PMID- 10495883
OWN - NLM
STAT- MEDLINE
DCOM- 19991115
LR  - 20191024
IS  - 0914-9465 (Print)
IS  - 0914-9465 (Linking)
VI  - 62
IP  - 3
DP  - 1999 Aug
TI  - Molecular chaperone calmegin localization to the endoplasmic reticulum of meiotic
      and post-meiotic germ cells in the mouse testis.
PG  - 283-93
AB  - Calmegin is a testis-specific Ca(2+)-binding protein that is homologous to
      calnexin. Recently, sperm from transgenic mice lacking calmegin have been shown
      to be infertile. To further characterize calmegin, we analyzed the precise stage 
      of expression and the intracellular localization of this protein in germ cells
      during mouse spermatogenesis by an immunoperoxidase technique using the
      anti-calmegin monoclonal antibody TRA369. Light microscopic immunocytochemistry
      showed that calmegin appeared in early pachytene spermatocytes, with the highest 
      expression in round and elongating spermatids, and disappeared in the maturation 
      phase of spematids at step 15. Immunoelectron microscopy showed that selective
      localization was found at the endoplasmic reticulum membrane and the nuclear
      envelope of spermatogenic cells. During the maturation phase, a dramatic
      reduction in calmegin occurred in the endoplasmic reticulum of the spermatids,
      suggesting that the major function of calmegin has been completed by the time
      spermatids reach step 14. In addition, although the immunoreactivity was
      completely absent in the calmegin-deficient mutant mouse testis, ultrastructural 
      analysis showed that mature sperm from the knockout mice were normal. This
      suggests that calmegin is not required for the morphogenesis of male germ cells. 
      Thus, our results suggest that calmegin has a major role in mouse
      spermatogenesis, and also indicate that this protein would be useful as a maker
      molecule to study the functional role of the endoplasmic reticulum in the process
      of spermatid differentiation.
FAU - Yoshinaga, K
AU  - Yoshinaga K
AD  - Department of Anatomy and Reproductive Cell Biology, Miyazaki Medical College,
      Japan. kyoshina@post.miyazaki-med.ac.jp
FAU - Tanii, I
AU  - Tanii I
FAU - Toshimori, K
AU  - Toshimori K
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Japan
TA  - Arch Histol Cytol
JT  - Archives of histology and cytology
JID - 8806082
RN  - 0 (Calcium-Binding Proteins)
RN  - 0 (Membrane Proteins)
RN  - 0 (Molecular Chaperones)
RN  - 0 (Phosphoproteins)
RN  - 139873-08-8 (Calnexin)
RN  - 155982-67-5 (calmegin)
SB  - IM
MH  - Animals
MH  - Calcium-Binding Proteins/*analysis
MH  - *Calnexin
MH  - Endoplasmic Reticulum/*chemistry
MH  - Epididymis
MH  - Germ Cells/*chemistry/*ultrastructure
MH  - Immunohistochemistry
MH  - Male
MH  - Meiosis
MH  - Membrane Proteins/analysis
MH  - Mice
MH  - Mice, Inbred C57BL
MH  - Mice, Knockout
MH  - Microscopy, Confocal
MH  - Microscopy, Electron
MH  - Molecular Chaperones/*analysis
MH  - Phosphoproteins/analysis
MH  - Spermatogenesis
MH  - Spermatozoa/ultrastructure
MH  - Testis/*cytology
EDAT- 1999/09/25 00:00
MHDA- 1999/09/25 00:01
CRDT- 1999/09/25 00:00
PHST- 1999/09/25 00:00 [pubmed]
PHST- 1999/09/25 00:01 [medline]
PHST- 1999/09/25 00:00 [entrez]
AID - 10.1679/aohc.62.283 [doi]
PST - ppublish
SO  - Arch Histol Cytol. 1999 Aug;62(3):283-93. doi: 10.1679/aohc.62.283.