The ability to regenerate lost body parts is shared by many animals. Although scientists have been interested in regeneration for a long time, our knowledge of this process remains very limited. With the exception of zebrafish, established genetic model organisms (flies, nematodes, and mammals) have very limited regenerative abilities. During my thesis project, I used the emerging model organism Parhyale hawaiensis and focused on their peripheral sensory organs (sensilla), to explore two fundamental questions of complex organ regeneration: first, how faithful is regeneration in restoring these organs? and second, which are the cellular progenitors of the sensilla during limb regeneration, and what is their developmental potential?
The comparison of the sensilla of regenerated and non-amputated legs of Parhyale revealed that the diversity, distribution, and function of the sensilla are faithfully restored during regeneration. Next, I focused on identifying the progenitors of sensilla cells during regeneration. I improved an existing live imaging and cell tracking technique of limb regeneration and extended it to record the entire course of regeneration. To identify the sensilla cells in these recordings, I tried to generate cell-type-specific reporter animals, first by inserting a reporter into putative marker genes using CRISPR, then by generating cisregulatory element reporters. As neither of these approaches was fruitful, I developed a method to identify cell fates in the regenerating limb via antibody stainings. This is a promising technique to identify the progenitors of different cell types in regenerating limbs.