The following point highlight the five main types of structural variation in chromosomes. The types are: 1. Deletion or Deficiency 2. Duplications 3. Translocations 4. Inversions 5. B-Chromosomes. Type # 1. Deletion or Deficiency: A deficiency means deletion of a small portion of a chromosome resulting in loss of one or more genes. A deficiency originates from breakage occurring at [...]
In this article we will discuss about the inversions in humans which occurs when the genes in a section of a chromosome is reversed. Pericentric Inversion: There are a number of reports of pericentric inversions in human. Breaks occur in both, short (p) and long (q) arms of the chromosomes. The length of inverted segment can be precisely identified by [...]
In this article we will discuss about the genetical and cytological methods of locating inversion break points. Cytological Location: Cytological analysis is an important method of the physical location of the break points of inversion. (a) In plants like maize, and other organisms where pachytene analysis is easy, the breakpoints can be located by measuring the position of the inversion [...]