A research team led by Professor Chaogu Zheng from @HKUSBS at The University of Hong Kong, in collaboration with scientists from Princeton University and Columbia University, has discovered how sensory-motor circuits — nerve circuits that turn sensory signals into reflex actions — remain reliable even when some genes or neural connections are disrupted. Using the gentle touch reflex of the nematode Caenorhabditis elegans (C. elegans) as a model, the team found that this essential survival response is not controlled by a single biological component. Instead, it is supported by several overlapping mechanisms, including existing alternative neural pathways and molecular components that enable neurons to send and receive signals. These layers of genetic redundancy help maintain the touch response and improve the animal’s ability to escape from predators. The study provides new insight into how nervous systems protect essential behaviours. It shows that robust neural circuits can be built through overlapping genes, synapses, and neural pathways, so that the loss of one component does not necessarily stop the behaviour. “From an evolutionary perspective, the findings suggest that components which appear redundant in a standard laboratory test may still be preserved because they improve survival in real-life situations, such as escaping from predators,” Professor Zheng explained. “In this way, redundancy is not merely a backup system, but part of how neural circuits produce reliable and effective behaviour.”

A new genomic study by researchers from the HKU School of Biological Sciences (SBS) has found that Hong Kong’s introduced population of yellow-crested cockatoos retains unexpectedly high genetic diversity and could serve as a genetic reservoir for this critically endangered species! Hong Kong is home to around 200 Yellow-crested Cockatoos—about 10% of the remaining global population. Although this urban population is small and isolated, it has so far avoided the severe genetic decline often expected in such cases. Some individuals may even carry genetic lineages that have disappeared from parts of the species’ native range in Indonesia. “Hong Kong’s population presents a natural, 60-year test case for the genetic impacts of interbreeding Yellow-crested Cockatoos subspecies,” says Dr Astrid Andersson of HKU SBS, lead author of the study. “Instead of dismissing urban, introduced populations as ecologically redundant, we should view them as a potential ‘Biodiversity Ark’ that can actively help prevent extinction.”