Description

​The daf-2 gene encodes an insulin-like growth factor/IGF-1 receptor that regulates C. elegans embryonic and larval development. It has previously been shown that DAF-2 inhibits neurite regeneration of the GABAergic motor neurons and PVD sensory neurons in an age-dependent fashion (Bryne et al., 2014; Kravtsov et al., 2017). Following injury, the posterior lateral microtubule (PLM) neurons are capable of regenerating through axonal fusion, a highly efficient regrowth mechanism in which separated fragments fuse back together (Ghosh-Roy et al., 2010; Neumann et al., 2011; Neumann et al. 2015; Abay et al., 2017). We previously established that a critical event for axonal fusion to occur is the exposure of injury-induced phosphatidylserine (PS) ‘save-me’ signals (Neumann et al., 2015). The level of PS exposed increases with advancing age (Abay et al., 2017). To determine if daf-2 is involved in this age-dependent modulation of PS exposure, we visualised and quantified the level of PS exposed after PLM axotomy using a secreted, tagged version of Annexin V (Neumann et al., 2011; Mapes et al., 2012; Neumann et al. 2015). Mutation of daf-2 had no effect on PS exposure 1 h post-axotomy, with no significant differences observed on either the distal or proximal axon segments (Table 1).​

Table 1. Quantification of the relative level of PS exposed 1 h post-axotomy.