The realm of diatoms is an intricate and compelling one, with these minuscule organisms being substantially influenced by a variety of internal and external factors. There has been longstanding interest among scientists in the dynamics of diatom blooms, and there is now significant progress being made in comprehending how population density is regulated at a molecular level.
A recent investigation, spearheaded by Prof. Wang Guangce from the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS), has brought to light the role of the marine diatom SLC24A in perceiving and governing population density signals. The findings, which were published in The ISME Journal, offer crucial insights into the ecological implications of diatom population dynamics.
The research team utilized advanced gene editing technology to target potential genes implicated in density signaling, ultimately pinpointing the central hub gene PtSLC24A. Through the use of CRISPR/Cas9 gene editing, they successfully generated two PtSLC24A knockout mutants of Phaeodactylum tricornutum, a type of marine diatom. Intriguingly, their results indicated that cell density could induce Ca2+ responses, and the knockout of PtSLC24A increased intracellular Ca2+ concentration.
Furthermore, the study revealed that high density could induce cell apoptosis, and the knockout of PtSLC24A exacerbated this phenomenon. The researchers also found that PtSLC24A influenced the expression of density-dependent genes at different cell densities. These findings highlight the pivotal role of SLC24A-mediated Ca2+ signaling in mediating density-dependent responses in natural marine ecosystems.
Bolstering the ecological relevance of SLC24A, its ubiquitous distribution across the Tara Oceans sites was highlighted, with expression patterns positively correlating with chlorophyll content in different marine phytoplankton taxa. This underscores the critical role of SLC24A in the ecological balance of marine ecosystems.
Moreover, drawing on data from molecular genetics, cell physiology, computational structural biology, and in situ marine data, the study proposes a model suggesting that PtSLC24A on the cell membrane facilitates the efflux of intracellular Ca2+ in response to chemical cues carrying population density signals, thereby aiding in regulating physiological processes and ultimately impacting the fate of the population.
The ramifications of this study are wide-ranging, with the depiction of a Ca2+-mediated intracellular signaling transduction mechanism facilitated by PtSLC24A not only enhancing our understanding of diatom bloom dynamics, but also having profound implications for the high-density cultivation of microalgae for industrial applications.
In conclusion, this research underscores the burgeoning potential of gene editing technology in elucidating the complexities of natural systems and furnishes valuable insights into the delicate balance of marine ecosystems. This breakthrough brings us one step closer to comprehending the intricate world of diatoms and the implications of their population dynamics on marine life.
For further details, the study “SLC24A-mediated calcium exchange as an indispensable component of the diatom cell density-driven signaling pathway” can be accessed in The ISME Journal. The study was conducted by the Chinese Academy of Sciences and was published in 2024.