Diel cell cycle analysis of Heterosigma akashiwo (Raphidophyceae) with special reference to vertical migration behavior

Lee, Juyun; Han, Moonsik; Chang, Man

doi:10.5176/2251-3140_2.1.19

Cited by 5 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In raphidophytes, H. akashiwo and C. antiqua, blue light receptor AUREO has been postulated to be a strong candidate gene that mediates their DVM behavior (Shikata et al, 2013(Shikata et al, , 2015. However, it was reported that upward migration of the cells started at 3 h before dawn under 14: 10 h LD cycle in Masan Bay (Lee et al, 2012), in agreement with our own observation (data not shown). In addition, previous reports showed that the light-induced function of AUREO seems to activate target gene expression through AUREO dimer formation, which enhanced affinity for target DNA sequence (Hisatomi et al, 2014).…”

Section: Diel Rhythm Of Haaureo1 Gene Expression and Potential Effectorssupporting

confidence: 85%

“…In two raphidophytes H. akashiwo and Chattonella antiqua, Shikata et al (2015) observed that these species required (blue) light to regulate diurnal vertical migration (DVM), which plays an important role on HAB development and formation. Moreover, light signals are also highly effective in controlling cyst germination, cell survival and accumulation, and cellular division in H. akashiwo (Doran and Cattolico, 1997;Lee et al, 2012;Shikata et al, 2007). In other stramenopiles algae such as diatoms, xanthophytes, and phaeophytes, BL also promotes germination of resting cells, modifies their growth and behavior, and controls their cell division (Huysman et al, 2010;Ishikawa et al, 2012;Kataoka, 1990;Kropf, 1992;Mercado et al, 2004;Shikata et al, 2009Shikata et al, , 2015Takahashi et al, 2001).…”

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

Identification and expression analysis of blue light receptor aureochrome in the harmful alga Heterosigma akashiwo (raphidophyceae)

Lin

et al. 2017

Harmful Algae

View full text Add to dashboard Cite

Section: Diel Rhythm Of Haaureo1 Gene Expression and Potential Effectorssupporting

confidence: 85%

Section: Introductionmentioning

confidence: 97%

Identification and expression analysis of blue light receptor aureochrome in the harmful alga Heterosigma akashiwo (raphidophyceae)

Lin

et al. 2017

Harmful Algae

View full text Add to dashboard Cite

“…In this study, the genes involved in DNA replication and cell division were also found to be regulated between morning and afternoon. It has been found that cell division of H. akashiwo occurs near the dark–light transition (Kohata and Watanabe, ; Lee et al ., ). Consistent with this, we found that the cell concentration increased rapidly later in the dark phase (Supporting Information Fig.…”

Section: Discussionmentioning

confidence: 97%

“…For instance, the diurnal vertical migration behaviour in H. akashiwo is regulated by light and dark cycles (Shikata et al, 2015). Moreover, previous research shows that the cell cycle of H. akashiwo is also regulated by photoperiods, where DNA synthesis and cell division occur at daylight and night respectively (Lee et al, 2012). However, it is still unclear which of those investigated environmental factors is at play in a bloom and how H. akashiwo adapts to the changing light and dark cycle, especially what molecular mechanisms or biochemical processes are involved remain unresolved.…”

Section: Introductionmentioning

confidence: 99%

Metatranscriptome analysis reveals environmental and diel regulation of a Heterosigma akashiwo (raphidophyceae) bloom

