Relationship Between Cell Flow and Midline Morphogenesis in Amniote Gastrulation

Core Concepts

The author explores the relationship between cell flow and midline morphogenesis in amniote gastrulation, highlighting the interplay between these processes.

Abstract

Large-scale cell flow characterizes gastrulation in amniotes, particularly avian gastrula. Experimental manipulations reveal relationships between cell flow patterns and primitive streak morphogenesis. The Wnt/PCP pathway plays a crucial role in maintaining cell flows despite deformed primitive streaks. Mitotic arrest affects primitive streak extension but preserves early polonaise movements. Ectopic Vg1 induction generates altered cell flows aligned to induced midlines. Despite changes in cell flow, primitive streak extension is maintained along both authentic and induced midlines. The study suggests that primitive streak morphogenesis is essential for maintaining large-scale cell flows during gastrulation.

Stats

"Mitotic arrest leads to diminished PS extension and maintains the early phase of the polonaise movements."
"The number of PS cells was not significantly different from the control- and ΔDEP-GFP-PS."
"The distance between the left-right rotating cell flows was wider in the ΔDEP embryos than the controls."
"The polonaise movements persisted even though the PS as a midline structure was deformed under suppression of the Wnt/PCP pathway."

Quotes

"The results suggest that PS morphogenesis is not responsible for initiating or maintaining the polonaise movements."
"Our data describe a previously undefined relationship between large-scale cell flow and midline morphogenesis in amniote gastrulation."

Key Insights Distilled From

Coupling and uncoupling of midline morphogenesis and cell flow in amniote gastrulation

by Asai,R., Pra... at www.biorxiv.org 05-28-2023

https://www.biorxiv.org/content/10.1101/2023.05.26.542486v4

Deeper Inquiries

How does mitotic arrest impact other aspects of embryonic development beyond PS extension

Mitotic arrest, induced by aphidicolin treatment, impacts various aspects of embryonic development beyond primitive streak (PS) extension. Firstly, it leads to a reduction in the number of PS precursor cells due to the inhibition of cell division. This decrease in cell population affects not only PS formation but also subsequent mesodermal and endodermal differentiation processes that rely on an adequate number of precursor cells for proper germ layer specification. Additionally, mitotic arrest can disrupt the normal progression of gastrulation by affecting tissue tension and biomechanical forces required for cell movements during this critical developmental stage. Furthermore, since mitosis is essential for overall embryo growth and patterning, its inhibition may have cascading effects on organogenesis and body axis establishment.

What alternative explanations could there be for the observed relationship between cell flow patterns and midline morphogenesis

The observed relationship between cell flow patterns and midline morphogenesis could potentially be explained by alternative mechanisms or factors influencing these processes:

Biomechanical Forces: Tissue tension generated by cellular activities such as intercalation and ingression could play a significant role in both cell flow patterns and midline morphogenesis. Changes in tissue tension due to alterations in cellular behaviors might impact the directionality and magnitude of large-scale cell flows.
Signaling Crosstalk: Cross-talk between different signaling pathways involved in both cell migration (cell flow) and midline structure formation could mediate their coordination during gastrulation. Interactions between Wnt/PCP pathway components with other signaling molecules might regulate these processes simultaneously.
Cellular Polarity: Disruption or maintenance of cellular polarity within the developing embryo could influence both cell movements along the midline axis (polonaise movements) as well as primitive streak morphogenesis through coordinated changes in cytoskeletal dynamics.

These alternative explanations suggest that multiple interconnected factors contribute to the complex relationship between large-scale cell flows and midline morphogenesis during embryonic development.

How might understanding this relationship contribute to advancements in regenerative medicine research

Understanding the intricate relationship between large-scale cell flow patterns and midline morphogenesis can significantly advance regenerative medicine research by providing insights into tissue regeneration strategies:

Bioengineering Approaches: Knowledge about how specific molecular signals induce or alter large-scale cellular movements can inform bioengineers designing scaffolds or microenvironments for guiding stem cells during tissue regeneration processes.
Organoid Development: Insights into how natural embryonic structures form through coordinated interactions between cells flowing along specific axes can guide researchers working on organoid development protocols aimed at mimicking native tissue organization.
Disease Modeling: Understanding how disruptions in normal developmental processes affect large-scale cellular behaviors can aid researchers studying congenital disorders or diseases related to abnormal tissue patterning where knowledge about precise spatial organization is crucial for disease modeling efforts.

By leveraging this understanding from developmental biology studies, regenerative medicine researchers can enhance their approaches towards creating functional tissues with organized structures similar to those seen during embryonic development but tailored for therapeutic applications like organ replacement therapies or disease modeling platforms