What is a map cross?

[John C Calhoun]

1) I am using a protocol as a guide in book about Zebrafish. The section this protocol falls under is called "Mapping and Cloning." By mapping it refers to mutant-defined genes rather than the normal gene. The first step is the "Quick lysis of embryos" in which the embryos to be used are called "Map cross F2 embryos." The 2 is in a subscript so I assume it means a second generation from wild embryo (Filial 2). What I do not understand is what a map cross embryo is!

[SciB]

I'm not sure what they mean either. Did they say which two genotypes were crossed to make the F2 generation? Mapping usually means identifying which chromosome that a variant gene is on, but it could in this case mean the location on the chromosome. If the gene in the cross is known, however, then the chromosome is probably also known so I'm not sure why you would need to do mapping.

It would be helpful if you would keep all your questions in one thread so that they are all together and the answers can be found together. Also, we don't know what your hypothesis is or what you are trying to prove. If you would take a minute and explain the purpose of your project it would make it easier for us to understand why you are asking certain questions and to guide you better.

Sybee

[John C Calhoun]

For now what I'm working on is the quick lysis of zebrafish embryo's. I'm glad you told me to include all questions in one thread, I recall reading a thread on the forum that was closed because it had too many questions. The argument being that one question keeps the thread on-topic.

[deleted-132180]

Hi there,

I agree with the previous expert that if you provide us with more details about your main question, your hypothesis, and the experimental procedure you are planning to use to test your hypothesis, we will be able to provide you with more helpful advice. Are you attempting to map the location of a gene within the zebrafish chromosome? Why do you need to lyse zebrafish embryos? What exact steps in the protocol are you confused about? If you could also show us the steps in the protocol that you're asking about so we can also read it ourselves, it may help us with trying to understand it.

Connie