Thank you very much for the question! Unfortunately, we do not have our own experience with Cre-based techniques in combination with optogenetics, so I cannot advice on this point.

However, if the goal is to express and activate these tools in specific cell types, alternative approaches could involve using cell type-specific promoters or targeted construct delivery using cell type specific vectors such as AAVs.

One thing to keep in mind is that different cell types vary in their sensitivity to different forms of cell death due to differential expression of downstream effectors (such as Gasdermins, MLKL etc) or endogenous regulatory mechanisms (such as post-translational modifications, protein-protein interactions etc) acting on optogenetic tools.

Why there are so many forms of cell death in nature is really an excellent question. The short answer is that we still do not know; however, a plausible explanation is that these various forms of cell death likely play a different role in homeostasis and host defence by 1) sensing different triggers or disruptions of internal environment, 2) being engaged in different tissues or cell types, and 3) providing different outcomes, such as "silent" elimination of old or damaged cells vs regeneration vs proinflammatory response, etc. For example, apoptosis is typically perceived as non-inflammatory form of cell death which is responsible for daily homeostatic cell turnover or is engaged in developmental context, while pyroptosis and necroptosis are typically activated in "danger" context, such as injury or infection, and are known to trigger massive proinflammatory response. Other forms of cell death, such as ferroptosis, have less clear physiological significance.

In my Webinar, I will address your other points about how we can control these forms of cell death with optogenetics and how we can use these tools to gain useful insights into both cell death itself and its contribution in tissue homeostasis and disease.

This is an excellent question, I will address this point in my presentation.

Thank you very much for the question! We do not have an experience combining optogenetics and MRI imaging. However, based on scientific literature, there are approaches to combine these two techniques, such as: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4941940/. In principle, this could be also used for optogenetic activation of cell death or other processes.

We never tested our tools in plant or fungal cells, but I would expect these techniques to be fully applicable. The only bottleneck would be the construct delivery and expression in these cell types, as well as compatibility with downstream effectors (such as caspases or gasdermins).

This depends on the protein you want to control. There is a number of optogenetic tools which enable control of membrane channels or receptors via conformational switch, homo- or heterodi(oligo)merization or recruitment of interaction partners. Selection of the optimal tool depends on 1) the activation mechanism of the protein you want to control, 2) cell type or tissue of interest and experimental setup (for example, some cell types have low tolerance of violet or blue light, and performing experiments in thicker samples might benefit from using red or far-red light-activated receptors), and 3) availability of endogenous cofactors for your photoreceptor in your model organism.

Thanks a lot for the question! I will address advantages and disadvantages of using optogenetics in my webinar, but in brief, one of the most significant advantages is the superior spatiotemporal control: you can target the specific cell (or group of cells) in a very defined moment of time.

So-called neuronal (or opsin) optogenetics is extremely signifiant in behavioural research, as it enables highly targeted activation or inhibition of specific neuronal populations combined with simultaneous behavioral assesment. Optogenetic induction of cell death could also be used in neuroscience to study effect of specific types of cell death in neuroinflammation and neurodegeneration or to assess behavioural impact following targeted elimination of neuronal populations.