Green microalga conserves substrate uptake pattern but changes their metabolic uses across trophic transition.

The terrestrial green alga is an emerging model species with potential applications including production of triacylglycerol or astaxanthin. How interacts with the diverse substrates during trophic transitions is unknown. To characterize its substrate utilization and secretion dynamics, we cultivated the alga in a soil-based defined medium in transition between conditions with and without glucose supplementation.

The 'photosynthetic C pathway' links carbon assimilation and growth in California poplar.

Although primarily studied in relation to photorespiration, serine metabolism in chloroplasts may play a key role in plant CO fertilization responses by linking CO assimilation with growth. Here, we show that the phosphorylated serine pathway is part of a 'photosynthetic C pathway' and demonstrate its high activity in foliage of a C tree where it rapidly integrates photosynthesis and C metabolism contributing to new biomass via methyl transfer reactions, imparting a large natural C-depleted signature. Using CO-labelling, we show that leaf serine, the S-methyl group of leaf methionine, pectin methyl esters, and the associated methanol released during cell wall expansion during growth, are directly produced from photosynthetically-linked C metabolism, within minutes of light exposure.

Iron rescues glucose-mediated photosynthesis repression during lipid accumulation in the green alga Chromochloris zofingiensis.

Energy status and nutrients regulate photosynthetic protein expression. The unicellular green alga Chromochloris zofingiensis switches off photosynthesis in the presence of exogenous glucose (+Glc) in a process that depends on hexokinase (HXK1). Here, we show that this response requires that cells lack sufficient iron (-Fe).

Magnetic field coupling with lunar soil simulants.

Wireless power transfer (WPT) using magnetically coupled resonators is being integrated into space vehicles destined for the lunar surface. The dusty soil on the Moon, called lunar regolith, is known to adhere to surfaces and is also known to contain iron, including iron oxides and metallic iron. Regolith samples are limited, and lunar soil simulants are commonly used in space science research for efforts in surface vehicle navigation, in-situ resource utilization, and power infrastructure.

Widespread polycistronic gene expression in green algae.

Polycistronic gene expression, common in prokaryotes, was thought to be extremely rare in eukaryotes. The development of long-read sequencing of full-length transcript isomers (Iso-Seq) has facilitated a reexamination of that dogma. Using Iso-Seq, we discovered hundreds of examples of polycistronic expression of nuclear genes in two divergent species of green algae: and Here, we employ a range of independent approaches to validate that multiple proteins are translated from a common transcript for hundreds of loci.

Hexokinase is necessary for glucose-mediated photosynthesis repression and lipid accumulation in a green alga.

Global primary production is driven largely by oxygenic photosynthesis, with algae as major contributors. The green alga reversibly switches off photosynthesis in the presence of glucose in the light and augments production of biofuel precursors (triacylglycerols) and the high-value antioxidant astaxanthin. Here we used forward genetics to reveal that this photosynthetic and metabolic switch is mediated by the glycolytic enzyme hexokinase (CzHXK1).

Regulation of Oxygenic Photosynthesis during Trophic Transitions in the Green Alga .

Light and nutrients are critical regulators of photosynthesis and metabolism in plants and algae. Many algae have the metabolic flexibility to grow photoautotrophically, heterotrophically, or mixotrophically. Here, we describe reversible Glc-dependent repression/activation of oxygenic photosynthesis in the unicellular green alga We observed rapid and reversible changes in photosynthesis, in the photosynthetic apparatus, in thylakoid ultrastructure, and in energy stores including lipids and starch.

Subdiffraction-resolution live-cell imaging for visualizing thylakoid membranes.

The chloroplast is the chlorophyll-containing organelle that produces energy through photosynthesis. Within the chloroplast is an intricate network of thylakoid membranes containing photosynthetic membrane proteins that mediate electron transport and generate chemical energy. Historically, electron microscopy (EM) has been a powerful tool for visualizing the macromolecular structure and organization of thylakoid membranes.

RNA Purification from the Unicellular Green Alga, .

is a unicellular green alga that is an emerging model species for studies in fields such as biofuel production, ketocarotenoid biosynthesis and metabolism. The recent availability of a high-quality genome assembly facilitates systems-level analysis, such as RNA-Seq. However, cells of this alga have a tough cell wall, which is a challenge for RNA purification.

