#embryo development

Head Over Heart

The rhythmic beat of our heart is fine-tuned by an orchestra of electrical and chemical signals from surrounding nerve cells. But how these neural signals influence heart development and maintenance remains unclear. The human heart is complex (both biologically and emotionally!), so researchers have turned to a more simple comparator: the sea squirt, Ciona robusta. The C. robusta heart (pictured, with muscle architecture in pink) grows throughout adulthood and has a line of progenitor cells that act as a reserve for further growth. A team tracked these cells over time and found that neural inputs control not just heartbeat, but how many heart muscle cells are produced during development. Understanding the subtle signals that guide heart formation could shed light on the nervous system’s wider role in healthy organ growth and repair.

Written by Anthony Lewis

Image from work by Hannah N. Gruner and C. J. Pickett, and colleagues

Department of Biology, Swarthmore College, Swarthmore, PA, USA

Image contributed by the authors and originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in PLOS Biology, April 2026

Grey Skulls

Embryos develop in a series of careful changes. One early stage involves neural crest cells migrating to different parts of the embryo, where they differentiate or specialise into the patterns that define the body. Each of these steps relies on 'switching on' of genes – gene expression – in the right cells at the right time. Here early bone cells called osteoblasts shape the normal skull of a developing mouse at the top, while the skull of the lower mouse is formed differently. The lower skull lacks a gene called Eed, which helps to guide gene expression inside osteoblast cells. Removing Eed interferes with epigenetic controls – chemical groups attached to the DNA which change access to certain genes. In humans and mice, epigenetic patterns can be inherited, raising new questions about how development might be shaped at delicate early stages of life.

Written by John Ankers

Image from work by Tim Casey-Clyde and colleagues

Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, USA

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in eLife, December 2025

Never Lose SIght

A new method called Ultrack that enables cells to be tracked in 2D and 3D, over time, and over different scales and packing densities. Here, cell tracking by Ultrack is shown in a developing zebrafish embryo

Read the published research article here

Video from work by Jordão Bragantini and colleagues

Chan Zuckerberg Biohub, San Francisco, CA, USA

Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Nature Methods, August 2025

Spinal Cord-anoids

Organoids – mini organs or tissues grown in the lab from relevant cells or stem cells – are powerful models for dissecting the characteristics, genetics and interactions that make up the real-life setting, commonly far too big and developed to track in real time or consider as a whole. Here, human pluripotent stem cells have been manipulated to grow as an organoid to mimic the early spinal cord and a key role revealed for a protein called YAP in shaping the cord's inner space or lumen (part of the cord's natural developmental process)

Read the published research article here

Image from work by José Blanco-Ameijeiras and colleagues

Cells and Tissues Dept, Instituto de Biología Molecular de Barcelona, CSIC, Barcelona, Spain

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in eLife, January 2026

Right Left Right

Like all vertebrates, our anatomy is notably asymmetrical, with certain organs on the left and others on the right. This is determined during development by a group of cells called the left-right organiser (LRO) – a structure that only exists transiently in the early embryo. The LRO initiates left-right asymmetry as the embryo develops by controlling directional fluid flow with cilia (whisker-like projections from cells), which induces asymmetric gene activity. Here, researchers investigate how the LRO forms through live-cell imaging in the early hours of developing zebrafish. Starting as a collection of cells, rounds of division shape a fleeting rosette-like structure after which a fluid-filled space (lumen) forms (image shows how normal lumen formation (left in amber) is affected and halted by increasing amounts of growth factor inhibitor middle and right)). The team found that to ensure this series of structural outcomes, events reliant on specific growth factors control the cell divisions and their timing. Understanding how the LRO begins could reveal its hitherto overlooked roles in developmental disorders.

Written by Lux Fatimathas

Image from work by Yan Wu and Yiling Lan and colleagues

Department of Biology, Syracuse University, Syracuse, NY, USA

Image contributed by the authors and originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Development, May 2025

Separate Ways

Symmetry is everywhere in life. Yet in these cells inside an early zebrafish embryo, asymmetry heralds a vital step in development. Different patterns must emerge in the embryonic cells, early steps in defining tissues and organs, driven by the transcribing ('switching on') of their genes – known as the maternal-to-zygotic transition. In this video, researchers use different fluorescent sensors to watch the cells progressing through the cell cycle (purple), and the timing of a burst of zygotic transcription (green dots). They find that the timing of cell division and transcription is influenced by the cell’s location, creating different patterns of activity around the developing embryo. Investigating similar patterns in human embryos may answer some questions about this most sensitive stage of life.

Written by John Ankers

Video from work by Nikhil Mishra and colleagues

Institute of Science and Technology Austria, Klosterneuburg, Austria

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Nature Physics, January 2026

Following Fate

Every cell is destined to fulfil a certain role – its cell fate. How cell fates are determined partly depends on interactions between cells. Measuring this is challenging because cell fates develop gradually over time and space in tissues of different shapes and sizes. Here, a computational image analysis solution measures the properties of each cell relative to those of its neighbours, flattening a 3D image of a curved structure into 2D for easier analysis. Researchers tested this toolkit, including an algorithm dubbed PRINGLE (referencing the convex/concave planes of the early embryonic tissue under study, reminiscent of a famous crisp-in-a-tube), on microscopy images of mouse embryos labelled fluorescently with markers of different cell types (pictured). After treating the embryos with a chemical to alter cell fates, PRINGLE was able to reveal the consequences for individual cells. This toolkit has, therefore, proved powerful for capturing twists in fate in the life of a cell.

Image created using Leica Microsystems microscopy

Written by Lux Fatimathas

Image from work by Matthew French and colleagues

Institute for Stem Cell Research, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK

Image contributed by the authors and originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in PLOS Biology, July 2025