skip to main content


Title: To what extent do physiological tolerances determine elevational range limits of mammals?
Abstract

A key question in biology concerns the extent to which distributional range limits of species are determined by intrinsic limits of physiological tolerance. Here, we use common‐garden data for wild rodents to assess whether species with higher elevational range limits typically have higher thermogenic capacities in comparison to closely related lowland species. Among South American leaf‐eared mice (genusPhyllotis), mean thermogenic performance is higher in species with higher elevational range limits, but there is little among‐species variation in the magnitude of plasticity in this trait. In the North American rodent genusPeromyscus, highland deer mice (Peromyscus maniculatus) have greater thermogenic maximal oxygen uptake () than lowland white‐footed mice (Peromyscus leucopus) at a level of hypoxia that matches the upper elevational range limit of the former species. In highland deer mice, the enhanced thermogenic in hypoxia is attributable to a combination of evolved and plastic changes in physiological pathways that govern the transport and utilization of O2and metabolic substrates. Experiments withPeromyscusmice also demonstrate that exposure to hypoxia during different stages of development elicits plastic changes in cardiorespiratory traits that improve thermogenic via distinct physiological mechanisms. Evolved differences in thermogenic capacity provide clues about why some species are able to persist in higher‐elevation habitats that lie slightly beyond the tolerable limits of other species. Such differences in environmental tolerance also suggest why some species might be more vulnerable to climate change than others.image

 
more » « less
Award ID(s):
2114465
PAR ID:
10471147
Author(s) / Creator(s):
 ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
The Journal of Physiology
ISSN:
0022-3751
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract

    Diverse alkenylboronic acids react smoothly with varioussp3‐carbon electrophiles such as unactivated alkyl triflates in the presence of mild bases such as K3PO4. The reaction protocol is very mild and thereby enables high functional group tolerance. This transition metal‐free condition is orthogonal towards the classic transition metal catalyzed Suzuki coupling.

    magnified image

     
    more » « less
  2. Abstract

    A Lewis acid‐catalyzed formal [3+3] cascade annulation strategy for the formation of diverse tricyclic compounds possessing functionalized pyrano[3,2‐c]chromen‐5(2H)‐one fragments has been developed using propargylic alcohols and 4‐hydroxy‐2H‐chromen‐2‐ones as the substrates. The protocol provides a one‐step, environmentally benign method of accessing a broad range of pyrano[3,2‐c]chromen‐5(2H)‐one derivatives in excellent yields under mild conditions and with good functional‐group tolerance. The method is effective on the gram scale, which highlights the inherent practicality of this synthetic transformation.

    magnified image

     
    more » « less
  3. Abstract

    An atom‐economic approach for the synthesis ofN‐(2‐acetoxyalkyl)isoquinolones from oxazolines and alkynes through rhodium(III)‐catalyzed auto‐tandem reactions involving C−H bond functionalization/C−N bond formation/ring opening/nucleophilic substitution is described. This protocol features high regioselectivity, tolerance of various functional groups, and retention of absolute configuration of chirality. Exploration of the reaction mechanism reveals that Cu(OAc)2not only acts as the oxidant, but also provides acetate to promote the reaction in this process.

    magnified image

     
    more » « less
  4. Abstract

    A novel copper(II) trifluoromethanesulfonate‐catalyzed intermolecular cascade annulation strategy for the construction of a great variety of pentacyclic compounds possessing valuable carbazole fragments was developed employing propargylic alcohols and (Z)‐2‐styryl‐1H‐indoles as the initial substrates. This protocol, which entails a sequential Meyer‐Schuster rearrangement/isomerization/‐cyclization cascade, enables facile and atom‐economical access to various pentacyclic compounds with broad functional‐group tolerance in good yields under mild conditions. The conversion could be efficiently scaled up to gram quantities, accentuating a potential application of this work.

    magnified image

     
    more » « less
  5. Environmental hypoxia challenges female reproductive physiology in placental mammals, increasing rates of gestational complications. Adaptation to high elevation has limited many of these effects in humans and other mammals, offering potential insight into the developmental processes that lead to and protect against hypoxia-related gestational complications. However, our understanding of these adaptations has been hampered by a lack of experimental work linking the functional, regulatory, and genetic underpinnings of gestational development in locally adapted populations. Here, we dissect high-elevation adaptation in the reproductive physiology of deer mice (Peromyscus maniculatus), a rodent species with an exceptionally broad elevational distribution that has emerged as a model for hypoxia adaptation. Using experimental acclimations, we show that lowland mice experience pronounced fetal growth restriction when challenged with gestational hypoxia, while highland mice maintain normal growth by expanding the compartment of the placenta that facilitates nutrient and gas exchange between gestational parent and fetus. We then use compartment-specific transcriptome analyses to show that adaptive structural remodeling of the placenta is coincident with widespread changes in gene expression within this same compartment. Genes associated with fetal growth in deer mice significantly overlap with genes involved in human placental development, pointing to conserved or convergent pathways underlying these processes. Finally, we overlay our results with genetic data from natural populations to identify candidate genes and genomic features that contribute to these placental adaptations. Collectively, these experiments advance our understanding of adaptation to hypoxic environments by revealing physiological and genetic mechanisms that shape fetal growth trajectories under maternal hypoxia.

     
    more » « less