Wednesday, December 29, 2010

What is Life? Evolution from invertebrates to vertebrates 2(無脊椎動物から脊椎動物への進化その2)

Good morning everyone. Are you in your country or still in your laboratory now? I was always in my laboratory to study with co-workers, when I was a graduate student of the University. Please take care and do not catch cold in this winter.


Anyway, this is the second for the class of evolution from invertebrates to vertebrates. At the last of this class, Sammy introduced about the basis of developmental biology. We human being is a member of vertebrates and belongs to Deutrostomia. Because the animal history is quite long, the evolution from invertebrates to vertebrates is one of the most attractive question for biologists.


(4) Sea urchins
By such reason, I tried for the question using the sea urchin larvae. Do you know the sea urchin? It is known as a source of sushi. The gonad of sea urchin are placed on the small rice ball surrounded by dried laver. It's quite nice, is'n it? In this class, the story of maturation of gonads in sea urchin will be explained in future. 


The sea urchin is a member of echinoderm. The echinoderm has many groups, which are sea urchin, sea star, sea cucumber, ophiuroid, crinoid, and others. In those groups, sea urchins and sea stars have been used as a sample of developmental biology. In particular, the sea urchins can be artificial fertilized in easy manner. Therefore sea urchin embryos have been used as experimental animals anciently.


In animal phylogeny, the echinoderm is existed at beneath of chordates, which contains protochordates and vertebrates. So, in order to elucidate the mechanism of evolution from invertebrates to vertebrates, the echinoderm is superior target.


I am sorry, it is little long and difficult. m(._.)m


Today's class is over. Have a nice day. Click the button at the bottom of this "What is Life?", if you are a student of this class. Mind you? If you have any question about life, please send an e-mail for me.


にほんブログ村 科学ブログ 生物学・生物科学へ人気ブログランキングへ


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