Video 8. Single and double centrosome ablations in a sand dollar embryo coexpressing ensconsin-3xGFP (cyan) and mC-H2B (yellow). Time-lapse sequence of single confocal sections (Atto CARV). Video corresponds to Fig. S5 B. Real times are indicated, and the video is encoded at 15 frames/s. Bar, 25 µm.
Animal cells decide where to build the cytokinetic apparatus by sensing the position of the mitotic spindle. Reflecting a long-standing presumption that a furrow-inducing stimulus travels from spindle to cortex via microtubules, debate continues about which microtubules, and in what geometry, are essential for accurate cytokinesis.
In normal cells, the cytokinetic apparatus forms in a region of lower cortical microtubule density. Ablation of a single centrosome displaces furrows away from the remaining centrosome; ablation of both centrosomes causes broad, inefficient furrowing.
Depictions of chick developmental anatomy. (A) Dorsal view (looking “down” at what will become the back) of a 2-day chick embryo, as depicted by Marcello Malpighi in 1672. (B) Ventral view (looking “up” at the prospective belly) of a chick embryo at a similar stage, seen through a dissecting microscope and rendered by F. R. Lillie in 1908. (C) Eduard d’Alton’s depiction of a later stage 2-day chick embryo in Pander (1817). (D) Modern rendering of a 3-day chick embryo. Details of the anatomy will be discussed in later chapters. (A from Malpighi 1672; B from Lillie 1908; C from Pander 1817, courtesy of Ernst Mayr Library of the Museum of Comparative Zoology, Harvard; D after Carlson 1981.)
Development of the Human Embryonic Brain from the Howard Hughes Medical Institute.
We were shown this video in class as part of a lecture on the biology of learning and memory. No matter how you look at it, it is impressive how much the brain grows in size, swelling with newly formed neurones who spread their fingerlike synapses impulsively through the far corners of the neurological system.
Chick embryo at 6x magnification, by Tomas Pais de Azevedo of Universidade de Lisboa in Portugal.
Tubes digestifs d’embryons de poulet, caille, poisson zèbre et souris
The digestive tracts of chick E12 (from left), quail E12, zebra finch E13, and mouse E16,5 embryos are shown with the mesenteric tissue still attached. The top row shows the relative size of the eggs (or embryo, in the case of the mammal).
Composite photo courtesy of Natasza Kurpios
source : What’s behind the predictably loopy gut, Harvard Science 2011
Reblogging this because I think it’s just too cool for my new followers to not see!
My unfairly sexy boyfriend is taking developmental biology this semester and sent me this video!
It’s a chick embryo that has been removed from the yolk after an incubation period of 72 hours. You can see the head in the right hand portion of the screen. Below that is a small sac-like organ. That would be the heart, and yes, it is beating.
My unfairly sexy boyfriend is taking developmental biology this semester and sent me this video!
It’s a chick embryo that has been removed from the yolk after an incubation period of 72 hours. You can see the head in the right hand portion of the screen. Below that is a small sac-like organ. That would be the heart, and yes, it is beating.
![the-star-stuff:
And now, a chicken grown in a Petri dish
A fertilized, incubated chicken egg takes about 21 days to hatch; and while most of us have seen what chicks look like at either end of the developmental spectrum (either sunny-side-up in a frying pan or newly hatched in a nature documentary), the fact that egg shells aren’t see-through means that not many people have seen what goes on between days 2 and 20.
Well… now you have.
Having said that, it is possible to grow a chicken in a petri dish. Several methods papers have been published on the subject of Petri-grown chicks, beginning with the Auerbach method in 1974. You can check out the full set of images over on imgur.
[Via reddit]](http://24.media.tumblr.com/tumblr_lxqk4r1Buz1qe649zo1_500.jpg)
And now, a chicken grown in a Petri dish
A fertilized, incubated chicken egg takes about 21 days to hatch; and while most of us have seen what chicks look like at either end of the developmental spectrum (either sunny-side-up in a frying pan or newly hatched in a nature documentary), the fact that egg shells aren’t see-through means that not many people have seen what goes on between days 2 and 20.
Well… now you have.
Having said that, it is possible to grow a chicken in a petri dish. Several methods papers have been published on the subject of Petri-grown chicks, beginning with the Auerbach method in 1974. You can check out the full set of images over on imgur.
[Via reddit]
Ocean Acidification May Harm Fish Eggs
Fossil fuel combustion, and with it the release of heat-trapping carbon dioxide (CO2), is still growing globally. Beyond climate change, this is also causing the world’s “other CO2 problem,” ocean acidification, i.e., the formation of carbonic acid when CO2 from the atmosphere enters seawater. Studies have already demonstrated a multitude of negative effects of elevated CO2 conditions for many groups of marine organisms such as corals, plankton, shellfish and sea urchins. To date, scientists have assumed marine fish were immune to ocean acidification.
However, in a new article published in the online edition of the journal Nature Climate Change, researchers from Stony Brook Univ. demonstrate that “the fish are okay” belief ignores an important knowledge gap—the possible effects of CO2 during the early development of fish eggs and larvae. Co-authors of the study, Christopher Gobler and Hannes Baumann, are professors at the Stony Brook Univ. School of Marine and Atmospheric Science (SoMAS) and represent one of several international teams working on closing this gap.
Read more: http://www.laboratoryequipment.com/news-Ocean-Acidification-May-Harm-Fish-Eggs-121211.aspx
