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Myostatin preferentially down-regulates the expression of fast 2x myosin heavy chain in cattle.

Hayashi S, Miyake M, Watanabe K, Aso H, Hayashi S, Ohwada S, Yamaguchi T - Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci. (2008)

Bottom Line: No significant difference existed in expressions of embryonic and slow MyHC mRNA between DM and NM myoblasts.Addition of myostatin for DMc resulted in less myotube formation and suppression of mRNA expression of fast 2x MyHC.These findings suggest that the endogenous myostatin preferentially down-regulates the expression of the fast 2x MyHC and participates in differentiation of myofiber types during early bovine myogenesis.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Functional Morphology, Department of Animal Biology, Graduate School of Agricultural Science, Tohoku University, Miyagi, Japan.

ABSTRACT
Myostatin is involved in an inhibitor of muscular growth and differentiation. Myoblasts derived from double-muscled Japanese shorthorn cattle (DM myoblasts) with absence of functional myostatin had higher abilities to proliferate and differentiate than myoblasts derived from normal-muscled cattle (NM myoblasts). In DM myoblasts, mRNA expressions of fetal myosin heavy chain (MyHC) in growth medium and of fast 2a and 2x MyHC in fusion medium were significantly greater than that in NM myoblasts. No significant difference existed in expressions of embryonic and slow MyHC mRNA between DM and NM myoblasts. The expression of MyoD mRNA was suppressed in myoblasts by administration of myostatin. Two cloned DM myoblast strains (DMc) were established. Addition of myostatin for DMc resulted in less myotube formation and suppression of mRNA expression of fast 2x MyHC. These findings suggest that the endogenous myostatin preferentially down-regulates the expression of the fast 2x MyHC and participates in differentiation of myofiber types during early bovine myogenesis.

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Related in: MedlinePlus

Increased proliferation and myotube formation of DM myoblasts.The cell number of DM and NM myoblasts was measured by the trypan blue exclusion method at indicated days (A). The data are shown as mean ± S.D. (n = 3) and the doubling time of myoblasts was assessed during exponential cell growth (B). Myotube formation in NM (C) and DM (D) cultures were visualized by Giemsa staining. *: P < 0.05. Arrows: myotubes. Bar = 100 μm.
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f2-354: Increased proliferation and myotube formation of DM myoblasts.The cell number of DM and NM myoblasts was measured by the trypan blue exclusion method at indicated days (A). The data are shown as mean ± S.D. (n = 3) and the doubling time of myoblasts was assessed during exponential cell growth (B). Myotube formation in NM (C) and DM (D) cultures were visualized by Giemsa staining. *: P < 0.05. Arrows: myotubes. Bar = 100 μm.

Mentions: In growth medium, the number of DM myoblasts was significantly larger than that of NM myoblasts during 2 to 5 days after seeding (Fig. 2A). The doubling time of DM myoblasts (11.4 h ± 0.44) was significantly shorter than that of NM myoblasts (12.6 h ± 0.32) (Fig. 2B). When growth medium was replaced to fusion medium, myotube formation from myoblasts was induced, in which DM myoblasts formed more and larger myotubes than NM myoblasts did (Fig. 2C, D). Thus, myostatin deficiency in DM myoblast cultures substantially enhanced the proliferation of myoblasts and myotube formation.


Myostatin preferentially down-regulates the expression of fast 2x myosin heavy chain in cattle.

Hayashi S, Miyake M, Watanabe K, Aso H, Hayashi S, Ohwada S, Yamaguchi T - Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci. (2008)

Increased proliferation and myotube formation of DM myoblasts.The cell number of DM and NM myoblasts was measured by the trypan blue exclusion method at indicated days (A). The data are shown as mean ± S.D. (n = 3) and the doubling time of myoblasts was assessed during exponential cell growth (B). Myotube formation in NM (C) and DM (D) cultures were visualized by Giemsa staining. *: P < 0.05. Arrows: myotubes. Bar = 100 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3722022&req=5

f2-354: Increased proliferation and myotube formation of DM myoblasts.The cell number of DM and NM myoblasts was measured by the trypan blue exclusion method at indicated days (A). The data are shown as mean ± S.D. (n = 3) and the doubling time of myoblasts was assessed during exponential cell growth (B). Myotube formation in NM (C) and DM (D) cultures were visualized by Giemsa staining. *: P < 0.05. Arrows: myotubes. Bar = 100 μm.
Mentions: In growth medium, the number of DM myoblasts was significantly larger than that of NM myoblasts during 2 to 5 days after seeding (Fig. 2A). The doubling time of DM myoblasts (11.4 h ± 0.44) was significantly shorter than that of NM myoblasts (12.6 h ± 0.32) (Fig. 2B). When growth medium was replaced to fusion medium, myotube formation from myoblasts was induced, in which DM myoblasts formed more and larger myotubes than NM myoblasts did (Fig. 2C, D). Thus, myostatin deficiency in DM myoblast cultures substantially enhanced the proliferation of myoblasts and myotube formation.

Bottom Line: No significant difference existed in expressions of embryonic and slow MyHC mRNA between DM and NM myoblasts.Addition of myostatin for DMc resulted in less myotube formation and suppression of mRNA expression of fast 2x MyHC.These findings suggest that the endogenous myostatin preferentially down-regulates the expression of the fast 2x MyHC and participates in differentiation of myofiber types during early bovine myogenesis.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Functional Morphology, Department of Animal Biology, Graduate School of Agricultural Science, Tohoku University, Miyagi, Japan.

ABSTRACT
Myostatin is involved in an inhibitor of muscular growth and differentiation. Myoblasts derived from double-muscled Japanese shorthorn cattle (DM myoblasts) with absence of functional myostatin had higher abilities to proliferate and differentiate than myoblasts derived from normal-muscled cattle (NM myoblasts). In DM myoblasts, mRNA expressions of fetal myosin heavy chain (MyHC) in growth medium and of fast 2a and 2x MyHC in fusion medium were significantly greater than that in NM myoblasts. No significant difference existed in expressions of embryonic and slow MyHC mRNA between DM and NM myoblasts. The expression of MyoD mRNA was suppressed in myoblasts by administration of myostatin. Two cloned DM myoblast strains (DMc) were established. Addition of myostatin for DMc resulted in less myotube formation and suppression of mRNA expression of fast 2x MyHC. These findings suggest that the endogenous myostatin preferentially down-regulates the expression of the fast 2x MyHC and participates in differentiation of myofiber types during early bovine myogenesis.

Show MeSH
Related in: MedlinePlus