scholarly journals Setting the pace of life: membrane composition of flight muscle varies with metabolic rate of hovering orchid bees

2015 ◽  
Vol 282 (1802) ◽  
pp. 20142232 ◽  
Author(s):  
Enrique Rodríguez ◽  
Jean-Michel Weber ◽  
Benoît Pagé ◽  
David W. Roubik ◽  
Raul K. Suarez ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Relative Abundance ◽  
Flight Muscle ◽  
Muscle Membrane ◽  
Rate Variation ◽  
Membrane Composition ◽  
Functional Link ◽  
Orchid Bees ◽  
Membrane Pacemaker

Patterns of metabolic rate variation have been documented extensively in animals, but their functional basis remains elusive. The membrane pacemaker hypothesis proposes that the relative abundance of polyunsaturated fatty acids in membrane phospholipids sets the metabolic rate of organisms. Using species of tropical orchid bees spanning a 16-fold range in body size, we show that the flight muscles of smaller bees have more linoleate (%18 : 3) and stearate (%18 : 0), but less oleate (%18 : 1). More importantly, flight metabolic rate (FlightMR) varies with the relative abundance of 18 : 3 according to the predictions of the membrane pacemaker hypothesis. Although this relationship was found across large differences in metabolic rate, a direct association could not be detected when taking phylogeny and body mass into account. Higher FlightMR, however, was related to lower %16 : 0, independent of phylogeny and body mass. Therefore, this study shows that flight muscle membrane composition plays a significant role in explaining diversity in FlightMR, but that body mass and phylogeny are other factors contributing to their variation. Multiple factors are at play to modulate metabolic capacity, and changing membrane composition can have gradual and stepwise effects to achieve a new range of metabolic rates. Orchid bees illustrate the correlated evolution between membrane composition and metabolic rate, supporting the functional link proposed in the membrane pacemaker hypothesis.

scholarly journals The relationship between genome size and metabolic rate in extant vertebrates

2020 ◽  
Vol 375 (1793) ◽  
pp. 20190146 ◽  
Author(s):  
Jacob D. Gardner ◽  
Michel Laurin ◽  
Chris L. Organ
Keyword(s):  
Metabolic Rate ◽  
Genome Size ◽  
Body Mass ◽  
Rate Variation ◽  
Large Nucleus ◽  
Functional Connection ◽  
Strong Positive Relationship ◽  
Elevated Rate ◽  
The Relationship ◽  
Rule Out

Genome size has long been hypothesized to affect the metabolic rate in various groups of animals. The mechanism behind this proposed association is the nucleotypic effect, in which large nucleus and cell sizes influence cellular metabolism through surface area-to-volume ratios. Here, we provide a review of the recent literature on the relationship between genome size and metabolic rate. We also conduct an analysis using phylogenetic comparative methods and a large sample of extant vertebrates. We find no evidence that the effect of genome size improves upon models in explaining metabolic rate variation. Not surprisingly, our results show a strong positive relationship between metabolic rate and body mass, as well as a substantial difference in metabolic rate between endothermic and ectothermic vertebrates, controlling for body mass. The presence of endothermy can also explain elevated rate shifts in metabolic rate whereas genome size cannot. We further find no evidence for a punctuated model of evolution for metabolic rate. Our results do not rule out the possibility that genome size affects cellular physiology in some tissues, but they are consistent with previous research suggesting little support for a direct functional connection between genome size and basal metabolic rate in extant vertebrates. This article is part of the theme issue ‘Vertebrate palaeophysiology’.

scholarly journals The Relationship Between Genome Size and Metabolic Rate in Extant Vertebrates

2019 ◽  
Author(s):  
Jacob D. Gardner ◽  
Michel Laurin ◽  
Chris L. Organ
Keyword(s):  
Metabolic Rate ◽  
Genome Size ◽  
Body Mass ◽  
Rate Variation ◽  
Large Nucleus ◽  
Functional Connection ◽  
Strong Positive Relationship ◽  
Elevated Rate ◽  
The Relationship ◽  
Rule Out

