Centromere and telomere sequence alterations reflect the rapid genome evolution within the carnivorous plant genus Genlisea |
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Authors: | Trung D Tran Hieu X Cao Gabriele Jovtchev Pavel Neumann Petr Novák Miloslava Fojtová Giang TH Vu Jiří Macas Jiří Fajkus Ingo Schubert Joerg Fuchs |
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Institution: | 1. Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Stadt Seeland, Germany;2. Biology Centre of the Academy of Sciences of the Czech Republic, Institute of Plant Molecular Biology, ?eské Budějovice, Czech Republic;3. Central European Institute of Technology (CEITEC) and Faculty of Science, Masaryk University, Brno, Czech Republic;4. Institute of Biophysics, Academy of Sciences of the Czech Republic v.v.i., Brno, Czech Republic |
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Abstract: | Linear chromosomes of eukaryotic organisms invariably possess centromeres and telomeres to ensure proper chromosome segregation during nuclear divisions and to protect the chromosome ends from deterioration and fusion, respectively. While centromeric sequences may differ between species, with arrays of tandemly repeated sequences and retrotransposons being the most abundant sequence types in plant centromeres, telomeric sequences are usually highly conserved among plants and other organisms. The genome size of the carnivorous genus Genlisea (Lentibulariaceae) is highly variable. Here we study evolutionary sequence plasticity of these chromosomal domains at an intrageneric level. We show that Genlisea nigrocaulis (1C = 86 Mbp; 2n = 40) and G. hispidula (1C = 1550 Mbp; 2n = 40) differ as to their DNA composition at centromeres and telomeres. G. nigrocaulis and its close relative G. pygmaea revealed mainly 161 bp tandem repeats, while G. hispidula and its close relative G. subglabra displayed a combination of four retroelements at centromeric positions. G. nigrocaulis and G. pygmaea chromosome ends are characterized by the Arabidopsis‐type telomeric repeats (TTTAGGG); G. hispidula and G. subglabra instead revealed two intermingled sequence variants (TTCAGG and TTTCAGG). These differences in centromeric and, surprisingly, also in telomeric DNA sequences, uncovered between groups with on average a > 9‐fold genome size difference, emphasize the fast genome evolution within this genus. Such intrageneric evolutionary alteration of telomeric repeats with cytosine in the guanine‐rich strand, not yet known for plants, might impact the epigenetic telomere chromatin modification. |
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Keywords: | Lentibulariaceae
Genlisea nigrocaulis
G   hispidula
centromeric tandem repeat centromeric retrotransposons plant telomeric repeat variants telomerase genome evolution |
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