+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Evidence for three adult fast myosin heavy chain isoforms in type II skeletal muscle fibers in pigs

Evidence for three adult fast myosin heavy chain isoforms in type II skeletal muscle fibers in pigs

Journal of Animal Science 76(6): 1584-1593

Three main fiber types (one slow [type I] and two fast [type IIA and IIB] can be distinguished using conventional actomyosin ATPase (AM-ATPase) histochemistry after acidic pretreatment in mature pig skeletal muscle. We report the isolation, characterization, and identification of four adult 3'-untranslated regions corresponding to types I, IIA, IIB, and IIX myosin heavy chains (MyHC) from a cDNA library. Identification of different type II clones was based on sequence homology, in situ hybridizations (ISH), AM-ATPase histochemistry, and immunocytochemistry. Enzyme histochemistry, immunocytochemistry, and ISH were performed on serial transverse sections of longissimus and red portion of semitendinosus muscle. Results showed that all three fast MyHC transcripts were expressed in the longissimus, whereas only type IIA and IIX transcripts were present in deep red semitendinosus muscle. Type I and IIA fibers contained mostly type I and IIA transcripts, respectively, whereas type IIB fibers contained a heterogeneous population of transcripts. In longissimus muscle, 18, 31, and 51% of conventional IIB fibers were pure IIX, hybrid IIX/IIB, and pure IIB fibers, respectively. Conversely, conventional IIB fibers were actually IIX in deep red semitendinosus muscle. Expression of the three fast adult MyHC isoforms in longissimus was spatially regulated around the typical islets of type I fibers encountered in pig skeletal muscle. Thus, IIA fibers were contiguous to type I fibers, pure IIX fibers were in the direct vicinity of type I and IIA fibers, and hybrid IIX/IIB fibers were located mostly within primary fascicles between the islets of type I fibers; however, pure IIB fibers were located mainly at the periphery of the rosettes near the edges of primary fascicles. In light of the present study, conventional IIB fibers, as defined with AM-ATPase staining, are a heterogeneous population that should be split into pure IIX, hybrid IIX/ IIB, and pure IIB fibers for a more accurate fiber typing.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 003134289

Download citation: RISBibTeXText

PMID: 9655578

DOI: 10.2527/1998.7661584x

Related references

Evidence for three fast myosin heavy chain isoforms in type II skeletal muscle fibers in the adult llama (Lama glama). Journal of Histochemistry and Cytochemistry 49(8): 1033-1044, 2001

Sequential accumulation of mRNAs encoding different myosin heavy chain isoforms during skeletal muscle development in vivo detected with a recombinant plasmid identified as coding for an adult fast myosin heavy chain from mouse skeletal muscle. Journal of Biological Chemistry 258(22): 13867-13874, 1983

Three myosin heavy chain isoforms in type 2 skeletal muscle fibers. Journal of Muscle Research & Cell Motility 10(3): 197-205, 1989

Coexpression of RNAs for fast myosin heavy chain isoforms in type I/beta fibers of human external oblique muscle. Molecular Biology of the Cell 11(Suppl.): 75a, 2000

Novel epigenetic regulation of skeletal muscle myosin heavy chain genes. Focus on "Differential epigenetic modifications of histones at the myosin heavy chain genes in fast and slow skeletal muscle fibers and in response to muscle unloading". American Journal of Physiology. Cell Physiology 297(1): C1-C3, 2009

Skeletal muscle fibers express cardiac type and repress fast type myosin heavy chain genes when subjected to stretch and isometric overload. Journal of Cellular Biochemistry Suppl. (13 Part E): 178, 1989

Loss of myostatin expression alters fiber-type distribution and expression of myosin heavy chain isoforms in slow- and fast-type skeletal muscle. Muscle and Nerve 31(1): 34-40, 2005

Transient appearance of a fast myosin heavy chain epitope in slow type muscle fibers during stretch hypertrophy of the anterior latissimus dorsi muscle in the adult chicken. Journal of Muscle Research & Cell Motility 8(3): 220-228, 1987

Increase in the degree of coexpression of myosin heavy chain isoforms in skeletal muscle fibers of the very old. Muscle & Nerve 22(4): 449-454, 1999

Kinetic properties of myosin heavy chain isoforms in single fibers from human skeletal muscle. Febs Letters 455(3): 267-270, 1999

Co existence of myosin heavy chain i and iia isoforms in human skeletal muscle fibers with endurance training. Pfluegers Archiv European Journal of Physiology 416(4): 470-472, 1990

Fast myosin heavy chain isoforms in horse skeletal muscle: an immunohistochemical and electrophoretic study. Pferdeheilkunde 12(4): 523-527, 1996

Reorganization of fast skeletal myosin heavy chain isoforms within the same muscle cell of thermally acclimated carp. Journal of Fish Biology 55(Suppl A): 245, 1999

Myosin subfragment-1 isoforms having different heavy chain structures from fast skeletal muscle of thermally acclimated carp. Journal of Biochemistry 116(4): 728-735, 1994

Myosin Subfragment-1 Isoforms Having Different Heavy Chain Structures from Fast Skeletal Muscle of Thermally Acclimated Carp1. The Journal of Biochemistry 116(4): 728-735, 1994