Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2006;5(1):2.
doi: 10.1186/jbiol32. Epub 2006 Feb 16.

A balancing act between the X chromosome and the autosomes

Mimi K Cheng  1 , Christine M Disteche
Affiliations
Review

A balancing act between the X chromosome and the autosomes

Mimi K Cheng et al. J Biol. 2006.

Abstract

Dosage compensation equalizes gene dosage between males and females, but its role in balancing expression between the X chromosome and the autosomes may be far more important. Now, DNA microarrays have shown equality between the average expression of X-linked genes and that of autosomal genes, in male and female tissues of flies, worms and mice.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Dosage compensation occurs in Drosophila, C. elegans, and mammals [8,9]. If the expression level of each pair of autosomes (gray for both males and females) is set to 1.0, then the expression level of the two X chromosomes in females (pink) and the single X chromosome in males (blue) is also equal to 1.0. To achieve this dosage compensation, the single X chromosome in the Drosophila male soma and germline, C. elegans male soma, and mammalian male soma is upregulated (dark blue, up-arrow). In Drosophila female soma, the X chromosomes are both expressed and thus not upregulated (light pink). According to Gupta et al. [8], each X chromosome in the Drosophila female germline is probably upregulated, and yet they must also be downregulated somehow, in order to prevent functional tetrasomy (light pink, double arrow). The X chromosomes in C. elegans hermaphrodite soma are presumably upregulated, but they are also known to be downregulated by half (light pink, double arrow). In mammalian females, one of the two X chromosomes is active and upregulated (dark pink, up-arrow), while the other X chromosome gets inactivated (white, down-arrow). The haploid germ cells of mammals express but do not upregulate their X chromosomes to achieve the same level of autosomal expression (0.5; light pink for female and light blue for male) [9]. Primary mammalian oocytes, which have two non-upregulated X chromosomes, and spermatocytes, in which the X chromosome is largely silenced, are not depicted.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Charlesworth B. The evolution of chromosomal sex determination and dosage compensation. Curr Biol. 1996;6:149–162. doi: 10.1016/S0960-9822(02)00448-7. - DOI - PubMed
    1. Lindsley DL, Sandler L, Baker BS, Carpenter AT, Denell RE, Hall JC, Jacobs PA, Miklos GL, Davis BK, Gethmann RC, et al. Segmental aneuploidy and the genetic gross structure of the Drosophila genome. Genetics. 1972;71:157–184. - PMC - PubMed
    1. Celniker SE, Wheeler DA, Kronmiller B, Carlson JW, Halpern A, Patel S, Adams M, Champe M, Dugan SP, Frise E, et al. Finishing a whole-genome shotgun: release 3 of the Drosophila melanogaster euchromatic genome sequence. Genome Biol. 2002;3:research0079.1–0079.14. doi: 10.1186/gb-2002-3-12-research0079. - DOI - PMC - PubMed
    1. Lakhotia SC, Mukherjee AS. Chromosomal basis of dosage compensation in Drosophila. 3. Early completion of replication by the polytene X-chromosome in male: further evidence and its implications. J Cell Biol. 1970;47:18–33. doi: 10.1083/jcb.47.1.18. - DOI - PMC - PubMed
    1. Rastelli L, Kuroda MI. An analysis of maleless and histone H4 acetylation in Drosophila melanogaster spermatogenesis. Mech Dev. 1998;71:107–117. doi: 10.1016/S0925-4773(98)00009-4. - DOI - PubMed

LinkOut - more resources