RRC ID 74721
Author de-Carvalho J, Tlili S, Hufnagel L, Saunders TE, Telley IA.
Title Aster repulsion drives short-ranged ordering in the Drosophila syncytial blastoderm.
Journal Development
Abstract Biological systems are highly complex, yet notably ordered structures can emerge. During syncytial stage development of the Drosophila melanogaster embryo, nuclei synchronously divide for nine cycles within a single cell, after which most of the nuclei reach the cell cortex. The arrival of nuclei at the cortex occurs with remarkable positional order, which is important for subsequent cellularisation and morphological transformations. Yet, the mechanical principles underlying this lattice-like positional order of nuclei remain untested. Here, using quantification of nuclei position and division orientation together with embryo explants, we show that short-ranged repulsive interactions between microtubule asters ensure the regular distribution and maintenance of nuclear positions in the embryo. Such ordered nuclear positioning still occurs with the loss of actin caps and even the loss of the nuclei themselves; the asters can self-organise with similar distribution to nuclei in the wild-type embryo. The explant assay enabled us to deduce the nature of the mechanical interaction between pairs of nuclei. We used this to predict how the nuclear division axis orientation changes upon nucleus removal from the embryo cortex, which we confirmed in vivo with laser ablation. Overall, we show that short-ranged microtubule-mediated repulsive interactions between asters are important for ordering in the early Drosophila embryo and minimising positional irregularity.
Volume 149(2)
Published 2022-1-15
DOI 10.1242/dev.199997
PII 274085
PMID 35001104
MeSH Animals Blastoderm / cytology Blastoderm / metabolism* Cell Nucleus / metabolism Cell Nucleus Division* Drosophila melanogaster Giant Cells / cytology Giant Cells / metabolism* Microtubules / metabolism Stress, Mechanical
IF 5.611
Drosophila DGRC#109603