Claudio Slamovits

Author's posts

Mini-synplastomes for plastid genetic engineering

In the age of synthetic biology, plastid engineering requires a nimble platform to introduce novel synthetic circuits in plants. While effective for integrating relatively small constructs into the plastome, plastid engineering via homologous recombination of transgenes is over thirty-years-old. Here we show the design-build-test of a novel synthetic genome structure that does not disturb the native plastome: the “mini-synplastome.” The mini-synplastome was inspired by dinoflagellate plastome…

Development of the Myzozoan Aquatic Parasite Perkinsus marinus as A Versatile Experimental Genetic Model Organism

The phylum Perkinsozoa is an aquatic parasite lineage that has devastating effects on commercial and natural mollusc populations, and also comprises parasites of algae, fish and amphibians. They are related to dinoflagellates and apicomplexans and thus offer excellent genetic models for both parasitological and evolutionary studies. Genetic transformation was previously achieved for Perkinsus spp. but with few tools for transgene expression and limited selection efficacy. We sought to expand the…

The cell wall polysaccharides of a photosynthetic relative of apicomplexans, Chromera velia

Chromerids are a group of alveolates, found in corals, that show peculiar morphological and genomic features. These organisms are evolutionary placed in-between symbiotic dinoflagellates and parasitic apicomplexans. There are two known species of chromerids: Chromera velia and Vitrella brassicaformis. Here, the biochemical composition of C. velia cell wall was analyzed. Several polysaccharides adorn this structure, with glucose being the most abundant monosaccharide (approx. 80%) and…

Spatial organization of dinoflagellate genomes: novel insights and remaining critical questions

As is true for many other aspects, genome architecture, evolution, and function in dinoflagellates are enigmatic and, in the meantime, continuous inspiration for scientific quests. Recent third-generation sequencing and Hi-C linkage analyses brought new insights into the spatial organization of symbiodiniacean genomes, revealing the topologically associated domains, discrete gene clusters and their cis and trans orientations, and relationships with transcription. Where do these new findings…

RNA-Seq analysis reveals potential regulators of programmed cell death and leaf remodelling in lace plant (Aponogeton madagascariensis)

BMC Plant Biol. 2021 Aug 13;21(1):375. doi: 10.1186/s12870-021-03066-7. ABSTRACT BACKGROUND: The lace plant (Aponogeton madagascariensis) is an aquatic monocot that develops leaves with uniquely formed perforations through the use of a developmentally regulated process called programmed cell death (PCD). The process of perforation formation in lace plant leaves is subdivided into several developmental stages: pre-perforation, …

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A Global Approach to Estimating the Abundance and Duplication of Polyketide Synthase Domains in Dinoflagellates

Many dinoflagellate species make toxins in a myriad of different molecular configurations but the underlying chemistry in all cases is presumably via modular synthases, primarily polyketide synthases. In many organisms modular synthases occur as discrete synthetic genes or domains within a gene that act in coordination thus forming a module that produces a particular fragment of a natural product. The modules usually occur in tandem as gene clusters with a syntenic arrangement that is often…

Shifts in amino acid preferences as proteins evolve: a synthesis of experimental and theoretical work

Protein Sci. 2021 Jul 28. doi: 10.1002/pro.4161. Online ahead of print. ABSTRACT Amino acid preferences vary across sites and time. While variation across sites is widely accepted, the extent and frequency of temporal shifts are contentious. Our understanding of the drivers of amino acid preference change is incomplete: To what extent are temporal shifts driven …

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Identification of a Metacaspase Gene in the Bloom-Forming Dinoflagellate Prorocentrum minimum and its Putative Function Involved in Programmed Cell Death

Programmed cell death (PCD) in dinoflagellates has been introduced as a new concept that facilitates the demise of harmful algal blooms. Metacaspases (MCAs) play a role in PCD, but their function in dinoflagellates is unclear. Here, we cloned a novel MCA gene (PmMCA) from the harmful dinoflagellate Prorocentrum minimum and examined its molecular characteristics and gene expression during cell death. The gene was encoded in the nuclear genome with two introns. The putative protein contained 288…

Coral symbionts evolved a functional polycistronic flavodiiron gene

Photosynthesis in cyanobacteria, green algae, and basal land plants is protected against excess reducing pressure on the photosynthetic chain by flavodiiron proteins (FLV) that dissipate photosynthetic electrons by reducing O(2). In these organisms, the genes encoding FLV are always conserved in the form of a pair of two-type isozymes (FLVA and FLVB) that are believed to function in O(2) photo-reduction as a heterodimer. While coral symbionts (dinoflagellates of the family Symbiodiniaceae) are…

Genomics and transcriptomics yields a system-level view of the biology of the pathogen Naegleria fowleri

CONCLUSIONS: In-depth analysis of Naegleria genomes and transcriptomes provides a model of cellular systems involved in opportunistic pathogenicity, uncovering new angles to understanding the biology of a rare but highly fatal pathogen.