Genome size shifts: karyotype evolution in Crepis section Neglectoides (Asteraceae). (9th April 2015)

• Record Type: Journal Article
• Authors: Enke, N.; Kunze, R.; Pustahija, F.; Glöckner, G.; Zimmermann, J.; Oberländer, J.; Kamari, G.; Siljak‐Yakovlev, S.; Keurentjes, J.
• Is Part Of: Plant biology. Volume 17:Number 4(2015:Jul.)
• Page Start: 775
• Page End: 786
• Publication Date: 2015-04-09
• Subjects: Botany -- Periodicals; Plants -- genetics -- Periodicals; Plants -- growth & development -- Periodicals; Plant Proteins -- Periodicals; Gene Expression Regulation, Plant -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1111/plb.12318
• Languages: English
• ISSNs: 1435-8603

Abstract

<abstract abstract-type="main" id="plb12318-abs-0001"> <title>Abstract</title> <p>Plant genome size evolution is a very dynamic process: the ancestral genome of angiosperms was initially most likely small, which led to a tendency towards genome increase during evolution. However, findings in several angiosperm lineages demonstrate mechanisms that also led to genome size contraction. Recent molecular investigations on the Asteraceae genus <italic>Crepis</italic> suggest that several genomic reduction events have occurred during the evolution of the genus. This study focuses on the Mediterranean <italic>Crepis</italic> sect. <italic>Neglectoides</italic>, which includes three species with some of the smallest genomes within the whole genus. <italic>Crepis neglecta</italic> has the largest genome in sect. <italic>Neglectoides, </italic> approximately twice the size of the two species <italic>Crepis cretica</italic> and <italic>Crepis hellenica</italic>. Whereas <italic>C. cretica</italic> and <italic>C. hellencia</italic> are more closely related to each other than to <italic>C. neglecta</italic> the karyotypes of the latter species and <italic>C. cretica</italic> are similar, while that of <italic>C. hellenica</italic> differs considerably. Here, the karyotypic organisation of the three species is investigated with fluorescence <italic>in‐situ</italic> hybridisation and studied in a molecular phylogenetic framework based on the nuclear markers <italic>Actin, CHR12, CPN60B, GPCR1</italic> and <italic>XTH23</italic>. Our findings further corroborate the occurrence of genome size contraction in <italic>Crepis</italic>, and suggest that the difference in genome size between <italic>C. neglecta</italic> and <italic>C. cretica</italic> is mostly due to elimination of dispersed repetitive elements, whereas chromosomal reorganisation was involved in the karyotype formation of <italic>C. hellenica</italic>.</p> </abstract>