mRNA levels of myogenic regulatory factors in rat slow and fast muscles regenerating from notexin-induced necrosis

Perturbations of the prenatal environment may influence fetal muscle development. This study investigated muscle cellularity and mRNA abundance of myogenic genes in fetal sheep divergent in their patterns of growth. Muscle samples were obtained from small and large fetuses on Days 50, 92 and 133 of pregnancy. Number of myofibres in the semitendinosus muscle increased between Day 92 and 133 of pregnancy, but did not differ between small and large fetuses at either stage of pregnancy. The semitendinosus of small fetuses had smaller cross-sectional areas of myofibres than did those of their large counterparts on Day 133 of pregnancy. The semitendinosus of small fetuses also had lower DNA concentration on Day 92 and lower protein concentration on Day 133 than did those of large fetuses. The mRNA levels of the myogenic regulatory factors (MRFs), myostatin, the insulin-like growth factors and embryonic myosin in fetal muscles varied with the stage of development, but no differences occurred in response to divergent fetal growth. Myostatin mRNA was more abundant in the semitendinosus than in the supraspinatus muscle on Days 92 and 133, as were myogenic regulatory factors, myf-5, myf-6 and follistatin mRNA on Day 133. The results indicated that muscle growth but not the number of myofibres in fetal sheep is modified by restricted fetal growth, and that genes that regulate muscle development are affected by the stage of development in an anatomical muscle-specific manner.

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Myogenic regulatory factors during regeneration of skeletal muscle in young, adult, and old rats

Journal of Applied Physiology ◽

10.1152/jappl.1997.83.4.1270 ◽

1997 ◽

Vol 83 (4) ◽

pp. 1270-1275 ◽

Cited By ~ 92

Author(s):

Daniel R. Marsh ◽

David S. Criswell ◽

James A. Carson ◽

Frank W. Booth

Keyword(s):

Skeletal Muscle ◽

Young Adult ◽

Muscle Regeneration ◽

Tibialis Anterior Muscle ◽

Brown Norway ◽

Mrna Levels ◽

Myogenic Regulatory Factors ◽

Adult Rats ◽

Regulatory Factors ◽

Old Rats

Marsh, Daniel R., David S. Criswell, James A. Carson, and Frank W. Booth. Myogenic regulatory factors during regeneration of skeletal muscle in young, adult, and old rats. J. Appl. Physiol. 83(4): 1270–1275, 1997.—Myogenic factor mRNA expression was examined during muscle regeneration after bupivacaine injection in Fischer 344/Brown Norway F1 rats aged 3, 18, and 31 mo of age (young, adult, and old, respectively). Mass of the tibialis anterior muscle in the young rats had recovered to control values by 21 days postbupivacaine injection but in adult and old rats remained 40% less than that of contralateral controls at 21 and 28 days of recovery. During muscle regeneration, myogenin mRNA was significantly increased in muscles of young, adult, and old rats 5 days after bupivacaine injection. Subsequently, myogenin mRNA levels in young rat muscle decreased to postinjection control values by day 21 but did not return to control values in 28-day regenerating muscles of adult and old rats. The expression of MyoD mRNA was also increased in muscles at day 5 of regeneration in young, adult, and old rats, decreased to control levels by day 14 in young and adult rats, and remained elevated in the old rats for 28 days. In summary, either a diminished ability to downregulate myogenin and MyoD mRNAs in regenerating muscle occurs in old rat muscles, or the continuing myogenic effort includes elevated expression of these mRNAs.

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Diet and Exercise Modulate GH-IGFs Axis, Proteolytic Markers and Myogenic Regulatory Factors in Juveniles of Gilthead Sea Bream (Sparus aurata)

Animals ◽

10.3390/ani11082182 ◽

2021 ◽

Vol 11 (8) ◽

pp. 2182

Author(s):

Miquel Perelló-Amorós ◽

Isabel García-Pérez ◽

Albert Sánchez-Moya ◽

Arnau Innamorati ◽

Emilio J. Vélez ◽

...

Keyword(s):

Sparus Aurata ◽

High Energy ◽

Culture Conditions ◽

Gilthead Sea Bream ◽

Sea Bream ◽

Mrna Levels ◽

Myogenic Regulatory Factors ◽

Regulatory Factors ◽

Gene And Protein Expression ◽

Plasma Gh

The physiological and endocrine benefits of sustained exercise in fish were largely demonstrated, and this work examines how the swimming activity can modify the effects of two diets (high-protein, HP: 54% proteins, 15% lipids; high-energy, HE: 50% proteins, 20% lipids) on different growth performance markers in gilthead sea bream juveniles. After 6 weeks of experimentation, fish under voluntary swimming and fed with HP showed significantly higher circulating growth hormone (GH) levels and plasma GH/insulin-like growth-1 (IGF-1) ratio than fish fed with HE, but under exercise, differences disappeared. The transcriptional profile of the GH-IGFs axis molecules and myogenic regulatory factors in liver and muscle was barely affected by diet and swimming conditions. Under voluntary swimming, fish fed with HE showed significantly increased mRNA levels of capn1, capn2, capn3, capns1a, n3, and ub, decreased gene and protein expression of Ctsl and Mafbx and lower muscle texture than fish fed with HP. When fish were exposed to sustained exercise, diet-induced differences in proteases’ expression and muscle texture almost disappeared. Overall, these results suggest that exercise might be a useful tool to minimize nutrient imbalances and that proteolytic genes could be good markers of the culture conditions and dietary treatments in fish.

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