This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Int. J.Uc\". BioI. ~o: 221-227 (1996) 221 Large scale genetics in a small vertebrate, the zebrafish PASCAL HAFFTER* and CHRISTIANE NUSSLEIN-VOLHARD Max-Planck-/nstitut fur Entwicklungsbiologie, Tubingen, Germany ABSTRACT The systematic isolation and characterization of mutants in Drosophila has enor- mously facilitated the analysis of molecular mechanisms underlying developmental pathways in the embryo. A similar approach is presently being used to study embryonic development of the zebrafish, which is becoming a mainstream model organism for vertebrate development. With its genetic versatility and sophisticated embryology, zebrafish offers the possibility to rapidly increase our knowledge of vertebrate development and add to what we have learned from other vertebrate model organisms. KEY WORDS: zebrajish, mutagenesis, 1..ler/ebmledroflojnnefl/, nnlJryunic dnlt'lupment, sa/uralion SCH'f'll Introduction The mystery of our own origin and mode of development has for over 100 years stimulated interest in vertebrate development. Fundamental processes of early development appear conserved among the vertebrates. By studying a particular vertebrate mod- el organism we can therefore draw conclusions about vertebrate development in general and ultimately come up with models about our own development. Genes encoding key functions in development show a high degree of conservation with each oth- er. Once we have identified a developmentally important gene from one vertebrate we can easily clone the homolog from other vertebrates and study its function in the vertebrate which is the most practical for the selected approach. This review is about a mutational approach towards the study of vertebrate develop- ment using the zebrafish, Danio rerio, as a system. Genes that may be important for vertebrate development have, so far, mainly been identified using two approaches. The 1irst approach was based on the finding that many genes wilh important functions in the development of Drosophila melanogaster have conserved counterparts in vertebrates. Frequently whole families of vertebrate genes were isolated by molecular screening for homology to specific Drosophila genes. The obvious limitation of this approach is that vertebrate genes without homology to previously cloned genes will go undetected. The second approach is to isolate genes displaying interesting spatial or temporal expression patterns in the embryo. The func. tion of these genes is studied by generating loss.of.function mu1ations using the powerlul ES-cell based knockout technolo- gy in the mouse (Mansour ef al.. 1988). Some 01 these knock- outs display interesting specific defects in embryonic develop- ment, whereas others have disappointingly little or no effect....
View Full Document