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Báo cáo y học: "Rapid chromosome territory relocation by nuclear motor activity in response to serum removal in primary human fibroblasts"

Tham khảo luận văn - đề án 'báo cáo y học: "rapid chromosome territory relocation by nuclear motor activity in response to serum removal in primary human fibroblasts"', luận văn - báo cáo phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Mehta et al. Genome Biology 2010 11 R5 http genomebiology.eom 2010 11 1 R5 w Genome Biology RESEARCH Open Access Rapid chromosome territory relocation by nuclear motor activity in response to serum removal in primary human fibroblasts Ishita S Mehtal Manelle Amira 1 2 Amanda J Harvey2 and Joanna M Bridger 1 Abstract Background Radial chromosome positioning in interphase nuclei is nonrandom and can alter according to developmental differentiation proliferation or disease status. However it is not yet clear when and how chromosome repositioning is elicited. Results By investigating the positioning of all human chromosomes in primary fibroblasts that have left the proliferative cell cycle we have demonstrated that in cells made quiescent by reversible growth arrest chromosome positioning is altered considerably. We found that with the removal of serum from the culture medium chromosome repositioning took less than 15 minutes required energy and was inhibited by drugs affecting the polymerization of myosin and actin. We also observed that when cells became quiescent the nuclear distribution of nuclear myosin 1p was dramatically different from that in proliferating cells. If we suppressed the expression of nuclear myosin ip by using RNA-interference procedures the movement of chromosomes after 15 minutes in low serum was inhibited. When high serum was restored to the serum-starved cultures chromosome repositioning was evident only after 24 to 36 hours and this coincided with a return to a proliferating distribution of nuclear myosin 1p. Conclusions These findings demonstrate that genome organization in interphase nuclei is altered considerably when cells leave the proliferative cell cycle and that repositioning of chromosomes relies on efficient functioning of an active nuclear motor complex that contains nuclear myosin 1p. Background Within interphase nuclei individual chromosomes are organized within their own nuclear space known as chromosome territories 1 2 . These