title: Localization and quantitative expression of the calcium-sensing receptor protein in human oocytes.
abstract: 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.
authors.affiliation: Department of Animal Production, University of Bari, Bari, Italy. e.dellaquila@veterinaria.uniba.it
authors.forename: Maria Elena
authors.initials: ME
authors.lastname: Dell'Aquila
authors.forename: Teresa
authors.initials: T
authors.lastname: De Santis
authors.forename: Yoon Sung
authors.initials: YS
authors.lastname: Cho
authors.forename: Stephan Joel
authors.initials: SJ
authors.lastname: Reshkin
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Caroli
authors.forename: Filippo
authors.initials: F
authors.lastname: Maritato
authors.forename: Paolo
authors.initials: P
authors.lastname: Minoia
authors.forename: Valeria
authors.initials: V
authors.lastname: Casavola
mesh_terms: 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
chemical_list: D044169:Receptors, Calcium-Sensing