Thursday, September 30, 2010

What is Life? 変態について(その5)


While I was captured and brought in the cage like a prison with no items, there may be something happened. Am I a crazy?

さて、本日は「変態」シリーズ5日目です。前回はE.H.Davidsonという発生生物学者がScinece誌に"Set a cells"という概念を発表したことを説明いたしました。この論文をご覧になりましたか?生命の進化と変態に関連する重要な知見(意見)を彼は示していました。その詳細について簡単に説明いたします。

Now, this is the fifth class about "Metamorphosis". At the last, I showed that E.H.Davidson revealed his mind about the relation of evelution and metamorphosis by using the concept of "set aside cells" on Science at 1995 as a paleontologist. Have you checked the article? In this class, I explained about "set aside cells" in simple.

この"set aside cells"の概念は現在の幹細胞に繋がるとても重要なものです。ウニの幼生はプルテウス幼生と呼ばれ、ちょうど、あなたの手の平でパーにしてから小指だけを曲げたような形をしています。写真をご覧ください。

I think the concept of "set aside cells" is quite important and was leaded to the "stem cells". The juvenile of sea urchin take charming shape and called as "pluteus larva" like your left hand with closing little finger. See the picture in below.


Pluteus larvae take foods, grow, have adult rudiment in their body at their left side, and perform metamorphosis to be sea urchin.


The larval body is constructed of about 2,000 cells. The number is not altered in their development until metamorphosis, like insect. They also grow with several ecdyses. But the number is not changed through their development, I learned so in the University.

そこで登場するのが"set aside cells"という概念なのです。昔々カンブリア時代のことをお話ししなければなりませんが、そろそろ時間のようです。

So, the concept of "set aside cells" is focused for discussion of evolution and development. It's quite interesting for me. To explain it, I have to bring you to the Cambrian period. But the time is over.


Today's class is over. Be careful. It is cold. Please click the button at the bottom of this What is Life?, if you are a student of this class.

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

1 comment:

  1. <野生>論を読んでいます。体の中の水分はやがて排泄されて雲になり雨となり、そして自然に帰る。体のタンパク質もカルシウムも同じ。だとすると、魂までもが自然の一部なのでは?


    生き物博士 サミぃ


Thank you!