Publications by authors named "Karen N Pelletreau"

Helping faculty develop high-quality instruction that positively affects student learning can be complicated by time limitations, a lack of resources, and inexperience using student data to make iterative improvements. We describe a community of 16 faculty from five institutions who overcame these challenges and collaboratively designed, taught, iteratively revised, and published an instructional unit about the potential effect of mutations on DNA replication, transcription, and translation. The unit was taught to more than 2000 students in 18 courses, and student performance improved from preassessment to postassessment in every classroom.

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Sacoglossan sea slugs offer fascinating systems to study the onset and persistence of algal-plastid symbioses. Elysia chlorotica is particularly noteworthy because it can survive for months, relying solely on energy produced by ingested plastids of the stramenopile alga Vaucheria litorea that are sequestered in cells lining its digestive diverticula. How this animal can maintain the actively photosynthesizing organelles without replenishment of proteins from the lost algal nucleus remains unknown.

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We conducted a study of 19 biology instructors participating in small, local groups at six research-intensive universities connected to the Automated Analysis of Constructed Response (AACR) project (www.msu.edu/∼aacr).

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Some sea slugs are capable of retaining functional sequestered chloroplasts (kleptoplasts) for variable periods of time. The mechanisms supporting the maintenance of these organelles in animal hosts are still largely unknown. Non-photochemical quenching (NPQ) and the occurrence of a xanthophyll cycle were investigated in the sea slugs Elysia viridis and E.

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The establishment of kleptoplasty (retention of "stolen plastids") in the digestive tissue of the sacoglossan Elysia chlorotica Gould was investigated using transmission electron microscopy. Cellular processes occurring during the initial exposure to plastids were observed in laboratory raised animals ranging from 1-14 days post metamorphosis (dpm). These observations revealed an abundance of lipid droplets (LDs) correlating to plastid abundance.

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The sea slug Elysia chlorotica offers a unique opportunity to study the evolution of a novel function (photosynthesis) in a complex multicellular host. Elysia chlorotica harvests plastids (absent of nuclei) from its heterokont algal prey, Vaucheria litorea. The "stolen" plastids are maintained for several months in cells of the digestive tract and are essential for animal development.

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The molluscan sea slug Elysia chlorotica is best known for its obligate endosymbiosis with chloroplasts (= kleptoplasty) from its algal prey Vaucheria litorea and its ability to sustain itself photoautotrophically for several months. This unusual photosynthetic sea slug also harbors an array of undescribed bacteria, which may contribute to the long-term success of the symbiosis. Here, we utilized 16S rDNA-based metagenomic analyses to characterize the microbial diversity associated with two populations of E.

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Symbiotic animals containing green photobionts challenge the common perception that only plants are capable of capturing the sun's rays and converting them into biological energy through photoautotrophic CO(2) fixation (photosynthesis). 'Solar-powered' sacoglossan molluscs, or sea slugs, have taken this type of symbiotic association one step further by solely harboring the photosynthetic organelle, the plastid (=chloroplast). One such sea slug, Elysia chlorotica, lives as a 'plant' when provided with only light and air as a result of acquiring plastids during feeding on its algal prey Vaucheria litorea.

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Phosphoribulokinase (PRK), a nuclear-encoded plastid-localized enzyme unique to the photosynthetic carbon reduction (Calvin) cycle, was cloned and characterized from the stramenopile alga Vaucheria litorea. This alga is the source of plastids for the mollusc (sea slug) Elysia chlorotica which enable the animal to survive for months solely by photoautotrophic CO2 fixation. The 1633-bp V.

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