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Impacts of the Callipyge mutation on ovine plasma metabolites and muscle fibre type.

Li J, Greenwood PL, Cockett NE, Hadfield TS, Vuocolo T, Byrne K, White JD, Tellam RL, Schirra HJ - PLoS ONE (2014)

Bottom Line: Using muscle fibre typing immunohistochemistry, we confirmed muscle specific effects and demonstrated that affected muscles had greater prevalence and hypertrophy of type 2X fast twitch glycolytic fibres and decreased representation of types 1, 2C, 2A and/or 2AX fibres.Microarray analysis of the perirenal adipose tissue depot did not reveal a transcriptional effect of the mutation in this tissue.We conclude that there is an indirect systemic effect of the Callipyge mutation in skeletal muscle in the form of changes of blood metabolites, which may contribute to secondary phenotypes such as body leanness.

View Article: PubMed Central - PubMed

Affiliation: CSIRO Animal, Food and Health Sciences, St Lucia, Brisbane, Australia.

ABSTRACT
The ovine Callipyge mutation causes postnatal muscle hypertrophy localized to the pelvic limbs and torso, as well as body leanness. The mechanism underpinning enhanced muscle mass is unclear, as is the systemic impact of the mutation. Using muscle fibre typing immunohistochemistry, we confirmed muscle specific effects and demonstrated that affected muscles had greater prevalence and hypertrophy of type 2X fast twitch glycolytic fibres and decreased representation of types 1, 2C, 2A and/or 2AX fibres. To investigate potential systemic effects of the mutation, proton NMR spectra of plasma taken from lambs at 8 and 12 weeks of age were measured. Multivariate statistical analysis of plasma metabolite profiles demonstrated effects of development and genotype but not gender. Plasma from Callipyge lambs at 12 weeks of age, but not 8 weeks, was characterized by a metabolic profile consistent with contributions from the affected hypertrophic fast twitch glycolytic muscle fibres. Microarray analysis of the perirenal adipose tissue depot did not reveal a transcriptional effect of the mutation in this tissue. We conclude that there is an indirect systemic effect of the Callipyge mutation in skeletal muscle in the form of changes of blood metabolites, which may contribute to secondary phenotypes such as body leanness.

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Immunohistochemical staining of ovine myosin heavy chains and laminin in serial sections of semimembranosus muscle.Representative myofibers are indicated: s, type 1 (slow oxidative); a, type 2A (fast twitch oxidative-glycolytic); c, type 2C (type 1–type 2A intermediate); ax, type 2AX (type 2A–type 2X intermediate). Non-labelled myofibers represent type 2X (fast twitch glycolytic). The top, middle and bottom panels were stained with myosin heavy chains (MHC) antibodies S5 8H2, WB-MHCs and MY32, respectively. Note the larger type 2X myofibres in the semimembranosus muscle of Callipyge (NmatCpat genotype) (right column) compared with normal (NmatNpat genotype) (left column) lambs, and the absence in the sections shown here and the overall very low prevalence of type 2A and type 2AX myofibres in Callipyge compared to normal semimembranosus muscle (see Table 1).
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pone-0099726-g001: Immunohistochemical staining of ovine myosin heavy chains and laminin in serial sections of semimembranosus muscle.Representative myofibers are indicated: s, type 1 (slow oxidative); a, type 2A (fast twitch oxidative-glycolytic); c, type 2C (type 1–type 2A intermediate); ax, type 2AX (type 2A–type 2X intermediate). Non-labelled myofibers represent type 2X (fast twitch glycolytic). The top, middle and bottom panels were stained with myosin heavy chains (MHC) antibodies S5 8H2, WB-MHCs and MY32, respectively. Note the larger type 2X myofibres in the semimembranosus muscle of Callipyge (NmatCpat genotype) (right column) compared with normal (NmatNpat genotype) (left column) lambs, and the absence in the sections shown here and the overall very low prevalence of type 2A and type 2AX myofibres in Callipyge compared to normal semimembranosus muscle (see Table 1).

Mentions: Skeletal muscle fibre type immunohistochemistry was used to examine the details of the previously reported muscle hypertrophy in Callipyge lambs at approximately 11 weeks of age (Figure 1 and Table 1) [6], [8], [9]. Each skeletal muscle typically has a mixture of fibre types that reflects the individual functional requirements of the muscle e.g. postural support and/or locomotion. Three functionally diverse skeletal muscles were examined to determine the effect of the NmatCpat genotype on fibre type composition and myofibre size, namely the semimembranosus, semitendinosus and supraspinatus. Figure 1 shows representative images of the fibre type immunocytochemical staining patterns for semimembranosus muscle taken from NmatNpat and NmatCpat lambs at 11 weeks of age. This muscle is located on the back and medial side of thigh and has a primary function in locomotion. The three panels for each genotype show staining patterns in a single section, with three different monoclonal antibodies to myosin heavy chains, characteristic of specific fibre types or fibre type mixtures. These differential staining patterns of myofibre types demonstrate that semimembranosus is predominantly represented by type 2X fibres i.e. fast twitch glycolytic fibres. The predominance of type 2X fibres reflects the role of this muscle in movement, which is associated with the need for generation of force over short periods using rapidly exhaustible energy stores. Strikingly, the type 2X fibres in the NmatCpat genotype were visibly much larger compared to the same fibre type in the NmatNpat genotype e.g. see the unstained myofibres in the middle panels. There were also substantial decreases in the number of type 1, 2C, 2A and/or type 2AX fibres in the NmatCpat genotype.


