An embryo is an amazing thing. From just one initial cell, an entire living, breathing body emerges, full of working cells and organs. It comes as no surprise that embryonic development is a very carefully orchestrated process—everything has to fall into the right place at the right time. Developmental and cell biologists study this very thing, unraveling the molecular cues that determine how we become human. (146)

Lewis Wolpert once famously stated “”It is not birth, marriage, or death, but gastrulation, which is truly the most important time in your life.”
What is Gastrulation?
During early development in majority of animals, the morphology of the embryo is dramatically reorganized by cell migration and this is termed as Gastrulation. During gastrulation, many cells which are near the surface of the embryo move to a new, more interior location.The main purpose of gastrulation is to position the 3 embryonic germ layers, the endoderm, ectoderm and mesoderm. ( See animations …

NK homeobox genes in Annelid Platynereis dumerilii:
So far in Annelids series we talked about three articles which were published recently in major scientific journals,in the form of two posts ( Annelids on a roll Part : I and Part II ) and today we will end this series by discussing a article from Guillaume Balavoine’s lab dealing about Homeobox NK genes in annelid Platynereis.
We talked already about NK genes couple of times but just to remind that NK genes are clustered and involved in patterning various mesodermal derivatives during embryo …

We Discussed so many times on this blog about the need of appropriate model system to under take the challenge provided by the genomic era and expansion of integrative disciplines like evo devo,which requires researchers to adopt a more integrative approach while choosing model organisms.Another important point which should be considered in choosing model systems is their phylogenic position ,so that they might serve as a complement to existing model systems in reconstructing evolutionary history.

DP2.1.1.6X.14.H
Originally uploaded by pelagosphera

The starlet anemone “Nematostella Vectensis” is becoming an increasingly important model system for …

Introduction:
Looks might be really deceiving and this statement holds true in case of heart formation in organisms. Even though Drosophila heart which looks very different from its vertebrates counter parts,but The molecular pathways controlling heart formation and differentiation are evolutionarily conserved. The similar rules in forming heart in flies and higher vertebrates and availability for various tools in Drosophila ,helped it in emerging as an excellent model system to study cardiac development,function and aging.

Heart Development:
In Drosophila melanogaster, heart precursor cells originate from the dorsal-most region of the mesoderm in …

In the last post of evo devo section , we saw that Comparison of whole genome sequences from different representatives animals it was observed that HOX, PARA HOX and NK were originally close to each other in the genome, forming a big mega cluster / super Hox cluster and later would have followed different evolutionary paths in each lineage.
The expression pattern of these three gene clusters are also interesting. Hox genes are expressed in all three germ layers but predominantly in ectodermal and neuroectoderm , ParaHox genes are expressed primarily …

At first, the embryo is just a small mass of cells. As it develops, it has to ‘know’ where its top and bottom are, as well as its front and back, and left and right sides. Different cells of the embryo grow into their designated organs and body parts. All must grow in the right place, and to the right size. Surprisingly, many of the genes that control the early embryo development of organisms such as mice, chickens and fruit flies are very similar to Human’s.
An animal’s body results …