Variation in Snow Algae Blooms in the Coast Range of British Columbia

Snow algae blooms cover vast areas of summer snowfields worldwide, reducing albedo and increasing snow melt. Despite their global prevalence, little is known about the algae species that comprise these blooms. We used 18S and rbcL metabarcoding and light microscopy to characterize algae species composition in 31 snow algae blooms in the Coast Range of British Columbia, Canada. This study is the first to thoroughly document regional variation between blooms. We found all blooms were dominated by the genera Sanguina, Chloromonas, and Chlainomonas. There was considerable variation between blooms, most notably species assemblages above treeline were distinct from forested sites. In contrast to previous studies, the snow algae genus Chlainomonas was abundant and widespread in snow algae blooms. We found few taxa using traditional 18S metabarcoding, but the high taxonomic resolution of rbcL revealed substantial diversity, including OTUs that likely represent unnamed species of snow algae. These three cross-referenced datasets (rbcL, 18S, and microscopy) reveal that alpine snow algae blooms are more diverse than previously thought, with different species of algae dominating different elevations

Phylogenetic Analysis of the Neks Reveals Early Diversification of Ciliary-Cell Cycle Kinases

NIMA-related kinases (Neks) have been studied in diverse eukaryotes, including the fungus Aspergillus and the ciliate Tetrahymena. In the former, a single Nek plays an essential role in cell cycle regulation; in the latter, which has more than 30 Neks in its genome, multiple Neks regulate ciliary length. Mammalian genomes encode an intermediate number of Neks, several of which are reported to play roles in cell cycle regulation and/or localize to centrosomes. Previously, we reported that organisms with cilia typically have more Neks than organisms without cilia, but were unable to establish the evolutionary history of the gene family

A NIMA-related Kinase, Fa2p, Localizes to a Novel Site in the Proximal Cilia of Chlamydomonas and Mouse Kidney Cells

Polycystic kidney disease and related syndromes involve dysregulation of cell proliferation in conjunction with ciliary defects. The relationship between cilia and cell cycle is enigmatic, but it may involve regulation by the NIMA-family of kinases (Neks). We previously showed that the Nek Fa2p is important for ciliary function and cell cycle in Chlamydomonas. We now show that Fa2p localizes to an important regulatory site at the proximal end of cilia in both Chlamydomonas and a mouse kidney cell line. Fa2p also is associated with the proximal end of centrioles. Its localization is dynamic during the cell cycle, following a similar pattern in both cell types. The cell cycle function of Fa2p is kinase independent, whereas its ciliary function is kinase dependent. Mice with mutations in Nek1 or Nek8 have cystic kidneys; therefore, our discovery that a member of this phylogenetic group of Nek proteins is localized to the same sites in Chlamydomonas and kidney epithelial cells suggests that Neks play conserved roles in the coordination of cilia and cell cycle progression