Session 11

This session was about a collaborative effort to get Retaria genomes with John Burns.

Accessing a near-shore, predictable bloom to sequence the first complete radiolaria genome: preliminary data and collaborative potential.
While radiolarians are predominantly known to inhabit deep-water oligotrophic environments, monitoring over the past six years has revealed the cyclical presence of Plagiacantha sp., a polycystine radiolarian (Order Nasselaria), in Maine's semi-eutrophic Damariscotta River estuary. This species exhibits a distinct bloom cycle from late summer through early fall, with samples collected from shallow (10m) dock waters. Dual quantification methods, plankton net counts and eDNA measurements, reveal concordant bloom dynamics, confirming that this Plagiacantha sp. appears seasonally, develops, enters a reproductive stage and then vanishes from the water column rather than persisting year-round in cryptic forms. Preliminary observations suggest mineralized cells develop from small juveniles (50 microns or less) to large reproductive cells (>100 microns) that each produce hundreds of small (2-3 micron) flagellated swarmers before the species disappears until the following year. These findings establish a 2-3 month developmental timeline for Plagiacantha sp, visible life cycle. While post-swarmer release stages remain uncharacterized, this established timeframe may apply to other radiolarian species, potentially advancing broader understanding of radiolarian biology and life history strategies. The predictable bloom cycle of this Plagiacantha sp. can be harnessed to collect cells for whole genome sequencing of this species. One mechanism to accomplish this would be to pool the resources of many labs, to crowd source this effort so that the first complete radiolarian genome emerges from a community effort rather than a single lab or grant. I will outline my vision for why I think Plagiacantha sp. is a good candidate for genome sequencing and strategies for a collaborative sequencing effort in the second half of the presentation.

Please find in this link the recording of the session.