AUTHOR=Zhang Mengjia , Cui Zongmei , Liu Feng , Chen Nansheng 

TITLE=Definition of a High-Resolution Molecular Marker for Tracking the Genetic Diversity of the Harmful Algal Species Eucampia zodiacus Through Comparative Analysis of Mitochondrial Genomes

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.631144

DOI=10.3389/fmicb.2021.631144

ISSN=1664-302X

ABSTRACT=<p>The cosmopolitan phytoplankton species <italic>Eucampia zodiacus</italic> is a common harmful algal bloom (HAB) species that have been found to cause HABs in essentially all coastal regions except the Polar regions. However, molecular information for this HAB species is limited with only a few molecular markers. In this project, we constructed the mitochondrial genome (mtDNA) of <italic>E. zodiacus</italic>, which was also the first mtDNA constructed for any species in the order Hemiaulales that includes 145 reported species (including two additional HAB species <italic>Cerataulina bicornis</italic> and <italic>Cerataulina pelagica</italic>). Comparative analysis of eight <italic>E. zodiacus</italic> strains revealed that they could not be distinguished using common molecular markers, suggesting that common molecular markers do not have adequate resolution for distinguishing <italic>E. zodiacus</italic> strains. However, these <italic>E. zodiacus</italic> strains could be distinguished using whole mtDNAs, suggesting the presence of different genotypes due to evolutionary divergence. Through comparative analysis of the mtDNAs of multiple <italic>E. zodiacus</italic> strains, we identified a new molecular marker <italic>ezmt1</italic> that could adequately distinguish different <italic>E. zodiacus</italic> strains isolated in various coastal regions in China. This molecular marker <italic>ezmt1</italic>, which was ∼400 bp in size, could be applied to identify causative genotypes during <italic>E. zodiacus</italic> HABs through tracking the dynamic changes of genetic diversity of <italic>E. zodiacus</italic> in HABs.</p>