Chromosome-level genome assembly and transcriptome of the green alga illuminates astaxanthin production.

Microalgae have potential to help meet energy and food demands without exacerbating environmental problems. There is interest in the unicellular green alga , because it produces lipids for biofuels and a highly valuable carotenoid nutraceutical, astaxanthin. To advance understanding of its biology and facilitate commercial development, we present a chromosome-level nuclear genome, organelle genomes, and transcriptome from diverse growth conditions.

Telepractice for pediatric Dysphagia: a case study.

A closed-ended intensive pediatric swallowing telepractice program was developed and piloted in one pediatric patient with Opitz BBB/G and Asperger's Syndromes, oropharyngeal dysphagia and aerophagia. The present study is a case report. Outcome variables included behavioral, swallowing and quality of life variables, and were assessed at baseline and at the end of the four-week program.

The engine of the reef: photobiology of the coral-algal symbiosis.

Coral reef ecosystems thrive in tropical oligotrophic oceans because of the relationship between corals and endosymbiotic dinoflagellate algae called Symbiodinium. Symbiodinium convert sunlight and carbon dioxide into organic carbon and oxygen to fuel coral growth and calcification, creating habitat for these diverse and productive ecosystems. Light is thus a key regulating factor shaping the productivity, physiology, and ecology of the coral holobiont.

Life history changes in coral fluorescence and the effects of light intensity on larval physiology and settlement in Seriatopora hystrix.

Fluorescence is common in both coral adult and larval stages, and is produced by fluorescent proteins that absorb higher energy light and emit lower energy light. This study investigated the changes of coral fluorescence in different life history stages and the effects of parental light environment on larval fluorescence, larval endosymbiotic dinoflagellate abundance, larval size and settlement in the brooding coral Seriatopora hystrix. Data showed that coral fluorescence changed during development from green in larvae to cyan in adult colonies.

Effects of cold stress and heat stress on coral fluorescence in reef-building corals.

Widespread temperature stress has caused catastrophic coral bleaching events that have been devastating for coral reefs. Here, we evaluate whether coral fluorescence could be utilized as a noninvasive assessment for coral health. We conducted cold and heat stress treatments on the branching coral Acropora yongei, and found that green fluorescent protein (GFP) concentration and fluorescence decreased with declining coral health, prior to initiation of bleaching.

Cold induces acute stress but heat is ultimately more deleterious for the reef-building coral Acropora yongei.

Climate change driven increases in intensity and frequency of both hot and cold extreme events contribute to coral reef decline by causing widespread coral bleaching and mortality. Here, we show that hot and cold temperature changes cause distinct physiological responses on different time scales in reef-building corals. We exposed the branching coral Acropora yongei in individual aquaria to a ± 5°C temperature change.

Green fluorescent protein regulation in the coral Acropora yongei during photoacclimation.

Reef-building corals inhabit high light environments and are dependent on photosynthetic endosymbiotic dinoflagellates for nutrition. While photoacclimation responses of the dinoflagellates to changes in illumination are well understood, host photoacclimation strategies are poorly known. This study investigated fluorescent protein expression in the shallow-water coral Acropora yongei during a 30 day laboratory photoacclimation experiment in the context of its dinoflagellate symbionts.

Red fluorescent protein responsible for pigmentation in trematode-infected Porites compressa tissues.

Reports of coral disease have increased dramatically over the last decade; however, the biological mechanisms that corals utilize to limit infection and resist disease remain poorly understood. Compromised coral tissues often display non-normal pigmentation that potentially represents an inflammation-like response, although these pigments remain uncharacterized. Using spectral emission analysis and cryo-histological and electrophoretic techniques, we investigated the pink pigmentation associated with trematodiasis, infection with Podocotyloides stenometre larval trematode, in Porites compressa.

Local selection and latitudinal variation in a marine predator-prey interaction.

Although pairs of species often interact over broad geographic ranges, few studies have explored how interactions vary across these large spatial scales. Surveys along 1500 kilometers of the Pacific coast of North America documented marked variation in the frequency of predation by the snail Nucella canaliculata on the intertidal mussel Mytilus californianus. Laboratory rearing experiments suggest that regional differences in drilling behavior have a genetic basis, and mitochondrial sequence variation confirms that gene flow is low among these snail populations.