PUBLICATION

Somites in zebrafish doubly mutant for knypek and trilobite form without internal mesenchymal cells or compaction

Authors
Henry, C.A., Hall, L.A., Hille, M.B., Solnica-Krezel, L., and Cooper, M.S.
ID
ZDB-PUB-001003-3
Date
2000
Source
Current biology : CB   10(17): 1063-1066 (Journal)
Registered Authors
Cooper, Mark S., Henry, Clarissa A., Hille, Merrill, Solnica-Krezel, Lilianna
Keywords
none
MeSH Terms
  • Animals
  • Mutation*
  • Zebrafish/genetics*
PubMed
10996075 Full text @ Curr. Biol.
Abstract
In vertebrates, paraxial mesoderm is partitioned into repeating units called somites. It is thought that the mechanical forces arising from compaction of the presumptive internal cells of prospective somites cause them to detach from the unsegmented presomitic mesoderm [1-3]. To determine how prospective somites physically segregate from each other, we used time-lapse microscopy to analyze the mechanics underlying early somitogenesis in wild-type zebrafish and in the mutants trilobite(m209) (tri), knypek(m119) (kny), and kny;tri, which are defective in convergent extension during gastrulation. Formation of somite boundaries in all of these embryos involved segregation, local alignment, and cell-shape changes of presumptive epitheloid border cells along nascent intersomitic boundaries. Although kny;tri somites formed without convergence of the presomitic mesoderm and were composed of only two cells in their anteroposterior (AP) dimension, they still exhibited AP intrasegmental polarity. Furthermore, morphogenesis of somite boundaries in these embryos proceeded in a manner similar to that in wild-type embryos. Thus, intersomitic boundary formation in zebrafish involves short-range movements of presumptive border cells that do not require mechanical forces generated by internal cells or compaction of the presomitic mesoderm.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping