Journal article
The Role of Maternal Axin in Patterning the Xenopus Embryo
Developmental biology, Vol.237(1), pp.183-201
09/01/2001
DOI: 10.1006/dbio.2001.0371
PMID: 11518515
Abstract
Regulation of the stability of β catenin protein is a critical role of Wnt signaling cascades. In early Xenopus development, dorsal axis specification depends on regulation of β catenin by both cytoplasmic and nuclear mechanisms. While the cytoplasmic protein axin is known as a key component of the cytoplasmic β catenin degradation complex, loss-of-function studies are needed to establish whether it is required for dorso-ventral patterning in the embryo, and to test where in the embryo it carries out its function. Here, we show that embryos lacking maternal axin protein have increased levels of soluble β catenin protein and increased nuclear localization of β catenin in ventral nuclei at the blastula stage. These embryos gastrulate abnormally and develop with excessive notochord and head structures, and reduced tail and ventral components. They show increased expression of dorsal markers, including siamois, Xnr3, chordin, gsc, Xhex, and Otx2, decreased expression of Xwnt 8 and Xbra, and little alteration of BMP4 and Xvent1 and -2 mRNA levels. The ventral halves of axin-depleted embryos at the gastrula stage have dramatically increased levels of chordin expression, and severely decreased levels of Xwnt 8 mRNA expression, while BMP4 transcript levels are only slightly reduced. This dorso-anterior phenotype is rescued by axin mRNA injected into the vegetal pole of axin-depleted oocytes before fertilization. Interestingly, the phenotype was rescued by ventral but not dorsal injection of axin mRNA, at the 4-cell stage, although dorsal injection into wild-type embryos does cause ventralization. These results show directly that the localized ventral activity of maternal axin is critical for the correct patterning of the early Xenopus embryo.
Details
- Title: Subtitle
- The Role of Maternal Axin in Patterning the Xenopus Embryo
- Creators
- Matt Kofron - Division of Developmental Biology, Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio, 45229-3039Peter Klein - Cell and Molecular Biology Graduate Group, Department of Medicine, and Howard Hughes Medical Institute, University of Pennsylvania School of Medicine, 415 Curie Boulevard, Philadelphia, Pennsylvania, 19104-6148Fang Zhang - Cell and Molecular Biology Graduate Group, Department of Medicine, and Howard Hughes Medical Institute, University of Pennsylvania School of Medicine, 415 Curie Boulevard, Philadelphia, Pennsylvania, 19104-6148Douglas W Houston - Division of Developmental Biology, Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio, 45229-3039Kyle Schaible - Division of Developmental Biology, Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio, 45229-3039Chris Wylie - Division of Developmental Biology, Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio, 45229-3039Janet Heasman - Division of Developmental Biology, Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio, 45229-3039
- Resource Type
- Journal article
- Publication Details
- Developmental biology, Vol.237(1), pp.183-201
- DOI
- 10.1006/dbio.2001.0371
- PMID
- 11518515
- NLM abbreviation
- Dev Biol
- ISSN
- 0012-1606
- eISSN
- 1095-564X
- Publisher
- Elsevier Inc
- Language
- English
- Date published
- 09/01/2001
- Academic Unit
- Biology
- Record Identifier
- 9983992061802771
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