Dioecy and sex chromosomes almost certainly evolved from ancestral hermaphrodites that only possessed autosomes. There is a growing body of evidence that genes for female or male function were then epigenetically suppressed in some of these hermaphrodites, creating the first males or females and nascent sex chromosomes. The incipient sex-determining epigenetic signals, such as cytosine methylat...

Chromatin undergoes dramatic condensation and decondensation as cells transition between the different phases of the cell cycle. The organization of chromatin in chromosomes is still one of the key challenges in structural biology. Fluorescence lifetime imaging (FLIM), a technique which utilizes a fluorophore's fluorescence lifetime to probe changes in its environment, was used to investigate v...

The genus Phyllactinia is one of the members of Erysiphaceae (Erysiphales, Ascomycota) which parasitize several host plant families. This taxon is well characterized by having acicular appendages with bulbous swelling at the base and penicillate cells which are outgrowth of some ascoma wall cells. A number of challenges exist to distinguish species assigned to this taxon. This is because of a f...

Most organisms experience competition for resources, probably most of the time. As the structure and requirements of closely related species are generally liable to be more similar than in distantly linked species, Darwin suggested that the potential for competition was greater in the former. Since that time, studies have concentrated on interactions of either conspecifics or congeneric species...

In this review, we describe the history of amniote sex determination as a classic example of Darwinian evolution. We suggest that evolutionary changes in sex determination provide a foundation for understanding important aspects of chromosome and genome organization that otherwise appear haphazard in their origins and contents. Species with genotypic sex determination often possess heteromorphi...

Primula species provide possibly the best known examples of heteromorphic flower development and this breeding system has attracted considerable attention, including that of Charles Darwin. However, despite considerable recent advances in molecular genetics, nothing is known about the molecular basis of floral heteromorphy. The first molecular marker for the Primula S-locus is reported here. Th...

Epigenetic mechanisms such as DNA methylation are a key component of dosage compensation on sex chromosomes and have been proposed as an important source of phenotypic variation influencing plasticity and adaptive evolutionary processes, yet little is known about the role of DNA methylation in an ecological or evolutionary context in vertebrates. The threespine stickleback (Gasterosteus aculeat...

The concept of a "potential taxon" as a nameand literature-related data area in botanical databases is introduced. A potential taxon is a name with taxon circumscription information attached to it by means of one or more literature references. As a compromise solution between linking information in database systems entirely to specimen data or only to accepted names, using potential taxa can ef...