Autistic Cre

 (Understanding Cre rats for my upcoming presentation, and why not learn which ones are used in autism space while I am at it)

First, what is a Cre-rat?

Cre rats are commonly used to study the genetics and neurobiology; to study the function of specific genes and circuits in the brain. There are several types of Cre rats that are used in autism research, each with specific genetic modifications to study different aspects of autism. Cre rats are as not as common in autism research, compared to other areas of neuroscience research. 

How is a Cre-Rat created?

A Cre rat is genetically engineered to express the Cre recombinase enzyme. Cre recombinase is a protein that is used in genetic research to manipulate DNA sequences in a specific and controlled manner. By expressing Cre recombinase in specific cells or tissues in the body, you create genetically modified rats that have altered or deleted genes, which can help to study the role of these genes in disease and biological processes.

"Conditional gene targeting' is the technique used to create a cre-rat. It introduces a specific DNA sequence encoding the Cre recombinase enzyme into the rat genome, thereby selectively activating/deactivating specific genes in specific tissues at certain times during dev. 

To activate or deactivate a specific gene in a particular tissue/time, researchers create a mouse that has 2 different types of genetic modifications.

1. floxed gene, which means that the gene is flanked by two loxP sites.
2. second modification that causes Cre recombinase to be expressed only in the specific tissue or at the specific time of interest. Achieved by placing the promoter of a specific gene that is expressed only in that tissue or at that time in front of the Cre recombinase gene. The promoter "flips" the switch to turn on the Cre recombinase gene only in that tissue or at the time that the promoter is active (promoter-flip is technique for selectively express Cre recombinase in specific tissue/time, which allows targeted activation/deactivation). 

When Cre recombinase is expressed, it can recombine the DNA sequences between the two loxP sites, leading to the deletion or activation of the gene of interest. This allows researchers to selectively study the role of specific genes in different tissues or at different times during development.

Once the Cre rat has been created, it can be bred with other genetically modified rats that carry a specific DNA sequence flanked by "loxP" sites. The Cre recombinase then acts on these loxP sites to delete or modify the DNA sequence of interest, allowing researchers to study the effects of these genetic changes in vivo.

Some commonly used Cre rats in autism research:

1. Shank3 Cre rats: Deletion the Shank3 gene (scaffolding protein), which has been implicated in autism and other NDD.
2. CNTNAP2 Cre rats: Deletion the CNTNAP2 gene, which has also been linked to autism and language disorders.
3. FMR1 Cre rats: Deletion of the FMR1 gene, which is associated with fragile X syndrome, a genetic condition that often co-occurs with autism. 
4. MeCP2 Cre rats: Deletion of the MeCP2 gene, which is associated with Rett syndrome, a genetic condition that shares some features with autism.