title: Checkpoint and physiological apoptosis in germ cells proceeds normally in spaceflown Caenorhabditis elegans.
abstract: It is important for human life in space to study the effects of environmental factors during spaceflight on a number of physiological phenomena. Apoptosis plays important roles in development and tissue homeostasis in metazoans. In this study, we have analyzed apoptotic activity in germ cells of the nematode C. elegans, following spaceflight. Comparison of the number of cell corpses in wild type or ced-1 mutants, grown under either ground or spaceflight conditions, showed that both pachytene-checkpoint apoptosis and physiological apoptosis in germ cells occurred normally under spaceflight conditions. In addition, the expression levels of the checkpoint and apoptosis related genes are comparable between spaceflight and ground conditions. This is the first report documenting the occurrence of checkpoint apoptosis in the space environment and suggests that metazoans, including humans, would be able to eliminate cells that have failed to repair DNA lesions introduced by cosmic radiation during spaceflight.
authors.affiliation: Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Higashitani
authors.forename: A
authors.initials: A
authors.lastname: Higashibata
authors.forename: Y
authors.initials: Y
authors.lastname: Sasagawa
authors.forename: T
authors.initials: T
authors.lastname: Sugimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Miyazawa
authors.forename: N J
authors.initials: NJ
authors.lastname: Szewcyk
authors.forename: M
authors.initials: M
authors.lastname: Viso
authors.forename: G
authors.initials: G
authors.lastname: Gasset
authors.forename: B
authors.initials: B
authors.lastname: Eche
authors.forename: K
authors.initials: K
authors.lastname: Fukui
authors.forename: T
authors.initials: T
authors.lastname: Shimazu
authors.forename: N
authors.initials: N
authors.lastname: Fujimoto
authors.forename: K
authors.initials: K
authors.lastname: Kuriyama
authors.forename: N
authors.initials: N
authors.lastname: Ishioka
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D016923:Cell Death / Q000502:physiology; D004249:DNA Damage / Q000502:physiology; D005854:Germ Cells / Q000502:physiology* / Q000528:radiation effects; D008565:Membrane Proteins / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D012097:Repressor Proteins / Q000235:genetics; D013026:Space Flight
chemical_list: D029742:Caenorhabditis elegans Proteins; C112486:EGL-1 protein, C elegans; D008565:Membrane Proteins; D012097:Repressor Proteins; C422043:ced-1 protein, C elegans