Structural diversity in muscle fibres of chicken breast

Abstract

Chicken breast muscle is usually considered to be a relatively homogeneous white muscle and has therefore been widely used for studies of muscle proteins. In a previous study, however, we have found different M-region structures in different fibres from this muscle. Because of this result, we have now carried out a combined histochemical and ultrastructural survey of this muscle. In particular, we have made use of large transverse cryo-sections that include most of the muscle cross-section. Although the white region is fairly homogeneous in fibre content according to normal histochemical criteria (mATPase), we have found that there is a gradation of fibre structure across the muscle. The bulk of the muscle stains conventionally for Type-II fibres according to mATPase tests (the "white" part) but, in the small "red" part of the muscle, there are also Type-I fibres together with the Type-II fibres. Superimposed on this division into Type-I and Type-II fibres are variations in fibre size, oxidative and glycolytic staining properties, and variations of Z-band width and M-band structure; there is no strict correlation among any of these parameters. The apparently uniform staining across most of the muscle when tested for myofibrillar ATPase may be a misleading indicator of fibre properties.

Contractile properties and protein isoforms of single fibres from the chicken pectoralis red strip muscle.

“…Differences also exist between red strip fibres and fast white fibres with respect to troponin T (TnT) isoform and tropomyosin expressions (Matsuda et al 1983;Dhoot, 1988). The ultrastructural characteristics of red strip fibres also differ markedly from those of the fast white fibres (Edman, Lexell, Sjostrom & Squire, 1988).…”

The role of monoxide hemoglobin in color improvement of chicken sausage

“…Color The objective of this study is to clarify the role of COHb in improvement of meat product color in the presence of NaNO 2 . In order to avoid interference of endogenous pigments, such as myoglobin, chicken breast was used as a raw material for preparation of sausage due to low pigment content (11).…”

Developmental Changes of Cardiac and Slow Skeletal Muscle Troponin T Expression in Chicken Cardiac and Skeletal Muscles

“…The extensive study of distributions of fTnT and sTnT isoforms in the chicken muscles (Yao et al, 1992) did not show any muscle which expressed simultaneously B-type fTnT and sTnT isoforms. The red strip region of pectoralis major has type II fibers expressing fast-skeletal-muscle-type isoforms and type I fibers expressing slow-skeletal-muscle-type isoforms (Matsuda et al, 1983;Edman et al, 1988;Reiser et al, 1996), although the bulk white region has type II fibers (Obinata, 1985). Therefore, the region is a suitable area to search for fiber-type-specific gene expression and expressional regulatory factors of fTnT and sTnT genes as well as alternative splicing factors for the fTnT gene.…”