Mouse breeding - (Oct/02/2006 )
Hello, I have a potentially very stupid question. I have several breeding pairs of het. mice who produce little or no knockout mice. Is there a way to increase the productivity of knockout mice? Do people always just breed het mice or is it okay to breed het X ko mice, or would that even produce any more of the ko and wild types?
I have problems remembering which symbols go with the different types of mice--which symbols do these represent: +/-, +/+, -/- . . . I'm trying to figure out which is which for hets, homozygous, wild type and knockouts. I am very confused with this.
Also, if someone wants me to breed for double knockout mice, what does that mean? I am having trouble with the genetics and I am too embarrassed to ask anyone at work. Please, please help me, if you can!!
Thank you!!
I am absolutely NOT trying to be harsh or to hurt your feelings, but I think you need to get over it and ask someone in your lab who is more experienced to help you.
transgenic mice are expensive and critical to any study. if you are managing the colony or even just helping out, you must know what you are doing or you will waste research time and money, as well as the lives of some of the mice.
Please please ask a more experienced technician in your lab to help you out. the only thing that should be embarrassing about your situation, is if you don't ask for help
good luck
I have problems remembering which symbols go with the different types of mice--which symbols do these represent: +/-, +/+, -/- . . . I'm trying to figure out which is which for hets, homozygous, wild type and knockouts. I am very confused with this.
Also, if someone wants me to breed for double knockout mice, what does that mean? I am having trouble with the genetics and I am too embarrassed to ask anyone at work. Please, please help me, if you can!!
Thank you!!
i hope you had your questions answered. i am sure yr lab would be glad to help you.
ask to see the animal protocol . you should have a copy of it for yourself.
i know that to get a KO you have to breed HT w/HT (+/-) if you do the cross you will see you can have three possibilities WT (+/+, ) HT (+/-) and KO (-/-) if there was a way to get more KO mice we'd all be pretty excited. that is, there is no way. but you always breed HT with HT to increase yr chances.
always, if you have a question ask. you were not born knowing this stuff, no one was!!!
Hello, I have a potentially very stupid question. I have several breeding pairs of het. mice who produce little or no knockout mice. Is there a way to increase the productivity of knockout mice? Do people always just breed het mice or is it okay to breed het X ko mice, or would that even produce any more of the ko and wild types?
I have problems remembering which symbols go with the different types of mice--which symbols do these represent: +/-, +/+, -/- . . . I'm trying to figure out which is which for hets, homozygous, wild type and knockouts. I am very confused with this.
Also, if someone wants me to breed for double knockout mice, what does that mean? I am having trouble with the genetics and I am too embarrassed to ask anyone at work. Please, please help me, if you can!!
Thank you!!
i hope you had your questions answered. i am sure yr lab would be glad to help you.
ask to see the animal protocol . you should have a copy of it for yourself.
i know that to get a KO you have to breed HT w/HT (+/-) if you do the cross you will see you can have three possibilities WT (+/+, ) HT (+/-) and KO (-/-) if there was a way to get more KO mice we'd all be pretty excited. that is, there is no way. but you always breed HT with HT to increase yr chances.
always, if you have a question ask. you were not born knowing this stuff, no one was!!!
THANK YOU, snakeplissken, for your very kind reply. You clarified my questions, I was unsure of the signs, so I thank you very much for helping me out. The woman who managed these colonies before me had used the het w/ko, so I was wondering why she would breed these pairs instead of the het w/het. I think I will increase my breeding pairs now that I know there are no other ways. And I will ask my lab and other labs when I have more questions about the mice.
Thank you again for the encouragement of my questions, I was fairly depressed until I read your reply. Thanks!!
Just to add to the previous comments, we usually do het by het breeding so that we have wt littermates to use as a control. In theory, as snakeplissken said, you should have 25% wt (+/+), 50% het (+/-), and 25% ko (-/-). By breading het by ko, you should theoretically get 50% het and 50% ko. So, het by ko would give you more ko per litter but no wt mice (for controls). If you are consistenly getting lower than expected numbers of kos, then the gene that is knocked out may be influencing some part of the reproduction.
one more thing--to the person who first posted--never breed WT with WT!!! WT /WT=no KO , so make sure you are keeping a record of the colony , who you mate with who and always check the cards. also make sure yr not mixing colonies (one strain with another) important!! good luck!!! :}
Thank you, jmdp, for the clarification on why to breed het by ko. It now makes sense to me why they have been set up that way in the past, especially since we are not getting very many kos as it is. I really appreciate all the replies that I have gotten on this subject.
Thanks again!!