Fig. 1
Isolation of MAR DNA from 5th instar posterior silk glands of B. mori. A The nuclear and MAR DNA of day 1, day 5 and day 7 were quantified using U.V spectrophotometry (n = 5, where n is the number of sample replicates). Student’s T-test (two sample using unequal variances) used for statistical analysis and no significant enrichment was found in MAR DNA from day 1 to day 7 was observed (p > 0.05) while significant difference was observed between concentrations of nuclei and nuclear matrix (NuMat) DNA (p < 0.005). The nuclear DNA increased significantly from day 1 to day 5 but no significant increase was found on day 7. B A 1 kb DNA ladder (labelled ‘M’), the isolated nuclear DNA and MAR DNA from 5th instar day 5 PSGs were run on lane 1, lane 2 and lane 3 respectively on a 1.2% agarose gel. C Transmission electron microscopy imaging of nucleus (left) isolated from day 5 of 5th instar larvae, Scale: 1 μm, showing nucleolus (Nu), peripheral condensed chromatin (dCh) and nuclear lamina (NL) and D Transmission electron microscopy image of NuMat (right) isolated from day 5 of 5th instar larvae revealed the continuation of the inner network towards the inner periphery of the nuclear lamina. The residual nucleolus was not observed in the NuMat preparation of this study. Scale: 1 μm. A contrasting line has drawn below the existing scale bar of both Fig. 1 (C) and (D) and the scale is also indicated above the original scale in contrasting colour for better visibility