Motor defects in a Drosophila model for spinal muscular atrophy result from SMN depletion during early neurogenesis

Journal article

(A) The Drosophila developmental stages. Drosophila go through two major rounds of neurogenesis during embryogenesis, in which the larval nervous system is set up, and during the larval stage, in which the adult neurons and glia are formed (these mature during metamorphosis and early adult life); (B) Smnx7/SmnA embryos were collected and the number of hatched larvae scored for each genotype and normalised to numbers observed from control Smnx7/+. Fewer Smnx7/SmnA larvae hatched from embryos at 25°C and 20°C (error bars [SEM] represent three experiments, each with n > 90; ***P Smnx7/SmnA larvae survived for a median of 3 and 4 days in a developmentally immature state when kept at 25°C and 20°C, respectively (error bars [SEM] represent three experiments, each with n > 60, *P Smnx7/+ and smnx7/smnA trans-heterozygous larvae aged 5 days; (E) counts of EdU-containing foci in the thoracic ganglion over 72 h for larvae kept at 25°C and 20°C. At both temperatures, Smnx7/SmnA failed to show an increase in EdU incorporation. (**P P n = 15 per genotype; Kruskal–Wallis test with Dunn’s multiple comparisons); (F and G) body wall contractions were scored at 0, 24 and 48 h after hatching over a 1-min period at (F) 25°C and (G) 20°C. Smnx7/SmnA larvae underwent significant contraction defects at 48 h at both 25°C (***P n = 36) and 20°C (**P n = 36). All error bars [SEM]Scale bar = 20 μm.

Authors: Grice, SJ; Liu, J-L

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Public Library of Science
• Journal: PLoS Genetics
• Volume: 18
• Issue: 7
• Pages: e1010325-e1010325
• Publication date: 2022-07-25
• DOI: 10.1371/journal.pgen.1010325
• EISSN: 1553-7404
• ISSN: 1553-7390
• Language: English
• Keywords: Spinal muscular atrophy; Neurogenesis; SMN1; Motor neuron; Spinal cord; Neuroblast; Gene; Biology; SMA*; Genetics; Gene knockdown; Neuroscience