In: Biology
Assume chromosome 1 has the following structure: A B centromere C D E F G What could be the result of a pericentric inversion? Where should the chromosome break to obtain this aberration?
Inversion is a kind of chromosomal rearrangement where breaks occur at two places and the chromosome region between the breaks get inverted. The process of inversion involves breakage and reunion.
Depending upon the involvement of centromere, inversions can be of two types:
In Paracentric inversion break ooccus within one arm of the chromosome and it does not include centromere.
However in pericentric inversion two breaks occurs on both sides of the centromere. Hence the position of centromere may change after pericentric inversions depending upon the number of genes present in between two breaks.
In the given question, pericentric inversion has occured in the chromosome having sequence
A B centromere C D E F G
As pericentric inversions involves centromere, and assuming that first break occured between A and B and second break occured between C and D, following sequnce will be obtained:
A C centromere B D E F G