Impacts of the Callipyge mutation on ovine plasma metabolites and muscle fibre type.

Li J, Greenwood PL, Cockett NE, Hadfield TS, Vuocolo T, Byrne K, White JD, Tellam RL, Schirra HJ - PLoS ONE (2014)

Immunohistochemical staining of ovine myosin heavy chains and laminin in serial sections of semimembranosus muscle.Representative myofibers are indicated: s, type 1 (slow oxidative); a, type 2A (fast twitch oxidative-glycolytic); c, type 2C (type 1–type 2A intermediate); ax, type 2AX (type 2A–type 2X intermediate). Non-labelled myofibers represent type 2X (fast twitch glycolytic). The top, middle and bottom panels were stained with myosin heavy chains (MHC) antibodies S5 8H2, WB-MHCs and MY32, respectively. Note the larger type 2X myofibres in the semimembranosus muscle of Callipyge (NmatCpat genotype) (right column) compared with normal (NmatNpat genotype) (left column) lambs, and the absence in the sections shown here and the overall very low prevalence of type 2A and type 2AX myofibres in Callipyge compared to normal semimembranosus muscle (see Table 1).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4061035&req=5

pone-0099726-g001: Immunohistochemical staining of ovine myosin heavy chains and laminin in serial sections of semimembranosus muscle.Representative myofibers are indicated: s, type 1 (slow oxidative); a, type 2A (fast twitch oxidative-glycolytic); c, type 2C (type 1–type 2A intermediate); ax, type 2AX (type 2A–type 2X intermediate). Non-labelled myofibers represent type 2X (fast twitch glycolytic). The top, middle and bottom panels were stained with myosin heavy chains (MHC) antibodies S5 8H2, WB-MHCs and MY32, respectively. Note the larger type 2X myofibres in the semimembranosus muscle of Callipyge (NmatCpat genotype) (right column) compared with normal (NmatNpat genotype) (left column) lambs, and the absence in the sections shown here and the overall very low prevalence of type 2A and type 2AX myofibres in Callipyge compared to normal semimembranosus muscle (see Table 1).
Mentions: Skeletal muscle fibre type immunohistochemistry was used to examine the details of the previously reported muscle hypertrophy in Callipyge lambs at approximately 11 weeks of age (Figure 1 and Table 1) [6], [8], [9]. Each skeletal muscle typically has a mixture of fibre types that reflects the individual functional requirements of the muscle e.g. postural support and/or locomotion. Three functionally diverse skeletal muscles were examined to determine the effect of the NmatCpat genotype on fibre type composition and myofibre size, namely the semimembranosus, semitendinosus and supraspinatus. Figure 1 shows representative images of the fibre type immunocytochemical staining patterns for semimembranosus muscle taken from NmatNpat and NmatCpat lambs at 11 weeks of age. This muscle is located on the back and medial side of thigh and has a primary function in locomotion. The three panels for each genotype show staining patterns in a single section, with three different monoclonal antibodies to myosin heavy chains, characteristic of specific fibre types or fibre type mixtures. These differential staining patterns of myofibre types demonstrate that semimembranosus is predominantly represented by type 2X fibres i.e. fast twitch glycolytic fibres. The predominance of type 2X fibres reflects the role of this muscle in movement, which is associated with the need for generation of force over short periods using rapidly exhaustible energy stores. Strikingly, the type 2X fibres in the NmatCpat genotype were visibly much larger compared to the same fibre type in the NmatNpat genotype e.g. see the unstained myofibres in the middle panels. There were also substantial decreases in the number of type 1, 2C, 2A and/or type 2AX fibres in the NmatCpat genotype.

Bottom Line: Using muscle fibre typing immunohistochemistry, we confirmed muscle specific effects and demonstrated that affected muscles had greater prevalence and hypertrophy of type 2X fast twitch glycolytic fibres and decreased representation of types 1, 2C, 2A and/or 2AX fibres.Microarray analysis of the perirenal adipose tissue depot did not reveal a transcriptional effect of the mutation in this tissue.We conclude that there is an indirect systemic effect of the Callipyge mutation in skeletal muscle in the form of changes of blood metabolites, which may contribute to secondary phenotypes such as body leanness.

View Article: PubMed Central - PubMed

Affiliation: CSIRO Animal, Food and Health Sciences, St Lucia, Brisbane, Australia.

ABSTRACT
The ovine Callipyge mutation causes postnatal muscle hypertrophy localized to the pelvic limbs and torso, as well as body leanness. The mechanism underpinning enhanced muscle mass is unclear, as is the systemic impact of the mutation. Using muscle fibre typing immunohistochemistry, we confirmed muscle specific effects and demonstrated that affected muscles had greater prevalence and hypertrophy of type 2X fast twitch glycolytic fibres and decreased representation of types 1, 2C, 2A and/or 2AX fibres. To investigate potential systemic effects of the mutation, proton NMR spectra of plasma taken from lambs at 8 and 12 weeks of age were measured. Multivariate statistical analysis of plasma metabolite profiles demonstrated effects of development and genotype but not gender. Plasma from Callipyge lambs at 12 weeks of age, but not 8 weeks, was characterized by a metabolic profile consistent with contributions from the affected hypertrophic fast twitch glycolytic muscle fibres. Microarray analysis of the perirenal adipose tissue depot did not reveal a transcriptional effect of the mutation in this tissue. We conclude that there is an indirect systemic effect of the Callipyge mutation in skeletal muscle in the form of changes of blood metabolites, which may contribute to secondary phenotypes such as body leanness.

Show MeSH
Related in: MedlinePlus