BOR - Papers in Press, published online ahead of print
April 30, 2003.
Biol Reprod 2003, 10.1095/biolreprod.102.013524
BIOLOGY OF REPRODUCTION 69, 885895 (2003)
DOI: 10.1095/biolreprod.102.013524
© 2003 by the Society for the Study of Reproduction, Inc.
Spatiotemporal Changes of Levels of a Moonlighting Protein, Phospholipid Hydroperoxide Glutathione Peroxidase, in Subcellular Compartments During Spermatogenesis in the Rat Testis
Celina M. Haraguchi2,
Tadashi Mabuchi3,
Shuji Hirata4,
Tomoko Shoda4,
Aureo T. Yamada5,
Kazuhiko Hoshi4, and
Sadaki Yokota1,2
Biology Laboratory,2
Department of Biochemistry,3
Department of Obstetrics and Gynecology,4 University of Yamanashi, Faculty of Medicine, Tamaho-cho, Yamanashi, 409-3898, Japan
Department of Histology and Embryology,5 Institute of Biology, State University of Campinas, Campinas, Brazil
We studied temporal changes in the subcellular localization and levels of a moonlighting protein, phospholipid hydroperoxide glutathione peroxidase (PHGPx), in spermatogenic cells and mature sperm of the rat by immunofluorescence and immunoelectron microscopy. The PHGPx signals were detected in chromatoid bodies, clear nucleoplasm, mitochondria-associated material, mitochondrial aggregates, granulated bodies, and vesicles in residual bodies in addition to mitochondria, nuclei, and acrosomes as previously reported. Within mitochondria, PHGPx moved from the matrix to the outermost membrane region in step 19 spermatid, suggesting that this spatiotemporal change is synchronized with the functional change of PHGPx in mitochondria. In the nucleus, PHGPx was associated with electron-lucent spots and with the nuclear envelope, and PHGPx in the latter region increased after step 16. In early pachytene spermatids, PHGPx signals were noted in the nuclear material exhibiting a very similar density to chromatoid bodies and in the intermitochondrial cement, supporting the previous proposal that chromatoid bodies originate from the nucleus and intermitochondrial cement. The presence of PHGPx in such various compartments suggested versatile roles for this protein in spermatogenesis. Quantitative immunoelectron microscopic analysis also revealed dynamic changes in the labeling density of PHGPx in different subcellular compartments as follows: 1) Total cellular PHGPx rapidly increased after step 5 and reached a maximum at step 18; 2) mitochondrial labeling density increased after step 1 and achieved a maximum in steps 1517; 3) nuclear labeling density suddenly increased in steps 1214 to a maximum; 4) in cytoplasmic matrix, the density remained low in all steps; and 5) the labeling density in chromatoid bodies gradually decreased from pachytene spermatocytes to spermatids at step 18. These spatiotemporal changes in the level of PHGPx during the differentiation of spermatogenic cells to sperm infer that PHGPx plays a diverse and important biological role in spermatogenesis.
1 Correspondence: Sadaki Yokota, Biology Laboratory, University of Yamanashi, Faculty of Medicine, Tamaho-cho, Yamanashi, 409-3898, Japan. FAX: 81 55 273 9365; syokota{at}yamanashi.ac.jp
Copyright © 2003 by the Society for the Study of Reproduction.