Open AccessGenome organization and DNA methylation patterns of B chromosomes in the red fox and Chinese raccoon dogs
Author(s) -
BugnoPoniewierska Monika,
Solek Przemysław,
Wronski Mariusz,
Potocki Leszek,
JezewskaWitkowska Grażyna,
Wnuk Maciej
Publication year - 2014
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1111/hrd2.00049
Subject(s) - biology , dna methylation , genetics , satellite dna , dna , repeated sequence , histone , genome , chromosome , microbiology and biotechnology , gene , gene expression
The molecular structure of B chromosomes (Bs) is relatively well studied. Previous research demonstrates that Bs of various species usually contain two types of repetitive DNA sequences, satellite DNA and ribosomal DNA, but Bs also contain genes encoding histone proteins and many others. However, many questions remain regarding the origin and function of these chromosomes. Here, we focused on the comparative cytogenetic characteristics of the red fox and Chinese raccoon dog B chromosomes with particular attention to the distribution of repetitive DNA sequences and their methylation status. We confirmed that the small Bs of the red fox show a typical fluorescent telomeric distal signal, whereas medium‐sized Bs of the Chinese raccoon dog were characterized by clusters of telomeric sequences along their length. We also found different DNA methylation patterns for the B chromosomes of both species. Therefore, we concluded that DNA methylation may maintain the transcriptional inactivation of DNA sequences localized to B chromosomes and may prevent genetic unbalancing and several negative phenotypic effects.