Nazerke Atinbayeva, Iris Valent, Fides Zenk, Eva Loeser, Michael Rauer, Shwetha Herur, Piergiuseppe Quarato, Giorgos Pyrowolakis, Alejandro Gomez-Auli, Gerhard Mittler, Germano Cecere, Sylvia Erhardt, Guido Tiana, Yinxiu Zhan, Nicola Iovino
Constitutive heterochromatin is essential for transcriptional silencing and genome integrity. The establishment of constitutive heterochromatin in early embryos and its role in early fruitfly development are unknown. Lysine 9 trimethylation of histone H3 (H3K9me3) and recruitment of its epigenetic reader, heterochromatin protein 1a (HP1a), are hallmarks of constitutive heterochromatin. Here, we show that H3K9me3 is transmitted from the maternal germline to the next generation. Maternally inherited H3K9me3, and the histone methyltransferases (HMT) depositing it, are required for the organization of constitutive heterochromatin: early embryos lacking H3K9 methylation display de-condensation of pericentromeric regions, centromere-centromere de-clustering, mitotic defects, and nuclear shape irregularities, resulting in embryo lethality...
June 3, 2024: EMBO Journal