title: Temporal/spatial expression and efflux activity of ABC transporter, P-glycoprotein/Abcb1 isoforms and Bcrp/Abcg2 during early murine development.
abstract: ABC transporters pump out from cells a large number of endo- and xenobiotics including signal molecules and toxins; they are molecular markers of stem/progenitor cells as well. Here, we present the study of temporal/spatial patterns of Abcb1 isoforms and Abcg2 transporter expression and efflux activity in pre- and early postimplantation murine embryos. We found in 2-cell embryos abcb1a, abcb1b and abcg2 mRNAs which were believed to be maternally inherited. The expression of abcb1b and abcg2 genes was found in blastocysts and in 7 days postcoitum (dpc) embryos, while in 9dpc embryos beside of abcb1b/abcg2, the abcb1a gene was expressed. The abcb2 mRNA was detectable neither in pre- nor in postimplantation embryos. Moreover, we analysed temporal/spatial patterns of rhodamine 123/Hoechst 33342 efflux, which mirrors the ABC transporter phenotype, from individual cells of pre- and postimplantation murine embryos. The blastomeres of 2-, 4- and 8-cell embryos had efflux-inactive phenotype. Single, efflux-active cells emerged first in the morulae and their number increased in blastocyst inner cell mass. In 6 and 7 dpc embryos, all embryonic cells hold the efflux-active phenotype. Proximal embryonic endoderm of 6-8 dpc embryos contained two sub-domains: one consisted of efflux-active cells and another one of efflux-inactive cells reflecting polarity of an embryo. Between 7 and 8 dpc, at the onset of organogenesis, the vehement surge of efflux-inactive embryonic cells occurred, and their number increased in 9 dpc embryos, which consequently contained few efflux-active cells.
authors.affiliation: Department of Histology and Embryology, Medical University of Warsaw, Poland. wsawicki@ib.amwaw.edu.pl
authors.forename: Wojciech T
authors.initials: WT
authors.lastname: Sawicki
authors.forename: Marek
authors.initials: M
authors.lastname: Kujawa
authors.forename: Ewa
authors.initials: E
authors.lastname: Jankowska-Steifer
authors.forename: Ewa T
authors.initials: ET
authors.lastname: Mystkowska
authors.forename: Anna
authors.initials: A
authors.lastname: Hyc
authors.forename: Cezary
authors.initials: C
authors.lastname: Kowalewski
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics* / Q000378:metabolism*; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D001755:Blastocyst / Q000378:metabolism; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism*; D047108:Embryonic Development / Q000235:genetics; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008297:Male; D051379:Mice; D008856:Microscopy, Fluorescence; D038081:Organogenesis / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; C501412:Abcg2 protein, mouse; D020033:Protein Isoforms; C507084:Abcb1b protein, mouse