Paracentric inversion

Paracentric inversion is a type of chromosomal inversion that occurs when a section of a chromosome that does not include the centromere is flipped in orientation. This is in contrast to a pericentric inversion, which does include the centromere.

Overview

In a paracentric inversion, the inverted section of the chromosome is reversed end to end, causing the gene sequence to be reversed. This can lead to a variety of genetic consequences, depending on the specific genes involved and the extent of the inversion.

Mechanism

Paracentric inversions occur during meiosis, the process of cell division that produces gametes. During the first division of meiosis, homologous chromosomes pair up and exchange genetic material in a process known as crossing over. If a crossing over event occurs within the inverted section of a chromosome, it can result in a dicentric chromosome (with two centromeres) and an acentric chromosome (with no centromere). These abnormal chromosomes are typically lost during cell division, leading to genetic imbalance in the resulting gametes.

Consequences

The consequences of paracentric inversions can vary widely, depending on the specific genes involved and the extent of the inversion. In some cases, paracentric inversions can lead to genetic disorders or infertility. However, in other cases, they may have no noticeable effect.

See also

• Chromosomal inversion
• Pericentric inversion
• Dicentric chromosome
• Acentric chromosome
• Genetic imbalance