y*********u
发帖数: 183 | 1 刚拿到chimera mouse，正要mate
其中有1只 100% ES cell agouti colour 的chimera mouse, facility说这样的老鼠
germ line transmission的概率非常高，因为100% agouti说明 targeted ES cell 完
全out growth 原 host embroyo 的细胞了。
但是我从另一方面想，似乎100% agouti也不是个好兆头，比如兴许发生了一些
aberrent使得ES cell长得飞快，但无法进行germ line contribution
周围没有特别熟悉这个Process的人，所以只好发到这里来问问 |
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f******e
发帖数: 53 | 2 The higher percentage of agouti color indicates higher chance for germline
transmission.But only you have to judge after getting F1 generation.
If ES grow fast due to some mutation, it will form the tumor rather than
skin and hire.So donot worry about it. |
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h******o
发帖数: 9 | 3 是129（ES)和C57BL/6老鼠。
我想无论ES毛色基因是怎么样的，如果和C57bl/6反复回交后，毛色基因应该已经被全
部替换成C57bl/6的毛色基因了，也就是说应该是黑色。可是我目前的老鼠有黑有灰。
高度怀疑没有回交。
网上查的Genotype of mice:
C57Bl/6: C/C, P/P, a/a
129/Sv C/C, P/P, Aw/Aw
black: C (or tyr+); tyrosinase locus
albino (white): c (or tyr-); loss of tyrosinase activity; no eumalanin,
little if any phaoemelanin
C/C black coat
C/c black coat
c/c white coat
Pink eye dilution: p locus; change in shape of the pigment; granule (lighter
black coat and pink eyes)
p/p pink eye light gray coat
P/p... 阅读全帖 |
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r****o
发帖数: 105 | 4 本文献给YL
（十）Richard Behringer的练习题
上一篇提到了小鼠的毛色。Blanche在讲课过程专门出了七道关于毛色的练习题
让我们思考。这七道题目是由MD Anderson的Richard Behringer准备的，这老哥精通小鼠
遗传学，是 “manipulating mouse embryo: a laboratory maual”的作者之一。由于实
在没有任何这方面的基础，在讨论这几个题目的时候，我完全是糊里糊涂的。现在上完课
之后，重新研习了一下毛色的基本知识，再来看这些题目，发现一点都不困难。下面就是
这些题目。
（１）albino的雌鼠和albino的雄鼠交配。子代的毛色是什么？C位点的基因型
是什么？
（２）albino的雌鼠和黑色雄鼠交配，子代全是agouti。请问亲代的A位点基因
型是什么？
（３）黑色雌鼠和褐色雄鼠交配。部分子代是冲淡的黑色和冲淡的褐色。请问亲
代的D位点基因型是什么？
（４）一只黑色的雌鼠和一只albino的雄鼠交配。所有的F1子代都是agouti。F1
子代相互交配后，F2子代有五种毛色表型, 包括agouti，albino，黑 |
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D*a
发帖数: 6830 | 5 C/C是黑色的话，对agouti是隐性，Aw/Aw是agouti显性。灰的是啥？Aw应
该是黄黑的啊。也就是说你母老鼠如果用129(Aw/Aw)，所有小鼠都是agouti色，一半是
纯的，一半是129-B6 |
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b*s
发帖数: 82482 | 6 http://en.wikipedia.org/wiki/Black_tiger_(animal)
A black tiger is a rare colour variant of the tiger and is not a distinct
species or geographic subspecies. There are reports and one painting (now
lost) of pure black non-striped tigers (true melanistic tigers). Most black
mammals are due to the non-agouti mutation. Agouti refers to the ticking of
each individual hair. In certain light, the pattern still shows up because
the background color is less dense than the colour of the markings.
there ... 阅读全帖 |
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y*********u
发帖数: 183 | 7 Early sign of chimera mice that carrying gremlin transmission.
Dear all, I am in a hurry to decide if it is worth to inject another ES cell
line of a KO mice.
The ES cell line I am using is SV129 cell line ,which carrying agouti coat
colour.
Right now I am having 9 male chimera mice and 1 female chimera mice, all of
the male chimera mice are with very high agouti number indicating a strong
ES cell contribution, and also, as stated above, a distorted gender ratio.