AbstractGenome size has long been hypothesized to affect metabolic rate in various groups of animals. The mechanism behind this proposed association is the nucleotypic effect, in which large nucleus and cell sizes influence cellular metabolism through surface area-to-volume ratios. Here, we provide a review of the recent literature on the relationship between genome size and metabolic rate. We also conduct an analysis using phylogenetic comparative methods and a large sample of extant vertebrates. We find no evidence that the effect of genome size improves upon models in explaining metabolic rate variation. Not surprisingly, our results show a strong positive relationship between metabolic rate and body mass, as well as a substantial difference in metabolic rate between endothermic and ectothermic vertebrates, controlling for body mass. The presence of endothermy can also explain elevated rate shifts in metabolic rate whereas genome size cannot. We further find no evidence for a punctuated model of evolution for metabolic rate. Our results do not rule out the possibility that genome size affects cellular physiology in some tissues, but they are consistent with previous research suggesting little support for a direct functional connection between genome size and basal metabolic rate in extant vertebrates.

CHARACTERISTICS OF POST-FLIGHT MUSCLE STRENGTH AND VELOCITY DYNAMICS IN COSMONAUTS AS A FUNCTION OF WEIGHT LOADING DURING LONG-TERM SPACE MISSIONS

2020 ◽  
Vol 54 (5) ◽  
pp. 23-28
Author(s):  
E.V. Fomina ◽  
◽  
T.B. Kukoba ◽  
Keyword(s):  
Muscle Strength ◽  
Body Mass ◽  
Flight Muscle ◽  
Space Mission ◽  
The Body ◽  
Maximum Strength ◽  
Training Device ◽  
Leg Muscle ◽  
Weight Loading

Testing of 25 cosmonauts showed that the amount of resistance training weight loading in long-term space mission influences dynamics of the leg-muscle strength and velocity recovery. On Earth, the loads equal from 70 to 130 % of the body mass is sufficient for keeping up endurance and maximum strength moments of shin and thigh muscles. In the group of cosmonauts who had not used the strength training device or chosen loads less than 30 % of the body mass the leg-muscle maximum strength and thigh endurance were decreased substantially on day 4 of return and all the more by day 15 back on Earth.

scholarly journals Body mass-specific Na+-K+-ATPase activity in the medullary thick ascending limb: implications for species-dependent urine concentrating mechanisms

2018 ◽  
Vol 314 (4) ◽  
pp. R563-R573 ◽  
Author(s):  
Mun Aw ◽  
Tamara M. Armstrong ◽  
C. Michele Nawata ◽  
Sarah N. Bodine ◽  
Jeeeun J. Oh ◽  
...  
Keyword(s):  
Protein Expression ◽  
Atpase Activity ◽  
Metabolic Rate ◽  
Body Mass ◽  
Whole Body ◽  
Osmotic Gradient ◽  
Thick Ascending Limb ◽  
Rat Strains ◽  
Kangaroo Rat ◽  
Gene And Protein Expression

In general, the mammalian whole body mass-specific metabolic rate correlates positively with maximal urine concentration (Umax) irrespective of whether or not the species have adapted to arid or mesic habitat. Accordingly, we hypothesized that the thick ascending limb (TAL) of a rodent with markedly higher whole body mass-specific metabolism than rat exhibits a substantially higher TAL metabolic rate as estimated by Na+-K+-ATPase activity and Na+-K+-ATPase α1-gene and protein expression. The kangaroo rat inner stripe of the outer medulla exhibits significantly higher mean Na+-K+-ATPase activity (~70%) compared with two rat strains (Sprague-Dawley and Munich-Wistar), extending prior studies showing rat activity exceeds rabbit. Furthermore, higher expression of Na+-K+-ATPase α1-protein (~4- to 6-fold) and mRNA (~13-fold) and higher TAL mitochondrial volume density (~20%) occur in the kangaroo rat compared with both rat strains. Rat TAL Na+-K+-ATPase α1-protein expression is relatively unaffected by body hydration status or, shown previously, by dietary Na+, arguing against confounding effects from two unavoidably dissimilar diets: grain-based diet without water (kangaroo rat) or grain-based diet with water (rat). We conclude that higher TAL Na+-K+-ATPase activity contributes to relationships between whole body mass-specific metabolic rate and high Umax. More vigorous TAL Na+-K+-ATPase activity in kangaroo rat than rat may contribute to its steeper Na+ and urea axial concentration gradients, adding support to a revised model of the urine concentrating mechanism, which hypothesizes a leading role for vigorous active transport of NaCl, rather than countercurrent multiplication, in generating the outer medullary axial osmotic gradient.

