Decreased expression of myogenic transcription factors and myosin heavy chains in Caenorhabditis elegans muscles developed during spaceflight.
The molecular mechanisms underlying muscle atrophy during spaceflight are not well understood. We have analyzed the effects of a 10-day spaceflight on Caenorhabditis elegans muscle development. DNA microarray, real-time quantitative PCR, and quantitative western blot analyses revealed that the amount of MHC in both body-wall and pharyngeal muscle decrease in response to spaceflight. Decreased transcription of the body-wall myogenic transcription factor HLH-1 (CeMyoD) and of the three pharyngeal myogenic transcription factors, PEB-1, CEH-22 and PHA-4 were also observed. Upon return to Earth animals displayed reduced rates of movement, indicating a functional defect. These results demonstrate that C. elegans muscle development is altered in response to spaceflight. This altered development occurs at the level of gene transcription and was observed in the presence of innervation, not simply in isolated cells. This important finding coupled with past observations of decreased levels of the same myogenic transcription factions in vertebrates after spaceflight raises the possibility that altered muscle development is a contributing factor to spaceflight-induced muscle atrophy in vertebrates.
Higashibata
Akira
A
Japan Aerospace Exploration Agency, 2-1-1, Sengen, Tsukuba, Ibaraki 305-8505, Japan. higashibata.akira@jaxa.jp
Szewczyk
Nathaniel J
NJ
Conley
Catharine A
CA
Imamizo-Sato
Mari
M
Higashitani
Atsushi
A
Ishioka
Noriaki
N
D000818:Animals; D017173:Caenorhabditis elegans / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D024510:Muscle Development / Q000502:physiology; D009124:Muscle Proteins; D009132:Muscles / Q000378:metabolism*; D018006:Myogenic Regulatory Factors / Q000235:genetics / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000378:metabolism*; D009687:Nuclear Proteins; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D013026:Space Flight; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014335:Tropomyosin / Q000378:metabolism
C109217:CEH-22 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D009124:Muscle Proteins; D018006:Myogenic Regulatory Factors; D009687:Nuclear Proteins; C113277:Pha-4 protein, C elegans; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors; D014335:Tropomyosin; C420182:peb-1 protein, C elegans; C066645:HLH-1 protein, C elegans; D018995:Myosin Heavy Chains