‘Omics & pumping iron Reflections of Symbiodiniaceae trace metal needs in genomic data & molecular estimation of metal uptake via gene expression
How do Symbiodiniaceae pump their iron?
Examination of trace metal profiles (content) revealed substantial differences both within and between Symbiodiniaceae species. However, the extent to which ‘metal acquisition strategy’ influences the differences in these needs is unknown. To correlate the uptake of trace metals (Fe, Mn, Cu, Zn, Ni, Co, Mo) with transporters and metalloenzymes, I generated transcriptomes for 5 Symbiodiniaceae species exposed to 3 iron concentrations (spanning from sufficient to sparse conditions; see Reich 2020). The identification of transcripts associated with 1) iron stress and 2) metal transport allows for the creation of molecular iron stress indices and metal uptake estimations. Furthermore, these indices will allow for additional detection of iron stress that may have been overlooked in previous transcriptomic studies. This project is in collaboration with bioinformatics wizards Caleb Butler & Stankiewicz!
The Acropora-Symbiodinium ‘fitti’ case study
The blossoming ‘omics era provides heaps of data for interrogating the blueprint of Symbiodiniaceae trace metal demands. My ‘rotation’ in the Baums Lab (in collaboration with Dr. Sheila Kitchen) resulted in a draft Symbiodinium ‘fitti’ (ITS2 type A3) genome assembly and create a SNP-list (Single Nucleotide Polymorphism) that reveals fine-scale differences between S. ‘fitti’ from its different host associations and geographic distribution. With the help of ~58,000 SNPs, we discovered that the fine-scale genomic differentiation of S. ‘fitti’ was largely by host association. These SNPs likely facilitate adaptation to the subtly different lifestyles dictated by different light environments in addition to putative biochemical and nutritional demands of each acroporid host. Moreover, the matching of selection outliers to metalloenzymes corroborates the importance of trace metals to Symbiodiniaceae diversification, co-evolution and adaptation to the lifestyle under many layers of host plasma membrane.