TY - GEN T1 - daf-2 modulates regeneration of mechanosensory neurons I AU - Abay, Zehra C AU - Wong, Michelle Yu-Ying AU - Neumann, Brent DO - 10.17912/W2XD3R UR - https://www.micropublication.org/journals/biology/w2xd3r/ AB - Caenorhabditis elegans (C. elegans) possess the ability to spontaneously regenerate injured axons via a highly efficient mechanism known as axonal fusion (Ghosh-Roy, et al., 2010; Neumann et al., 2011; Neumann et al., 2015; Abay et al., 2017). Following laser axotomy, regrowth from the proximal axon segment (still attached to the cell body) reconnects and fuses with its separated distal segment (Fig. 1A). We recently demonstrated that the level of axonal fusion increases with age (Abay et al., 2017). The daf-2 gene encodes an insulin-like growth factor/IGF-1 receptor that has previously been shown to inhibits neurite regeneration in an age-dependent fashion (Bryne et al., 2014; Kravtsov et al., 2017). To determine if DAF-2 functions in a similar fashion in the mechanosensory neurons to mediate the age-dependent modulation of axonal regrowth and axonal fusion, we studied axonal regeneration in the posterior lateral microtubule (PLM) neurons of animals carrying the daf-2(e1370) mutation. daf-2 mutants displayed significantly reduced regrowth of PLM specifically at the final larval stage (L4), and in seven-day-old adults (A7) (Fig. 1B). Mutation of daf-2 also reduced the level of reconnection in A7 animals, but had no effect at other ages (Fig. 1C). The level of successful axonal fusion was not affected by the daf-2 mutation at any age. As daf-2 also mediates age-dependent changes in retraction length after transection of motor neurons (Byrne et al., 2014), we next quantified the length of retraction between the severed ends of the PLM axon. The length of retraction significantly decreased in L4 stage daf-2 mutants, but was unchanged in adult stages (Fig. 1D). The average number of branches was reduced in daf-2(e1370) animals across all ages analysed, with significant reductions observed in A5 and A7 animals (Fig. 1E). ​ PY - 2017 PB - microPublication Biology ER -