idw – Informationsdienst Wissenschaft

Nachrichten, Termine, Experten

Grafik: idw-Logo
Grafik: idw-Logo

idw - Informationsdienst
Wissenschaft

Science Video Project
idw-Abo

idw-News App:

AppStore

Google Play Store



Instance:
Share on: 
06/07/2024 11:11

Marsupials Key to Discovering the Origin of Heater organs in Mammals

Dr. Gesine Steiner Pressestelle
Museum für Naturkunde - Leibniz-Institut für Evolutions- und Biodiversitätsforschung

    New research from Stockholm University with participation of the Museum für Naturkunde Berlin shows that the typical mammalian heater organ, brown fat, evolved exclusively in modern placental mammals. In collaboration with the Helmholtz Munich and the University of East Anglia in the U.K., the Stockholm University research team demonstrated that marsupials, our distant relatives, possess a not fully evolved form of brown fat. They discovered that the pivotal heat-producing protein called UCP1 became active after the divergence of placental and marsupial mammals. This finding is crucial for understanding the role of brown fat in mammalian evolution, endothermy, and metabolism.

    “Our study is an important contribution to understanding the origin and regulation of brown fat,” says Susanne Keipert, co-first author of the study. “The energy-consuming function of brown fat is a major focus of medical research due to its potential to improve obesity, diabetes, and cardiometabolic diseases; all of which have reached pandemic proportions and are among the greatest threats to our healthcare system.”

    This work marks the latest milestone from the Jastroch Laboratory at Stockholm University, which has pioneered research on the evolution of mammalian heat production and integrated these evolutionary insights into understanding human metabolic diseases. The Museum für Naturkunde Berlin has maintained a collaboration with the Jastroch Lab for several years, working together on this aspect of mammal evolution.

    The new study “Two-stage evolution of mammalian adipose tissue thermogenesis” published in Science shows:

    … that the marsupial UCP1 gene is actively transcribed in the adipose tissue of young opossums during a critical developmental period when they first leave their mother and experience cold stress. This is similar to birth of placental mammals, when most babies require brown fat to regulate body temperature.

    … that during UCP1 transcription, many but not all genes commonly expressed in brown fat are present in marsupials. This indicates that marsupials do not possess the fully evolved brown adipose tissue found in placental mammals.

    … that the heater protein UCP1 does not produce heat in marsupials, suggesting that this proto-form of brown fat lacks thermogenic function. The function of marsupial UCP1, however, still remains to be discovered.

    “This evidence suggests that the gene networks required to enable thermogenesis existed before the divergence of marsupials and placental mammals. However, the pivotal UCP1 protein evolved its ability to produce heat only after the split from marsupials,” explains Martin Jastroch.

    Why is it important to study the mammalian family tree to decipher the origin of the brown adipose tissue?

    “To find the origin of the brown fat, we cannot use a time machine. However, by examining living species that diverged at different points in evolutionary history, we can determine which have brown adipose tissue and which components of the heat-producing machinery are present. Marsupials have split from placental mammals about 120-180 million years ago. If marsupials had functional brown fat and its thermogenic protein, it would suggest that the organ existed before this split. Since it does not, it likely evolved later,” says Susanne Keipert.

    Using bioinformatic tools on UCP1 sequence information from many animals, the researchers reconstructed the ancient UCP1 of the stem placental mammal, as it may have existed about 110 million years ago. They found that this ancient protein could produce heat, indicating the presence of heat-producing brown fat in the ancestor of placental mammals, but not before. This innovation likely enabled placental mammals to thrive in new cold environments.

    FACTS on brown fat:

    What does this unique heater organ do?
    Brown fat is a unique heater organ in placental mammals, producing heat through a protein called uncoupling protein 1 (UCP1). The UCP1 protein transforms mitochondria, which are the powerhouses of cells, into little heater units which directly convert fat and sugar into heat.

    Why is it important that brown fat dissipates energy as heat?
    The brown fat enables newborn placental mammals, including human infants, to survive cold stress after leaving the warm womb. It helps maintain body temperature in the cold, as the immature muscle cannot sufficiently shiver. Later in life, the brown fat can protect against metabolic complications by combusting excessive fat and sugars. Understanding how brown fat works is critical for developing therapeutic interventions for metabolic disorders.

    Find the study “Two-stage evolution of mammalian adipose tissue thermogenesis” published in Science at: 10.1126/science.adg1947


    Images

    Criteria of this press release:
    Journalists
    Biology, Medicine
    transregional, national
    Research results, Scientific Publications
    English


     

    Help

    Search / advanced search of the idw archives
    Combination of search terms

    You can combine search terms with and, or and/or not, e.g. Philo not logy.

    Brackets

    You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).

    Phrases

    Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.

    Selection criteria

    You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).

    If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).