Complex sentence: Mutations or deletions of clock gene in mice have demonstrated the importance of body clocks to ensure the proper timing of cellular/metabolic events; clock mutant mice are hyperphagic, obese and have altered glucose metabolism.
Split into simpler sentences: Mutations or deletions of clock gene in mice have demonstrated the importance of our body clocks to ensure the proper timing of cellular/metabolic events. Clock mutant mice are hyperphagic, obese and have altered glucose metabolism.