understanding freshwater brown algae using molecular and ...€¦ · references conclusion...
TRANSCRIPT
References
Conclusion
Introduction
Methods
Results
Phylogeny study: phylogeny relationship between different population of P. lacustris were generated and suggested that despite geological distance and isolation of each location, P. lacustris population from North America and Europe are phylogenetically the same. Sporangia Observation: H. fluviatilis on the other hand is quite the opposite. Populations from different locations have been confirmed to be genetically different by previous study. But they are morphologically similar. This study seeks to look for potential morphology differences between North America and Europe population, so far no apparent differences have been observed by this study and further study is needed to continue the investigation.
Phylogeny Study (Pleurocladia lacustris ):
DNA was extracted from both the fresh samples
and the herbarium samples with the GE DNA
Extraction Kit Phytopure. NANOdrop and gel
electrophoresis were used to examine
concentration. Specific primers were designed for
different molecular markers and used for PCR.
Nested PCR was performed for each sample and
the products were examined through gel
electrophoresis. The lyses process was extended
to try to break down the samples even farther for
herbarium samples. DNA was diluted before PCR
to avoid inhibitors. PCR products were sent out for
sequencing. The sequences were edited with
Sequencher 4.9., then aligned with ClustalW.
Maximum likelihood, Maximum parsimony, and
Baysian analysis were used to generate
phylogenetic tree.
Sporangia Observation (Heribaudiella fluviatilis ): Four different media were created with a variety of salinities. 0 ppt (Desmidiacean) , 5 ppt, 10 ppt and 15 ppt concentrations. Samples from North America and Europe were used in 2 replicates for each treatment.
Understanding freshwater Brown Algae using molecular and culture based methods
Kimberly Proenca, Juniata College/ Fordham University
Xian Wang, Fordham University
McCauley , Linda, and John Wehr. "Taxonomic reappraisal of the freshwater
brown algae Bodanella, Ectocarpus, Heribaudiella, and Pleurocladia
(Phaeophyceae) on the basis of rbcL sequences and morphological characters
." Phycologia. 46.4 (2007): 429-439. Print.
Sheth, Robert, Stancheva, Rosalina, Truhn, Kam and Wehr, John,. "Discovery of
the “rare” freshwater brown alga Pleurocladia lacustris (Ectocarpales,
Phaeophyceae) in California streams." Western North American Naturalist. 3.2
(2013): n. page. Print.
Wehr, J. D. (2003). Brown algae. In: Freshwater algae of North America. Ecology
and Classification (Ed. by J. D. Wehr and R. G. Sheath), pp. 757-773.
Academic Press, San Diego, CA.
Pleurocladia lacustris: can be found in fast
moving bodies of water. Its color ranges from olive brown to dark brown. It forms a crust about 1 mm in its natural habitat. Distribution were found in North America, Europe, Australia and the Arctic Ocean. The filaments are lose branched under the microscope.
Heribaudiella fluviatilis: also form dark brown crusts. It usually lives in fast moving bodies of water. It’s found all over the world, but mainly in North America, Europe and Asia. Its filaments and branches are tightly appressed together.
Goals
The number of freshwater brown algae is significantly smaller than its marine counterpart. Although freshwater brown algae has been known for more than 100 years, the taxonomy of them is unclear because of the lack of research.
To gather more information on these species and answer some taxonomic questions. To investigate new morphological differences between Heribaudiella species from different locations in new environments.
Hypothesis
Pleurocladia lacustris populations from different localities are phylogenetically different because of diverse environmental factors and geological isolation: populations from North America and Europe are hypothesized to be phylogenetically different. Heribaudiella fluviatilis will grow Plurilocular sporangia under salt simulation condition in its media.
Phylogeny of Pleurocladia lacustris
Genes used:
Mitochondrial: cox1, cox3, nad1
Plastid: atpB, psaA, psbA, rbcL
mtDNA: nad1
ptDNA : psbA
Sporangia Observation- Week 1 Sporangia Observation- Week 5 European H. fluviatilis N. American H. fluviatilis
0ppt
5ppt
10ppt
15ppt
European H. fluviatilis N. American H. fluviatilis