Diurnal regulation of flagellar size and swimming velocity within the red-tide raphidophyte Chattonella marina

Abstract

The raphidophyte Chattonella marina is a dangerous algal bloom (HAB) species identified for its distinct diurnal vertical migration (DVM), a habits vital for its survival and bloom formation. However, the single-cell mechanisms governing this migration stay unclear. In this research, we investigated the swimming traits of particular person C. marina cells throughout day (mild) and night time (darkish) phases. We noticed a robust constructive correlation between the size of the propulsive anterior flagellum and the cell’s swimming velocity. We found that the size distribution of the anterior flagellum is totally different through the day and at night time. We additionally discovered that the beat frequency of the anterior flagellum was considerably larger through the day in comparison with the night time. This resulted in sooner imply swimming speeds through the mild section. To examine the mechanism of size regulation, we examined the function of intraflagellar transport (IFT) utilizing the IFT dynein inhibitor, ciliobrevin D. Treatment with ciliobrevin D induced a time- and concentration-dependent shortening of the anterior flagellum. This is the primary pharmacological proof to recommend that an IFT-like mechanism might actively management motile flagellar size in C. marina. These findings recommend that C. marina modulates its swimming velocity by diurnal adjustments in each flagellar size and beat frequency, probably as an energy-saving technique coupled to its DVM.