The genomic adaptations to cope with unpredictable climates over the course of life

Projektinformationen

ClimAdaptLife

ID Finanzhilfevereinbarung: 101077722

DOI

10.3030/101077722

EK-Unterschriftsdatum 12 Dezember 2022

Startdatum 1 Mai 2023

Enddatum 30 April 2028

Finanziert unter

• European Research Council (ERC)

Gesamtkosten

€ 1 497 883,00

EU-Beitrag

€ 1 497 883,00

Koordiniert durch

AARHUS UNIVERSITET
Denmark

Periodic Reporting for period 1 - ClimAdaptLife (The genomic adaptations to cope with unpredictable climates over the course of life)

Berichtszeitraum: 2023-05-01 bis 2025-10-31

Zusammenfassung vom Kontext und den Gesamtzielen des Projekts

To determine how animals will respond to climate change, we must first understand the evolution of heat and cold tolerance. Large animals are particularly challenged by temperature changes, as they have a disproportionately large change in body size from young to adult. As young animals, their small bodies make them vulnerable to cold but resilient to heat. Conversely, the large bodies make adults resilient to cold and vulnerable to heat. In this project, we use the world's largest bird, the ostrich, as a representative of large warm-blooded animals and map the genes that are important for their persistence when it gets really hot and cold for both young and adults. The ostrich is unique in that it reproduces in both hot areas such as the Kalahari Desert and temperate regions such as the Cape of Good Hope, and can thus provide insight into what is required of different life-stages in extreme environments. This project will give us an understanding of how large animals adapt to temperature changes, and which life stages set the limits to this adaptation. This will give us unprecedented insight into the potential and limitations for both wild and domesticated large animals to adapt to a future more variable climate.

We will test two hypotheses

a) Heat and cold resilience are mechanistically linked causing thermoregulatory trade-offs.
b) Differences in selection for cold and heat resilience across life will constrain responses to fluctuating climates.

To test these hypotheses, we will 1) identify the genes important for heat and cold resilience in young and older individuals, 2) determine the associated molecular and physiological mechanisms involved in trade-offs between heat and cold tolerance, and 3) establish the role of these mechanisms in adaptation to natural local climatic conditions.

Arbeit, die ab Beginn des Projekts bis zum Ende des durch den Bericht erfassten Berichtszeitraums geleistet wurde, und die wichtigsten bis dahin erzielten Ergebnisse

1. Finding genes underlying juvenile and adult thermal resilience

We have successfully estimated adult heat and cold resilience of all captive females at the ostrich research farm in Oudtshoorn, South Africa. We have successfully extracted DNA and sequenced the first batch of the most informative individual adults and will continue this effort in the coming year. Preliminary analyses of the first batch show that sequencing was successful and that it will allow estimation of individual genotypes by imputation.

2. Finding the molecular mechanisms involved in thermoregulation

In 2023, my PhD student and myself undertook a field expedition to Oudtshoorn Research Farm in South Africa. Here we sampled blood from ostrich chicks when hot and cold. We have successfully extracted RNA from these samples and sequenced this RNA. With this data we have now identified the mechanisms that are important for thermoregulation when cold and hot. Interestingly there appears to be a very large overlap between genes involved in the heat and cold response, confirming hypothesis a of the project. As we sampled both very young juveniles and intermediate aged juveniles, we are currently analysing how the cold vs heat response differs across life (hypothesis b of the project).

In fall 2024 we again visited Oudtshoorn Research Farm in South Africa to set up an experiment monitoring the body temperature of ostrich chicks. All these chicks were exposed to natural temperature fluctuations, and we repeatably took blood samples at very hot days, very cold days and more benign days. With this design we can achieve the planned outcome of identifying the individual variation in thermoregulatory capacity. By extracting and sequencing RNA from the sampled blood and relating this to the individual thermoregulatory capacity we can identify the genes that differentiate individual thermoregulatory capacity when hot versus cold (hypothesis a of the project). As the birds are monitored from young to very close to full adult weight, we will be able to analyse how thermoregulatory capacity changes across life-stages (hypothesis b of the project), and link this to individual genotypes.

3. Role of temperature-related genes in local adaptation of natural populations

We have developed and successfully tested a DNA extraction protocol from feathers. This is important as it means we can collect DNA samples non-invasively from natural populations by collecting dropped feathers. Based on this work we have established several contacts in South Africa that have so far resulted in the collection of 60 samples from natural populations at two sites. We have also secured 3 samples from Tanzania and have established new contacts in Kenya.
In fall 2025 we will go on a field trip to South Africa to finalise collections of samples.

Fortschritte, die über den aktuellen Stand der Technik hinausgehen und voraussichtliche potenzielle Auswirkungen (einschließlich der bis dato erzielten sozioökonomischen Auswirkungen und weiter gefassten gesellschaftlichen Auswirkungen des Projekts)

1. Genes involved in heat and cold responses were generally unknown for birds and other endotherms. With these characterised in this project, the research community can target gene evolution across species, and in this way, gain understanding for how heat and cold resilience evolved across species in different habitats. This will further our understanding of how some species may be more vulnerable to climatic change than others. We will continue the research by completing analyses of already collected data.

2. Heat and cold tolerance in ostriches have a shared genetic basis. Typically heat or cold tolerance are considered independent traits that have evolved independently and will evolve independently in the future. Our results change this perception. This is critical for further research into how animals cope with temperature fluctuations between heat and cold, which requires that research integrates analyses and experiments on heat and cold tolerance. We will continue the research on this to extend the knowledge across life-stages.

Female and male ostrich under the African sun