loxp-frt-neo-frt是什么，有什么作用

loxp-frt-neo-frt是什么，有什么作用

这个不知道你所指的具体情况是什么。
个人认为应该是载体系统。
loxp和frt都是位点特异性重组酶，主要的用途就是载体转录（转染）的过程中将目的基因重组到基因组的特定位置。
如果你能再提供更多的资料，可能我还能给你更准确的答案。追问是质粒上加进去的一个片段，用来做基因敲除的追答哦，有机会研究一下~

loxP-FRT-PGK-gb2-neo-FRT
( 英文名称：Pro- and Eukaryotic Neomycin Selection Cassette flanked by FRT-sites and one additional upstream lox)
类别：分子生物学试剂
The loxP-FRT-PGK-gb2-neo-FRT template is designed to allow kanamycin/neomycin selection in prokaryotic and eukaryotic cells, respectively.
It combines a prokaryotic promoter (gb2) for expression of kanamycin resistance in E.coli with a eukaryotic promoter (PGK) for expression of neomycin resistance in mammalian cells.
The prokaryotic promoter gb2 is a slightly modified version of the Em7 promoter. It mediates higher transcription efficiency than the generally used Tn5 promoter. The promoter of the mouse Phosphoglucokinase gene (PGK) is used as the eukaryotic promoter. A synthetic polyadenylation signal terminates the kanamycin/neomycin expression. The cassette is flanked by FRT sites for later excision by Flprecombinase.
An additional single loxP site is located at the 5’ end of the cassette. Unique NotI and XhoI sites flank the cassette for convenient cloning with restriction sites.
Using the provided PCR template one can easily create a loxP-FRT-PGK-gb2-neo-FRT cassette flanked by any other restriction sites to clone the cassette
into the vector of choice. The restriction sites can be introduced by adding the corresponding sequence in the PCR primer. The template can easily be used to generate targeting constructs mediated by Red/ET Recombination.
The loxP-FRT-PGK-gb2-neo-FRT template is not linear but plasmid based (3485 bp in size). Due to its R6K origin the plasmid cannot replicate in most E.coli strains. The PCR product can therefore be used directly for downstream applications without any further purification.
At least 20 PCR reactions can be performed using 1 ul per reaction as template.

我暂时保留我的看法！