PMID- 23410024
OWN - NLM
STAT- MEDLINE
DCOM- 20130530
LR  - 20220321
IS  - 1471-2148 (Electronic)
IS  - 1471-2148 (Linking)
VI  - 13
DP  - 2013 Feb 14
TI  - Genome differentiation in a species pair of coregonine fishes: an extremely rapid 
      speciation driven by stress-activated retrotransposons mediating extensive 
      ribosomal DNA multiplications.
PG  - 42
LID - 10.1186/1471-2148-13-42 [doi]
AB  - BACKGROUND: Sympatric species pairs are particularly common in freshwater fishes 
      associated with postglacial lakes in northern temperate environments. The nature 
      of divergences between co-occurring sympatric species, factors contributing to 
      reproductive isolation and modes of genome evolution is a much debated topic in 
      evolutionary biology addressed by various experimental tools. To the best of our 
      knowledge, nobody approached this field using molecular cytogenetics. We examined 
      chromosomes and genomes of one postglacial species pair, sympatric European 
      winter-spawning Coregonus albula and the local endemic dwarf-sized 
      spring-spawning C. fontanae, both originating in Lake Stechlin. We have employed 
      molecular cytogenetic tools to identify the genomic differences between the two 
      species of the sympatric pair on the sub-chromosomal level of resolution. 
      RESULTS: Fluorescence in situ hybridization (FISH) experiments consistently 
      revealed a distinct variation in the copy number of loci of the major ribosomal 
      DNA (the 45S unit) between C. albula and C. fontanae genomes. In C. fontanae, up 
      to 40 chromosomes were identified to bear a part of the major ribosomal DNA, 
      while in C. albula only 8-10 chromosomes possessed these genes. To determine 
      mechanisms how such extensive genome alternation might have arisen, a PCR 
      screening for retrotransposons from genomic DNA of both species was performed. 
      The amplified retrotransposon Rex1 was used as a probe for FISH mapping onto 
      chromosomes of both species. These experiments showed a clear co-localization of 
      the ribosomal DNA and the retrotransposon Rex1 in a pericentromeric region of one 
      or two acrocentric chromosomes in both species. CONCLUSION: We demonstrated 
      genomic consequences of a rapid ecological speciation on the level undetectable 
      by neither sequence nor karyotype analysis. We provide indirect evidence that 
      ribosomal DNA probably utilized the spreading mechanism of retrotransposons 
      subsequently affecting recombination rates in both genomes, thus, leading to a 
      rapid genome divergence. We attribute these extensive genome re-arrangements 
      associated with speciation event to stress-induced retrotransposons 
      (re)activation. Such causal interplay between genome differentiation, 
      retrotransposons (re)activation and environmental conditions may become a topic 
      to be explored in a broader genomic context in future evolutionary studies.
FAU - Symonova, Radka
AU  - Symonova R
AD  - Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech 
      Academy of Sciences, Rumburska 89, 277 21, Libechov, Czech Republic. 
      radka.symonova@natur.cuni.cz
FAU - Majtanova, Zuzana
AU  - Majtanova Z
FAU - Sember, Alexandr
AU  - Sember A
FAU - Staaks, Georg B O
AU  - Staaks GB
FAU - Bohlen, Jorg
AU  - Bohlen J
FAU - Freyhof, Jorg
AU  - Freyhof J
FAU - Rabova, Marie
AU  - Rabova M
FAU - Rab, Petr
AU  - Rab P
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20130214
PL  - England
TA  - BMC Evol Biol
JT  - BMC evolutionary biology
JID - 100966975
RN  - 0 (DNA, Ribosomal)
RN  - 0 (RNA, Ribosomal)
RN  - 0 (RNA, ribosomal, 45S)
RN  - 0 (Retroelements)
SB  - IM
MH  - Animals
MH  - Comparative Genomic Hybridization
MH  - DNA, Ribosomal/genetics
MH  - Gene Dosage
MH  - *Genetic Speciation
MH  - Germany
MH  - In Situ Hybridization, Fluorescence
MH  - Karyotype
MH  - Lakes
MH  - RNA, Ribosomal/genetics
MH  - *Retroelements
MH  - Salmonidae/*classification/genetics
MH  - Sequence Analysis, DNA
MH  - *Sympatry
PMC - PMC3585787
EDAT- 2013/02/16 06:00
MHDA- 2013/06/01 06:00
PMCR- 2013/02/14
CRDT- 2013/02/16 06:00
PHST- 2012/05/29 00:00 [received]
PHST- 2013/02/11 00:00 [accepted]
PHST- 2013/02/16 06:00 [entrez]
PHST- 2013/02/16 06:00 [pubmed]
PHST- 2013/06/01 06:00 [medline]
PHST- 2013/02/14 00:00 [pmc-release]
AID - 1471-2148-13-42 [pii]
AID - 10.1186/1471-2148-13-42 [doi]
PST - epublish
SO  - BMC Evol Biol. 2013 Feb 14;13:42. doi: 10.1186/1471-2148-13-42.