1st Page

Journal of Animal Science Abstract - Animal Products

Enhancement of adipogenesis and fibrogenesis in skeletal muscle of Wagyu compared with Angus cattle


This article in JAS

  1. Vol. 91 No. 6, p. 2938-2946
    Received: Sept 22, 2012
    Accepted: Mar 2, 2013
    Published: November 25, 2014

    1 Corresponding author(s):

  1. M. S. Duarte*†,
  2. P. V. R. Paulino,
  3. A. K. Das*,
  4. S. Wei*,
  5. N. V. L. Serão,
  6. X. Fu*,
  7. S. M. Harris*,
  8. M. V. Dodson* and
  9. M. Du 1
  1. Department of Animal Sciences, Washington State University, Pullman 99164
    Department of Animal Science, Universidade Federal de Viçosa, Viçosa, Brazil
    Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana 61801


Intramuscular fat and collagen content are major factors affecting beef quality, but mechanisms regulating intramuscular adipose and connective tissue deposition are far from clear. Japanese Wagyu cattle are well known for their extremely high marbling. The objective of this study was to evaluate intramuscular fat (IMF) and collagen deposition in the muscle of Wagyu compared with Angus cattle. Animals were managed under the same condition and slaughtered at an averaging 585 ± 12.1 kg of BW. Samples of sternomandibularis muscle were collected from Wagyu (n = 3) and Angus (n = 3) for molecular and histological investigations of adipogenesis and fibrogenesis. With exception of C/EBPβ (P = 0.2864), the expression of the adipogenic markers C/EBPα (P = 0.008), PPARγ (P = 0.028), and zip finger protein 423 (Zfp423; P = 0.047) in Wagyu were greater than in Angus muscle, which was consistent with greater IMF deposition in Wagyu (P < 0.05). In addition, more adipocytes and preadipocytes were detected intramuscularly in Wagyu cattle. Similarly, fibrogenesis was also enhanced in Wagyu, with a greater expression of fibroblast growth factor (FGF)-2 (P = 0.028), FGF receptor 1 (P = 0.030), transforming growth factor (TGF)-β (P = 0.028), collagen I (P = 0.012), and collagen III (P = 0.025). Similarly, Wagyu muscle had greater collagen content (P = 0.002) and decreased collagen solubility (P = 0.005). In addition, muscle fiber diameter was larger (P < 0.0001) in Wagyu than in Angus cattle. These results clearly show that both IMF and collagen contents are enhanced in Wagyu cattle and more adipogenic cells are detected in Wagyu muscle, indicating intramuscular adipogenesis is enhanced in Wagyu compared with Angus muscle.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2013. American Society of Animal Science