Slide 2:
Arrangement of chromosome is require at least two breaks. These break region may occur by recombination between DNA sequences repeated and dispersed through out the genome. It may only affect one chromosome,or may involve transfer or exchange between two nonhomologous chromosome. Ex- Drosophila malanogaster Introduction
Structural changes in Chromosomes:
Structural changes in Chromosomes
Slide 4:
1. Delition or Deficiency 2. Duplication 3. Inversion 4. Translocation
Deletion:
Deletion Part of the chromosome is missing ..Starts with breaks in the chromosome ..Effected by radiation, heat, viruses, chemicals, etc. ..May cause an unpaired loop ..May give rise to pseudodominance Example- Cri-du-chat syndrome (Chrom. #5)
Duplication:
Duplication Doubling of a segment of a chromosome * Tandem * Reverse tandem * Terminal tandem Example- Position Effect of barring eyes in Drosophila
Inversion:
Inversion Results when a segment of a chromosome is excised and then reintegrated in an orientation 180 degrees from the original orientation. Resulting from a dicentric bridge Pericentric inversion Paracentric inversion
Translocation:
Translocation Change in position of chromosome segments and the gene sequences they contain to a different location Nonreciprocal intrachromosomal Nonreciprocal interchromosomal Reciprocal interchromosomal
Slide 13:
13
Reference:
Reference www.sciencedirect.com Molecular biology- verma and Aggrawal
Thank you:
Thank you