@article {zhang_intense_2022,
	title = {Intense blooms of Phaeocystis globosa in the South China Sea are caused by a unique {\textquotedblleft}giant-colony{\textquotedblright} ecotype},
	journal = {Harmful Algae},
	volume = {114},
	year = {2022},
	pages = {102227},
	abstract = {The haptophyte Phaeocystis globosa, an important causative agent of harmful algal blooms globally, exhibits varying morphological and physiological features and high genetic diversity, yet the relationship among these has never been elucidated. In this study, colony sizes and pigment profiles of 19 P. globosa isolates from the Pacific and Atlantic Oceans were determined. Genetic divergence of these strains was analyzed using the chloroplast rbcS-rpl27 intergenic spacer, a novel high-resolution molecular marker. Strains could be divided into four genetic clades based on these sequences, or two groups based on colony size and the identity of diagnostic pigments (19{\textquoteright}-hexanoyloxyfucoxanthin, hex-fuco, and 19{\textquoteright}-butanoyloxyfucoxanthin, but-fuco). Three strains from the South China Sea (SCS), all belonging to the same genetic clade, have unique biological features in forming giant colonies and possessing but-fuco as their diagnostic pigment. Based on these findings, we propose that these SCS strains should be a unique {\textquotedblleft}giant-colony{\textquotedblright} ecotype of P. globosa. During the period 2016-2021, more than 1000 rbcS-rpl27 sequences were obtained from 16 P. globosa colony samples and 18 phytoplankton samples containing solitary P. globosa cells in the SCS. Phylogenetic analysis indicated that >95\% of the sequences from P. globosa colonies in the SCS were comprised of the {\textquotedblleft}giant-colony{\textquotedblright} ecotype, whereas the genetic diversity of solitary cells was much higher. Results demonstrated that intense blooms of P. globosa featuring giant colonies in the SCS were mainly caused by this giant-colony P. globosa ecotype.},
	keywords = {ecotype, genetic diversity, Giant colony, Marker pigment, RCC1736, RCC2055, RCC678, RCC736},
	issn = {1568-9883},
	doi = {10.1016/j.hal.2022.102227},
	url = {https://www.sciencedirect.com/science/article/pii/S1568988322000555},
	author = {Zhang, Qing-Chun and Liu, Chao and Wang, Jin-Xiu and Kong, Fan-Zhou and Niu, Zhuang and Xiang, Ling and Yu, Ren-Cheng}
}
@article {Kamikawa2015,
	title = {Multiple losses of photosynthesis in Nitzschia (Bacillariophyceae)},
	journal = {Phycological Research},
	volume = {63},
	year = {2015},
	note = {tex.mendeley-tags: rcc},
	pages = {19{\textendash}28},
	abstract = {In order to obtain insights into the evolution of colorless (apochlorotic) diatoms, we investigated newly established apochlorotic strains of Nitzschia spp. using light and electron microscopy and molecular phylogenetic analyses. Fluores- cence microscopic observations demonstrated that the apochlorotic diatoms lack chlorophylls. Transmission electron microscopy of two apochlorotic strains also demonstrated that their plastids lacked thylakoids; instead, having four- membrane-bound organelles without thylakoids, similar to nonphotosynthetic plastid remnants. From the apochlorotic strains, we also found plastid small subunit rRNA genes that were unusually long branched in phylogenetic analyses, as observed in other nonphotosynthetic plastids. Molecular phylogenetic analysis of the nucleus-encoded large subunit rRNA genes showed eight distinct lineages for apochlo- rotic diatoms. The eight apochlorotic lineages were not monophyletic, suggesting that the loss of photosynthesis took place multiple times independently within Nitzschia. Several diatoms, including Nitzschia spp., are mixotrophic, which is an expected mode of nutrition that would help explain the evolutionary switch from a photosynthetic lifestyle to a heterotrophic lifestyle. Key},
	keywords = {apochlorotic diatoms, genetic diversity, large subunit rrna, molecular phylogenetic analysis, nonphotosynthetic plastids, plastid 16s rrna, rcc},
	issn = {13220829},
	doi = {10.1111/pre.12072},
	url = {http://doi.wiley.com/10.1111/pre.12072},
	author = {Kamikawa, Ryoma and Yubuki, Naoji and Yoshida, Masaki and Taira, Misaka and Nakamura, Noriaki and Ishida, Ken-ichiro and Leander, Brian S. and Miyashita, Hideaki and Hashimoto, Tetsuo and Mayama, Shigeki and Inagaki, Yuji}
}
@article {Rocap2002,
	title = {Resolution of Prochlorococcus and Synechococcus ecotypes by using 16S-23S ribosomal DNA internal transcribed spacer sequences},
	journal = {Applied and Environmental Microbiology},
	volume = {68},
	number = {3},
	year = {2002},
	note = {tex.mendeley-tags: RCC,rcc},
	pages = {1180{\textendash}1191},
	abstract = {Cultured isolates of the marine cyanobacteria Prochlorococcus and Synechococcus vary widely in their pigment compositions and growth responses to light and nutrients, yet show greater than 96\% identity in their 16S ribosomal DNA (rDNA) sequences. In order to better define the genetic variation that accompanies their physiological diversity, sequences for the 16S-23S rDNA internal transcribed spacer (ITS) region were determined in 32 Prochlorococcus isolates and 25 Synechococcus isolates from around the globe. Each strain examined yielded one ITS sequence that contained two tRNA genes. Dramatic variations in the length and G+C content of the spacer were observed among the strains, particularly among Prochlorococcus strains. Secondary-structure models of the ITS were predicted in order to facilitate alignment of the sequences for phylogenetic analyses. The previously observed division of Prochlorococcus into two ecotypes (called high and low-B/A after their differences in chlorophyll content) were supported, as was the subdivision of the high-B/A ecotype into four genetically distinct clades. ITS-based phylogenies partitioned marine cluster A Synechococcus into six clades, three of which can be associated with a particular phenotype (motility, chromatic adaptation, and lack of phycourobilin). The pattern of sequence divergence within and between clades is suggestive of a mode of evolution driven by adaptive sweeps and implies that each clade represents an ecologically distinct population. Furthermore, many of the clades consist of strains isolated from disparate regions of the world{\textquoteright}s oceans, implying that they are geographically widely distributed. These results provide further evidence that natural populations of Prochlorococcus and Synechococcus consist of multiple coexisting ecotypes, genetically closely related but physiologically distinct, which may vary in relative abundance with changing environmental conditions.},
	keywords = {Divinyl Chlorophyll a, genetic diversity, Marine Cyanobacterium Synechococcus, Multiple Evolutionary Origins, North Atlantic, Nucleotide Sequence, rcc, Region, Rna Operon, sargasso sea, Water Column},
	doi = {10.1128/AEM.68.3.1180-1191.2002},
	author = {Rocap, G and Distel, D L and Waterbury, J B and Chisholm, S W}
}
