Explore the intricate process of vertebrate embryo development in this 91-minute lecture from the International Centre for Theoretical Sciences' discussion meeting on theoretical biology. Delve into the complexities of cell size regulation and its impact on embryonic development using zebrafish as a model organism. Examine how cell size affects migration during gastrulation, and investigate the consequences of altered cell sizes in haploid and tetraploid embryos. Learn about experimental techniques for manipulating cell size and observe the effects on membrane dynamics and organ formation. Gain insights into the fundamental question of how embryos establish optimal cell sizes and the broader implications for understanding vertebrate embryogenesis.
The Logistics of Shaping a Vertebrate Embryo in Developmental Space and Time by Sreelaja Nair
International Centre for Theoretical Sciences via YouTube
Overview
Syllabus
The logistics of shaping a vertebrate embryo in developmental space and time
Everything complex is simple to begin with..
The "teenage angst" of embryos
Early zebrafish embryos as an experimental paradigm to understand cell size scaling during embryonic development
Cells decrease in size during early zebrafish development
Cell size decrease during early zebrafish development
Dynamically evolving cell sizes are distributed in conserved proportions during early development
Why study cell size during early embryonic development?
How does one change cell size when one does not know what regulates cell size?
Generation of zebrafish haploids and tetraploids
Cell sizes in haploid and tetraploid zebrafish embryos are altered in comparison to diploid embryos
Haploid and tetraploid embryos generate cell collectives of altered sizes
Movement is an inherently complex phenomenon
Gastrulation is the phenomenon of en mass cell migration in animal embryos,
Model organisms allow us to study evolutionary commonalities between species
The conundrum
Early cell divisions in embryos result in constantly shrinking cell sizes to generate a cell mass
Generated zebrafish haploids and tetraploids to create embryos made of altered cell sizes
Haploid and tetraploid embryos are delayed in epiboly initiation, progression and gastrulate abnormally
Haploids and tetraploids embryos have defects in anterior migration,
Haploid and tetraploid embryos generate cell collectives of altered sizes
Dynamically evolving cell sizes are distributed in conserved proportions during early development
Movement in an embryological context always gives rise to form
Haploids and tetraploids embryos have defects in anterior migration,
If cells in diploid embryos are made to be of suboptimal sizes,
If smaller cells are induced to achieve normal cell size optima,
Do sub-optimally sized cells migrate aberrantly during gastrulation?
Do sub-optimally sized cells migrate aberrantly during gastrulation? - Yes
The migratory behaviour of cells in a suboptimal sized cell collective is altered
Do sub-optimally sized cells migrate aberrantly during gastrulation? Analysing cells in an embryo by generating mosaic embryos
Smaller or larger cells continue to migrate aberrantly during gastrulation,
Migration is influenced by environment of the cell collective
Why does a cell of suboptimal size migrate poorly? Assaying membrane action dynamics during gastrulation in live embryos
Membrane protrusion dynamics change when cell size changes
Membrane protrusion dynamics of action containing protrusions change when cell size changes
Quick recap...
Why is this interesting, besides it just being interesting?
Endodermal organogenesis and function is also compromised
The big question: How do embryos set up cell size optima?
The logistics of shaping a vertebrate embryo in developmental space and time
Vertebrate Embryogenesis Group
Taught by
International Centre for Theoretical Sciences
