Dynamics of Nuclear Matrix Attachment Regions During 5th Instar Posterior Silk Gland Development in Bombyx Mori

Abstract

Chromatin architecture is critical for gene expression during development. Matrix attachment regions (MARs) control and regulate chromatin dynamics. The position of MARs in the genome determines the expression of genes in the organism. In this study, we set out to elucidate how MARs temporally regulate the expression of the fibroin heavy chain (FIBH) gene during development. We addressed this by identifying MARs and studying their distribution and differentiation, in the posterior silk glands of Bombyx mori during 5th instar development. Of the MARs identified on three different days, 7.15% MARs were common to all three, whereas, 1.41%, 19.27% and 52.47% MARs were unique to day 1, day 5, and day 7, respectively highlighting the dynamic nature of the matrix associated DNA. Further, significant changes in the MARs in the vicinity of the FIBH gene were found during different days of 5th instar development which implied their role in the regulation and expression of the FIBH gene.