In:
eLife, eLife Sciences Publications, Ltd, Vol. 6 ( 2017-12-18)
Abstract:
Multicellular life relies on a group of cells working together for a common interest. To study these cells, researchers take them out of the organism and grow them in the laboratory. Instead of growing as part of organs and tissues, the cells normally have a free-living lifestyle. Because multicellular life evolved from single-celled organisms, laboratory-grown cells can be considered as life forms that are evolving backward from a multicellular to a single-celled existence. Normally, the cells that make up most of the tissues in the human body have 22 pairs of chromosomes known as autosomes and a pair of sex chromosomes. The cells of women have two X sex chromosomes, one of which is inactive, while those of men have one X and one Y chromosome. However, free-living single cells do not need to distinguish between male and female cells. Xu, Peng, Chen et al. have now studied the chromosomes of cancer cells taken from over 600 people and grown in the laboratory. As the cells evolved in response to their free-living lifestyle, they became ‘de-sexualized’; male cells lost their Y chromosome, while female cells abandoned their inactive X chromosome. The cells then evolved toward a new state in which they possessed two active X chromosomes and three sets of autosomes. This new configuration suggests that the current X chromosome to autosome ratio may not be optimal for fitness and hence sheds some light on how mammalian sex chromosomes evolved. It is currently thought that as cancerous tumors grow, their cells evolve to favor their own interests over the common interests of the rest of the organism. In this way, they develop characteristics more like those of single cells. Further research is therefore needed to investigate whether changes occur to the chromosomes of cancer cells growing within the body, and whether this gives them an advantage over normal cells.
Type of Medium:
Online Resource
ISSN:
2050-084X
DOI:
10.7554/eLife.28070.001
DOI:
10.7554/eLife.28070.002
DOI:
10.7554/eLife.28070.003
DOI:
10.7554/eLife.28070.004
DOI:
10.7554/eLife.28070.005
DOI:
10.7554/eLife.28070.006
DOI:
10.7554/eLife.28070.007
DOI:
10.7554/eLife.28070.008
DOI:
10.7554/eLife.28070.009
DOI:
10.7554/eLife.28070.010
DOI:
10.7554/eLife.28070.011
DOI:
10.7554/eLife.28070.012
DOI:
10.7554/eLife.28070.013
DOI:
10.7554/eLife.28070.014
DOI:
10.7554/eLife.28070.015
DOI:
10.7554/eLife.28070.016
DOI:
10.7554/eLife.28070.017
DOI:
10.7554/eLife.28070.018
DOI:
10.7554/eLife.28070.026
DOI:
10.7554/eLife.28070.027
Language:
English
Publisher:
eLife Sciences Publications, Ltd
Publication Date:
2017
detail.hit.zdb_id:
2687154-3