Presentation on theme: "The Making of a Photosynthetic Animal Group 16: Charlotte Myers, Vy Vu, Wout Moulin, Renata Bade, and Janek Witharana."— Presentation transcript:
The Making of a Photosynthetic Animal Group 16: Charlotte Myers, Vy Vu, Wout Moulin, Renata Bade, and Janek Witharana
Introduction Can animals be photosynthetic? Elysia chlorotica (Sea Slug) Vaucheria litorea (algae)
Elysia chlorotica Scientists discovered kleptoplasts (chloroplasts taken from algae) in digestive tract of Elysia chlorotica Sea slugs photosynthesize by using kleptoplasts to sustain themselves for up to one year Previous experiments have shown that no significant correlation exists between genes of sea slugs and kleptoplasts
Photosynthesis Photosynthesis is the process of converting light energy to chemical energy and storing it in the bonds of sugar. Photosynthesis takes place in chlorophyll- containing plants, algae, and some bacteria.
Experiment Hypothesis: There is a small number of transcripts for nuclear- encoded and plastid- encoded proteins present in slug cells. Meaning: There are little similarities between the host genes and the kleptoplast genes.
Procedure Established a laboratory culture system as a control Optimized an artificial saltwater (ASW) culture system using aposymbiotic eggs The development of the planktotrophic was recorded for all the developing larvae The developing larvae were fed a diet of Isochrysis galbana
Procedure After the larvae underwent metamorphosis the experiment could truly begin because they started eating filamentous alga, which contains plastids. The result of metamorphosis is juvenile sea slugs Some sea slugs ate filamentous alga Another group did not eat filamentous alga
Procedure In adulthood the sea slugs were starved Possible photosynthetic behavior was observed in sea slugs Genes were then compared between the matured sea slugs and chloroplasts
Data Numerous functional chloroplast-encoded sequences were found in the DNA of the Elysia chlorotica One hundred and one chloroplast-encoded protein coding genes were found in the sea slugs transcriptome which matched the sequences found in the Vaucheria litorea.
Data 27 transcript sets found in the Elysia chlorotica were identical to gene coding sequences found in the Vaucheria litorea. Among these were genes involved in photosynthesis, carbon fixation, carbohydrate metabolism, and other processes performed in chloroplasts.
Discussion Contrary to the previous studies -Transcriptome of the slug contains several transcripts for nuclear-encoded algal proteins. Symbiotic chloroplasts are translationally active and a variety of functional algal genes have been transferred into the slug genome.
Conclusion Multiple approaches to kleptoplastic association understanding Temporary function of plastids and photosynthesis Permanent photosynthesis?
Clicker Question Q: Plastids such as chloroplast are eventually digested by the animal, releasing the contents of the chloroplasts’ photosynthetic reactions. In the acidic environment of a stomach, what products will be released upon the digestion of chloroplast? A.Carbohydrates and O 2 B.NADPH and ATP C.CO 2 and O 2 D.NADPH and H 2 O
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