Non-random inter-speckle material transfer mediated by dynamic multiphase interchromatin connections.

Dynamic multiphase interchromatin connections mediate non-random transfer of nuclear speckle material across the nucleus.

• Why it matters: Understanding how nuclear speckle components redistribute is crucial for revealing mechanisms that regulate gene expression and cellular responses. The extent of their dynamic redistribution remains unclear, limiting insights into nuclear organization and function.
• What they did: Using live-cell imaging of endogenous nuclear speckle proteins, the study identified an interchromatin network linking speckles and tracked material transfer through curvilinear connections over tens of seconds to minutes, contrasting with current diffusion-based models.
• The result: The findings demonstrate a multiphase, ATP- and transcription-dependent structure that facilitates coordinated inter-speckle protein trafficking, suggesting a cellular mechanism for dynamic nuclear organization.