Horizontal and vertical distribution of Gambierdiscus spp. (Dinophyceae) including novel phylotypes in Japan identified by 18S rDNA metabarcoding

Hiroshi Funaki; Chetan Chandrakant Gaonkar; Takafumi Kataoka; Tomohiro Nishimura; Kouki Tanaka; Ippei Yanagida; Shouta Abe; Haruo Yamaguchi; Keizo Nagasaki; Masao Adachi

doi:10.1016/j.hal.2021.102163

Horizontal and vertical distribution of Gambierdiscus spp. (Dinophyceae) including novel phylotypes in Japan identified by 18S rDNA metabarcoding

Harmful Algae. 2022 Jan:111:102163. doi: 10.1016/j.hal.2021.102163. Epub 2021 Dec 20.

Authors

Affiliations

¹ Laboratory of Aquatic Environmental Science (LAQUES), Faculty of Agriculture and Marine Science, Kochi University, 200 Otsu, Monobe, Nankoku, Kochi, 783-8502, Japan; The United Graduate School of Agricultural Sciences, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime, 790-8566, Japan. Electronic address: hiroshifunakisci@gmail.com.
² Laboratory of Aquatic Environmental Science (LAQUES), Faculty of Agriculture and Marine Science, Kochi University, 200 Otsu, Monobe, Nankoku, Kochi, 783-8502, Japan. Electronic address: chetan.gaonkar@gmail.com.
³ Faculty of Marine Science and Technology, Fukui Prefectural University, 1-1 Gakuen-cho, Obama, Fukui, 917-0003, Japan. Electronic address: kataoka@fpu.ac.jp.
⁴ Laboratory of Aquatic Environmental Science (LAQUES), Faculty of Agriculture and Marine Science, Kochi University, 200 Otsu, Monobe, Nankoku, Kochi, 783-8502, Japan. Electronic address: aquariumuirauqa@gmail.com.
⁵ Usa Marine Biological Institute, Kochi University, 194 Inoshiri, Usa, Tosa, Kochi, 781-1164, Japan. Electronic address: jm-kouki@kochi-u.ac.jp.
⁶ INO, 228 Koja, Okinawa, Okinawa, 904-2161, Japan. Electronic address: okinawa@ino-npo.com.
⁷ Laboratory of Aquatic Environmental Science (LAQUES), Faculty of Agriculture and Marine Science, Kochi University, 200 Otsu, Monobe, Nankoku, Kochi, 783-8502, Japan. Electronic address: shiyouta_abe@pref.okayama.lg.jp.
⁸ Laboratory of Aquatic Environmental Science (LAQUES), Faculty of Agriculture and Marine Science, Kochi University, 200 Otsu, Monobe, Nankoku, Kochi, 783-8502, Japan; The United Graduate School of Agricultural Sciences, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime, 790-8566, Japan. Electronic address: yharuo@kochi-u.ac.jp.
⁹ Faculty of Agriculture and Marine Science, Kochi University, 200 Otsu, Monobe, Nankoku, Kochi, 783-8502, Japan. Electronic address: nagasaki@kochi-u.ac.jp.
¹⁰ Laboratory of Aquatic Environmental Science (LAQUES), Faculty of Agriculture and Marine Science, Kochi University, 200 Otsu, Monobe, Nankoku, Kochi, 783-8502, Japan; The United Graduate School of Agricultural Sciences, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime, 790-8566, Japan. Electronic address: madachi@kochi-u.ac.jp.

PMID: 35016767
DOI: 10.1016/j.hal.2021.102163

Abstract

The genus Gambierdiscus is a marine benthic/epiphytic dinoflagellate considered the causative agent of ciguatera poisoning (CP). Clarifying the geographical distribution of this genus to understand the potential risk of CP is important. Many studies have focused only on the species/phylotype composition of Gambierdiscus in shallow waters, but no study has investigated the species/phylotype composition of the genus in deep waters. In the present study, the distributions of Gambierdiscus species/phylotypes at two depths (2-8 and 30 m) and two sampling sites (temperate and subtropical) in Japan was investigated using high throughput sequencing (HTS) with a newly developed primer set that preferentially amplifies the 18S rDNA V8-V9 region of Alveolata. A phylogenetic analysis using 89 samples collected over three years revealed of ten Gambierdiscus species/phylotypes including not only two species that have not been reported in Japan (G. caribaeus and G. silvae) but also four novel phylotypes (Gambierdiscus spp. Clade II_1, Clade II_2, Clade II_3, and Clade VI_1). Uncorrected genetic distances also supported that these new phylotypes clearly diverged from other Gambierdiscus species. All four new phylotypes, G. caribaeus, and G. silvae were distributed in the subtropical region. Among them, Clade II_2, Clade VI_1, and G. silvae were also distributed in the temperate region. Four species/phylotypes previously reported from Japan showed a similar distribution as reported previously. Among the ten species/phylotypes, Gambierdiscus sp. type 3 and Clade VI_1 were found only in deep waters, whereas five species/phylotypes were observed only in shallow waters. The other three species/phylotypes were found in both deep and shallow waters. The results of the horizontal and vertical distribution suggest that the growth characteristics of each species/phylotypes found in Japan might adapt to the ambient environmental conditions. This study revealed an inclusive assemblage of Gambierdiscus species/phylotypes in Japan through metabarcoding using the Alveolata primer set. In the future, the abundance and toxicities/toxin productions of the newly reported species/phylotypes need to be clarified to understand the mechanism of CP outbreaks in Japan.

Keywords: 18S rDNA; Alveolata primer; Benthic/epiphytic dinoflagellate; Ciguatera poisoning; Gambierdiscus; Metabarcoding.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Ciguatera Poisoning*
DNA, Ribosomal / genetics
Dinoflagellida*
Japan
Phylogeny

Substances

DNA, Ribosomal