10-02-2012, 03:52 PM
Inversion
Inversion.ppt (Size: 2.68 MB / Downloads: 47)
Introduction
Inversion are those structural change in chromosome , where a segment of a chromosome has a reverse order of genes relative to the normal order
It results when a segment of a chromosome is excised , inverted 180 degree reintegrated into the same chromosome
Inversion were discovered for the first time , when linkage studies were being undertaken in drosophila
Cytogenetic techniques may be able to detect inversion , or inversion may be inferred from genetic analysis
Types of inversion
Depending upon the position of breaks in chromosomes , there are two main types of inversion-
Paracentric inversion - an inversion of a segment of the chromosome that does not involve the centromeric region and the two breaks are in the same arm.
Pericentric inversion - an inversion of a segment of the chromosome that involves the centromeric region and the two breaks are in the different arm.
An inversion may be found on both the chromosome of a homologous pair or may restricted to one of the two chromosome ,so that the individual carrying it will be called inversion homozygote or inversion heterozygote respectively