Plag1 Regulates Sensorimotor Modulation in Zebrafish.

The zinc finger transcription factor PLAG1 has been implicated in multiple diverse cellular processes, yet its role in the onset of vertebrate neurodevelopment and behaviour remains largely unexplored. Notably, dysregulation of PLAG1 has been associated with Silver-Russell syndrome (SRS) in humans, a growth disorder often presenting with neurodevelopmental delay and craniofacial abnormalities. Here, we investigate the function of plag1 in zebrafish embryogenesis, focusing on behavioural phenotypes, neural development and craniofacial morphogenesis, as a potential novel model of SRS. Using antisense morpholino-mediated knockdown, we assessed the impact of plag1 loss on brain architecture, motor neuron development, craniofacial patterning and stimulus-evoked behavioural responses. While plag1-deficient embryos displayed pronounced locomotor defects when housed in groups, these phenotypes were not recapitulated under isolated, individual tracking conditions, suggesting a role for plag1 in modulating specific behavioural outputs. Morphological analyses revealed no overt disruptions to gross brain structure or primary motor neuron patterning. However, quantitation of craniofacial skeleton formation identified subtle abnormalities in jaw and cranial cartilage development, consistent with features observed in SRS. Furthermore, plag1 morphants exhibited significantly altered responses to sensory stimuli, implicating plag1 in the regulation of sensorimotor integration during early development. Collectively, these findings uncover a novel role for plag1 in early neurobehavioural modulation and craniofacial patterning, phenocopying multiple features of SRS, and highlight the importance of environmental and social context in the phenotypic interpretation of neurodevelopmental gene function.