Body and organ mass dynamics during remigial moult in a wing–foot-propelled diving sea duck: the Common Eider (Atlantic) (Somateria mollissima dresseri)

2015 ◽  
Vol 93 (10) ◽  
pp. 755-764 ◽  
Author(s):  
A. Viain ◽  
M. Guillemette ◽  
J.-P.L. Savard
Keyword(s):  
Muscle Mass ◽  
Body Mass ◽  
Flight Muscle ◽  
Somateria Mollissima ◽  
Dabbling Ducks ◽  
Diving Ducks ◽  
Common Eiders ◽  
Sea Duck ◽  
Remigial Moult ◽  
Atrophy Of The Heart

Body and organ dynamics, during remigial moult, have been mainly explored on geese, dabbling ducks, and foot-propelled diving ducks, but weakly on sea ducks. This study investigated the internal changes in a wing–foot-propelled sea duck to determine the adaptive strategies implemented. Forty-five male Common Eiders (Atlantic) (Somateria mollissima dresseri Sharpe, 1871), collected in the Gulf of St. Lawrence, were dissected; their body mass, muscle mass, and organ sizes were measured. We tested three hypotheses: (1) S. m. dresseri use a strategic reduction of body mass to reduce the flightlessness duration; (2) organs will exhibit changes consistent with a trade-off between function and maintenance to save and reallocate energy and proteins to feather growth; (3) S. m. dresseri would show lower flight muscle reduction than foot-propelled diving ducks. Somateria mollissima dresseri did not lose body mass, which does not support the first hypothesis. Atrophy of the heart followed by hypertrophy and opposite changes in leg muscle mass and gizzard mass are consistent with the second hypothesis. Flight muscle mass showed lower variations than in other ducks, validating the third hypothesis. We also suggest that the lipid depletion observed early in the moult could be a strategy to reduce foraging effort and minimize the risk of damaging the growing feathers.

scholarly journals Does the membrane pacemaker theory of metabolism explain the size dependence of metabolic rate in marine mussels?

2017 ◽  
Vol 220 (8) ◽  
pp. 1423-1434 ◽  
Author(s):  
Alexey Sukhotin ◽  
Natalia Fokina ◽  
Tatiana Ruokolainen ◽  
Christian Bock ◽  
Hans-Otto Pörtner ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Size Dependence ◽  
Marine Mussels ◽  
Membrane Pacemaker

scholarly journals The relationship between body mass and field metabolic rate among individual birds and mammals

2013 ◽  
Vol 82 (5) ◽  
pp. 1009-1020 ◽  
Author(s):  
Lawrence N. Hudson ◽  
Nick J. B. Isaac ◽  
Daniel C. Reuman
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Field Metabolic Rate ◽  
The Relationship

scholarly journals Fowl play and the price of petrel: long-living Procellariiformes have peroxidation-resistant membrane composition compared with short-living Galliformes

2008 ◽  
Vol 4 (4) ◽  
pp. 351-354 ◽  
Author(s):  
William A Buttemer ◽  
Harry Battam ◽  
A.J Hulbert
Keyword(s):  
Fatty Acid Composition ◽  
Membrane Lipids ◽  
Published Data ◽  
Commercial Fishing ◽  
Membrane Composition ◽  
Physiological Trait ◽  
Living Species ◽  
Membrane Pacemaker ◽  
By Catch ◽  
Peroxidation Index

The membrane pacemaker hypothesis predicts that long-living species will have more peroxidation-resistant membrane lipids than shorter living species. We tested this hypothesis by comparing the fatty acid composition of heart phospholipids from long-living Procellariiformes (petrels and albatrosses) to those of shorter living Galliformes (fowl). The seabirds were obtained from by-catch of commercial fishing operations and the fowl values from published data. The 3.8-fold greater predicted longevity of the seabirds was associated with elevated content of peroxidation-resistant monounsaturates and reduced content of peroxidation-prone polyunsaturates and, consequently, a significantly reduced peroxidation index in heart membrane lipids, compared with fowl. Peroxidation-resistant membrane composition may be an important physiological trait for longevous species.

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