Cellular Metabolic Rate Is Influenced by Life-History Traits in Tropical and Temperate Birds.
A post-doc in EEOB, Ana Jimenez, recently had a paper out in PLoS One. She is shortly moving to the Hopkins marine station and Loyola Marymount in California. She describes her work here.
Animals of the same body mass at the slow end of the life-history continuum are characterized by low annual reproductive output and low mortality rate, such as is found in many tropical birds, whereas at the fast end, rates of reproduction and mortality are high, as in temperate birds. These differences in life-history traits are thought to result from trade-offs between investment in reproduction or self-maintenance as mediated by the biotic and abiotic environment. Thus, tropical and temperate birds provide a unique system to examine physiological consequences of life-history trade-offs at opposing ends of the "pace of life" spectrum.
We have explored the implications of these trade-offs at several levels of physiological organization including whole-animal, organ systems, and cells. Tropical birds tend to have lower rates of whole animal basal metabolic rate (BMR) and peak metabolic rate (PMR), and smaller metabolically active organs compared with temperate birds. To explore whether cells from tropical and temperate birds might have different rates of metabolism consistent with the pattern of metabolism that we found at the whole-organism level, we isolated primary dermal fibroblasts from tropical and temperate birds and measured cellular metabolism and found that cells from tropical birds had lower cellular metabolic rates than cells from temperate birds. The linkages between a slow pace of life, whole-animal metabolic rate and the physiology of cells, depicts, for the first time, patterns of cell biology that are fashioned as a result of selection for disparate life-history strategies and natural selection.
You can read more about Ana's work here
Ana G. Jimenez, J. Van Brocklyn, M. Wortman, and J.B. Williams. 2014. Cellular Metabolic Rate Is Influenced by Life-History Traits in Tropical and Temperate Birds. PLoS ONE 9(1): e87349. DOI: 10.1371/journal.pone.0087349
Ana Gabriela Jimenez, Richard M. Dillaman and Stephen T. Kinsey. 2013 Large fibre size in skeletal muscle is metabolically advantageous. Nature Communications 4, 2150. DOI: 10.1038/ncomms3150
Popko Wiersma, Agusti Munoz-Garcia, Amy Walker, and Joseph B. Williams. 2007. Tropical birds have a slow pace of life. Proceedings of the National Academy of Sciences 104, 9340--9345. DOI: 10.1073/pnas.0702212104
Popko Wiersma, Brittany Nowak and Joseph B. Williams. 2012. Small organ size contributes to the slow pace of life in tropical birds. Journal of Experimental Biology 215, 1662--1669. DOI: 10.1242/jeb.065144