Pros and Cons

There are a variety of different model organisms that are available for use in developmental genetics. Weighing up the pros and cons of each one is something geneticists have to do when choosing the model to perform their research on.  Below is a selection of the most commonly used model organisms and the advantages and disadvantages these carry.

1. Yeast: Saccharomyces cerevisiae


Advantages

·      Small organism that can be easily cultured

·      Short generation time

·      Fully sequenced genome

·      Inexpensive

·      Grow as haploid strain – simplifies knockout

·      Complete set of deletion mutants 

Disadvantages

·      Don’t have a nervous system

 

2. Fruit Fly: Drosophila melanogaster

 Advantages

 ·      Short generation time 

·      Well established base ok knowledge (Flybase)

·      Findings transferable to humans – 60% conservation

·      Don’t need a license to use

 Disadvantages

·      Small embryo

·      Homologous recombination difficult

·      Cannot freeze flies

 

3. Nematode worm: Caenorhabditis elegans 

Advantages 

 ·      Fully sequenced genome

·      Short generation time

·      Optical transparency

·      WormBase = bioinformatics database

 Disadvantages

·      Can only visualise one organism at a time

·      Small embryo

4. Frog: Xenopus laevis
 

Advantages

·      Large batches of embryos

·      External fertilisation/development

·      Robust-large embryo and cells

·      Many genes characteried

·      Can produce stable transgenic lines

·      Easily kept and bred under laboratory conditions

 Disadvantages

·      Longer generation time

·      Yolky embryo

 

 

 5. Zebrafish: Danio rerio

Advantages

·      Small vertebrate

·      Large batches of embryos

·      Transparent embryos

·      Amenable to genetic analysis

·      Large and robust embryos

·      Regeneration ability

 Disadvantages

·      Targeted transgenesi not possible

·      Overall generation time longer

 

      6. Chick: Gallus gallus

Advantages

·      Large embryo

·      Amniote (model for man)

·      Most advanced model organism suitable

·      Large and robust embryos

·      Large numbers of embryos can incubated at one time

·      Embryos are inexpensive and cheaper to maintain compared to mice

·      Resembles other higher vertebrates

 Disadvantages

·      Embryo isn’t accessible early – post-implantation

 

7. Mouse: Mus musculus

Advantages

·      Mammal! Great deal of homology to humans

·      Small vertebrate

·      Model for man

·      Embryonic stem cells

·      Targeted trangenesis

·      Can create inbred and outbred strains

·      Whole Mouse Catalogue 

Disadvantages

·      Poor accessibility

·      Small embryo batches

·      Expensive