title: Expression and function of bicarbonate/chloride exchangers in the preimplantation mouse embryo.
abstract: Bicarbonate/chloride (HCO3-/Cl-) exchangers regulate intracellular pH in the alkaline range. Previously, it has been shown that mouse embryos at the two-cell stage exhibit this activity, but that the otherwise ubiquitous mechanisms for regulating intracellular pH in the acid-to-neutral range are undetectable. We have examined mouse embryos during preimplantation development (one-cell zygote through blastocyst) to determine whether HCO3-/Cl- exchange activity exists at all stages, whether it is necessary for preimplantation development, and whether messenger RNAs from the known HCO3-/Cl- exchanger genes are expressed. We have found that all stages of preimplantation embryo have detectable HCO3-/Cl- exchange activity. In addition, inhibition of this activity with the stilbene anion exchange inhibitor DIDS (4,4'-diisothiocyanostilbene-2,2'-disulfonic acid) disrupts intracellular pH homeostasis and markedly inhibits embryo development from the two-cell stage to blastocysts in culture under conditions of moderately high external pH. Finally, mRNA encoding two members of the band 3-related AE anion exchanger gene family are expressed in preimplantation embryos.
authors.affiliation: Loeb Medical Research Institute, Ottawa Civic Hospital, Ontario, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhao
authors.forename: P J
authors.initials: PJ
authors.lastname: Chauvet
authors.forename: S L
authors.initials: SL
authors.lastname: Alper
authors.forename: J M
authors.initials: JM
authors.lastname: Baltz
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000818:Animals; D017920:Antiporters / Q000096:biosynthesis / Q000378:metabolism*; D001483:Base Sequence; D001639:Bicarbonates / Q000378:metabolism; D001755:Blastocyst / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D027963:Chloride-Bicarbonate Antiporters; D002712:Chlorides / Q000378:metabolism; D017931:DNA Primers; D005314:Embryonic and Fetal Development / Q000187:drug effects; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D009924:Organ Culture Techniques; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis*; D015183:Restriction Mapping
chemical_list: D017920:Antiporters; D001639:Bicarbonates; D027963:Chloride-Bicarbonate Antiporters; D002712:Chlorides; D017931:DNA Primers; D012333:RNA, Messenger; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid