Novel nematode species, a relative of model organisms, discovered at the university research station

Tsukuba, Japan—Nematodes, a diverse group of invertebrates, are believed to rival or even surpass insects in species count that have over a million known species. Phylum Nematoda includes harmful (parasites, agricultural, and forestry pests) and beneficial species (biocontrol materials, model organisms). However, with less than 30,000 identified species, our understanding on nematode diversity is incomplete. Hence, continuous collection from various environments is likely to reveal new, potentially, valuable species.

In this study, nematode diversity surveys were conducted at the Sugadaira Research Station, Mountain Science Center, University of Tsukuba (Ueda City, Nagano Prefecture), located in a high-altitude, cold region. The aim was to identify nematode species consistently detected in the soil-dwelling, eusocial bee, Halictus (Seladonia) aerarius.

The nematode discovered was identified as a new species of the Pristionchus genus, an omnivorous nematode used as a model system in genome evolution, self-recognition, and developmental plasticity studies a phenomenon in which body structures change in response to the environment. Detailed morphological observations and molecular phylogenetic analysis led to its description as Pristionchus seladoniae.

P. seladoniae exhibits physiological traits, such as unstable growth on E. coli medium, commonly used for other Pristionchus nematodes, and a lack of plasticity under culture conditions. Its ecological traits include continuous detection from soil bees and clumping on culture media, indicative of hypoxia adaptation. The species has potential to be studied in the fields of genome biology, physiology, and environmental adaptation studies as a comparative material (satellite model) with model species.

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This study was supported in part by the Grants-in-Aid for Scientific Research Nos 20H03026, 23K23953 and 23K17381 from the Japan Society for the Promotion of Science.

_{Original Paper}

Title of original paper:
Pristionchus seladoniae n. sp. (Diplogastridae) isolated from a eusocial soil-dwelling bee, Halictus (Seladonia) aerarius, in Nagano, Japan

Journal:
Nematology

DOI:
10.1163/15685411-bja10326

_{Correspondence}

Associate Professor DEGAWA, Yousuke
Institute of Life and Environmental Sciences, University of Tsukuba / Sugadaira Research Station, Mountain Science Center, University of Tsukuba

Senior Researcher KANZAKI, Natsumi
Kansai Research Center, Forestry and Forest Products Research Institute (FFPRI)

_{Related Link}

Institute of Life and Environmental Sciences
Sugadaira Research Station