Fig. 3: Toxic effects on larval crawling behaviour and mortality in Drosophila melanogaster are specific to the secreted Aβ42 isoform.
From: Amyloid-beta induces distinct forms of cell death in different neuronal populations
A Schematic representing the differences in the Aβ being expressed by neurons using the nSyb driver in our tested strains. In the ‘No Aβ’ strain the PENK secretory peptide is expressed without any attached Aβ, so no Aβ is being expressed or secreted in the neurons [White]. In the ‘Secreted hAβ42’ strain, human Aβ42 is attached to the PENK secretory peptide so it is produced and released from neurons [Pink]. In the ‘Secreted hAβ40’ strain, the shorter, non-toxic human Aβ40 is attached to the PENK secretory peptide so it is produced and released from neurons [Yellow]. In the ‘Non-secreted hAβ42’ strain, human Aβ42 is expressed without the PENK secretory peptide so it is produced but not released from neurons [Blue]. B Images showing the right hemisphere from the dissected CNS of later third instar Drosophila larvae (L3) fixed and stained with Aβ42 primary antibody and Alexa 488 secondary antibody [Green]. Pink boxed panel highlights localisation of Aβ42 staining at neuronal soma (some indicated with closed white arrows) and punctate-like staining at neuronal axons in the CNS neuropil (some indicated with open white arrows) from larvae secreting hAβ42 neuronally using an nSyb driver. Other panels show that there is no labelling of Aβ42 in the CNS when the nSyb driver is used to drive neuronal expression of no Aβ [White] or secreted hAβ40 [Yellow], and staining appears homogeneously expressed in neurons with non-secreted hAβ42 [Blue]. C Survival curves of Drosophila expressing nSyb to drive neuronal expression of no Aβ [Black], secreted hAβ42 [Pink], secreted hAβ40 [Yellow] and non-secreted hAβ42 [Blue]. D Distance travelled (mm) during 1 min of second instar larval crawling in Drosophila expressing nSyb to drive neuronal expression of no Aβ [Black], secreted hAβ42 [Pink], secreted hAβ40 [Yellow] and non-secreted hAβ42 [Blue]. E Mean velocity (mm/s) for 1 min of second instar larval crawling in Drosophila expressing nSyb to drive neuronal expression of no Aβ [Black], secreted hAβ42 [Pink], secreted hAβ40 [Yellow] and non-secreted hAβ42 [Blue]. F Mean displacement (mm) after 1 min of second instar larval crawling in Drosophila expressing nSyb to drive neuronal expression of no Aβ [Black], secreted hAβ42 [Pink], secreted hAβ40 [Yellow] and non-secreted hAβ42 [Blue].
