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The green alga Chlamydomonas reinhardtii is a popular unicellular organism for studying photosynthesis, cilia biogenesis, and micronutrient homeostasis. Ten years since its genome project was initiated an iterative process of improvements to the genome and gene predictions has propelled this organism to the forefront of the omics era. Housed at Phytozome, the plant genomics portal of the Joint Genome Institute (JGI), the most up-to-date genomic data include a genome arranged on chromosomes and high-quality gene models with alternative splice forms supported by an abundance of whole transcriptome sequencing (RNA-Seq) data. We present here the past, present, and future of Chlamydomonas genomics. Specifically, we detail progress on genome assembly and gene model refinement, discuss resources for gene annotations, functional predictions, and locus ID mapping between versions and, importantly, outline a standardized framework for naming genes.

Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the 120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella.

Chlamydomonas reinhardtii, the first alga subject to a genome project, has been the object of numerous morphological, physiological, and genetic studies. The organism has two genetically determined mating types (plus and minus) and all stages of the simple life cycle can be evoked in culture. In the nearly 60 years since the first standard laboratory strains were isolated, numerous crosses and exchanges among laboratories have led to some confusion concerning strain genealogy. Here we use analyses of the nuclear internal transcribed spacer regions and other genetic traits to resolve these issues, correctly identify strains currently available, and analyze phylogenetic relationships with all other available similar chlamydomonad types. The presence of a 10-bp indel in ITS2 in some but not all copies of the nuclear ribosomal cistrons of an individual organism, and the charting ratios of these in crosses, provide a tool to investigate mechanisms of concerted evolution. The standard C. reinhardtii strains, plus C smithii +, plus the new eastern North American C. reinhardtii isolates, comprise one morphological species, one biological species of high sexual intercompatibility, and essentially identical ITS sequences (except the tip of helix I of ITS2). However, variant RFLP patterns characterize strains from each geographic site.

IN BRIEF Individuals with type 2 diabetes have a higher incidence of liver function test abnormalities than individuals who do not have diabetes. Mild chronic elevations of transaminases often reflect [...]

Sequential analysis of chloroplast ribosomes enables a comprehension of the specific domains involved in ribosome function and their function in protein synthesis. Synthesis of proteins begins with the formation of a preinitiation complex followed by peptide chain elongation. This expansion takes place through three steps, including the formation of a peptide bond. The completed protein is released by hydrolyzing the peptidyl-tRNA. The need for this synthesis in cells and synthesis and structures of chloroplast ribosomes are discussed.

Chloroplast recombination events in the chloroplast gene of Chlamydomonas reinhardtii were analyzed using biolistic transformation after sexual crosses. Results indicate that the exchange of genetic materials was not random, rather, it occurs primarily at a 700-base region in the downstream terminus of the psbA gene. Recombination in an adjacent 2 kilobase region was much less frequent. Further studies showed that the direct repeats in the 700-base region were not responsible for the increased incidence of recombination in the region.

Objective: Despite advances in exogenous insulin therapy, many patients with type 1 diabetes do not achieve acceptable glycemic control and remain at risk for ketosis and insulin-induced hypoglycemia. We conducted a randomized controlled trial to determine whether TTP399, a novel hepatoselective glucokinase activator, improved glycemic control in people with type 1 diabetes without increasing hypoglycemia or ketosis.Research Design and Methods: SimpliciT1 was a phase 1b/2 adaptive study. Phase 2 activities were conducted in two parts. Part 1 randomly assigned 20 participants using continuous glucose monitors and continuous subcutaneous insulin infusion (CSII). Part 2 randomly assigned 85 participants receiving multiple daily injections of insulin or CSII. In both parts 1 and 2, participants were randomly assigned to 800 mg TTP399 or matched placebo (fully blinded) and treated for 12 weeks. The primary end point was change in HbA1c from baseline to week 12.Results: The difference in change in HbA1c from baseline to week 12 between TTP399 and placebo was -0.7% (95% CI -1.3, -0.07) in part 1 and -0.21% (95% CI -0.39, -0.04) in part 2. Despite a greater decrease in HbA1c with TTP399, the frequency of severe or symptomatic hypoglycemia decreased by 40% relative to placebo in part 2. In both parts 1 and 2, plasma β-hydroxybutyrate and urinary ketones were lower during treatment with TTP399 than placebo.Conclusions: TTP399 lowers HbA1c and reduces hypoglycemia without increasing the risk of ketosis and should be further evaluated as an adjunctive therapy for the treatment of type 1 diabetes. [ABSTRACT FROM AUTHOR]