Limb immobilization, limb suspension, and bed rest cause substantial loss of skeletal muscle mass, a phenomenon termed disuse atrophy. To acquire new knowledge that will assist in the development therapeutic strategies for minimizing atrophy, present study was undertaken with aim identifying molecular mechanisms mediate control protein synthesis mechanistic target rapamycin complex 1 (mTORC1) signaling. Male Sprague-Dawley rats were subjected to unilateral hindlimb immobilization 1, 2, 3, or...

Climate change presents a major threat to species distribution and persistence. Understanding what abiotic or biotic factors influence the thermal tolerances of natural populations is critical assessing their vulnerability under rapidly changing regimes. This study evaluates how body mass, local climate, pathogen intensity heat tolerance its population-level variation (SD) among individuals solitary bee

Abstract Long-distance flight is crucial for the survival of migratory insects, and disruptions to their capacity can have significant consequences conservation. In this study, we examined how a widely used insecticide, clothianidin (class: neonicotinoid), impacted performance two species butterflies, monarchs (Danaus plexippus) painted ladies (Vanessa cardui). To do this, quantified free-flight energetics tethered-flight velocity distance using flow-through respirometry mill assays. Our...

Dragonflies infected with noninvasive gregarine gut parasites (Microsporidia, Apicomplexa) have reduced flight-muscle performance, an inability to metabolize lipid in their muscles, twofold-elevated hemolymph carbohydrate concentrations, and they accumulate fat thorax a manner analogous mammalian obesity. Gregarine infection is associated inappropriate responses of concentration insulin chronic activation the flight muscles p38 MAP kinase, signaling molecule involved immune stress responses....

Oxygen conductance to the tissues determines aerobic metabolic performance in most eukaryotes but has cost/benefit tradeoffs. Here we examine lowland populations of a butterfly genetic polymorphism affecting oxygen via hypoxia-inducible factor (HIF) pathway, which senses intracellular and controls development delivery networks. Genetically distinct clades Glanville fritillary (Melitaea cinxia) across continental scale maintain, at intermediate frequencies, alleles enzyme (succinate...

Abstract Animals derive resources from their diet and allocate them to organismal functions such as growth, maintenance, reproduction, dispersal. How variation in quality can affect resource allocation life-history traits, particular those important locomotion dispersal, is poorly understood. We hypothesize that, particularly for specialist herbivore insects that are co-evolutionary arms races with host plants, changes plant will impact performance. From coevolutionary arms-race a complex...

Wing polymorphism is a powerful model for examining many aspects of adaptation. The wing dimorphic cricket species, Gryllus firmus, consists long-winged morph with functional flight muscles that capable flight, and two flightless morphs. One (obligately) emerges as an adult vestigial wings muscles. other (plastic) fully-developed but later in adulthood histolyzes its Importantly both morphs have substantially increased reproductive output relative to the flight-capable morph. Much known...

SUMMARY Maximum isometric force output by single muscles has long been known to be proportional muscle mass0.67, i.e cross-sectional area. However, locomotion often requires a different contraction regime than that used under conditions. Moreover, lever mechanisms generally affect the outputs of muscle–limb linkages, which is one reason why scaling net intact musculoskeletal systems can differ from mass0.67. Indeed, several studies have demonstrated and non-biological motor mass1.0. Here we...

Do animals know at a physiological level how much they weigh, and, if so, do make homeostatic adjustments in response to changes body weight? Skeletal muscle is likely tissue for such plasticity, as weight-bearing muscles receive mechanical feedback regarding weight and consume ATP order generate forces sufficient counteract gravity. Using rats, we examined variation affected alternative splicing of fast skeletal troponin T (Tnnt3), component the thin filament that regulates actin-myosin...

Managed and wild bee populations are in decline around the globe due to several biotic abiotic stressors. Pathogenic viruses associated with Western honey (Apis mellifera) have been identified as key contributors losses of managed colonies, known be transmitted through shared floral resources. However, little is about prevalence intensity these populations, or how visitation flowers impacts viral transmission agroecosystems. This study surveyed bee, bumble (Bombus impatiens) squash (Eucera...

