How to Make Eyeball Stew - Editor’s choice in developmental biology
By HANNAH WATERS - THESCIENTIST
Added: Wed, 14 Mar 2012 23:11:34 UTC
For nearly two decades now, developmental biologist Yoshiki Sasai from Japan’s RIKEN Center for Developmental Biology has slaved away to perfect a recipe: the culture medium that could induce mouse embryonic stem cells to form organs with no additional ingredients. Disheartened by his incomplete success in generating brain tissue from stem cells, Sasai began a side project to grow early-stage mouse eyes, because they are “relatively simpler in structure than cortex” tissue, he said.
In his free time, Sasai fussed over his medium, fine-tuning the concentrations of ingredients—adding a gel containing laminin proteins essential for constructing basement membranes, decreasing growth factor levels. With his latest recipe complete, Sasai mixed in mouse embryonic stem cells—and then sat back to see what would happen, if anything.
Like most embryonic cells, aggregates of stem cells first formed hollowed spheres. But after 7 days Sasai and his colleagues noticed some “funny structures” sprouting off the outer fringes of the spheres and glowing green with a marker indicating retinal differentiation, Sasai recalls. Within the next few days each of those small buds folded in upon itself to form a goblet shape with two cell layers: an outer retinal pigment epithelium, which provides nutrients to the visual cells, and an inner layer of retinal neural cells. These structures were optic cups, the precursor to the fully differentiated retina—and they appeared to be forming “hands-off” within Sasai’s culture mixture.
Hannah Krakauer - New Scientist Comments
Kanzi the bonobo is able to create and use stone tools
- - URMC Comments
Newer Imaging Technique Brings ‘Glymphatic System’ to Light
- - The Royal Society Comments
Research suggesting that grey parrots can reason about cause and effect from audio cues alone- a skill that monkeys and dogs lack- is presented in Proceedings of the Royal Society B today.
- - Science Blog Comments
Why, after millions of years of evolution, do organisms build structures that seemingly serve no purpose?
Charles Choi - CBS News Comments
Four decades ago, in 1972, the Koobi Fora Research Project discovered the enigmatic fossilized skull known as KNM-ER 1470 which ignited a now long-standing debate about how many different species of early Homos existed.
Adam Cole - NPR Comments
One day in May of 2011, Shaun Winterton was looking at pictures of bugs on the Internet when something unusual caught his eye. It was a close shot of a green lacewing — an insect he knew well — but on its wing was an unfamiliar network of black lines and a few flecks of blue.