Model Systems for Development

KAP
Biology Dept
Kenyon College

KAP Genetics and Development

Model Systems for Development

Organism	Useful Features of Model System
Microbes
Bacteria, Caulobacter	Single cell differentiates into two different kinds of cell.
Cyanobacteria	Differentiation of heterocysts for nitrogen fixation
Slime mold, Myxococcus	Cells communicate and aggregate. Differentiate into multicellular structures.
Plants
Arabidopsis	Fertilization by pollination Development of embryo with meristem and three layers Flower development; homeotic genes encode transcription factors Genome sequenced
Animals
Sea urchin	Fertilization of egg by sperm Cleavage and gastrulation
Nematode, Caenorrhabditis elegans	Developmental pathway follows a predictable pattern, cell by cell Completed genome Major organ systems have many human homologs, including genes involved in cancer, aging and neural function Grown on a plate, like bacteria -- "The microbial human."
Fruit Fly, Drosophila	Model for segmentation and molecular control of development Genome sequenced Genetics and molecular studies Many genes have human homologs
Zebrafish	Vertebrate model for gastrulation, neurulation, and organ development Large number of progeny, transparent embryos
Frog, Xenopus	Vertebrate model for gastrulation, neurulation, and organ development Large number of progeny
Mouse	Mammalian model for neurulation and organ development Genome sequenced Transgenic lines easily constructed Embryonic stem cells Can be cloned
Human	Genome sequenced Many "natural mutants" available (see OMIM) Embryonic stem cells Can be cloned??