The squash bee Eucera (Peponapis) pruinosa is emerging as a model species to study how stressors impact solitary wild bees in North America. Here, we describe the prevalence of trypanosomes, microsporidians and mollicute bacteria E. two other species, Bombus impatiens Apis mellifera, that together comprise over 97% pollinator visitors Cucurbita agroecosystems Pennsylvania (United States). Our results indicate all three parasite groups are commonly detected these but often exhibit higher...

SUMMARY In previous work, we found that dragonflies infected with gregarine gut parasites have reduced muscle power output, loss of lipid oxidation in their flight muscles, and a suite symptoms similar to mammalian metabolic syndrome. Here, test the hypothesis changes protein composition underlie observed contractile performance. We infection was associated 10-fold average reduction abundance ∼155 kDa fragment myosin heavy chain (MHC;∼206 intact size). Insect MHC gene sequences contain...

A key challenge for linking experiments of organisms performed in a laboratory environment to their performance more complex environments is determine thermal differences between and the energetically terrestrial ecosystem. Studies do not account many factors that contribute realized temperature an organism its natural environment. This can lead modelling approaches use experimentally derived data erroneously link air temperatures heterogenous ecosystems. Traditional solutions this classic...

How mechanochemical signals induced by the amount of weight borne skeletal musculature are translated into modifications to muscle sarcomeres is poorly understood. Our laboratory recently demonstrated that, in response experimentally increases load a rat, alternative splicing fast troponin T ( Tnnt3) pre-mRNA gastrocnemius was adjusted correlated fashion with added weight. (Schilder RJ, Kimball SR, Marden JH, Jefferson LS. J Exp Biol 214: 1523–1532, 2011). Thus perceived quantitatively body,...

Although whole-organism aspects of life-history physiology are well studied and molecular information (e.g., transcript abundance) on variation is accumulating rapidly, much less available the biochemical (enzymological) basis adaptation. The present study investigated causes specific activity differences lipogenic enzyme, NADP+-isocitrate dehydrogenase, between genetic lines wing-polymorphic cricket, Gryllus firmus, which differ in lipid biosynthesis life history. With one exception, among...

Emerging research suggests that intestinal microbiome composition is an important factor in the development of obesity. However, little known about mechanistic details this relationship. A recent insect study demonstrated for first time metabolic syndrome and symptoms such as obesity insulin resistance are not restricted to mammals can be induced by means a protozoan infection. This article describes findings integrates them with from studies relating gut microbiota mammals.

Ageing is associated with a loss of skeletal muscle performance, condition referred to as sarcopenia. In part, the age-related reduction in performance due selective fiber mass, but mass-independent effects have also been demonstrated. An important determinant pattern expression isoforms proteins that participate contraction (e.g., troponins). present study, we tested hypothesis ageing impairs alternative splicing pre-mRNA encoding fast troponin T (TNNT3) human vastus lateralis muscle....

Abstract Predicted changes in global temperature are expected to increase extinction risk for ectotherms, primarily through increased metabolic rates. Higher rates generate maintenance energy costs which a major component of budgets. Organisms often employ plastic or evolutionary (e.g., local adaptation) mechanisms optimize rate with respect their environment. We examined relationships between and standard across four populations widespread amphibian species determine if vary response...

ABSTRACT Studies of organismal and tissue biomechanics have clearly demonstrated that musculoskeletal design is strongly dependent on experienced loads, which can vary in the short term, as a result growth during life history evolution animal body size. However, how animals actually perceive make adjustments to their load-bearing elements accommodate variation weight poorly understood. We developed an experimental model system be used start addressing these open questions, uses hypergravity...

Among some of the most unusual traits gasteruptiid wasps is their unique hovering flight and expansion hind tibiae. Tibial expansions in female parasitoid hymenopterans often involve an enlarged sensory structure for vibration detection, subgenual organ, thus enabling refined substrate-borne detection concealed hosts. In present paper, we utilize a combination microscopy, chemical analysis, gene expression, behavior to explore function expanded tibia wasps. We find that gasteruptiids filled...

Abstract As a model organism, the tobacco hornworm Manduca sexta (Linnaeus 1763) has contributed much to our knowledge of developmental processes in insects, and major changes between different larval instars are generally well understood. Second later M. do not produce silk, their spinneret accessory labial glands (=Lyonet’s glands), structures thought be key players silk production other lepidopterans, highly reduced. To knowledge, mouthparts gland morphology silk-producing first instar...