AUTHOR=Bačovský Václav , Čegan Radim , Šimoníková Denisa , Hřibová Eva , Hobza Roman 

TITLE=The Formation of Sex Chromosomes in Silene latifolia and S. dioica Was Accompanied by Multiple Chromosomal Rearrangements

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.00205

DOI=10.3389/fpls.2020.00205

ISSN=1664-462X

ABSTRACT=<p>The genus <italic>Silene</italic> includes a plethora of dioecious and gynodioecious species. Two species, <italic>Silene latifolia</italic> (white campion) and <italic>Silene dioica</italic> (red campion), are dioecious plants, having heteromorphic sex chromosomes with an XX/XY sex determination system. The X and Y chromosomes differ mainly in size, DNA content and posttranslational histone modifications. Although it is generally assumed that the sex chromosomes evolved from a single pair of autosomes, it is difficult to distinguish the ancestral pair of chromosomes in related gynodioecious and hermaphroditic plants. We designed an oligo painting probe enriched for X-linked scaffolds from currently available genomic data and used this probe on metaphase chromosomes of <italic>S. latifolia</italic> (2n = 24, XY), <italic>S. dioica</italic> (2n = 24, XY), and two gynodioecious species, <italic>S. vulgaris</italic> (2n = 24) and S. <italic>maritima</italic> (2n = 24). The X chromosome-specific oligo probe produces a signal specifically on the X and Y chromosomes in <italic>S. latifolia</italic> and <italic>S. dioica</italic>, mainly in the subtelomeric regions. Surprisingly, in <italic>S. vulgaris</italic> and <italic>S. maritima</italic>, the probe hybridized to three pairs of autosomes labeling their p-arms. This distribution suggests that sex chromosome evolution was accompanied by extensive chromosomal rearrangements in studied dioecious plants.</p>