detection of mutations updated

Detection of mutations

By Sumanth.B.S

Mutations induced due to radiations or chemicals can be broadly classified into two types Lethal mutations. Visible mutations.

They could be located on either sex chromosomes or autosomes.

Detection of sex linked lethals. Muller’s ClB method. Muller-5 method.

Detection of autosomal mutations(visible or lethal) .

Muller’s ClB method.

This method involves the use of ClB stock which carries.

An inversion in a heterozygous state to work as crossover suppressor (c ).

A recessive lethal (l) on X-chromosome in heterozygous state.

A dominant marker Barred (B) for the barred eye. One of the two X-chromosomes in the female flies

carries all the three features and the other X-chromosome was normal.

Male flies is irradiated for mutations.

Muller- 5 method

This method makes use of muller-5 drosophila stock which carries two marker genes.

Dominant bar (barred eye) . Recessive “apricot” . In F2 generation 50% are muller-5 phenotype.

Detection of autosomal mutations

Detection is done using balanced lethal stock (BLS). BLS is one which carries recessive lethal alleles on

two specific homologous chromosomes. These mutations can be best understood using

Drosophila as an example.

Questions………….?