TY - JOUR

T1 - Sequence composition and evolution of mammalian B chromosomes

AU - Rubtsov, Nikolay B.

AU - Borisov, Yury M.

N1 - Publisher Copyright: © 2018 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2018/10/10

Y1 - 2018/10/10

N2 - 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.

AB - 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.

KW - B chromosomes

KW - Genes

KW - Genome evolution

KW - Interphase nucleus

KW - Karyotypes

KW - Mammals

KW - Repetitive DNA

KW - Transcription of heterochromatin

KW - UBIQUITIN LIGASE

KW - interphase nucleus

KW - PERICENTRIC REGIONS

KW - transcription of heterochromatin

KW - GENE-EXPRESSION

KW - SUPERNUMERARY MARKER CHROMOSOMES

KW - APODEMUS-PENINSULAE RODENTIA

KW - genes

KW - genome evolution

KW - repetitive DNA

KW - WOOD MICE

KW - mammals

KW - COMPARATIVE FISH ANALYSIS

KW - KOREAN FIELD-MOUSE

KW - karyotypes

KW - NYCTEREUTES-PROCYONOIDES

KW - FLAVICOLLIS RODENTIA

UR - http://www.scopus.com/inward/record.url?scp=85055544413&partnerID=8YFLogxK

U2 - 10.3390/genes9100490

DO - 10.3390/genes9100490

M3 - Review article

C2 - 30309007

AN - SCOPUS:85055544413

VL - 9

JO - Genes

JF - Genes

SN - 2073-4425

IS - 10

M1 - 490

ER -