We present preliminary results of a multi-wavelength study focused on the evolution of spiral galaxies in the UV-optical colour-magnitude (CM) diagram. By combining HI, UV and optical observations of the Coma-Abell1367 supercluster we are able to identify galaxies at different stages of their evolution: from healthy star-forming galaxies, to blue HI-poor spirals and transition objects. Our analysis shows that galaxies in the transition region are likely to be the progeny of healthy spirals,

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... e star-formation has been quenched by the harsh cluster environment. This result suggests that, at least in clusters of galaxies, the migration of galaxies from the blue to the red sequence might be due to environmental processes.