TY - JOUR

T1 - The smallest known heliozoans are the erebor lineage (Nom. clad. n.) inside microheliella maris (eukaryota, diaphoretickes), with the amendation of m. maris diagnosis and description of berkeleyaesol magnus gen. nov., comb. nov. (eukaryota, incertae sedis)

AU - Shishkin, Yegor

AU - Drachko, Daria

AU - Zlatogursky, Vasily V.

N1 - Publisher Copyright: © 2021 The Authors. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/4/22

Y1 - 2021/4/22

N2 - A new strain of planktonic heliozoans (ZI172) belonging to the genus Microheliella (the sister group of Cryptista in Diapho-retickes), closely related to the only one known strain of Microheliella maris (CCAP 1945/1), was studied with light microscopy and SSU rRNA gene sequencing. Morphometric data obtained from 127 cells and based on 254 measurements showed that this strain represents the smallest heliozoan (1.66–3.42 µm, av. 2.56 µm) in diameter known to date and one of the smallest free-living eukaryotes. We also did morphometry for strain CCAP 1945/1. Its cell body size is 3.20–6.47 µm (av. 4.15 µm; n=141; m=282). The secondary structures of hairpin 15 of the SSU rRNA molecules were reconstructed for ZI172 and CCAP 1945/1 and they were compared The possible biochemical explanation for the smaller size of the ZI172 strain, which is smaller than the CCAP 1945/1 strain, is discussed, including all published electron micrographs of CCAP 1945/1. The necessary taxonomic work is also carried out. The diagnosis of Microheliella maris is amended and the new infraspecific clade Erebor is described to include ZI172. The measurements and systematics of the enigmatic heliozoan ‘Raphidiophrys’ magna O’Donoghue 1922 (non 1921; the biggest known heliozoan) are also discussed and it is transferred to the new genus Berkeleyaesol.

AB - A new strain of planktonic heliozoans (ZI172) belonging to the genus Microheliella (the sister group of Cryptista in Diapho-retickes), closely related to the only one known strain of Microheliella maris (CCAP 1945/1), was studied with light microscopy and SSU rRNA gene sequencing. Morphometric data obtained from 127 cells and based on 254 measurements showed that this strain represents the smallest heliozoan (1.66–3.42 µm, av. 2.56 µm) in diameter known to date and one of the smallest free-living eukaryotes. We also did morphometry for strain CCAP 1945/1. Its cell body size is 3.20–6.47 µm (av. 4.15 µm; n=141; m=282). The secondary structures of hairpin 15 of the SSU rRNA molecules were reconstructed for ZI172 and CCAP 1945/1 and they were compared The possible biochemical explanation for the smaller size of the ZI172 strain, which is smaller than the CCAP 1945/1 strain, is discussed, including all published electron micrographs of CCAP 1945/1. The necessary taxonomic work is also carried out. The diagnosis of Microheliella maris is amended and the new infraspecific clade Erebor is described to include ZI172. The measurements and systematics of the enigmatic heliozoan ‘Raphidiophrys’ magna O’Donoghue 1922 (non 1921; the biggest known heliozoan) are also discussed and it is transferred to the new genus Berkeleyaesol.

KW - Axopodial protists

KW - Biggest heliozoan

KW - ICPN, International Code of Phylogenetic Nomenclature

KW - ICZN, International Code

KW - Light microscopy

KW - Raphidiophrys magna

KW - Smallest heliozoan

KW - SSU rRNA secondary structure. Abbreviations: CCAP, Culture Collection of Algae and Protozoa, UK

KW - RNA

KW - biggest heliozoan

KW - SEAVIEW

KW - MOLECULAR PHYLOGENY

KW - smallest heliozoan

KW - SEQUENCE ALIGNMENT

KW - SSU rRNA secondary structure

KW - axopodial protists

KW - light microscopy

UR - http://www.scopus.com/inward/record.url?scp=85104564074&partnerID=8YFLogxK

U2 - 10.1099/ijsem.0.004776

DO - 10.1099/ijsem.0.004776

M3 - Article

C2 - 33886450

AN - SCOPUS:85104564074

VL - 71

JO - International Journal of Systematic and Evolutionary Microbiology

JF - International Journal of Systematic and Evolutionary Microbiology

SN - 1466-5026

IS - 4

M1 - 004776

ER -