title: Chromatoid bodies: aggresome-like characteristics and degradation sites for organelles of spermiogenic cells.
abstract: We investigated the localization of several markers for lysosomes and aggresomes in the chromatoid bodies (CBs) by immunoelectron microscopy. We found so-called aggresomal markers such as Hsp70 and ubiquitin in the core of the CBs and vimentin and proteasome subunit around the CBs. Ubiquitin-conjugating enzyme (E2) was also found in the CBs. In tubulovesicular structures surrounding the CBs, lysosomal markers were detected but an endoplasmic reticulum retention signal (KDEL) was not. Moreover, proteins located in each subcellular compartment, including the cytosol, mitochondria, and nucleus, were detected in the CBs. Signals for cytochrome oxidase I (COXI) coded on mitochondrial DNA were also found in the CBs. Quantitative analysis of labeling density showed that all proteins examined were concentrated in the CBs to some extent. These results show that the CBs have some aggresomal features, suggesting that they are not a synthetic site as proposed previously but a degradation site where unnecessary DNA, RNA, and proteins are digested.
authors.affiliation: Biology Laboratory, University of Yamanashi, Yamanashi, Japan.
authors.forename: Celina M
authors.initials: CM
authors.lastname: Haraguchi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Mabuchi
authors.forename: Shuji
authors.initials: S
authors.lastname: Hirata
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shoda
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Hoshi
authors.forename: Kenji
authors.initials: K
authors.lastname: Akasaki
authors.forename: Sadaki
authors.initials: S
authors.lastname: Yokota
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D007150:Immunohistochemistry; D002479:Inclusion Bodies / Q000378:metabolism / Q000648:ultrastructure*; D008247:Lysosomes / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D016253:Microscopy, Immunoelectron; D024101:Mitochondrial Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D015388:Organelles / Q000378:metabolism / Q000648:ultrastructure*; D051381:Rats; D017208:Rats, Wistar; D013090:Spermatocytes / Q000378:metabolism / Q000648:ultrastructure; D013091:Spermatogenesis; D013737:Testis / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D015415:Biomarkers; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins