H(+)/K(+) ATPase activity is required for biomineralization in sea urchin embryos.
The bioelectrical signatures associated with regeneration, wound healing, development, and cancer are changes in the polarization state of the cell that persist over long durations, and are mediated by ion channel activity. To identify physiologically relevant bioelectrical changes that occur during normal development of the sea urchin Lytechinus variegatus, we tested a range of ion channel inhibitors, and thereby identified SCH28080, a chemical inhibitor of the H(+)/K(+) ATPase (HKA), as an inhibitor of skeletogenesis. In sea urchin embryos, the primary mesodermal lineage, the PMCs, produce biomineral in response to signals from the ectoderm. However, in SCH28080-treated embryos, aside from randomization of the left-right axis, the ectoderm is normally specified and differentiated, indicating that the block to skeletogenesis observed in SCH28080-treated embryos is PMC-specific. HKA inhibition did not interfere with PMC specification, and was sufficient to block continuing biomineralization when embryos were treated with SCH28080 after the initiation of skeletogenesis, indicating that HKA activity is continuously required during biomineralization. Ion concentrations and voltage potential were abnormal in the PMCs in SCH28080-treated embryos, suggesting that these bioelectrical abnormalities prevent biomineralization. Our results indicate that this effect is due to the inhibition of amorphous calcium carbonate precipitation within PMC vesicles.
Department of Biology, Boston University, Boston, MA 02215, USA.
Daphne
D
Schatzberg
Department of Biology, Boston University, Boston, MA 02215, USA.
Matthew
M
Lawton
Department of Biology, Boston University, Boston, MA 02215, USA.
Sarah E
SE
Hadyniak
Department of Biology, Boston University, Boston, MA 02215, USA.
Erik J
EJ
Ross
Department of Biology, Boston University, Boston, MA 02215, USA.
Tamara
T
Carney
Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008, USA.
Wendy S
WS
Beane
Department of Biology, Tufts University, Medford, MA 02155, USA.
Michael
M
Levin
Department of Biology, Boston University, Boston, MA 02215, USA. Electronic address: cbradham@bu.edu.
Cynthia A
CA
Bradham
D060105:Animal Shells / Q000737:chemistry*; D000818:Animals; D017931:DNA Primers / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000201:enzymology*; D005455:Fluorescent Antibody Technique; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics / Q000502:physiology*; D017506:H(+)-K(+)-Exchanging ATPase / Q000378:metabolism*; D007093:Imidazoles; D017404:In Situ Hybridization, Fluorescence; D008903:Minerals / Q000032:analysis; D009024:Morphogenesis / Q000502:physiology*; D016133:Polymerase Chain Reaction; D012617:Sea Urchins / Q000196:embryology* / Q000201:enzymology
D017931:DNA Primers; D007093:Imidazoles; D008903:Minerals; C035235:Sch 28080; D017506:H(+)-K(+)-Exchanging ATPase
Bioelectricity; SCH28080; Sea urchin embryo; Skeletogenesis