Changes in muscle composition during the development of diving ability in the Australian fur seal

LaRosa, Domenic A.; Cannata, David J.; Arnould, John P. Y.; O’Sullivan, Lynda A.; Snow, Rod J.; West, Jan M.

doi:10.1071/zo11072

Cited by 5 publications

(4 citation statements)

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“…The level of creatine loading in the gastrocnemius 24 h after birth, measured as concentration of total creatine (creatine + phosphocreatine), was determined in cesarean-delivered pups from control and creatinefed mothers (n = 5 for both groups) as previously published (36,37).…”

Section: Muscle Total Creatine Content At 24 Hmentioning

confidence: 99%

“…Sections were then submerged sequentially in 30, 60, and 90% aqueous acetone before being rinsed in dH 2 O. Incubation without succinate was carried out to determine nonspecific staining. Densitometric analysis using Image J software (NIH, MA) was then employed to categorize the oxidative capacity of individual fibers based on their staining intensity, with greater optical density indicating higher abundance of this enzyme (15,37). As these were serial sections to those stained for ATPase activity, the ATPase-stained images were used as a reference and the same fibers were found on the SDHstained slides.…”

Section: Oxidative Enzyme Activitymentioning

confidence: 99%

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Maternal creatine supplementation during pregnancy prevents acute and long-term deficits in skeletal muscle after birth asphyxia: a study of structure and function of hind limb muscle in the spiny mouse

et al. 2016

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Section: Muscle Total Creatine Content At 24 Hmentioning

confidence: 99%

Section: Oxidative Enzyme Activitymentioning

confidence: 99%

Maternal creatine supplementation during pregnancy prevents acute and long-term deficits in skeletal muscle after birth asphyxia: a study of structure and function of hind limb muscle in the spiny mouse

et al. 2016

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“…Given the sensitivity of the model to factors affecting the value of independent young, even subtle effects, such as basing the relative fat content of weaned young on a phocid, might have biased the model toward capital-breeding outcomes. Despite considerable work on the development of diving ability (Prewitt et al 2010, VillegasAmtmann and Costa 2010, LaRosa et al 2012, the development of foraging ability itself is poorly understood, making the process of offspring development difficult to model with confidence. Particularly important in this regard is our assumption that the foraging competence of young seals developed only after weaning, thereby being related only to the time since weaning and not to the age of the pups as well.…”

Section: Effects Of Food Supplymentioning

confidence: 99%

Capital and income breeding: the role of food supply

Stephens

Houston

Hårding

et al. 2014

Ecology

101

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Publisher's copyright statement:Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Abstract. An aspect of life history that has seen increasing attention in recent years is that of strategies for financing the costs of offspring production. These strategies are often described by a continuum ranging from capital breeding, in which costs are met purely from endogenous reserves, to income breeding, in which costs are met purely from concurrent intake. A variety of factors that might drive strategies toward a given point on the capitalincome continuum has been reviewed, and assessed using analytical models. However, aspects of food supply, including seasonality and unpredictability, have often been cited as important drivers of capital and income breeding, but are difficult to assess using analytical models. Consequently, we used dynamic programming to assess the role of the food supply in shaping offspring provisioning strategies. Our model is parameterized for a pinniped (one taxon remarkable for the range of offspring-provisioning strategies that it illustrates). We show that increased food availability, increased seasonality, and, to a lesser extent, increased unpredictability can all favor the emergence of capital breeding. In terms of the conversion of energy into offspring growth, the shorter periods of care associated with capital breeding are considerably more energetically efficient than income breeding, because shorter periods of care are associated with a higher ratio of energy put into offspring growth to energy spent on parent and offspring maintenance metabolism. Moreover, no clear costs are currently associated with capital accumulation in pinnipeds. This contrasts with general assumptions about endotherms, which suggest that income breeding will usually be preferred. Our model emphasizes the role of seasonally high abundances of food in enabling mothers to pursue an energetically efficient capital-breeding strategy. We discuss the importance of offspring development for dictating strategies for financing offspring production.

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“…The asphyxia-induced changes in diaphragm function observed in this study are consistent with the structural changes. The increased fatigue is consistent with the increased proportion of Type IIb fibres in the control diet birth asphyxia group, because these glycolytic, fast-twitch fibres are known to fatigue more quickly than the oxidative, Type IIa fibres [ 44 , 45 ]. Taken together with the significant reduction in the oxidative capacity, as assessed by reduced SDH abundance, of Type I and Type IIb fibres, the decrease in fatigue resistance of the diaphragm after birth asphyxia are explicable if there is a greater reliance on Type IIb/d fibres during forced contractions, which were also found to have a lower oxidative capacity in male birth asphyxia offspring.…”

Section: Discussionmentioning

confidence: 55%

Maternal Creatine Supplementation during Pregnancy Prevents Long-Term Changes in Diaphragm Muscle Structure and Function after Birth Asphyxia

et al. 2016

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Using a model of birth asphyxia, we previously reported significant structural and functional deficits in the diaphragm muscle in spiny mice, deficits that are prevented by supplementing the maternal diet with 5% creatine from mid-pregnancy. The long-term effects of this exposure are unknown. Pregnant spiny mice were fed control or 5% creatine-supplemented diet for the second half of pregnancy, and fetuses were delivered by caesarean section with or without 7.5 min of in-utero asphyxia. Surviving pups were raised by a cross-foster dam until 33±2 days of age when they were euthanized to obtain the diaphragm muscle for ex-vivo study of twitch tension and muscle fatigue, and for structural and enzymatic analyses. Functional analysis of the diaphragm revealed no differences in single twitch contractile parameters between any groups. However, muscle fatigue, induced by stimulation of diaphragm strips with a train of pulses (330ms train/sec, 40Hz) for 300sec, was significantly greater for asphyxia pups compared with controls (p<0.05), and this did not occur in diaphragms of creatine + asphyxia pups. Birth asphyxia resulted in a significant increase in the proportion of glycolytic, fast-twitch fibres and a reduction in oxidative capacity of Type I and IIb fibres in male offspring, as well as reduced cross-sectional area of all muscle fibre types (Type I, IIa, IIb/d) in both males and females at 33 days of age. None of these changes were observed in creatine + asphyxia animals. Thus, the changes in diaphragm fatigue and structure induced by birth asphyxia persist long-term but are prevented by maternal creatine supplementation.

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Changes in muscle composition during the development of diving ability in the Australian fur seal

Cited by 5 publications

References 63 publications

Maternal creatine supplementation during pregnancy prevents acute and long-term deficits in skeletal muscle after birth asphyxia: a study of structure and function of hind limb muscle in the spiny mouse

Maternal creatine supplementation during pregnancy prevents acute and long-term deficits in skeletal muscle after birth asphyxia: a study of structure and function of hind limb muscle in the spiny mouse

Capital and income breeding: the role of food supply

Maternal Creatine Supplementation during Pregnancy Prevents Long-Term Changes in Diaphragm Muscle Structure and Function after Birth Asphyxia

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