Do you ever wonder how you developed in the human womb or either shape of a cat or a sheep (Developmental biology : Introduction)

 Developmental Biology

Hello, do you ever wonder how you developed in the human womb or either shape of a cat or a sheep or somatic cells??

How does everything takes place at  the right time at the right line??

Developmental biology is the study of this questions.

In essence, it is the study of how the embryos develop and becomes in to the human form.

Many theories have tried to explain how the embryo develops, one early theory 

suggested , a very tiny sperm becomes bigger and bigger in contact with the egg.

Amazingly, have we wondered many species of animal look remarkably similar?

In 1935, a small group of cells can instruct the other cells to form a embryo.These instructions are identifiied as signaling molecules.One found in fly has a relative molecule that is found in chicken.

Finding the genes in the proteins will help to open the door for developmental biology.

500 MILLION YEARS OF EVOLUTIONARY DISTANCE

The human condition aniridia ,characterized by small lens in which is by the defect in same lens in flies which caused the loss of the entire eye that shows up 500 million year old ancestor has the same genes that involved in eye development.

It is not new genes or new structures but it is the changes where and when it is used. Look at the spaces between your fingers,these were webs when you are in embryo, when the cells in the spaces die create the gaps, Ducks however turn off the genes in web regions prevents cell death.

HOW DO THESE DIFFERENCES IN THE GENE EXPRESSION OCCUR

In the regions of DNA, Various controllers have been discovered certain genes are on or off inside the cells.

It is the evolution and generation of the controllers, upstream genes that controls where is the gene is turned on thus influence and changes in to  development .

Although, many questions remains unanswered.

How are these controllers generated?

How do controllers get activated at the correct time of the development , on my favour how do your limbs going on the same line ??

References:

https://en.wikipedia.org/wiki/Developmental_biology 

https://www.sciencedirect.com/journal/developmental-biology 

https://en.wikipedia.org/wiki/Child_development 

https://www.nature.com/subjects/developmental-biology