Muscular senescence in cetaceans: adaptation towards a slow muscle fibre phenotype

Sierra, Eva; Fernández, A.; Monteros, A. Espinosa de los; Arbelo, Manuel; Quirós, Yara Bernaldo de; Herráez, P.

doi:10.1038/srep01795

Cited by 18 publications

(16 citation statements)

References 56 publications

(85 reference statements)

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“…A broader examination of physiological changes across the lifespan would no doubt identify further markers of bodily decline associated with age-dependent and age-independent mass variation (e.g. muscle wasting, Sierra et al, 2013), but it would be particularly useful to know whether reductions in body mass compromise foraging efficiency. A large proportion of the daily activity budget of meerkats is spent digging for subterranean invertebrates so any downturn in foraging ability is likely to be particularly damaging for individual condition.…”

Section: Discussionmentioning

confidence: 99%

Sex‐independent senescence in a cooperatively breeding mammal

Thorley

Duncan

Sharp

et al. 2020

Journal of Animal Ecology

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Researchers studying mammals have frequently interpreted earlier or faster rates of ageing in males as resulting from polygyny and the associated higher costs of reproductive competition. Yet, few studies conducted on wild populations have compared sex‐specific senescence trajectories outside of polygynous species, making it difficult to make generalized inferences on the role of reproductive competition in driving senescence, particularly when other differences between males and females might also contribute to sex‐specific changes in performance across lifespan. Here, we examine age‐related variation in body mass, reproductive output and survival in dominant male and female meerkats, Suricata suricatta. Meerkats are socially monogamous cooperative breeders where a single dominant pair virtually monopolizes reproduction in each group and subordinate group members help to rear offspring produced by breeders. In contrast to many polygynous societies, we find that neither the onset nor the rate of senescence in body mass or reproductive output shows clear differences between males and females. Both sexes also display similar patterns of age‐related survival across lifespan, but unlike most wild vertebrates, survival senescence (increases in annual mortality with rising age) was absent in dominants of both sexes, and as a result, the fitness costs of senescence were entirely attributable to declines in reproductive output from mid‐ to late‐life. We suggest that the potential for intrasexual competition to increase rates of senescence in females—who are hormonally masculinized and frequently aggressive—is offset by their ability to maintain longer tenures of dominance than males, and that these processes when combined lead to similar patterns of senescence in both sexes. Our results stress the need to consider the form and intensity of sexual competition as well as other sex‐specific features of life history when investigating the operation of senescence in wild populations.

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Section: Discussionmentioning

confidence: 99%

Sex‐independent senescence in a cooperatively breeding mammal

Thorley

Duncan

Sharp

et al. 2020

Journal of Animal Ecology

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“…Variations in fiber type composition among marine mammals have been proposed to result from differences in routine dive duration and swimming speed, as well as from age. 16,75,77 Intramyofiber inclusions/deposits were identified with the HE and PAS stains. PAS-positive, diastase-resistant inclusions within skeletal muscles are consistent with deposits of abnormal glycogen, often referred to as a complex polysaccharide.…”

Section: Stranding Epidemiologic Data and Necropsy Examinationmentioning

confidence: 99%

“…42,43,76 Agerelated histological findings, including variations in the number and the size of different types of myofibers, have also been described in this group of animals. 75 In addition, the presence of sarcoplasmic masses within the skeletal muscle of a stranded pygmy sperm whale (Kogia breviceps) have been previously published. 74 Given the scarcity of reports on the muscle pathology of these species and the wide range of muscle lesions encountered in the stranded cetaceans of our study, this article aimed to determine the nature and prevalence of skeletal muscle lesions in small and large odontocetes and mysticetes stranded on the Canary Islands, Spain.…”

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confidence: 99%

Muscle Pathology in Free-Ranging Stranded Cetaceans

et al. 2016

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Despite the profound impact that skeletal muscle disorders may pose for the daily activities of wild terrestrial and marine mammals, such conditions have been rarely described in cetaceans. In this study, the authors aimed to determine the nature and prevalence of skeletal muscle lesions in small and large odontocetes and mysticetes ( n = 153) from 19 different species. A macroscopic evaluation of the epaxial muscle mass and a histologic examination of the longissimus dorsi muscle were performed in all cases. The only macroscopically evident change was variable degrees of atrophy of the epaxial muscles ( longissimus dorsi, multifidus, spinalis) in emaciated specimens. The histopathological study revealed single or combined morphological changes in 91.5% of the cases. These changes included the following: degenerative lesions (75.2%), muscle atrophy (37.9%), chronic myopathic changes (25.5%), parasitic infestation (9.2%), and myositis (1.9%). The skeletal muscle is easily sampled during a necropsy and provides essential microscopic information that reflects both local and systemic conditions. Thus, skeletal muscle should be systematically sampled, processed, and examined in all stranded cetaceans.

