Localization and quantitative expression of the calcium-sensing receptor protein in human oocytes.
OBJECTIVE
To investigate the expression of the calcium-sensing receptor (CaSR) protein in human oocytes at the germinal vesicle (GV) and metaphase I (MI) and II (MII) stages.


METHODS
Prospective study.


METHODS
Academic basic research laboratory and hospital-based fertility center.


METHODS
Immature and supernumerary mature oocytes (n = 118) excluded from intracytoplasmic sperm injection treatment.


METHODS
Immunofluorescence and Western blot with a primary antibody against human CaSR. Confocal laser scanning microscopy (CLSM) together with quantitative image analysis used to measure the fluorescence intensity variations in oocytes at GV, MI, and MII stages.


METHODS
The CaSR expression pattern as evaluated by immunostaining in denuded oocytes and cumulus cells, CLSM, and three-dimensional image reconstructions; quantitative analysis at the equatorial plane of the oocyte.


RESULTS
We identified CaSR in human oocytes and cumulus cells. The fluorescence intensity within the oocyte varied with the developmental stage, with the greatest increase at the MI stage.


CONCLUSIONS
The present study demonstrates for the first time the expression and localization of CaSR protein in human oocytes. Increased CaSR protein expression in the MI stage suggests that it may be involved in the regulation of human oocyte development and maturation.
Dell'Aquila
Maria Elena
ME
Department of Animal Production, University of Bari, Bari, Italy. e.dellaquila@veterinaria.uniba.it
De Santis
Teresa
T
Cho
Yoon Sung
YS
Reshkin
Stephan Joel
SJ
Caroli
Anna Maria
AM
Maritato
Filippo
F
Minoia
Paolo
P
Casavola
Valeria
V
D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D008938:Mitosis / Q000502:physiology*; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism*; D044169:Receptors, Calcium-Sensing / Q000032:analysis* / Q000378:metabolism*; D014018:Tissue Distribution
D044169:Receptors, Calcium-Sensing