-corrected BMR and MMR were significantly higher in most highland species relative to their lowland counterparts, but there was no uniform elevational trend across all pairs of species. Summary statementWe tested for altitude-related variation in aerobic metabolism in species pairs with contrasting elevational ranges. Metabolic rates were significantly higher in most highland species but there was no uniform elevational trend.

physiology↗

bioRxiv2017

An extinct hummingbird species that never was: a cautionary tale about sampling issues in molecular phylogenetics

The Bogota Sunangel (Heliangelus zusii) was described based on a historical specimen lacking locality data as a striking-and potentially extinct- new species of hummingbird more than two decades ago. However, it was considered a dubious taxon by some researchers until a molecular study with strong species-level taxon sampling revealed its phylogenetic affinities and validated its status as a distinct species. We reanalysed existing mitochondrial DNA data together with a new data set sampling multiple populations of the Long-tailed Sylph (Aglaiocercus kingii), a species broadly distributed in the Andes of South America. In contrast to previous work, we found that H. zusii shares a haplotype with specimens of A. kingii from the Eastern Cordillera of Colombia, which is phylogenetically nested within a clade formed by populations of A. kingii from the Colombian Andes. These results suggest that H. zusii is not a distinct species, but is most likely the result of hybridization between a female A. kingii and a male of another hummingbird species. These findings highlight the importance of thorough taxonomic and geographic sampling when assessing the likelihood of hybrid origin of an organism, particularly in cases potentially involving wide-ranging species in areas where deep phylogeographic structure is likely.

evolutionary biology↗