Do the shuffle: Changes in Symbiodinium consortia throughout juvenile coral development.

Previous studies of symbiotic associations between scleractinians corals and Symbiodinium have demonstrated that the consortium of symbionts can change in response to environmental conditions. However, less is known about symbiont shuffling during early coral development, particularly in brooding species. This study examined whether Symbiodinium consortia (1) varied in Porites astreoides on shallow (10m) and upper mesophotic (30m) reefs, (2) changed during coral development, and (3) influenced growth of juveniles in different environments.

Molecular evolution of nitrogen assimilatory enzymes in marine prasinophytes.

Nitrogen assimilation is a highly regulated process requiring metabolic coordination of enzymes and pathways in the cytosol, chloroplast, and mitochondria. Previous studies of prasinophyte genomes revealed that genes encoding nitrate and ammonium transporters have a complex evolutionary history involving both vertical and horizontal transmission. Here we examine the evolutionary history of well-conserved nitrogen-assimilating enzymes to determine if a similar complex history is observed.

Gene expression studies for the analysis of domoic acid production in the marine diatom Pseudo-nitzschia multiseries.

Background: Pseudo-nitzschia multiseries Hasle (Hasle) (Ps-n) is distinctive among the ecologically important marine diatoms because it produces the neurotoxin domoic acid. Although the biology of Ps-n has been investigated intensely, the characterization of the genes and biochemical pathways leading to domoic acid biosynthesis has been limited. To identify transcripts whose levels correlate with domoic acid production, we analyzed Ps-n under conditions of high and low domoic acid production by cDNA microarray technology and reverse-transcription quantitative PCR (RT-qPCR) methods.

MOLECULAR EVOLUTION OF GLUTAMINE SYNTHETASE II AND III IN THE CHROMALVEOLATES(1).

Glutamine synthetase (GS) is encoded by three distinct gene families (GSI, GSII, and GSIII) that are broadly distributed among the three domains of life. Previous studies established that GSII and GSIII isoenzymes were expressed in diatoms; however, less is known about the distribution and evolution of the gene families in other chromalveolate lineages. Thus, GSII cDNA sequences were isolated from three cryptophytes (Guillardia theta D.

Characterization of three mnp genes of Fomitiporia mediterranea and report of additional class II peroxidases in the order hymenochaetales.

We report the sequence-based characterization and expression patterns of three manganese peroxidase genes from the white rot fungus and grape vine pathogen Fomitiporia mediterranea (Agaricomycotina, Hymenochaetales), termed Fmmnp1, Fmmnp2, and Fmmnp3. The predicted open reading frames (ORFs) are 1,516-, 1,351-, and 1,345-bp long and are interrupted by seven, four, and four introns, respectively. The deduced amino acid sequences encode manganese peroxidases (EC 1.

Molecular evolution of glutamine synthetase II: Phylogenetic evidence of a non-endosymbiotic gene transfer event early in plant evolution.

Background: Glutamine synthetase (GS) is essential for ammonium assimilation and the biosynthesis of glutamine. The three GS gene families (GSI, GSII, and GSIII) are represented in both prokaryotic and eukaryotic organisms. In this study, we examined the evolutionary relationship of GSII from eubacterial and eukaryotic lineages and present robust phylogenetic evidence that GSII was transferred from gamma-Proteobacteria (Eubacteria) to the Chloroplastida.

UNRAVELING THE REGULATION OF NITROGEN ASSIMILATION IN THE MARINE DIATOM THALASSIOSIRA PSEUDONANA (BACILLARIOPHYCEAE): DIURNAL VARIATIONS IN TRANSCRIPT LEVELS FOR FIVE GENES INVOLVED IN NITROGEN ASSIMILATION(1).

We examined the diurnal expression of five genes encoding nitrogen-assimilating enzymes in the marine diatom Thalassiosira pseudonana (Hust.) Hasle et Heimdal following a transition from NH4 (+) - to NO3 (-) -supplemented media. The accumulation of nia transcripts (encoding nitrate reductase, NR) following the transition to NO3 (-) -supplemented media was similar to previously reported changes in NR abundance and activity.

Hydrophobins Sc3 and Sc4 gene expression in mounds, fruiting bodies and vegetative hyphae of Schizophyllum commune.

An abnormal growth form called mound has been hypothesized to be a neoplasm in the filamentous fungus Schizophyllum commune. An alternative hypothesis is that mounds represent some unusual developmental form in the fruiting body morphogenetic pathway. Hydrophobin proteins have been found in fruiting bodies where they line the surface of gas exchange pores and function to keep the pores hydrophobic.

Evolution of glutamine synthetase in heterokonts: evidence for endosymbiotic gene transfer and the early evolution of photosynthesis.

Although the endosymbiotic evolution of chloroplasts through primary and secondary associations is well established, the evolutionary timing and stability of the secondary endosymbiotic events is less well resolved. Heterokonts include both photosynthetic and nonphotosynthetic members and the nonphotosynthetic lineages branch basally in phylogenetic reconstructions. Molecular and morphological data indicate that heterokont chloroplasts evolved via a secondary endosymbiosis, involving a heterotrophic host cell and a photosynthetic ancestor of the red algae and this endosymbiotic event may have preceded the divergence of heterokonts and alveolates.