Task 3: Zebrafish forward genetic screens [8 marks]

Genome-wide genetic screens for phenotypes can identify new gene candidates and reveal novel mechanistic pathways that control development of tissues and organs. So-called “forward genetics screens” employ ENU-induced mutagenesis to produce random mutations in the genome. Phenotypes are observed and through breeding and mapping the affected gene can be identified. Two large scale ENU-mutagenesis zebrafish genetic screens performed in the mid-1990s produced thousands of mutations affecting development and organogenesis. 

Question 3: 

3a) Take a photograph of the wild type fish to compare your mutants. (1 mark)

3b) Take a photograph of the nacre mutant zebrafish and identify the defect/s compared to the wild type fish. (2 marks; one mark for the image and one for the labelling of defect.)

3c) Take a photograph of the casper mutant zebrafish and identify the defect/s compared to wild type fish. (3 marks; one mark for each correct drawing and correct labelling of defects - note, plural!)

3d) Take a photograph of the leopard

mutant zebrafish and identify

the defect/s compared to wild type fish.   ( 2 marks; one mark for the image and one for labelling of defect.)

Combine your images for Q3 into a single figure together with

labels indicating each zebrafish (ppt is a good place to do this).  Upload the