Ashbya gossypii: Difference between revisions
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===Cell Structure=== | ===Cell Structure=== | ||
To the naked eye, ''Ashbya gossypii'' colonies are flat and similar in size and appearance to hair. Under a microscope, they range in color from pale-yellow to vibrant yellow. Their asci, or sexual spore-bearing cells, are long and thin, like thread, and translucent. The ascospores are long and thin as well and also have hooked appendages. [http://www.atcc.org/products/all/10895.aspx#generalinformation]. | |||
===Metabolism=== | ===Metabolism=== |
Revision as of 17:47, 5 December 2013
Classification
Higher Order Taxa:
Fungi, Ascomycota, Saccharomycetes, Saccharomycetales, Saccharomycetaceae
Species:
A. gossypii
Description and Significance
Ashbya gossypii (Eremothecium gossypii) is a filamentous fungus, meaning that it is an infectious agent of the fungus kingdom consisting of a long series of attached cells. It is closely related to unicellular yeasts, especially Saccharomyces cerevisiae, a yeast with which it shares more than 90% of its genome.
Ashbya gossypii is an effective fungus in which to study the growth of long and multinucleate (more than one nucleus) fungal cells. It has a small genome, haploid nuclei, and efficient gene targeting methods, characteristics that make it favorable in studies. Through the work of Professor Peter Philippsen and research team, basic yet essential knowledge was gained on the species which is now applied to problems in medicine and agriculture [1].
In addition, because this fungal species is so closely related to the yeasts (especially Sacharomyces cerevisiae,) it acts as a model for studying regulatory networks. Explorations of these networks reveal the functional differences between filamentous growth and yeast growth. This is important to understanding diseases that affect the environment and humans, such as Candida albicans, a human fungal pathogen [2].
Genome Structure
The genome for Ashbya gossypii is the smallest genome of a free-living eukaryote thus far, coming up to only 9.2 megabases. It contains a total of 4718 protein-coding genes. As mentioned above, more than 90% of its genes are similar to that of Saccharomyces cerevisiae. Importantly, the gene order was conserved (in evolution.)
The comparison of these genes reveals shared homology and synteny (the condition of two or more genes being located on the same chromosome) between the two species.
Professor Peter Philippsen, Ordinarius of Microbiology at the Biozentrum Basel, was the first scientist to fully examine Ashbya Gossypii (a few years they completed the sequencing of the Saccahromyces cerevisiae genome in 1996.)[3] In these explorations of the two species, these scientists were able to find such extensive similarities.
Growth, Cell Structure and Metabolism
Growth
Ashbya gossypii grows isotropically. Its isotropic growth involves the haploid spore's germination and the formation of a germ bubble. Once the germ bubble is formed, two germ tubes grow from opposite sites of the bubble. Apical growth follows, which allows fungi to extend into their environment and release enzymes from the tips for nutrient intake.
Cell Structure
To the naked eye, Ashbya gossypii colonies are flat and similar in size and appearance to hair. Under a microscope, they range in color from pale-yellow to vibrant yellow. Their asci, or sexual spore-bearing cells, are long and thin, like thread, and translucent. The ascospores are long and thin as well and also have hooked appendages. [4].
Metabolism
Ecology
As briefly mentioned under Growth, Ashbya gossypii and fungi in general involve apical growth. This form of growth allows it to extend into fresh zones of substrate, (which its enzymes will erode.) This is especially important for growth when the fungi cells encounter an insoluble polymer such as cellulose, which decreases the organism's rate of enzyme diffusion.
Pathology
Ashbya gossypii is a pathogen in certain crops that causes stigmatomycosis. (Ashby and Novell, 1926.) This fungal disease, discovered in cotton, affects the development of hair cells in cotton bolls. It can then transfer to citrus fruits, causing dry rot disease in which the fruits dry out and collapse.
References
- Jaspersen Lab, 2007. "Sue Jaspersen, Ph.D, Profile." Stowers Institute for Medical Research.
- Biozentrum: The Center for Molecular Life Sciences, 2013. "Election of Peter Philippsen to the Rank of AAAS Fellow, [5]." University of Basel.
- Nature Reviews Microbiology, May 2005 "Ashbya gossypii: A Model for Fungal Developmental Biology." Nature Publishing Group, 2013.
- Gladfelter Lab, 2013. "Nuclear Anarchy: Timing Variability in the Cell Division Cycle." Trustees of Dartmouth College.
- "Ashbya gossypii Ashbya Genome Database," September 2013. EnsemblFungi.
- Jim Deacon, Institute of Cell and Molecular Biology, 2008. The Microbial World: Fungal tip growth and hyphal tropisms. University of Edinbergh.
Edited by Jenna Cartusciello, student of Joan Slonczewski for BIOL 116 Information in Living Systems, 2013, Kenyon College.