Why are echinoderms studied in embryology?

Answer 1

because their embryos are convinient to study

- each female have millions of eggs that can be fertilized in vitro

- embryos at 48h of development forms a small larvae with all major organs formed : nerve cells, guts, mesodermal squeletton, imune cells etc ...

This is a great advantage, lots of experiments can be done in a short time

- synchronous development : each egg fertlised at a given time and at a given temperature will develop at the very same rate, so lots and lots of camprable embryos can be observed in each experiment (not the same with mouse)

- they are transparent thus easyly observable under a microscope, well suited for all forms of stainings

- Scientists have tools to perform loss and gain of function (shut down or overexpress a specific gene during development)

- Genome of an American specie (S Purpuratus)is fully sequenced, other species will soon have their genome sequenced as well

- They are non chordate deuterostomes. This makes urchins in an evolutionary point of view much closer cousins to human than drosophila (fly) which is as well extensively studied in embryology - roughly : results found in sea urchin may be more likely to reflect a situation found in vertebrates than those found in drosophila

etc etc ...

one major drawback of sea urchins is that its long life cycle (env 2 years) cannot permit the generation of mutant strains (no genetic tools like in mouse zebrafish or drosophila)