Chromosome Deletions,Cytologically,Homozygous State,Gene

www.molecular-plant-biotechnology.info

Home >> Mutations >> Chromosome Deletions

	Chromosome Deletions - Deletions are caused when a chromosome breaks and loses a segment. Deletions lead to decrease in gene number. Deletion was first discovered by Bridges in 1917. Chromosomes with a deletion cannot be reverted back to wild type conditions. These are usually lethal in homozygous state. Cytologically, deletions can be detected by failure of a segment of a chromosome to pair properly. Deletions are classified into two types based upon the position where deletion occurs.
Terminal deletionIt involves loss of a segment of a chromosome from the end. Normally telomere is lost, e.g. cri-du chat syndrome. This type of mutation occurs rarely. Interstitial deletion It involves loss of a segment between the telomere and centromere region. This type of mutation is not rare.