Molecular Development

Introduction

This page is a link to many different resources related to Molecular Development. In current years we have turned from wanting to merely describe the events of embryogenesis, to a desire to understand the mechanisms of development.

Fly Heads of wildtype and antennapedia (Hox) mutant (Images Dr. Rudi Turner)

I am 2.85 billion nucleotides of DNA, but so is a chimpanzee, and all this DNA encodes only about 20,000-25,000 protein-coding genes.

In development, I am not that different from a mouse or a fly and many of the signals that regulate development are used time and time again.

We have come a long way from just observing development to now wanting to understand how the complex program of development is controlled. Using new research tools and some excellent animal models researchers have discovered common themes and mechanisms that tie all embryonic development together.

What is remarkable, given our biological diversity, is the strong evolutionary conservation of developmental mechanisms. This has been a boon in allowing the use of many (easier) model systems such as the genetist's tool the fruitfly, and the worm, frog, chicken, zebrafish and mouse (see other embryos page).

A continuing theme also seems to be the reuse of signals at different times and places within the embryo, for diiferent jobs. This has given rise to the concept of "switches" which by themselves may contain no "information" but to activate other genes or switches. Finally, you can imagine that of our 20,000-25,000 protein-coding genes, a large number of these may only be expressed during development or if reused, have a completely different role in the mature animal.

In terms of molecular mechanisms, the field of epigenetics has begun to florish with some recent important findings.

Molecular mechanisms of development is an exciting area and requires a variety of different skills. This page introduces only a few examples and should give you a feel for the topic. Note that each section of system notes has a page covering molecular development in that system.

Links: Epigenetics

Starting Out

There are several different ways to begin to look at molecular development.

look at the earliest molecular events involved in patterning the differentiation of cells- axis formation.
or look at early events in patterning with differentiation and migration of cells to form the trilaminar embryo (gastrulation).
or look at the signaling mechanisms and the different types of factors involved.
or look at their role in the development of specific systems.

Signaling during development, though complex, can also be grouped into a few specific classes. These mechanisms have also been listed and described briefly on Signaling Mechanisms page.

For this section, Molecular Biology of the Cell (now indexed and available online from PubMed) and the extracted Cell Biology version are good reference texts. Also the key journals in this area are: Development, Genes and Development, PNAS, EMBOJ.

There is also detailed molecular information available from the abnormalities (page 2 of each section of notes) where there are links to the OMIM Database entry for specific genetic disorders.

Please understand that these notes are a new addition and are therefore under constant revision.

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2024, May 5) Embryology Molecular Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Molecular_Development

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