CPB Student Research Grant Winner – Neal Callaghan

Investigating cuttlefish arm regeneration in Portugal!

I was pleasantly surprised to be awarded a CPB section Student Research Grant from the Canadian Society of Zoologists in the spring of 2018. With this award, I traveled to Universidad do Algarve in Faro, Portugal, with a team of researchers from Canada (Bill Driedzic from Memorial University, Tyson MacCormack from Mount Allison University, and Simon Lamarre from Université de Moncton). We collaborated with the lab of Antonio Sykes, who maintains an experimental aquaculture facility, for a series of projects concerning the physiology of juvenile cuttlefish. Our group was able to complete studies on the metabolism underlying the jetting movements of cephalopods, as well as the development of excitation-contraction coupling in their mantle muscle.

With the support of CPB, I carried out a small pilot study to investigate the capacity of cuttlefish to regenerate an amputated arm. Regeneration in different species generally follows one of two paradigms; in the first, cells proximal to the area of injury in an animal are regressed to a less quiescent, proliferative state and they can replace damaged or missing tissue. In the second, circulating and putatively multipotent satellite cells are recruited to the site of injury, and undertake pathways that resemble those found in early development to replace the tissue. My goal was to characterize the morphological progression of the regenerating limb, and to broadly define the nature of the pathways by which the arm was replaced. Our results are very exciting, suggesting that the cuttlefish invokes early developmental pathways to regenerate its arm, and that the transcription factors involved may prove to be of particular use in a new regenerative model. Although I hope to follow up further, our manuscript from this effort has just been published in the Journal of Experimental Zoology B (https://doi.org/10.1002/jez.b.22849), which is the same journal that published one of the earliest descriptions of cephalopod limb regeneration in incredible detail (with 39 meticulously hand-drawn figures!) 99 years ago (Lange MM. 1920. On the regeneration and finer structure of the arms of the cephalopods. J Exp Zool 31,1).