RNA-seq and Cut & Tag analyses of mouse 2-cell embryos in which lamin B1 dissociation from the nuclear envelope is inhibited

We have found that lamin B1 is dissociated from the nuclear envelope transiently at the 2-cell stage during mouse embryonic development. This lamin B1 dissociation is mediated by autophagy and can be inhibited by interfering with lamin B1’s binding to LC3, a factor responsible for early autophagosome formation. In order to block interaction between lamin B1 and LC3, we injected mRNA harboring the LC3-binding domain of lamin B1 to mouse embryos and examined transcriptomes of the injected embryos by RNA sequencing (RNA-seq) analysis. In addition, embryos expressed with full-length lamin B1 mRNA harboring two different types of mutations (flLB1(F454A/L457A) and flLB1(5A)) were analyzed by RNA-seq, together with non-injection control (Non2). Another injection control (flLB1(F454A/L457A)ΔC) was also performed, together with a non-injection control (Non3). Furthermore, the effect of nuclear stiffening was examined by expressing the molecular tether-anchor system (tWT), together with a mutant carrying LaG165A (tMut) and a non-injection control (Non4). Chromatin states of such embryos were analyzed by Cut & Tag using anti-H3K4me3 antibody.