Dynamic microtubules drive yolk-cytoplasm segregation in the syncytial Drosophila embryo
- 1Indian Institute of Science Education and Research
Abstract
Yolk-cytoplasm segregation is among the earliest spatial organization events in the developing embryo of many oviparous animals. The segregation process is intimately linked to early embryonic cleavage and pattern formation, and exhibits a wide range of spatial and temporal diversity. However, the underlying cytoskeletal mechanism remains largely unknown, except for a small number of species. Using quantitative live imaging, we investigated yolk segregation in the Drosophila embryo during the syncytial nuclear cycles 11-14. We find that the yolk vesicles move progressively inward in spatial and temporal coordination with the inward expanding microtubule networks that are nucleated from centrosomes positioned at the cortex, whereas cortical actin meshwork remains spatially restricted. Using the gnu RNAi embryo to decouple nuclear migration and division from cytoskeletal dynamics, we establish causality with targeted pharmacological disruption and find that microtubule dynamics is required for yolk segregation, while depolymerization of actin has no discernible effect. In support of a mechanism of growth-propelled passive displacement, microtubule plus end comets come in apparent contact with yolk vesicles, and injected, inert microbeads are displaced towards the embryo center presumably by the same pushing force. These findings identify microtubule polymerization as a predominant driver of yolk-cytoplasm segregation in Drosophila and suggest that diverse cytoskeletal mechanisms evolved to accomplish this crucial reorganization process
Related
- FapA extends the flagellar cage-dependent network into the cytoplasm to control surface-associated behaviors in Helicobacter pylori
- Lenacapavir-induced lattice hyperstabilization is central to HIV-1 capsid failure at the nuclear pore complex and in the cytoplasm
- Structural streamlining of axonemal doublet microtubules in Plasmodium male gametes
- Microtubules coordinate with actin assembly and disassembly to elongate cortical actin cables
- NuSAP1 promotes spindle assembly in Trypanosoma brucei by bundling spindle microtubules
BibTeX
@misc{thukral2026dynamic,
title = {{Dynamic microtubules drive yolk-cytoplasm segregation in the syncytial Drosophila embryo}},
author = {S. Thukral and P. Dey and B. Kaity and S. S and S. Goswami and Y.-C. Wang and M. K. Mitra and A. Nandi and R. Rikhy},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.02.748760},
url = {https://www.biorxiv.org/content/10.64898/2026.09.02.748760v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Dynamic microtubules drive yolk-cytoplasm segregation in the syncytial Drosophila embryo
AU - S. Thukral
AU - P. Dey
AU - B. Kaity
AU - S. S
AU - S. Goswami
AU - Y.-C. Wang
AU - M. K. Mitra
AU - A. Nandi
AU - R. Rikhy
PY - 2026
DA - 2026/09/02
PB - bioRxiv
DO - 10.64898/2026.09.02.748760
UR - https://www.biorxiv.org/content/10.64898/2026.09.02.748760v1
AB - Yolk-cytoplasm segregation is among the earliest spatial organization events in the developing embryo of many oviparous animals. The segregation process is intimately linked to early embryonic cleavage and pattern formation, and exhibits a wide range of spatial and temporal diversity. However, the underlying cytoskeletal mechanism remains largely unknown, except for a small number of species. Using quantitative live imaging, we investigated yolk segregation in the Drosophila embryo during the syncytial nuclear cycles 11-14. We find that the yolk vesicles move progressively inward in spatial and temporal coordination with the inward expanding microtubule networks that are nucleated from centrosomes positioned at the cortex, whereas cortical actin meshwork remains spatially restricted. Using the gnu RNAi embryo to decouple nuclear migration and division from cytoskeletal dynamics, we establish causality with targeted pharmacological disruption and find that microtubule dynamics is required for yolk segregation, while depolymerization of actin has no discernible effect. In support of a mechanism of growth-propelled passive displacement, microtubule plus end comets come in apparent contact with yolk vesicles, and injected, inert microbeads are displaced towards the embryo center presumably by the same pushing force. These findings identify microtubule polymerization as a predominant driver of yolk-cytoplasm segregation in Drosophila and suggest that diverse cytoskeletal mechanisms evolved to accomplish this crucial reorganization process
ER -