Tag Archives: gene research

Tabby cat

How tabby cats earn their stripes – genetics answer

A feline genetic study has revealed that a particular gene variation in a cat’s chromosome is responsible for the stripped fur so many cat lovers adore. According to the researchers, the same gene gives cheetahs, the house cat’s larger and wilder cousin, stripes instead of the regular spots.

Tabby cat

Tabby cats are stripped with a variety of patterns.

The research was lead by Stephen O’Brien of the National Laboratory for Cancer Research, who also was part of the team which decoded the entire domestic cat genome back in 2007. An intriguing subject, which was just recently solved, was how exactly did cats get their varied coats, from plain solid colors to tabby narrow stripe or d “mackerel” pattern, as it’s also called.

Using the genetic mapping of the domestic cat’s genome, scientists narrowed their search down to one region of the chromosome containing three large genes. Further filtering by sequencing of both  blotched and stripped coated felines reveled that the specific gene in cause is “Taqpep“. Narrow stripes coated cats have a working copy of this gene, while cats with a blotchy “classic” pattern have the gene turned off by a mutation.

The researchers suspect, however, that the gene has a function far useful than simply offering stripes. Apparently the Taqpep gene also holds the blueprint for a molecule usually found on cell membranes and used for passing messages from outside the cell to the inside. These types of membrane molecules are often associated with the immune system. Since this color mutation occurs fairly often among cats, it may be safe to say that it has a role in strengthening cats’ immune system.

“What this is, is the first connection of a gene involved in pattern formation in cats to their molecular status,” said study researcher Stephen O’Brien of the National Laboratory for Cancer Research.

Also, it’s been found that a mutation in the same gene produces the blotches and stripes of the rare “king” cheetah, rather than the spots most cheetahs have.  The research itself wasn’t initiated out of a fluke of curiosity in a quest to establish why tabby cats get their stripes. O’Brien said, cat genetics may help researchers understand human disease and genetic development.

Findings were reported in the journal Science.

Switching genes off and on

geneWorking with genes is something very delicate and dangerous at the same time. If scientists were able to, say, turn a gene off when it is not needed or harmful and then turn it on at a certain point then that would be a huge breakthrough, with a list of benefits that could go on for miles.

It seems that fire, which gave the ancient man a great boost, can also be the answer now, after all these milleniums; well not exactly fire, but heat. By exploiting the heat shock response, an ancient mechanism that protects cells from dangerously high temperatures, researchers have developed a new method to introduce foreign genes, called transgenes, into an organism and control when and where these transgenes are expressed. Other techniques had been previously tested, but the results were not overwhelming. The researchers at Rockefeller University have suggested this method.

The thing is that during the heat shock a protein called heat shock factor-1 travels from a cell’s cytoplasm to the nucleus, where it binds to a specific sequence of DNA. This interaction then leads to the transcription of heat shock protein, a shield that deflects excess heat from cells and protects them from damage. However, while scientists could know when this transgene was expressed, they couldn’t limit its expression in specific cell types and study a particular protein’s effect on them. To do so, they would have to target a single cell with a laser beam until the heat shock response kicked in for the transgene to be expressed. In Caenorhabditis elegans, that’s 34 degrees Celsius.

“If you’re good, each animal would take a couple of minutes,” says Shai Shaham, head of the Laboratory of Developmental Genetics. “And you would need to repeat this many times if you wanted to study a cell’s function and that cell’s role in behavior.”
“So, instead of using a laser beam to ablate cells,” says Bacaj, “you could create a responder with a gene that encoded a toxin, one that killed the cells whose function you want to specifically study. Since the heat shock response only occurs in those cells, all you have to do after you create these transgenic animals is turn up the heat to 34 degrees.”