TY - JOUR
T1 - Seasonal upregulation of catabolic enzymes and fatty acid transporters in the flight muscle of migrating hoary bats, Lasiurus cinereus
AU - McGuire, Liam P.
AU - Fenton, M. Brock
AU - Guglielmo, Christopher G.
N1 - Funding Information:
Thanks to Eddy Price, Alex Gerson, Nusha Keyghobadi, Lindsay Crawford, Gordana Rasic, Daria Koscinski, and Meg Haggit for helpful discussions and assistance in developing laboratory analysis methods. We also thank Mark Brigham, Craig Willis, Robert Barclay, Blair Wolf, Paul Cryan, and Ernie Valdez for discussion and assistance in determining field sites and coordinating collecting trips. Lauren Hooton, Amanda Adams, Quentin Hays, Julia Kilgour, Erin Gillam, and Joe Poissant provided invaluable assistance in the field. Three anonymous reviewers provided helpful comments on an earlier draft of the manuscript. Funding for this study was provided by Bat Conservation International (student scholarship to LPM), Society for Integrative and Comparative Biology (travel fellowship to LPM), University of Western Ontario (research grant to LPM), the Natural Sciences and Engineering Research Council (Discovery grants to CGG and MBF), and the Canada Foundation for Innovation/Ontario Research Fund (Leaders Opportunity Fund to CGG). LPM was supported by a Canada Graduate Scholarship from the Natural Sciences and Engineering Research Council of Canada .
PY - 2013/6
Y1 - 2013/6
N2 - The high energy density of fat, and limited capacity for carbohydrate storage suggest that migrating bats should fuel endurance flights with fat, as observed in migrating birds. Yet, cursorial mammals are unable to support high intensity exercise with fat stores. We hypothesized that migratory bats and birds have converged on similar physiological mechanisms to fuel endurance flight with fat. We predicted bats would seasonally upregulate fatty acid transport and oxidation pathways when migration demands were high. We studied seasonal variation in mitochondrial oxidative enzyme activities and fatty acid transport protein expression in the flight muscle of hoary bats (Lasiurus cinereus). Carnitine palmitoyl transferase, 3-hydroxyacyl-CoA dehydrogenase and citrate synthase activity increased during migration. There were no changes in expression of fatty acid translocase or plasma membrane fatty acid binding protein. Heart-type fatty acid binding protein expression increased 5-fold in migrating females, but did not vary seasonally in males. An aerial insectivore lifestyle, and the coincidence of migration and pregnancy may explain differences in transporter expression compared to previously studied birds. Overall, our results are consistent with seasonal upregulation of lipid metabolism and aerobic capacity, and confirm that migration poses distinct physiological challenges for bats.
AB - The high energy density of fat, and limited capacity for carbohydrate storage suggest that migrating bats should fuel endurance flights with fat, as observed in migrating birds. Yet, cursorial mammals are unable to support high intensity exercise with fat stores. We hypothesized that migratory bats and birds have converged on similar physiological mechanisms to fuel endurance flight with fat. We predicted bats would seasonally upregulate fatty acid transport and oxidation pathways when migration demands were high. We studied seasonal variation in mitochondrial oxidative enzyme activities and fatty acid transport protein expression in the flight muscle of hoary bats (Lasiurus cinereus). Carnitine palmitoyl transferase, 3-hydroxyacyl-CoA dehydrogenase and citrate synthase activity increased during migration. There were no changes in expression of fatty acid translocase or plasma membrane fatty acid binding protein. Heart-type fatty acid binding protein expression increased 5-fold in migrating females, but did not vary seasonally in males. An aerial insectivore lifestyle, and the coincidence of migration and pregnancy may explain differences in transporter expression compared to previously studied birds. Overall, our results are consistent with seasonal upregulation of lipid metabolism and aerobic capacity, and confirm that migration poses distinct physiological challenges for bats.
KW - Aerobic capacity
KW - Fatty acid binding protein
KW - Lipid oxidation
KW - Lipid transport
KW - Migration
UR - http://www.scopus.com/inward/record.url?scp=84876431625&partnerID=8YFLogxK
U2 - 10.1016/j.cbpb.2013.03.013
DO - 10.1016/j.cbpb.2013.03.013
M3 - Article
C2 - 23545469
AN - SCOPUS:84876431625
SN - 1096-4959
VL - 165
SP - 138
EP - 143
JO - Comparative Biochemistry and Physiology - B Biochemistry and Molecular Biology
JF - Comparative Biochemistry and Physiology - B Biochemistry and Molecular Biology
IS - 2
ER -