Identification of antibiotics for use in selection of the chytrid fungi Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans.

Global amphibian populations are being decimated by chytridiomycosis, a deadly skin infection caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). Although ongoing efforts are attempting to limit the spread of these infections, targeted treatments are necessary to manage the disease. Currently, no tools for genetic manipulation are available to identify and test specific drug targets in these fungi. To facilitate the development of genetic tools in Bd and Bsal, we have tested five commonly used antibiotics with available resistance genes: Hygromycin, Blasticidin, Puromycin, Zeocin, and Neomycin. We have identified effective concentrations of each for selection in both liquid culture and on solid media. These concentrations are within the range of concentrations used for selecting genetically modified cells from a variety of other eukaryotic species.

High-efficiency electroporation of chytrid fungi.

Two species of parasitic fungi from the phylum Chytridiomycota (chytrids) are annihilating global amphibian populations. These chytrid species-Batrachochytrium dendrobatidis and B. salamandrivorans-have high rates of mortality and transmission. Upon establishing infection in amphibians, chytrids rapidly multiply within the skin and disrupt their hosts' vital homeostasis mechanisms. Current disease models suggest that chytrid fungi locate and infect their hosts during a motile, unicellular 'zoospore' life stage. Moreover, other chytrid species parasitize organisms from across the tree of life, making future epidemics in new hosts a likely possibility. Efforts to mitigate the damage and spread of chytrid disease have been stymied by the lack of knowledge about basic chytrid biology and tools with which to test molecular hypotheses about disease mechanisms. To overcome this bottleneck, we have developed high-efficiency delivery of molecular payloads into chytrid zoospores using electroporation. Our electroporation protocols result in payload delivery to between 75 and 97% of living cells of three species: B. dendrobatidis, B. salamandrivorans, and a non-pathogenic relative, Spizellomyces punctatus. This method lays the foundation for molecular genetic tools needed to establish ecological mitigation strategies and answer broader questions in evolutionary and cell biology.

"The Missing Link": The Tubulin Mutation Database Connects Over 1500 Missense Mutations With Phenotypes Across Eukaryotes.

As outlined in their recent paper (A Tubulin Mutation Database: A Resource for the Cytoskeletal Community), Catherine Pham and Naomi Morrissette from the University of California, Irvine, scoured the literature and catalogued data for 489 point mutations for 𝛂-tubulin, 729 for ß-tubulin, and 343 for 𝛄, ẟ, 𝛆, and 𝛇 tubulins to create the tubulin mutation database (http://tubulinmutations.bio.uci.edu). The database is a searchable catalog of missense mutations and phenotypes that is expected to grow with biannual updates. Data entries regarding the species and isoform, as well as links to available sequences and the original study which characterized the mutant are intuitively displayed and color coded (Pham & Morrissette, 2019). This database represents a unique opportunity for clinicians and cell biologists to rapidly connect sequence data to mutant phenotypes and gather primary literature which promises to facilitate discoveries on topics including microtubule dynamics, antimitotic drug use and resistance, and evolution. We expect that many researchers will find this tool of great use to their research. This article is protected by copyright. All rights reserved.