Gene expression of myostatin during development and regeneration of skeletal mus

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J Anim Sci. 2006 Nov;84(11):2983-9.

Gene expression of myostatin during development and regeneration of

skeletal muscle in Japanese Black Cattle.

Shibata M, Matsumoto K, Aikawa K, Muramoto T, Fujimura S, Kadowaki

M.

National Agricultural Research Center for Western Region, Ohda-shi,

Shimane-ken, 694-0013, Japan.

Myostatin is a specific negative regulator of skeletal muscle growth

and is regarded as one of the most important factors for myogenesis.

The aim of the current study was to analyze the developmental change

in the gene expression of myostatin and an adipogenic transcription

factor (peroxisome proliferator-activated receptor lambda2) in the

semitendinosus muscle of Japanese Black Cattle throughout the whole

life cycle. An additional aim was to compare the temporal expression

patterns of myostatin and relevant myogenic regulatory factors (MRF)

mRNA during muscle regeneration after frostbite injury at 16 mo of

age. The developmental pattern of myostatin gene expression

exhibited 2 peaks: the greatest expression occurred in utero (P

<0.05) and the second greatest occurred at 16 mo of age (P <0.05).

The greatest level of peroxisome proliferator-activated receptor

lambda2 expression was observed at 16 mo of age (P <0.05), which

paralleled myostatin expression. During frostbite-induced muscle

regeneration, gene expression for myostatin and 4 MRF; i.e., Myf5,

MyoD, myogenin and MRF4, showed contrasting responses. Myostatin

mRNA dramatically declined by 68.1 and 82.6% at 3 and 5 d after

injury (P <0.05), respectively, which paralleled its protein

expression, and was restored at 10 d. In contrast, the expressions

of all 4 MRF mRNA were low initially but increased by 5 d after

injury (P <0.05) and then remained constant or decreased slightly.

These results suggest that myostatin may play a role in muscle

marbling in the fattening period by decreasing myogenesis and

increasing adipogenesis, and that the interaction between myostatin

and MRF genes may take place at an early stage of skeletal muscle

regeneration.