Regulatory Mechanism Of Space Microgravity On Muscle Movement Of C.Elegans

The mechanism of muscle atrophy caused by microgravity has been a key medical issue in the study of space biology.In Shen Zhou-8(SZ-8)experiment,the dauer wild-type and dys-1 mutant Caenorhabditis elegans were selected as the experimental materials.The result showed that microgravity affected expressions of wild-type genes associated with locomotion but not in dys-1 mutant.In order to study the related functional protein profiles,wild-type and dys-1 mutant Caenorhabditis elegans were carried in ShiJian-10(SJ-10)recoverable satellite for repeated processing.After about 303-hour spaceflight,the ability of C.elegans locomotion were observed and followed for their whole life-cycle.By comparing the muscle motor ability and expression levels of proteins especially participate in regulating muscle contract pathways between wild type(N2)and gravity-sensing defect C.elegans(dys-1 mutation),We look forward to finding the effect of space microgravity on generation,transmission and regulation of C.elegans locomotion ability.Experiments also used simulated microgravity to verify changes in phenotypes,combined with the results of space experiments.The aim of this stuty is to discussing the space microgravity effects on C.elegans locomotion mechanisms and regulatory pathways.The results showed that space microgravity slowed the decline rate of C.elegans movement ability as growth.The phenomenon of over-bending in dys-1 mutant disappeared after space flight and returned to the same level as the wild type.By simulating microgravity treatment,this result was repeated and showed that space microgravity significantly affected the locomotion of C.elegans.The protein expression profiles contained a total of 3343 proteins.Gene Ontology enrichment analysis and differential protein clustering analysis showed that,compared with N2 wild-type,less proteins of dys-1 mutant were significantly changed,especially lacking of proteins involved in muscle contraction-related pathways.Thus,Dystrophy plays an important role in muscle response to microgravity.The effect of the disappearance of gravity signals on C.elegans movement leaded to the decrease of mechanical signal transduction into the muscle cells,the process of muscle contraction and the cytoskeleton structural protein expression level.At the same time,the nucleus initiated a series of reactions that regulated the effects of microgravity.Comparative analysis of C.elegans differentially expressed proteins of movement pathways revealed that Ca2+ binding and transduction pathways were important during the Dystrophy to respond to space microgravity.Gene expression verification analysis showed that the expression of muscle-related genes were down-regulated in wild type,which was the same as Proteomic analysis.But dys-1 gene mutation disturbed such microgravity response patterns.This study revealed that Dystrophy is an important factor that responds to microgravity stress and probably acts by affecting Ca2+ transduction and binding pathways.This finding reveal the mechanisms of the changes in muscle function under space microgravity.