Lin

et al. 2018

Environmental Microbiology

View full text Add to dashboard Cite

Despite numerous laboratory studies on physiologies of harmful algal bloom (HAB) species, physiologies of these algae during a natural bloom are understudied. Here, we investigated a bloom of the raphidophyte Heterosigma akashiwo in the East China Sea in 2014 using metabarcode (18S rDNA) and metatranscriptome sequencing. Based on 18S rDNA analyses, the phytoplankton community shifted from high diversity in the pre-bloom stage to H. akashiwo predominance during the bloom. A sharp decrease in ambient dissolved inorganic phosphate and strong up-regulation of phosphate and dissolved organic phosphorus (DOP) uptake genes, including the rarely documented (ppGpp)ase, in H. akashiwo from pre-bloom to bloom was indicative of rapid phosphorus uptake and efficient utilization of DOP that might be a driver of the H. akashiwo bloom. Furthermore, observed up-regulated expression of mixotrophy-related genes suggests potential contribution of mixotrophy to the bloom. Accelerating photosynthetic carbon fixation was also implied by the up-regulation of carbonic anhydrase genes during the bloom. Notably, we also observed a strong morning-to-afternoon shift in the expression of many genes. Our findings provide insights into metabolic processes likely important for H. akashiwo bloom formation, and suggest the need to consider timing of sampling in field studies on this alga.

show abstract

“…Approximately 8,000 cells were transferred to a microfuge tube containing beads and the lysis buffer from the PowerSoil® DNA Isolation Kit. Sampling was performed 3 h after the lights were turned on in order to only obtain G1 phase cells [ 32 ]. DNA extraction of the vegetative cells was performed using the same process as for the cysts and then diluted 40-fold in TE buffer (10 mM Tris-HCl, 1.0 mM EDTA, pH 8) to match the concentration of the cyst DNA for standard curves construction.…”

Section: Methodsmentioning

confidence: 99%

An Improved Quantitative Real-Time PCR Assay for the Enumeration of Heterosigma akashiwo (Raphidophyceae) Cysts Using a DNA Debris Removal Method and a Cyst-Based Standard Curve

Kim

Wang

et al. 2016

PLoS ONE

Self Cite

View full text Add to dashboard Cite

The identification and quantification of Heterosigma akashiwo cysts in sediments by light microscopy can be difficult due to the small size and morphology of the cysts, which are often indistinguishable from those of other types of algae. Quantitative real-time PCR (qPCR) based assays represent a potentially efficient method for quantifying the abundance of H. akashiwo cysts, although standard curves must be based on cyst DNA rather than on vegetative cell DNA due to differences in gene copy number and DNA extraction yield between these two cell types. Furthermore, qPCR on sediment samples can be complicated by the presence of extracellular DNA debris. To solve these problems, we constructed a cyst-based standard curve and developed a simple method for removing DNA debris from sediment samples. This cyst-based standard curve was compared with a standard curve based on vegetative cells, as vegetative cells may have twice the gene copy number of cysts. To remove DNA debris from the sediment, we developed a simple method involving dilution with distilled water and heating at 75°C. A total of 18 sediment samples were used to evaluate this method. Cyst abundance determined using the qPCR assay without DNA debris removal yielded results up to 51-fold greater than with direct counting. By contrast, a highly significant correlation was observed between cyst abundance determined by direct counting and the qPCR assay in conjunction with DNA debris removal (r2 = 0.72, slope = 1.07, p < 0.001). Therefore, this improved qPCR method should be a powerful tool for the accurate quantification of H. akashiwo cysts in sediment samples.

show abstract

Diel cell cycle analysis of Heterosigma akashiwo (Raphidophyceae) with special reference to vertical migration behavior

Cited by 5 publications

References 0 publications

Identification and expression analysis of blue light receptor aureochrome in the harmful alga Heterosigma akashiwo (raphidophyceae)

Identification and expression analysis of blue light receptor aureochrome in the harmful alga Heterosigma akashiwo (raphidophyceae)

Metatranscriptome analysis reveals environmental and diel regulation of a Heterosigma akashiwo (raphidophyceae) bloom

An Improved Quantitative Real-Time PCR Assay for the Enumeration of Heterosigma akashiwo (Raphidophyceae) Cysts Using a DNA Debris Removal Method and a Cyst-Based Standard Curve

Contact Info

Product

Resources

About