Back to Search
Start Over
Contrasting origin of B chromosomes in two cervids (Siberian roe deer and grey brocket deer) unravelled by chromosome-specific DNA sequencing
- Source :
- BMC Genomics
- Publication Year :
- 2016
- Publisher :
- Springer Science and Business Media LLC, 2016.
-
Abstract
- Background B chromosomes are dispensable and variable karyotypic elements found in some species of animals, plants and fungi. They often originate from duplications and translocations of host genomic regions or result from hybridization. In most species, little is known about their DNA content. Here we perform high-throughput sequencing and analysis of B chromosomes of roe deer and brocket deer, the only representatives of Cetartiodactyla known to have B chromosomes. Results In this study we developed an approach to identify genomic regions present on chromosomes by high-throughput sequencing of DNA generated from flow-sorted chromosomes using degenerate-oligonucleotide-primed PCR. Application of this method on small cattle autosomes revealed a previously described KIT gene region translocation associated with colour sidedness. Implementing this approach to B chromosomes from two cervid species, Siberian roe deer (Capreolus pygargus) and grey brocket deer (Mazama gouazoubira), revealed dramatically different genetic content: roe deer B chromosomes consisted of two duplicated genomic regions (a total of 1.42-1.98 Mbp) involving three genes, while grey brocket deer B chromosomes contained 26 duplicated regions (a total of 8.28-9.31 Mbp) with 34 complete and 21 partial genes, including KIT and RET protooncogenes, previously found on supernumerary chromosomes in canids. Sequence variation analysis of roe deer B chromosomes revealed a high frequency of mutations and increased heterozygosity due to either amplification within B chromosomes or divergence between different Bs. In contrast, grey brocket deer B chromosomes were found to be more homogeneous and resembled autosomes in patterns of sequence variation. Similar tendencies were observed in repetitive DNA composition. Conclusions Our data demonstrate independent origins of B chromosomes in the grey brocket and roe deer. We hypothesize that the B chromosomes of these two cervid species represent different stages of B chromosome sequences evolution: probably nascent and similar to autosomal copies in brocket deer, highly derived in roe deer. Based on the presence of the same orthologous protooncogenes in canids and brocket deer Bs we argue that genomic regions involved in B chromosome formation are not random. In addition, our approach is also applicable to the characterization of other evolutionary and clinical rearrangements. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2933-6) contains supplementary material, which is available to authorized users.
- Subjects :
- Siberian Roe Deer
0301 basic medicine
Heterozygote
B chromosome Evolution
Gene Expression
Biology
Polymerase Chain Reaction
Capreolus pygargus
DNA sequencing
03 medical and health sciences
Mutation Rate
Species Specificity
Gene Duplication
biology.animal
Genetics
Animals
Humans
Chromosomes, Human, 4-5
Brocket deer
DNA Primers
Protooncogenes
B chromosome
Autosome
Deer
Proto-Oncogene Proteins c-ret
Chromosome Mapping
High-Throughput Nucleotide Sequencing
Chromosome
Karyotype
DOP-PCR
biology.organism_classification
Biological Evolution
Chromosomes, Mammalian
High-throughput Sequencing
Roe deer
Proto-Oncogene Proteins c-kit
Grey Brocket Deer
030104 developmental biology
Karyotyping
Research Article
Biotechnology
Subjects
Details
- ISSN :
- 14712164
- Volume :
- 17
- Database :
- OpenAIRE
- Journal :
- BMC Genomics
- Accession number :
- edsair.doi.dedup.....eff313208dba1c68c485ec157a3e738e