Objective  To detect the expression of nesprin-1 gene mRNA and protein and to localize the sub-cellular protein during the development of mouse heart.   Methods  Samples of embryonic heart tissue were collected from postnatal and adult mice on embryo 12.5 days (E12.5)

E14.5

E16.5

and E18.5

respectively. Expression levels of nesprin-1 mRNA and protein and the protein sub-cellular location in samples of embryonic heart tissue from mice were detected by reverse transcriptase PCR

Western blot analysis and immunofluorescence at different time points.   Results  The expression level of nesprin-1 mRNA and protein in samples of embryonic heart tissue from postnatal and adult mice was measured on E12.5

E16.5 and E18.5

respectively

which increased with the development of mouse heart

reached it peak on E16.5 and E18.5. The lowest expression level of nesprin-1 mRNA and protein was found in adult mice. Immunofluorescence showed that nesprin-1 was distributed in nuclear envelope and in spaces around the nuclei.   Conclusion  nesprin-1 is dynamically expressed during the development of mouse heart

and highly expressed in the mature period of cardiac conduction system and cardiac muscle cells

indicating that it plays an important role in the development of cardiac conduction system and cardiac muscle cells.