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“…The morphologic changes associated with sarcopenia seem to have many aspects already described in humans and other species. 9,32,52,60 Results refer to muscle samples from only female cows; thus, possible sex-related differences should be further investigated in future studies. 61 More detailed studies on the molecular pathway involved in those alterations will show if cattle could be considered a spontaneous animal model for sarcopenia and other age-related muscle pathologies.…”

Section: Discussionmentioning

confidence: 99%

“…3 Sarcopenia has been described in several animal species, from nematodes, flies, rodents, domestic and wild animals, and nonhuman primates to humans. 6,32,39,43,45,52 No information is available about sarcopenia in farm animals because of their short period of lifespan. Some exceptions are presented, such as Podolica breed, which is a dual-purpose bovine breed very common in the south of Italy that it is usually raised free outdoors in the mountains with a lifespan of about 15 years.…”

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confidence: 99%

Age-Related Changes in Skeletal Muscle of Cattle

et al. 2016

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Sarcopenia, the age-related loss of muscle mass and strength, is a multifactorial condition that represents a major healthcare concern for the elderly population. Although its morphologic features have been extensively studied in humans, animal models, and domestic and wild animals, only a few reports about spontaneous sarcopenia exist in other long-lived animals. In this work, muscle samples from 60 healthy Podolica-breed old cows (aged 15-23 years) were examined and compared with muscle samples from 10 young cows (3-6 years old). Frozen sections were studied through standard histologic and histoenzymatic procedures, as well as by immunohistochemistry, immunofluorescence, and Western blot analysis. The most prominent age-related myopathic features seen in the studied material included angular fiber atrophy (90% of cases), mitochondrial alterations (ragged red fibers, 70%; COX-negative fibers, 60%), presence of vacuolated fibers (75%), lymphocytic (predominantly CD8þ) inflammation (40%), and type II selective fiber atrophy (40%). Immunohistochemistry revealed increased expression of major histocompatibility complex I in 36 cases (60%) and sarcoplasmic accumulations of b-amyloid precursor protein-positive material in 18 cases (30%). In aged cows, muscle atrophy was associated with accumulation of myostatin. Western blot analysis indicated increased amount of both proteins-myostatin and b-amyloid precursor protein-in muscles of aged animals compared with controls. These findings confirm the presence of age-related morphologic changes in cows similar to human sarcopenia and underline the possible role of amyloid deposition and subsequent inflammation in muscle senescence.Keywords aging, amyloid, cattle, MHC I, muscle, myostatin, sarcopeniaAging is a natural life process in all animal species 39 ; some of its most serious consequences are the effects on skeletal muscle. 43 Given the number of functions of muscle, such as deambulation and protein metabolism, alterations of contractile structures or metabolic pathways in skeletal muscle may severely impair animal health. 48 Moreover, in the elderly, the morphofunctional decline of the neuromuscular system is one of the most common causes of independence loss. 16,38 The word ''sarcopenia'' was used for the first time in 1989 by Irwin Rosenberg to state the age-related decrease of muscle mass. 12,43,44,45 At present, sarcopenia has been defined as the condition of muscle wasting strictly linked to aging, characterized by loss of skeletal muscle mass and function, which may affect both animals and humans, at different stages of severity 12,27,43 ; it is characterized by gradual loss of skeletal muscle mass resulting in decline of muscle function characterized by a decline in force-producing capacity and maximum velocity of shortening of muscle fibers.48 These age-related alterations in skeletal muscle are attributed to a complex of factors involving neuromuscular junction, 26 muscle structure (architecture and fiber composition), and metabolism. 43,47,49 The los...

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Muscular senescence in cetaceans: adaptation towards a slow muscle fibre phenotype

Cited by 18 publications

References 56 publications

Sex‐independent senescence in a cooperatively breeding mammal

Sex‐independent senescence in a cooperatively breeding mammal

Muscle Pathology in Free-Ranging Stranded Cetaceans

Age-Related Changes in Skeletal Muscle of Cattle

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