title: A disintegrin and metalloprotease-12 is type I myofiber specific in Bos taurus and Bos indicus cattle.
abstract: A disintegrin and metalloproteinase-12 (ADAM12) is involved in the regulation of myogenesis and adipogenesis and is of interest as a potential target to manipulate skeletal muscle development and intramuscular fat (IMF) deposition in cattle to increase beef yield and improve meat quality. The longissimus thoracis muscle (LM) and semitendinosus muscle (STM) from 5 Bos taurus (Angus) and 5 Bos indicus (Brahman) cattle were collected for histological and ADAM12 gene and protein expression analysis. Myofiber typing was used to determine if ADAM12 expression patterns related to differences in muscling and IMF deposition, which are influenced by proportions of the different myofiber types. The STM was found to contain a higher proportion of glycolytic myofibers than the LM, which contained a greater proportion of oxidative myofibers (myofiber ratio of glycolytic to more oxidative types in LM and STM of 1.1 and 3.5, respectively; P < 0.05). ADAM12 gene expression, fluorescent immunohistochemical staining for ADAM12, and image analysis found ADAM12 to be greater in the LM (P < 0.05). Regression analysis found a strong, positive relationship for the distribution of ADAM12 against the proportion of type I myofibers (P < 0.05, r(2) = 0.86). These findings suggest ADAM12 is upregulated in muscles with more slow-oxidative myofibres, such as the LM, and is linked to type I myofibers in cattle. ADAM12 may be important in the regulation and maintenance slow myofibers in the LM muscle.
authors.affiliation: Victorian Department of Environment and Primary Industries, Bundoora, VIC 3083, Australia.
authors.forename: C A
authors.initials: CA
authors.lastname: Coles
authors.forename: J
authors.initials: J
authors.lastname: Wadeson
authors.forename: M I
authors.initials: MI
authors.lastname: Knight
authors.forename: L M
authors.initials: LM
authors.lastname: Cafe
authors.forename: W H
authors.initials: WH
authors.lastname: Johns
authors.forename: J D
authors.initials: JD
authors.lastname: White
authors.forename: P L
authors.initials: PL
authors.lastname: Greenwood
authors.forename: M B
authors.initials: MB
authors.lastname: McDonagh
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism*; D000072199:ADAM12 Protein; D000818:Animals; D015153:Blotting, Western; D002417:Cattle / Q000502:physiology*; D015180:Electrophoresis, Gel, Two-Dimensional; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D018657:Muscle Fibers, Slow-Twitch / Q000201:enzymology* / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D051722:ADAM Proteins; D000072199:ADAM12 Protein