• Journal of Species Research
• /
• 제10권2호
• /
• pp.142-153
• /
• 2021

Algal genomics approaches provide a massive number of genome/transcriptome sequences and reveal the evolutionary history vis-à-vis primary and serial endosymbiosis events that contributed to the biodiversity of photosynthetic eukaryotes in the eukaryote tree of life. In particular, phylogenomic methods using several hundred or thousands of genes have provided new insights into algal taxonomy and systematics. Using this method, many novel insights into algal species diversity and systematics occurred, leading to taxonomic revisions. In addition, horizontal gene transfers (HGTs) of functional genes have been identified in algal genomes that played essential roles in environmental adaptation and genomic diversification. Finally, algal genomics data can be used to address the pangenome, including core genes shared among all isolates and partially shared strain-specific genes. However, some aspects of the pangenome concept (genome variability of intraspecies level) conflict with population genomics concepts, and the issue is closely related to defining species boundaries using genome variability. This review suggests a desirable future direction to merge algal pangenomics and population genomics beyond traditional molecular phylogeny and taxonomy.

• ALGAE
• /
• 제21권1호
• /
• pp.1-10
• /
• 2006

Genomic data is accumulating in public database at an unprecedented rate. Although presently dominated by the sequences of metazoan, plant, parasitic, and picoeukaryotic taxa, both expressed sequence tag (EST) and complete genomes of free-living algae are also slowly appearing. This wealth of information offers the opportunity to clarify many long-standing issues in algal and plant evolution such as the contribution of the plastid endosymbiont to nuclear genome evolution using the tools of comparative genomics and multi-gene phylogenetics. A particularly powerful approach for the automated analysis of genome data from multiple taxa is termed phylogenomics. Phylogenomics is the convergence of genomics science (the study of the function and structure of genes and genomes) and molecular phylogenetics (the study of the hierarchical evolutionary relationships among organisms, their genes and genomes). The use of phylogenetics to drive comparative genome analyses has facilitated the reconstruction of the evolutionary history of genes, gene families, and organisms. Here we survey the available genome data, introduce phylogenomic pipelines, and review some initial results of phylogenomic analyses of algal genome data.

• 한국미생물·생명공학회지
• /
• 제34권1호
• /
• pp.1-6
• /
• 2006

Harmful algal blooms (HABs or red tides), caused by uncontrolled proliferation of marine phytoplankton, impose a severe environmental problem and occasionally threaten even public health. We sequenced the genome of an EPS-producing marine bacterium Hahella chejuensis that produces a red pigment with the lytic activity against red-tide dinoflagellates at parts per billion level. H. chejuensis is the first sequenced species among algicidal bacteria as well as in the order Oceanospirillales. Sequence analysis indicated a distant relationship to the Pseudomonas group. Its 7.2-megabase genome encodes basic metabolic functions and a large number of proteins involved in regulation or transport. One of the prominent features of the H. chejuensis genome is a multitude of genes of functional equivalence or of possible foreign origin. A significant proportion (${\sim}23%$) of the genome appears to be of foreign origin, i.e. genomic islands, which encode genes for biosynthesis of exopolysaccharides, toxins, polyketides or non-ribosomal peptides, iron utilization, motility, type III protein secretion and pigment production. Molecular structure of the algicidal pigment was determined to be prodigiosin by LC-ESI-MS/MS and NMR analyses. The genomics-based research on H. chejuensis opens a new possibility for controlling algal blooms by exploiting biotic interactions in the natural environment and provides a model in marine bioprospecting through genome research.

• ALGAE
• /
• 제26권1호
• /
• pp.3-20
• /
• 2011

The physiology of the unicellular green alga Dunaliella salina in response to abiotic stress has been studied for several decades. Early D. salina research focused on its remarkable salinity tolerance and ability, upon exposure to various abiotic stresses, to accumulate high concentrations of $\beta$-carotene and other carotenoid pigments valued highly as nutraceuticals. The simple life cycle and growth requirements of D. salina make this organism one of the large-scale commercially exploited microalgae for natural carotenoids. Recent advances in genomics and proteomics now allow investigation of abiotic stress responses at the molecular level. Detailed knowledge of isoprenoid biosynthesis mechanisms and the development of molecular tools and techniques for D. salina will allow the improvement of physiological characteristics of algal strains and the use of transgenic algae in bioreactors. Here we review D. salina isoprenoid and carotenoid biosynthesis regulation, and also the biotechnological and genetic transformation procedures developed for this alga that set the stage for its future use as a production system.

• 생태와환경
• /
• 제51권1호
• /
• pp.16-28
• /
• 2018

남조류에 대한 오랜 연구로 많은 사실을 알게 되었음에도 여전히 미지의 영역으로 남아있는 부분이 많은데, 분자 생물학에 기반한 오믹스 기술의 발전으로 새로운 도구를 이용한 다른 관점에서의 연구가 최근 활발해지고 있다. 일차적으로는 유전체 염기서열 분석기술을 사용하여 다양한 남조류의 유전체 비교분석과 유전자의 발현 양상을 연구함으로써, 독소 합성의 조절 기작 등 생리적 특성이 나타나는 원리 규명에 많은 노력이 기울여지고 있다. 또한 남조류 유전형의 다양성과 이들이 밀접하게 상호작용하는 박테리아 군집이 계절적 및 환경적 요인에 어떻게 반응하여 변화하고, 이러한 변화가 생태계에는 어떤 영향을 미치는지에 대한 연구가 생물정보학 분석기법과 결합하면서, 생태계의 복잡한 작동방식에 대한 이해도 늘어나고 있다. 특히 다양한 오믹스 기법을 복합 적용함으로써 생태계 안에서 일어나는 모든 층위의 생물학적 반응에 대한 총체적 그림을 그리는 것이 현실화되고 있으며, 이렇게 그려진 설계도로부터 녹조를 효과적으로 제어하고 건강한 수생태계를 유지할 수 있는 새로운 통찰의 가능성에 대한 기대가 고조되고 있다.