Maternal and zygotic activity of the zebrafish ogon locus antagonizes BMP signaling

Valarie Miller-Bertoglio, Amanda Carmany-Rampey, Maximilian Fürthauer, Encina M. Gonzalez, Christine Thisse, Bernard Thisse, Marnie E. Halpern, Lilianna Solnica-Krezel

Research output: Contribution to journalArticlepeer-review

Abstract

The dorsal-ventral axis of vertebrate embryos is thought to be specified by a gradient of bone morphogenetic protein (BMP) activity, which, in part, arises through the interaction of dorsally expressed antagonists Chordin and Noggin with the ventralizing BMPs. The zebrafish mercedes(tm305), ogon(m60), and short tail(b180) mutations produce ventralized phenotypes, including expanded bmp2b/4 expression domains. We find that the three mutations are allelic and that the locus they define, renamed ogon (ogo), maps to linkage group 25. The ogo(160) and ogo(b180) mutations are deficiencies and thus represent null alleles, whereas the ENU-induced allele ogo(tm305) retains partial function. Aspects of the ogo(m60) and ogo(tm305) mutant phenotypes are fully suppressed by overexpression of BMP antagonists. Moreover, swirl(tc300), a null mutation in bmp2b, is epistatic to ogo(m60) mutation, providing further evidence that ogo normally functions in a BMP-dependent manner. Embryonic patterning is highly sensitive to maternal and zygotic ogo gene dosage, especially when the level of zygotic chordin activity is also reduced. However, elimination of the zygotic activity of both genes does not result in a completely ventralized embryo. Thus, while ogo and chordin are required to limit activity of BMPs, additional mechanisms must exist to block these ventralizing signals. We have ruled out zebrafish noggin homologues as candidates for the ogo gene, including a newly identified gene, nog1, which is specifically expressed in the gastrula organizer. The results suggest that ogo encodes an as yet unidentified dorsalizing factor that mediates dorsoventral patterning by directly or indirectly antagonizing BMP activity.

Original languageEnglish (US)
Pages (from-to)72-86
Number of pages15
JournalDevelopmental biology
Volume214
Issue number1
DOIs
StatePublished - Oct 1 1999

Keywords

  • Dorsal-ventral axis
  • Gastrulation
  • Maternal effect
  • Mercedes
  • Noggin
  • Short tail
  • Ventralized mutant

ASJC Scopus subject areas

  • Molecular Biology
  • Developmental Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Maternal and zygotic activity of the zebrafish ogon locus antagonizes BMP signaling'. Together they form a unique fingerprint.

Cite this