Meantime , I am getting above 80... 阅读全帖 |
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s******a
发帖数: 472 | 8 250只里有多少是agouti的？
我感觉一窝里只要有agouti pub，基本上就有戏 |
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f****n
发帖数: 1823 | 9 How to Identify Wild Cottontails
Cottontails are always agouti (reddish-brown with black and gray hairs
throughout.) They average 3 lbs. at adulthood. They have longer legs,
slimmer ears, and a more narrow face than the domestic rabbit. If you find a
nest of baby cottontails outside, unless you know the mother is dead or a
baby is injured, you should not disturb the nest. Mother cottontails nurse
only a couple times a day, and otherwise stay away from the nest to divert
predators. Cottontails ar |
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D******r
发帖数: 479 | 10 前几天有人发信问我贝儿叽咕子是什么品种，我只知道是mini rex旦一直以为这个颜色
叫做橘色。然后一查才发现，哦，原来是标准的红色，呵呵
网上转来个，感兴趣的可以去那个网站看所有mini rex的颜色，有些好漂亮阿，真是毛
色丰富的品种，呵呵
http://mr-colors.tripod.com/index.html
Red
**RED-Genetically these are agouti colored rabbits, but what we are
looking for is the appearance of a 'self' colored rabbit. It is difficult to
find good Red Mini Rex that don't retain some lingering signs of their
castor origins by the way of dark ear lacing or blue under color. Again
clean reds to clean reds is the best way t... 阅读全帖 |
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D*a
发帖数: 6830 | 11 貌似有不少的knockout mice 都有strain特异性的。。。
具体例子不知。。。
对了，好像agouti这个基因就跟obesity有点儿关系。。。 |
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g***y
发帖数: 201 | 12 取决于你们做KO用的embryonic stem cell 是从那个strain里面提的。
传统上很多都是用129，129 coat color 就是agouti
如果是从129来的，cross with b6,
F2 就会出现segregating coat colors.
如果想得到品系纯的老鼠, 或者把现在的不纯的backcross，或者把最初的chimera，直
接breed 到
跟ES cell 背景一致的129 substrain |
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y*********u
发帖数: 183 | 13 非常感谢！另外，如果ES cell 性别是ｍａｌｅ的话，从ｃｈｉｍｅｒａ的性别比例能
否看出germ line transmission的概率呢？
如果拿到了很多只ｃｈｉｍｅｒａ的话 |
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y*********u
发帖数: 183 | 15 I am having the same problem: some people here said that high agouti combine
with distorted sex ratio is usually a guarantee of successful germ line
transmission
but I am waiting for it to really happen -_ |
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D*a
发帖数: 6830 | 16 嵌合鼠的“不纯”和需要回交的老鼠的不纯不是一个概念。
在基因敲除老鼠中，一般把做过基因修饰的胚胎干细胞注射到小鼠的完整胚胎中，借助
小鼠的完整胚胎进行发育。这个过程中为了区分外源胚胎干细胞和受体小鼠细胞，一般
采用两种花色的老鼠比如agouti色的129老鼠注入到黑色B6老鼠中，这样出来的是嵌合
鼠，它的每个细胞都是纯合的，或者是129纯合，或者是B6纯合，但是老鼠全身因为含
有两种品系的老鼠细胞，所以总体上不是“纯系”。
这样的老鼠，理论上生殖系统也会有这两种品系的细胞构成，因此，跟129交配，生出
来的或者是杂合的129-B6的老鼠（不带有转基因），或者是纯合的129老鼠（带有转基
因）。
做回交的老鼠，是比如上面我拿到了纯合129的转基因老鼠，我希望研究这个基因在C3H
这个品系上的应用，那么我用纯的129老鼠和C3H老鼠交配，这样的老鼠出来的每个细胞
都是不纯的，因为每个细胞都含有一条C3H的染色体和一条129的染色体。然后这样的第
一代老鼠F1继续跟C3H老鼠交配，第二代老鼠就含有多一点C3H(大约75%)，少一点129。
循环往复跟C3H老鼠交配，129越来越少，直到达到纯... 阅读全帖 |
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j**W
发帖数: 89 | 17 You are right about a couple of things.I switch field and learned biology (
not including molecular biology) in English.And I did not make the targeting
vector. I took over the project starting from agouti mouse. Please bear
with me if I could not be clearer. I am sorry about the confusion on the
primer used for sequencing. We did sequencing with both P1 and P2. One came
back with no good sequence at all. From the sequencing result of the other,
it seems to me like P1. The sequencing result cove... 阅读全帖 |
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l********e
发帖数: 415 | 18 JM8A3是杂合的，所以还会有agouti ... |
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