Master's Defensio

23.11.2022

Iulia Barutia

Building legs: a morphological investigation of leg development and regeneration in post-embryonic stages of Scutigera coleoptrata (Chilopoda)

Advisor: Thomas Schwaha

Master's Defensio

Wednesday, November 23rd 2022, 11:30 am CET
SR 1.3, UBB
Djerassiplatz 1, 1030 Vienna

Abstract

Arthropod regeneration is mostly limited to appendages and, if present, depends on factors such as the molting cycle and the developmental stage. It is often associated with a preferred breakage point (PBP) and a diaphragm that prevents bleeding. The degree to which arthropods can regenerate varies greatly. Most arthropods undergo multiple molting cycles before a leg is regenerated, whereas some achieve that within one molting cycle. Scutigera coleotprata (Myriapoda) can fully regenerate all 30 legs after only one molt. This study focuses on the morphological aspects of its appendage regeneration, compared to anamorphic development, its timing and limitations, and the role the diaphragm and the PBP have in wound healing and regeneration. S. coleptrata has a PBP between the trochanter and prefemur and possesses a complex diaphragm in the trochanter. Regeneration occurs only if the leg was lost before a critical point during the intermolt. The regenerate grows coiled inside the old coxa between the cuticle and epidermis of the body wall. The morphogenesis of the regenerating and the developing leg show separate temporal patterns, suggesting different regulatory mechanisms. Moreover, the anatomical adaptations that play key roles in the speed of S. coleoptrata are possibly also related to its regeneration. Having a long lifespan, progressive and incomplete regeneration, as seen in most other arthropods, would be extremely disadvantageous. It is thus crucial for an arthropod which, owing to its ecological niche greatly depends on its agility, to be able to fully restore its locomotory system throughout its life, and to do so as quickly as possible.