GSE134250
Binding of SU(VAR)3-9 partially depends on SETDB1 in the chromosomes of Drosophila melanogaster
Histone modifications are a class of epigenetic marks with prominent roles in gene regulation in eukaryotes. One such mark, predominantly inactivation-related, is methylation of histone H3 lysine 9 (H3K9). In the present study, we decipher the interplay between two evolutionary conserved Drosophila H3K9-specific histone methyltransferases, SU(VAR)3-9 and SETDB1. We asked whether SETDB1 is required for targeting of SU(VAR)3-9. Using DamID-seq, we obtained SU(VAR)3-9 binding profiles for the chromosomes from larval salivary glands and germline cells from adult females, and compared profiles between the wild type and SETDB1-mutant backgrounds. Our analyses indicate that the vast majority of single-copy genes in euchromatin are targeted by SU(VAR)3-9 only in the presence of SETDB1, whereas repeated sequences in heterochromatin is largely SETDB1-independent. Interestingly, piRNA clusters 42AB and 38C behave differently in terms of SU(VAR)3-9 binding in somatic and germline cells. Namely, SU(VAR)3-9 binding to these piRNA clusters is independent of SETDB1 in somatic cells, whereas it is SETDB1-dependent in the germline. In addition, we compared SU(VAR)3-9 profiles in female germline cells at different developmental stages (whole juvenile ovaries and mature nurse cells). It turned out that SU(VAR)3-9 binding is influenced both by the presence of SETDB1, as well as by the differentiation stage. Overall design: Examination of Su(var)3-9 protein binding on chromosomes of juvenile ovaries in presence or absence of SET-DB1 mutation using DamID technique.