Histology of Muscle Development in Pigs, Epigenetics from Myotubes to Tapered Fibres

Authors

  • Howard J. Swatland University of Guelph, Canada

DOI:

https://doi.org/10.24203/ajafs.v9i6.6800

Keywords:

Pig muscle growth, Myotubes, Tapered fibres, Light scattering in pork

Abstract

Pre-natal muscle development in pigs starts with myotubes (axial nuclei in a tube of myofibrils) and secondary fibres (peripheral nuclei on an axial strand of myofibrils). By the time of birth, the nuclei of myotubes move to a peripheral position like secondary fibres. As pre-natal secondary fibres grow in length, the number of fibres in a transverse section may appear to increase. This stereology may also occur in post-natal muscles that have tapered fibres anchored in endomysial connective tissue around adjacent fibres and with one or both ends not reaching the end of their fasciculus. Up to 100 days gestation, Peroneus longus (no tapered fibres) had larger (P < 0.001) diameter secondary fibres than Longissimus thoracis (with tapered fibres). Up to 100 days gestation, no radial growth of secondary fibres was detected, but myotubes decreased in diameter (P < 0.001).  From a curve showing the relative numbers of myotubes and secondary fibres, it was deduced that approximately 80% of muscle fibres in pigs are derived from secondary fibres. In post-natal Sartorius muscle there was an increase (P < 0.005) in the apparent number of muscle fibres attributed to longitudinal growth of tapered fibres. Myotubes located centrally within their fasciculi had the same position as slow-contracting fibres with a high myoglobin content in adult muscle. Post-natal changes in muscle fibre histochemistry were achieved through transitional types, probably neurally regulated rather than by differential longitudinal growth of tapered endings. Secondary fibres are important – they give rise to both the majority of muscle fibres in adult pigs and affect subsurface optical pathways and pork colourimetry.

Author Biography

Howard J. Swatland, University of Guelph, Canada

University Emeritus Professor

References

Schwann, T. (1839) Mikroskopische Untersuchungen über die Uebereinstimmung in der Struktur und dem Wachsthum der Thiere und Pflanzen. Berlin: Verlag der Sander’schen Buchhandlung (G.E. Reimer), https://www.deutschestextarchiv.de/book/show/schwann_mikroskopische_1839

MacCallum,J.B. (1898) On the histogenesis of the striated muscle fibre, and the growth of the human Sartorius muscle. Bulletin of the Johns Hopkins Hospital. 9: 208-215. https://babel.hathitrust.org/cgi/pt?id=coo.31924069247538&view=1up&seq=254&skin=2021

Waddington, C.H. (1952). The Epigenetics of Birds. Cambridge University Press. https://www.google.ca/books/edition/The_Epigenetics_of_Birds/HQs9AAAAIAAJ?hl=en&gbpv=1&dq=epigenetics+of+birds&printsec=frontcover

Bardeen, C.R. (1900). The development of the musculature of the body wall in the pig, including its histogenesis and its relation to the myotomes and to the skeletal and nervous apparatus. Johns Hopkins Hospital Report. 9: 367-399. https://books.google.ca/books?id=PZE1AQAAMAAJ&pg=PA141&lpg=PA141&dq=The+development+of+the+musculature+of+the+body+wall+in+the+pig,&source=bl&ots=10qiaGkbQQ&sig=ACfU3U2sZmpv7CtkNPHs2jWMGAfPdebW9Q&hl=en&sa=X&ved=2ahUKEwiQpN2O_NHzAhU1mGoFHUt9ARsQ6AF6BAgPEAM#v=onepage&q=The%20development%20of%20the%20musculature%20of%20the%20body%20wall%20in%20the%20pig%2C&f=false

H.J. Swatland and R.G. Cassens, (1973). Pre-natal development, histochemistry and innervation of porcine muscle. Journal of Animal Science 36: 343-354. DOI 10.2527/jas1973.362343x

Swatland, H.J. (1971). Development and Innervation of Muscle Subject to Selective Breeding. Ph.D. Thesis, University of Wisconsin. https://books.google.ca/books/about/Development_and_Innervation_of_Muscle_Su.html?id=bHbUAAAAMAAJ&redir_esc=y

Swatland, H.J. and Cassens, R.G. (1972). Muscle growth: the problem of muscle fibers with an intrafascicular termination. Journal of Animal Science 35: 336-344. https://www.researchgate.net/publication/19049265_Muscle_Growth_The_Problem_of_Muscle_Fibers_with_an_Intrafascicular_Termination#fullTextFileContent

Swatland, H.J. (1976). Effect of growth and plane of nutrition on apparent muscle fibers numbers in the pig. Growth 40: 285-292. https://www.researchgate.net/publication/22177734_Effect_of_growth_and_plane_of_nutrition_on_apparent_muscle_fiber_numbers_in_the_pig

Swatland, H.J. (1983). The histochemistry of very small muscle fibres in growing skeletal muscles. Journal of the Neurological Sciences 61: 435-442. DOI: 10.1016/0022-510X(83)90176-4

Swatland, H.J. (1982). Histology of allometric growth in hindlimb muscles of pigs. Journal of Agricultural Science, Cambridge 98: 629-632. DOI: 10.1017/S0021859600054423

H.J. Swatland, (2006). Growth and Structure of Meat Animals. An undergraduate teaching site with original micrographs by the author. https://animalbiosciences.uoguelph.ca/~swatland/gasman.html

Swatland, H.J. (1975) Histochemical development of myofibers in neonatal piglets. Research in Veterinary Science 18: 253-257. DOI: 10.1111/j.1439-0442.1977.tb01570.x

Sakuma, K. and Yamaguchi, A. (2011). The recent understanding of the neurotrophin’s role in skeletal muscle adaptation. Journal of Biomedicine and Biotechnology . doi: 10.1155/2011/201696. Epub 2011 Sep 25.

Swatland, H.J. (1977). Transitional stages in the histochemical development of muscle fibres during post-natal growth. Histochemical Journal 9: 751-7. DOI: 10.1007/BF01003069

Swatland, H.J. (1977). Cytophotometry of postmortem glycogenolysis in different histochemical types of muscle fibres in the pig. Histochemical Journal 9: 163-170. DOI: 10.1007/BF01003628

Swatland, H.J. (1983). Measurement of electrical stunning, rate of exsanguination, and reflex activity of pigs in an abattoir. Canadian Institute of Food Science and Technology 16: 35-38. DOI: 10.1016/S0315-5463(83)72016-X

Bendall, J.R and Swatland, H.J. (1988). A review of the relationships between pH and physical aspects of pork quality. Meat Science 24: 85-126. DOI: 10.1016/0309-1740(88)90052-6

Swatland, H.J. (2021). An explanation of subsurface optical pathways through food myosystems. Asian Journal of Agriculture and Food Sciences 9: 143-157. DOI: 10.24203/ajafs.v9i4.6706

Swatland, H.J. (2004). Absorbance of light by mitochondria in pork muscle fibres differing in myoglobin content. Meat Science 67: 371-375. DOI: .org/10.1016/j.meatsci.2003.11.005

Downloads

Published

2021-12-31

How to Cite

Swatland, H. J. (2021). Histology of Muscle Development in Pigs, Epigenetics from Myotubes to Tapered Fibres. Asian Journal of Agriculture and Food Sciences, 9(6). https://doi.org/10.24203/ajafs.v9i6.6800