TY - JOUR
T1 - Polyploid polynuclear consecutive cell-cycle enables large genome-size in Haematococcus pluvialis
AU - Reinecke, Diana L.
AU - Castillo-Flores, Antonio
AU - Boussiba, Sammy
AU - Zarka, Aliza
N1 - Funding Information:
This work was supported by the European Union's Seventh Framework Programme (FP7), project GIAVAP, project ID 266401. There are no non-financial competing interests. The funders had no role in study design, data collection and analysis, the decision to publish or preparation of the manuscript.
Funding Information:
This work was supported by the European Union's Seventh Framework Programme (FP7), project GIAVAP, project ID 266401 . There are no non-financial competing interests. The funders had no role in study design, data collection and analysis, the decision to publish or preparation of the manuscript.
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/7/1
Y1 - 2018/7/1
N2 - Studies revealed and keep revealing a staggering diversity of life-cycle patterns and genome-sizes in microalgae. Even within a single order like the Volvocales with Volvox carteri, Chlamydomonas reinhardtii, and Dunaliella salina, differences are significant. Additional knowledge gaps in microalgal physiology and genetics hinder our understanding of their evolution and valorization. Herein, we present for the first time, the multiple fission cell-cycle with corresponding DNA quantities of the economically important Volvocales Haematococcus pluvialis. Further, we provide two straightforward protocols for efficient culture synchronization, based on filtration or skimming of zoospores. The cell-cycle and nuclear DNA content where monitored by flow cytometry and fluorescence microscopy after staining with dsDNA dye PICO- or SYBR-green®. The average nuclear DNA content was 3.6–4.1 and 22.6–25.2 pg in zoospores/coenobial daughter-cells and aplanospores, respectively. We found a single DNA replication step for all coenobial daughter cells prior mitosis, followed by one consecutive cytokinesis. Thus, our results suggest a new Haematococcus-type Cn cell-cycle with unusual polyploid and polynuclear phases. This cell-cycle regime might allow for the large genome-size of Haematococcus and is consistent with the mutational-hazard hypothesis for Volvocales microalgae.
AB - Studies revealed and keep revealing a staggering diversity of life-cycle patterns and genome-sizes in microalgae. Even within a single order like the Volvocales with Volvox carteri, Chlamydomonas reinhardtii, and Dunaliella salina, differences are significant. Additional knowledge gaps in microalgal physiology and genetics hinder our understanding of their evolution and valorization. Herein, we present for the first time, the multiple fission cell-cycle with corresponding DNA quantities of the economically important Volvocales Haematococcus pluvialis. Further, we provide two straightforward protocols for efficient culture synchronization, based on filtration or skimming of zoospores. The cell-cycle and nuclear DNA content where monitored by flow cytometry and fluorescence microscopy after staining with dsDNA dye PICO- or SYBR-green®. The average nuclear DNA content was 3.6–4.1 and 22.6–25.2 pg in zoospores/coenobial daughter-cells and aplanospores, respectively. We found a single DNA replication step for all coenobial daughter cells prior mitosis, followed by one consecutive cytokinesis. Thus, our results suggest a new Haematococcus-type Cn cell-cycle with unusual polyploid and polynuclear phases. This cell-cycle regime might allow for the large genome-size of Haematococcus and is consistent with the mutational-hazard hypothesis for Volvocales microalgae.
KW - Algal genome
KW - Clustered cell-cycle
KW - Culture synchronization
KW - Flow cytometry
KW - Multiple-fission cell-cycle
KW - Mutational hazard hypothesis
UR - http://www.scopus.com/inward/record.url?scp=85049483751&partnerID=8YFLogxK
U2 - 10.1016/j.algal.2018.06.013
DO - 10.1016/j.algal.2018.06.013
M3 - Article
AN - SCOPUS:85049483751
SN - 2211-9264
VL - 33
SP - 456
EP - 461
JO - Algal Research
JF - Algal Research
ER -