BIOL 114
Biology Dept
Kenyon College
BIOL 114   Genetics and Development
Fall Section Spring Section 1 Spring Section 2

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??