The number of growing microtubules and nucleus-nucleus interactions uniquely regulate nuclear movement in Drosophila muscle

Nuclear movement is a fundamental process of eukaryotic cell biology. Skeletal muscle presents an intriguing model to study nuclear movement because its development requires the precise positioning of multiple nuclei within a single cytoplasm. Furthermore, there is a high correlation between aberrant nuclear positioning and poor muscle function. Although many genes that regulate nuclear movement have been identified, the mechanisms by which these genes act is not known. Using Drosophila melanogaster muscle development as a model system, and a combination of live-embryo microscopy and laser ablation of nuclei, we have found that phenotypically similar mutants are based in different molecular disruptions. Specifically, ensconsin (Drosophila MAP7) regulates the number of growing microtubules that are used to move nuclei whereas bocksbeutel (Drosophila emerin) and klarsicht (Drosophila KASH-protein regulate interactions between nuclei.