DAY 1:

The Journey Begins

Chicken Embryology
An Overview of the Timing of Major Embryonic Developments

Before Egg Laying:
Fertilization Division and growth of living cells
Segregation of cells into groups of special function (gastrulation)
Between Laying and Incubation
Virtually no growth. Stage of inactive embryonic life.

During Incubation:
Day 1
Development of area pellucida and area opaca of blastoderm
Major developments visible under microscope:

18 hours: Appearance of alimentary tract
19 hours: Beginning of brain crease
20 hours: Appearance of vertebral column
21 hours: Beginning of formation of brain and nervous system
22 hours: Beginning formation of head
23 hours: Appearance of blood islands
24 hours: Beginning formation of eyes

This picture shows the yolk of a fertilized egg. The true egg is the small white spot called a blastoderm and is indicated by the arrow.

In the infertile egg, the true egg is merely a light spot where the unfertilized true egg is located.

In the first day's MRI scan you may not be able to see very much, but the image might look like these.

An infertile egg and a fertile egg. Can you tell the difference? The chalazae cord is much more prominent in the infertile egg. However, there is no correlation between fertility and the chalazae cords. The chalazae cord are mucin fibers, a special kind of protein, which hold the yolk in place.

After one day in the incubator, the small light spot has grown to the size of a nickel or quarter. This image shows the differentiation very well, but as yet there are no blood vessels visible.

Movie Test Page

CHICK MOVIES

24 Hours Black and white reconstructed embryo. This is the closest to what it actually looks like in the egg if you could separate the chick from the yolk.
Colored 24 Hour Embryo In this clip the organ systems have been colored to make it easier to see. Blue is the nervous system, the purple is the notochord, and the red-violet are the somites which will become the vertebrae and the back muscles. The yellow is the digestive system and will become the mouth and the esophagus and stomach.