转基因动物-transgenic animal.ppt

转基因动物
transgenic animal
一、概述
(一)基本概念
(transgenesis)
是借助基因工程将确定的外源基因导入动植物的染色体上,使其发生整合并遗传的过程。
广义地说,向细菌、微生物、动植物细胞、动植物个体导入外源基因都可称之为转基因,所以转化(transformation)、转导(transduction)和转染(transfection)在转基因这个概念上得到了统一。
(transgenic animal)
是指用人工方法将外源基因导入或整合到基因组内,外源基因能够表达并能稳定传代(按孟德尔定律遗传)的一类动物。
(二)基因工程技术的特点
上个世纪70年代诞生的基因工程技术特点是“分子水平操作,细胞水平表达”,是把外源基因间接(载体介导)或直接转入细胞内,利用细胞这个报小的生物工厂达到生产或科研的目的。
这里基因转移的对象是细胞,转移过程是在细胞水平上进行的,目的只是把改造了单个细胞的遗传特性。
获得产品或进行实验研究需要大量的细菌培养或细胞培养技术。
(三)基因工程技术引起人们思考的3个问题
1. 能否跨越细胞水平,直接在机体整体水平上进行操作。
2. 能否培育高效表达基因工程产品的动植物,取代目前大量细菌培养和细胞培养呢?
如果获得这样的动植物,人们获得所需要的生物活性物质就像挤牛奶那么方便(如培育一种高效表达胰岛素动物),只需定期从这个生物工厂收获就行了。
3. 能否利用基因工程技术创造高产,抗病和具有某种特殊性能的新品种乃至改造人类的基因结构呢?
1984 – A live lamb was cloned from sheep embryo cells
1986 – Early embryo cells were used to clone a cow
1993 – Calves were produced by transfer of nuclei from cultured embryonic cells
1995 – Two sheep, named Megan & Morag, were cloned using embryo cells
1996 – Birth of Dolly, the anism to be cloned from a fully differentiated adult cell
1997 – Transgenic sheep named Polly was cloned containing a human gene
Mammal Cloning Timeline
1/WORLD/europe/08/06/
Megan and Morag
Dolly
From: student presentation Aman Arya, Nancy Chen, Dan Perz, Dave Reichert, Ronnie Wong
1998 – 50 mice were cloned in three generations from a single mouse
1998 – 8 calves were cloned from a single adult cow, but only 4 survived to their first birthday
1999 – A female rhesus monkey named Tetra was cloned by splitting early embryo cells.
2000 – Pigs and goats reported cloned from adult cells
2002 – Rabbits and a kitten reported cloned from adult cells
Tetra
http://hs./hspva/academic/Science/Thinkquest/gail/text/
From: student presentation Aman Arya, Nancy Chen, Dan Perz, Dave Reichert, Ronnie Wong
Dolly
Dolly with her first newborn, Bonnie
Born in July 1996 at the Roslin Institute in Scotland
First mammal to be cloned from an adult mammal using the nuclear transfer techn