Next Article in Journal
Chromosome Painting in Neotropical Long- and Short-Tailed Parrots (Aves, Psittaciformes): Phylogeny and Proposal for a Putative Ancestral Karyotype for Tribe Arini
Next Article in Special Issue
B Chromosomes in Grasshoppers: Different Origins and Pathways to the Modern Bs
Previous Article in Journal
Genes Contributing to Domestication of Rice Seed Traits and Its Global Expansion
Previous Article in Special Issue
B Chromosomes in Populations of Mammals Revisited
Article Menu
Issue 10 (October) cover image

Export Article

Open AccessReview
Genes 2018, 9(10), 490;

Sequence Composition and Evolution of Mammalian B Chromosomes

The Federal Research Center Institute of Cytology and Genetics SB RAS, Lavrentiev Ave. 10, Novosibirsk 630090, Russia
Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russia
Severtzov Institute of Ecology and Evolution, Russia Academy of Sciences, Leninsky Pr. 33, Moscow 119071, Russia
Author to whom correspondence should be addressed.
Received: 28 August 2018 / Revised: 1 October 2018 / Accepted: 1 October 2018 / Published: 10 October 2018
(This article belongs to the Special Issue Evolution, Composition and Regulation of Supernumerary B Chromosomes)
Full-Text   |   PDF [1418 KB, uploaded 10 October 2018]   |  


B chromosomes (Bs) revealed more than a hundred years ago remain to be some of the most mysterious elements of the eukaryotic genome. Their origin and evolution, DNA composition, transcriptional activity, impact on adaptiveness, behavior in meiosis, and transfer to the next generation require intensive investigations using modern methods. Over the past years, new experimental techniques have been applied and helped us gain a deeper insight into the nature of Bs. Here, we consider mammalian Bs, taking into account data on their DNA sequencing, transcriptional activity, positions in nuclei of somatic and meiotic cells, and impact on genome functioning. Comparative cytogenetics of Bs suggests the existence of different mechanisms of their formation and evolution. Due to the long and complicated evolvement of Bs, the similarity of their morphology could be explained by the similar mechanisms involved in their development while the difference between Bs even of the same origin could appear due to their positioning at different stages of their evolution. A complex analysis of their DNA composition and other features is required to clarify the origin and evolutionary history of Bs in the species studied. The intraspecific diversity of Bs makes this analysis a very important element of B chromosome studies. View Full-Text
Keywords: B chromosomes; karyotypes; genome evolution; interphase nucleus; mammals; genes; repetitive DNA; transcription of heterochromatin B chromosomes; karyotypes; genome evolution; interphase nucleus; mammals; genes; repetitive DNA; transcription of heterochromatin

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Rubtsov, N.B.; Borisov, Y.M. Sequence Composition and Evolution of Mammalian B Chromosomes. Genes 2018, 9, 490.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Genes EISSN 2073-4425 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top