Genetic study solves the mystery of ‘selfish’ B chromosomes in rye
Genetic study solves the mystery of ‘selfish’ B chromosomes in rye
Tags: Chromosomal drive, Selfish genetic elementsLeibniz Institute of Plant Genetics and Crop Plant Research, Phys.org, 2024.
Some chromosomes, such as B chromosomes, can increase their inheritance rate to their own advantage. These extra chromosomes are found in many plants, animals, and fungi and rely upon various strategies to avoid being eliminated over time, as most organisms tend to remove non-essential genetic elements.
However, the genetic mechanisms by which B chromosomes avoid elimination are poorly understood. An international research team led by IPK Leibniz Institute identified genes on the rye B chromosome that are likely responsible for regulating this process. The results were published in Nature Communications.
Supernumerary B chromosomes, unlike A (standard) chromosomes, are not required for the normal growth and development of organisms and as of 2024, B chromosomes have been discovered in almost 3,000 species from all eukaryotic phyla. Most B chromosomes confer no detectable selective consequences at low numbers, but increased numbers can result in phenotypic aberrations and reduced fertility. To avoid elimination, many B chromosomes influence cell division in their favor and increase their copy number in the process. This phenomenon is called chromosome drive. The “selfish” B chromosomes, therefore, only become active when their existence is at stake and not for the benefit of the plant.
