{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T05:57:09Z","timestamp":1778738229449,"version":"3.51.4"},"reference-count":0,"publisher":"The Company of Biologists","license":[{"start":{"date-parts":[[2025,7,23]],"date-time":"2025-07-23T00:00:00Z","timestamp":1753228800000},"content-version":"am","delay-in-days":0,"URL":"http:\/\/www.biologists.com\/user-licence-1-1\/"}],"funder":[{"name":"ANR","award":["18-CE02-0018-01"],"award-info":[{"award-number":["18-CE02-0018-01"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:p>Thermoregulation is a major challenge for extremely small mammals such as the African pygmy mice Mus mattheyi and Mus minutoides, weighing less than 12g. A previous study showed that these tiny mice exhibit different mitochondrial energy efficiency for ATP synthesis, with a higher efficiency in M. mattheyi (\u223c6 g) than in M. minutoides (\u223c10 g). This result suggests a lower mitochondrial heat production at rest in M. mattheyi, despite its lower body weight and inevitably greater heat loss from its body surface, than in M. minutoides. Consequently, a compensatory thermoregulatory strategy should exist in M. mattheyi to maintain homeothermy. The present study aimed to assess whether M. mattheyi uses non-shivering thermogenesis in brown adipose tissue (BAT) and\/or activity-thermoregulatory heat substitution. For this purpose, multidisciplinary approaches involving behavioral, physiological, biochemical and molecular analyses were used. Mus mattheyi showed higher daily mass-specific energy expenditure and food intake per unit weight and allocated more daily energy to vital function, spent less time moving in their cage during daytime but exhibited higher non-locomotor activity and higher movement-related energy cost compared to M. minutoides. BAT of M. mattheyi, was metabolically more active, exhibiting higher mitochondrial respiration rates and citrate synthase activity than in M. minutoides, but lower uncoupling protein 1 content. Altogether, these results suggest that the tiny M. mattheyi mainly uses non-exercise activity thermogenesis, increased cost of movement, and to a lesser extent BAT non-shivering thermogenesis for remaining warm.<\/jats:p>","DOI":"10.1242\/jeb.250373","type":"journal-article","created":{"date-parts":[[2025,7,23]],"date-time":"2025-07-23T07:51:08Z","timestamp":1753257068000},"source":"Crossref","is-referenced-by-count":1,"title":["When size matters: energy allocation and thermogenic mechanisms in very small mammals, the African pygmy mice"],"prefix":"10.1242","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4286-6139","authenticated-orcid":false,"given":"M\u00e9lanie","family":"Bo\u00ebl","sequence":"first","affiliation":[{"name":"1 Universit\u00e9 Claude Bernard Lyon 1, LEHNA UMR 5023, CNRS, ENTPE, Vaulx-en-Velin, France"},{"name":"2 Universit\u00e9 de Rennes, Ecosyst\u00e8mes, Biodiversit\u00e9, Evolution \u2013 ECOBIO UMR 6553, CNRS, Rennes, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"L\u00e9a","family":"Herpe","sequence":"additional","affiliation":[{"name":"3 Universit\u00e9 de Moncton, D\u00e9partement de chimie et biochimie, Moncton, Nouveau-Brunswick, Canada"},{"name":"4 Universit\u00e9 Claude Bernard Lyon 1, LEHNA UMR 5023, CNRS, ENTPE, Villeurbanne, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Claude","family":"Duchamp","sequence":"additional","affiliation":[{"name":"4 Universit\u00e9 Claude Bernard Lyon 1, LEHNA UMR 5023, CNRS, ENTPE, Villeurbanne, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Caroline","family":"Romestaing","sequence":"additional","affiliation":[{"name":"4 Universit\u00e9 Claude Bernard Lyon 1, LEHNA UMR 5023, CNRS, ENTPE, Villeurbanne, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fran\u00e7ois-Xavier","family":"Dechaume-Moncharmont","sequence":"additional","affiliation":[{"name":"4 Universit\u00e9 Claude Bernard Lyon 1, LEHNA UMR 5023, CNRS, ENTPE, Villeurbanne, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lo\u00efc","family":"Teulier","sequence":"additional","affiliation":[{"name":"4 Universit\u00e9 Claude Bernard Lyon 1, LEHNA UMR 5023, CNRS, ENTPE, Villeurbanne, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fr\u00e9d\u00e9ric","family":"Veyrunes","sequence":"additional","affiliation":[{"name":"5 Universit\u00e9 de Montpellier, ISEM UMR 5554, CNRS, IRD, Montpellier, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Damien","family":"Roussel","sequence":"additional","affiliation":[{"name":"4 Universit\u00e9 Claude Bernard Lyon 1, LEHNA UMR 5023, CNRS, ENTPE, Villeurbanne, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nicolas","family":"Pichaud","sequence":"additional","affiliation":[{"name":"3 Universit\u00e9 de Moncton, D\u00e9partement de chimie et biochimie, Moncton, Nouveau-Brunswick, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yann","family":"Voituron","sequence":"additional","affiliation":[{"name":"4 Universit\u00e9 Claude Bernard Lyon 1, LEHNA UMR 5023, CNRS, ENTPE, Villeurbanne, France"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"237","published-online":{"date-parts":[[2025,7,23]]},"container-title":["Journal of Experimental Biology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.biologists.com\/jeb\/article-pdf\/doi\/10.1242\/jeb.250373\/3658016\/jeb250373.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/journals.biologists.com\/jeb\/article-pdf\/doi\/10.1242\/jeb.250373\/3658016\/jeb250373.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,7,23]],"date-time":"2025-07-23T07:51:09Z","timestamp":1753257069000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.biologists.com\/jeb\/article\/doi\/10.1242\/jeb.250373\/368670\/When-size-matters-energy-allocation-and"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,7,23]]},"references-count":0,"URL":"https:\/\/doi.org\/10.1242\/jeb.250373","relation":{},"ISSN":["0022-0949","1477-9145"],"issn-type":[{"value":"0022-0949","type":"print"},{"value":"1477-9145","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,7,23]]},"article-number":"jeb.250373"}}