Multiple purple and pink renditions of stem cells appear as spherical clusters enveloped in translucent bubbles
Mammalian Embryos Might Not Need Primitive Streaks After All
The primitive streak, a structure that emerges during mammalian and avian gastrulation, might be a byproduct rather than a landmark of the embryonic development process.
ABOVE: © ISTOCK.COM, ANUSORN NAKDEE
Mammalian Embryos Might Not Need Primitive Streaks After All
Mammalian Embryos Might Not Need Primitive Streaks After All

The primitive streak, a structure that emerges during mammalian and avian gastrulation, might be a byproduct rather than a landmark of the embryonic development process.

The primitive streak, a structure that emerges during mammalian and avian gastrulation, might be a byproduct rather than a landmark of the embryonic development process.

ABOVE: © ISTOCK.COM, ANUSORN NAKDEE
embryology
lewis wolpert obituary developmental biology embryo 14 day rule
High Profile Developmental Biologist Lewis Wolpert Dies at 91
Shawna Williams | Feb 16, 2021
Wolpert, who conducted research at University College London, was known for his work on morphogenesis and pattern development in embryos and for his multiple books and broadcast appearances.
These Molecules Zipper Embryos Closed
Ashley Yeager | Aug 1, 2018
Actin rings seal off the ball of cells, aiding in implantation in the uterus. But faults in the process could explain why some pregnancies fail.
Infographic: Embryonic Zippering
Ashley Yeager | Jul 31, 2018
How actin seals embryos early in development
Animals’ Embryonic Organizer Now Discovered in Human Cells
Jim Daley | May 23, 2018
The finding confirms that a cluster of cells that directs the fate of other cells in the developing embryo is evolutionarily conserved across the animal kingdom.
Passing the Torch
Mary Beth Aberlin | Dec 1, 2017
Looking back, looking forward
Image of the Day: Brand New Pyjamas
The Scientist Staff | Aug 23, 2017
As it matures, this chromatophore-clad pyjama squid (Sepioloidea lineolata) hatchling will learn to use the color-changing cells that adorn its body to alter its appearance.
Image of the Day: Embryonic Ripples
The Scientist Staff | Jul 26, 2017
This fluttering clump of colorful cells is a zebrafish embryo, visualized by many stacked images.
Embryonic Evolution Through Ernst Haeckel’s Eyes
Diana Kwon | May 1, 2017
The 19th century biologist’s drawings, tainted by scandal, helped bolster, then later dismiss, his biogenetic law.
Famed Mammalian Embryologist Dies
Jef Akst | Dec 1, 2016
Andrzej Tarkowski’s research laid the groundwork for future advances in cloning, stem cell research, and in vitro fertilization.
Study: IVF Media Affects Treatment Outcomes
Ben Andrew Henry | Aug 24, 2016
Differences between cultures used for in vitro fertilization techniques can impact fertility and offspring health, researchers report.
Notable Science Quotes
The Scientist Staff | Jun 1, 2016
14-day-old embryos, prioritizing biodiversity, and more
Organelle Architecture
Mary Beth Aberlin | Dec 1, 2013
There’s beauty in a cell’s marriage of structure and function.
Seeing Clearly
Jef Akst | Apr 1, 2013
Zebrafish are showing the way to new insights in cancer research.
Go Forth, Cells
Dan Cossins | Jan 31, 2013
Watch the cell transplant experiments in zebrafish that suggest certain embryonic cells rely on intrinsic directional cues for collective migration.
Contributors
Beth Marie Mole | Nov 1, 2012
Meet some of the people featured in the November 2012 issue of The Scientist.
Long and Rocky Roads
Mary Beth Aberlin | Nov 1, 2012
From basic research to beneficial therapies