[All-postdocs] Bioseminar 2/10 Fatma Gomaa

[Ana M Velez]

Woods Hole Oceanographic Institution
Biology Department Seminar
Thursday, February 10, 2022 - 12:00 Noon

Dr. Fatma Gomaa
Research Associate, Department Geology and Geophysics, WHOI
Visiting Research Associate, Department of Organismic and Evolutionary Biology, Harvard University

Protist Symbiosis and Metabolic Adaptation to Challenging Environments
Research on protist-bacteria interactions and symbiosis is increasingly relevant as these associations are now known to play important roles in ecosystem and human health. Free-living amoebae are abundant in all environments and are frequent hosts for bacterial endosymbionts including pathogenic bacteria. Here, we use the testate amoeba Arcella spp. as model organisms to investigate the diversity and specificity of Arcella-associated microbial communities using the 16S rRNA amplicon gene sequence. Our results revealed that Arcella host diverse bacterial communities and that the Arcella-bacteria associations appear to be species-specific and distinct from that of the surrounding media.

The benthic foraminifer Nonionella stella dominates the abundant foraminiferal community inhabiting laminated, oxygen depleted and sometimes sulfidic sediments of the Santa Barbara Basin, comprising up to ~80% of the living assemblage, with densities sometimes exceeding 200 specimens per cubic cm.  Gene expression from field-collected and laboratory-incubated samples, showed that N. stella expressed denitrification genes regardless of oxygen regime, and anerobic energy metabolism genes. Our results also revealed, a near-complete expression of a diatom's plastid genome, suggests kleptoplasty, sequestration of functional plastids, conferring a metabolic advantage despite the host living far below the euphotic zone. Benthic foraminifera, through a unique integration of functions largely unrecognized among "typical" eukaryotes, represent winning micro-eukaryotes in the face of ongoing oceanic deoxygenation.

There are many groups of protists known as excellent bioindicators for monitoring ecosystem health. I studied the effect of Arsenic pollution on eukaryotic cell using Ciliate Tetrahymena thermophila as a model organism in laboratory cultures. Transcriptomic data from cells exposed to different concentration of ASIII showed that Arsenic induced changes in gene expression and identified genes and pathways that play roles in AS III metabolism, transportation and detoxification. Our results leverage the use of protists as ecological monitoring and bioremediation.


Zoom https://whoi-edu.zoom.us/j/94719910746 Meeting ID: 947 1991 0746 Passcode: NV%a9e
By dial: Find your local number: https://whoi-edu.zoom.us/u/abqBZh0tam Passcode: 667420
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.whoi.edu/pipermail/all-postdocs/attachments/20220207/b750201e/attachment.htm