title: Myostatin from the American lobster, Homarus americanus: Cloning and effects of molting on expression in skeletal muscles.
abstract: A cDNA encoding a myostatin (Mstn)-like gene from an astacuran crustacean, Homarus americanus, was cloned and characterized. Mstn inhibits skeletal muscle growth in vertebrates and may play a role in crustacean muscle as a suppressor of protein synthesis. Sequence analysis and three-dimensional modeling of the Ha-Mstn protein predicted a high degree of conservation with vertebrate and other invertebrate myostatins. Qualitative polymerase chain reaction (PCR) demonstrated ubiquitous expression of transcript in all tissues, including skeletal muscles. Quantitative PCR analysis was used to determine the effects of natural molting and eyestalk ablation (ESA) on Ha-Mstn expression in the cutter claw (CT) and crusher claw (CR) closer muscles and deep abdominal (DA) muscle. In intermolt lobsters, the Ha-Mstn mRNA level in the DA muscle was significantly lower than the mRNA levels in the CT and CR muscles. Spontaneous molting decreased Ha-Mstn mRNA during premolt, with the CR muscle, which is composed of slow-twitch (S₁) fibers, responding preferentially (82% decrease) to the atrophic signal compared to fast fibers in CT (51% decrease) and DA (69% decrease) muscles. However, acute increases in circulating ecdysteroids caused by ESA had no effect on Ha-Mstn mRNA levels in the three muscles. These data indicate that the transcription of Ha-Mstn is differentially regulated during the natural molt cycle and it is an important regulator of protein turnover in molt-induced claw muscle atrophy.
authors.affiliation: Department of Biology, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Kyle S
authors.initials: KS
authors.lastname: MacLea
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Covi
authors.forename: Hyun-Woo
authors.initials: HW
authors.lastname: Kim
authors.forename: Erica
authors.initials: E
authors.lastname: Chao
authors.forename: Scott
authors.initials: S
authors.lastname: Medler
authors.forename: Ernest S
authors.initials: ES
authors.lastname: Chang
authors.forename: Donald L
authors.initials: DL
authors.lastname: Mykles
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D018978:Molting / Q000235:genetics*; D018482:Muscle, Skeletal / Q000378:metabolism*; D055435:Myostatin / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008121:Nephropidae / Q000235:genetics*; D016366:Open Reading Frames / Q000235:genetics; D020652:Peptide Elongation Factor 2 / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D020413:3' Untranslated Regions; D018076:DNA, Complementary; D055435:Myostatin; D020652:Peptide Elongation Factor 2; D012333:RNA, Messenger