Sentences with word «placode»

Indeed, we have identified in reptiles new molecular signatures that are identical to those observed during the development of hairs and feathers, as well as the presence of the same anatomical placode as in mammals and birds.

Knowing where and when to look, he found placodes in other reptiles, too.

It wasn't until 2016 that scientists realized reptile scales developed from placodes.

Each of these structures, called placodes and displayed in dark blue, will give rise to a hair, a scale or a feather.

When mutations occur there, the vertebrates may end up with missing placodes, or sweat glands, teeth or nails that are deformed or just absent.

Scales were thought to develop from raised skin areas without placodes.

He also discovered why his dragons were naked: A mutated gene involved in placode formation.

This would imply that birds and mammals have independently «invented» placodes during their evolution.

This possibility is intriguing, since subsets of the EFTFs are coordinately expressed in specific regions of the forebrain and developing olfactory placodes [7].

But it seemed unlikely, because the body coverings were thought to grow differently: Feathers and hair develop from specialized plates of thickened ectoderm — an embryonic cell layer — called anatomical placodes, structures not seen in reptiles.

Multi-photon imaging of the embryonic eye: A false - coloured image showing a cutaway through the invaginating lens placode (blue tissue layer) situated within the optic cup (yellow tissue layer) of a 2.5 - day chick embryo.

As Milinkovitch scrutinized differences between embryos of his naked dragons and normal lizards, he realized normal lizards do have placodes, but they exist for a few hours and appear in different places depending on the species and the developmental stage.

Mammalian hairs and avian feathers develop from a similar primordial structure called a «placode»: a local thickening of the epidermis with columnar cells that reduce their rate of proliferation and express very specific genes.

The Swiss researchers have demonstrated that, when EDA is malfunctioning in lizards, they fail to develop a proper scale placode, exactly as mammals or birds affected with similar mutations in that same gene can not develop proper hairs or feathers placodes.

Today, Nicolas Di - Poï and Michel C. Milinkovitch at the Department of Genetics and Evolution of the UNIGE Faculty of Science and at the SIB put this long controversy to rest by demonstrating that scales in reptiles develop from a placode with all the anatomical and molecular signatures of avian and mammalian placodes.

Placodes (spots stained in dark blue by the expression of an early developmental gene) are visible before the development of hair, scales and feathers in (from left to right) the mouse, the snake, the chicken and the crocodile.

According to previous studies, reptiles» scales however do not develop from an anatomical placode.

Ectoderm; reprinted from Streit, A., The cranial sensory nervous system: specification of sensory progenitors and placodes (December 15, 2008), StemBook, ed.