Date of Award
12-1995
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Ocean Engineering and Marine Sciences
First Advisor
Kerry B. Clark
Second Advisor
Russel C. Weigel
Third Advisor
Alan B. Brown
Fourth Advisor
Gary N. Wells
Abstract
The retention by ascoglossan sea slugs of photosynthetically functional algal chloroplasts (kleptoplastids) has been the subject of intense study over the past three decades. The question of whether kleptoplastids are capable of de novo chlorophyll biosynthesis was seemingly answered by Trench and Smith (1970) and Trench et al. (1973), who found no 14C uptake into chlorophylls in the ascoglossans, Elvsia viridis and E. crispata, after brief radioisotope incubations. However, Clark and Waugh (unpub.) demonstrated some 14C uptake into chlorophyll in CQStasiqlla ocellifera, a long-term kleptoplasad retainer, which promoted a re-analysis of these experiments. In order to prove the occurrence of de novo chlorophyll biosynthesis, Q.ocellifera. the short-term kleptoplastid retainers E. tuca and CQSfasielH sp., and Avrainvillea nigricans, the algal food of £• ocellifera, were separately incubated with 0.1 pCi 44C-labeled glutamic acid for a starvation period of 5 d. The kleptoplastid retention level of CdStasiellg sp. Was determined in a starvation experiment. After 48 and 120 h incubation, kleptoplastid pigments were extracted and separated with silica-gel thin layer chromatography and assayed for 14C incorporation (DPM/jig chl). Obvious 14C incorporation into chlorophyll occurred in £ (Xellifgra and E. iusa, but was generally absent in CPStasie"a sp. Statistical analyses were additionally performed to test whether individual HC-chlorophyll peaks were significant relative to sample means, and whether incubation period affected uptake. 14C-chlorophyll was significant in three of five E. iuca samples (p< .05 to p< .0025, single sample t-Test) and after 120 h incubation (p< .0125, paired two-group t-Test). Pooled counts from both incubations indicated significant overall 14C uptake into chlorophyll (p< .0125). Significant 14Cchlorophyll occurred in all five £. ocellifgra samples (p< -05 to p< .0025) and after 48 h incubation (p< .0125). Pooled counts indicated significant 14C uptake into chlorophyll (p< .05). Significant 44C-chlorophyll occurred in three of five Costasiella sp. samples (p< .025 to p< .0025) and after 48 h incubation (p< .05), but overall uptake was insignificant. Costasi
Recommended Citation
Swatski, Robert Joseph, "Chlorophyll Biosynthesis In Kleptoplastid Symbioses" (1995). Theses and Dissertations. 1570.
https://repository.fit.edu/etd/1570
