Here we introduce a new model species, Silene colpophylla, that could facilitate research of sex chromosome evolution and sex-determining systems. This species is related to the well-established dioecious plant model Silene latifolia. Our results show that S. colpophylla is, similarly to S. latifolia, a male heterogametic species, but its sex chromosomes have evolved from a different pair of au...

The sex chromosomes of dioecious white campion, Silene latifolia (Caryophyllaceae), are of relatively recent origin (10-20 million years), providing a unique opportunity to trace the origin and evolution of sex chromosomes in this genus by comparing closely related Silene species with and without sex chromosomes. Here I demonstrate that four genes that are X-linked in S. latifolia are also link...

The detection of incipient host-shifts is important to the study of emergent diseases because it allows the examination of ecological and genetic conditions that favor novel inter-species transmission. Mixed populations of Silene latifolia and Silene vulgaris were investigated for the putative occurrence of host-shifts by the fungal plant pathogen Microbotryum violaceum (the cause of anther-smu...

Transposable elements often accumulate in nonrecombining regions, such as Y chromosomes. Contrary to this trend, a new Silene retrotransposon described here, has spread recently all over the genome of plant Silene latifolia, except its Y chromosome. This coincided with the latest steps of sex chromosome evolution in this species.

Microbotryum violaceum (anther-smut) from Silene caroliniana and S. virginica produced promycelia that frequently appeared to contain more than three cells according to the number of septations. This is in contrast to samples from S. latifolia and to previous descriptions of this species. Apparent four-celled promycelia contained three nucleate cells and one anucleate zone. Anucleate zones were...

The relatively recent origin of sex chromosomes in the plant genus Silene provides an opportunity to study the early stages of sex chromosome evolution and, potentially, to test between the different population genetic processes likely to operate in nonrecombining chromosomes such as Y chromosomes. We previously reported much lower nucleotide polymorphism in a Y-linked gene (SlY1) of the plant ...

• Sex ratio polymorphism has been extensively studied in Silene latifolia, but it is neither known whether inbreeding (which is likely to occur under field conditions) affects it nor which of the proposed mechanisms (Y degeneration, X-linked drive) is more important. Both mechanisms predict reduced pollen performance. • In this study, females were crossed with pollen from related and unrelated ...

We used herbarium specimens of Silene virginica, S. caroliniana, S. rotundifolia, and S. latifolia to survey the incidence of anther-smut disease (caused by Microbotryum violaceum sensu lato) in the eastern USA. We found no evidence of a collector bias against diseased specimens. Diseased specimens were frequently found in collections of S. virginica and S. caroliniana, but not in those of S. r...

In the plant genus Silene, separate sexes and sex chromosomes are believed to have evolved twice. Silene species that are wholly or largely hermaphroditic are assumed to represent the ancestral state from which dioecy evolved. This assumption is important for choice of outgroup species for inferring the genetic and chromosomal changes involved in the evolution of dioecy, but is mainly based on ...

Dioecious plants in the Caryophyllaceae family are susceptible to infection by members of the anthericolous smut fungi. In our studies of the Silene latifolia/Microbotryum lychnidis-dioicae pathosystem, we were interested in characterizing the plant-pathogen interaction at the molecular level before and during teliosporogenesis. This takes place during floral bud development, and we hoped to ca...