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Mechanisms that favour rare species are key to the maintenance of diverse communities.sup.1-3. One of the most critical tasks for conservation of flowering plant biodiversity is to understand how plant-pollinator interactions contribute to the maintenance of rare species.sup.4-7. Here we show that niche partitioning in pollinator use and asymmetric facilitation confer fitness advantage of rarer species in a biodiversity hotspot using phylogenetic structural equation modelling that integrates plant-pollinator and interspecific pollen transfer networks with floral functional traits. Co-flowering species filtered pollinators via floral traits, and rarer species showed greater pollinator specialization leading to higher pollination-mediated male and female fitness than more abundant species. When plants shared pollinator resources, asymmetric facilitation via pollen transport dynamics benefitted the rarer species at the cost of more abundant species, serving as an alternative diversity-promoting mechanism. Our results emphasize the importance of community-wide plant-pollinator interactions that affect reproduction for biodiversity maintenance. The authors show that plant-pollinator interactions confer a fitness advantage to rare plant species in a biodiversity hotspot., Author(s): Na Wei [sup.1] [sup.2] , Rainee L. Kaczorowski [sup.1] , Gerardo Arceo-Gómez [sup.1] [sup.3] , Elizabeth M. O'Neill [sup.1] , Rebecca A. Hayes [sup.1] , Tia-Lynn Ashman [sup.1] Author [...]

Transcription factor, kinase and replication factor movements between nucleus and cytoplasm are important in activity control. The way in which phosphorylation promotes protein export from the nucleus is not well understood. The export of the yeast transcription factor Pho4 was investigated to determine how it is regulated in response to alterations in phosphate availability. The importin-beta-family member MSn5 is the shuttling receptor used by Pho4 for nuclear export.

M. Wahi and A.D. Johnson have investigated the SRB genes and discovered that the SRB10 and SRB11 are actively involved in the phosphorylation of the II carboxy-terminal domain (CTD). The CTD is phylogenetically conserved and the SRB10 and SRB11 facilitate the conservation process. CTD are sometimes removed by deletion mutations that are lethal to cells. The SRB genes restrict the deletion mutations thereby enhancing the phylogenetic conservation of the CTD.