Cinnamon genes

Cold Spring Harbor Laboratory: Embargoed for release: 31-Oct-2007 17:00 Eastern US Time

Cinnamon genes

The cat genome has been sequenced for the first time. Scientists used samples taken from a four-year-old Abyssinian cat called Cinnamon. The report appears in Genome Research (www.genome.org).

Cinnamon is one of several mammals now being studied using a new method called light genome sequencing. The research team started with Cinnamon’s raw sequence data. Then scientists at a number of centres worked together. They used information from the genomes of other mammals that had been sequenced, together with earlier studies of the cat.

Six other mammal genomes have recently been completed. They are the human, chimpanzee, mouse, rat, dog, and cow. The human genome was finally sequenced in February 2001.

Similarities between the cat genome and these six let the scientists identify 20,285 possible cat genes.

They found hundreds of rearrangements within the chromosomes. These took place among the different mammals since they evolved from their common ancestor. This ancestor roamed the earth among the dinosaurs around 100 million years ago.

This latest research is expected to lead to health benefits for domestic cats. Ninety million are owned by Americans alone, according to The Humane Society. But the domestic cat is also a good model for human disease. This is why the National Human Genome Research Institute authorised the cat genome project three years ago.

Domestic cats can suffer from over 250 hereditary diseases. Many of these are like genetic diseases in humans. Cinnamon has a mutation, for example, that causes retinitis pigmentosa. This is an eye disease that can lead to blindness. In humans, retinitis pigmentosa affects 1 in 3,500 Americans.

The cat is also a good model for human infectious diseases such as HIV/AIDS. Feline immunodeficiency virus (FIV) is a relative of human immunodeficiency virus (HIV), which causes AIDS.

Using the cat genome data, the researchers identified several hundred thousand variants in the genes (known as SNPs, DIPs, and STRs). These can be used to discover the genes that cause hereditary diseases in cats and humans.

The scientists have already used these variants to identify the gene that causes Cinnamon’s retinitis pigmentosa. They published a paper on this in the May/June, 2007 issue of the Journal of Heredity.

These gene variants will also be useful for parentage testing, forensic analysis and studies of evolution. They will shed light on how the cat was domesticated. They will provide information on the development of fancy breeds. They will tell scientists how the great roaring cats have adapted to their environment.

The researchers also analysed the cat genome for interesting features, such as fragments of genes that migrated to the chromosomes from the mitochondria.

They also looked at a sea of repeating patterns that don't seem to do much. These included scores of genomic stretches from historic retroviruses. Some of these have known links to cancer.

The Cat Genome Project is based at the National Cancer Institute (Frederick, Md.). Cinnamon lives in a cat colony at the University of Missouri-Columbia. The sequencing data were generated by Agencourt Bioscience Corporation (Beverly, Mass.)

More help with words

cell

conception

conference

DNA

environment

evolution

fertilisation

individual

inherit

journal

molecule

protein

RNA

species

sperm

structure

What's it all about?

1. What was the name of the cat used in this research?
2. What kind of cat was she?
3. This research is all about sequencing the cat ------.
4. The scientists used a new method called ----- genome sequencing.
5. This meant they did not need to do as much work on the cat genome because they used information other scientists already had. Information about what?
6. The genomes of six mammals have recently been sequenced. If you had one of each of these in a room, how many legs would you have altogether?
7. The human genome has around 30,000 genes. Does the cat have more, fewer or about the same number of genes?
8. None of the six mammals studied was around at the time of the dinosaurs. But a type of animal related to all of them was. What two words does the story use for that animal?
9. What does each of the two words mean?
10. This new understanding of cat genes should eventually lead to ways of treating some cat diseases. It might also lead to ways of treating diseases in another living thing. Which one?
11. What is a hereditary disease?
12. Which hereditary disease does Cinnamon suffer from?
13. What would be the purpose of studying FIV (other than trying to treat the disease in cats)?
14. Hereditary diseases are caused by variants in the genes. What does this mean?
15. By studying variants of genes, scientists can learn lots of things about cats, humans and other living things. State three of these.
16. Viruses that infect a person or animal can sometimes leave genes inside the chromosomes of their sperm and eggs, which can then be passed on to children and children's children, and so on. What type of disease can these genes sometimes make more likely?
17. If you were these scientists what would you like to do next?
18. What question would that be trying to answer?

More science teaching resources for this story

Cinnamon genes UK US 31-Oct-2007

Topic for discussion, research or pupil presentations

Here are a few of the issues, implications and applications extracted from the cat genome research story:

1. This new research will lead to health benefits for cats. But the cat is also a good model for human disease.
2. Domestic cats can suffer from over 250 hereditary diseases. Many of these are like genetic diseases in humans. Cinnamon has a mutation, that causes retinitis pigmentosa, an eye disease that also affects humans.
3. The cat is also a good model for human infectious diseases such as HIV/AIDS. Feline immunodeficiency virus is a relative of human immunodeficiency virus (HIV), which causes AIDS.
4. Using the new cat genome data, the researchers identified several hundred thousand variants in the genes. These can be used to discover the genes that cause hereditary diseases in cats and humans.
5. The gene variants discovered in the cat will be useful for parentage testing, forensic analysis and studies of evolution. They will shed light on how the cat was domesticated. They will provide information on the development of fancy breeds. They will tell scientists how the great roaring cats have adapted to their environment.

Here are a few of the group research and/or discussion topics arising from the above. No doubt you will be able to think of others yourself.

1. What does it mean to be "a good model for human disease". Find three other animal models for human disease. What is the basic reason that studying one animal can provide useful information about another?
2. Find as many other hereditary diseases as possible that both cats and humans can suffer from.
3. Find as many other infectious diseases that both cats and humans can catch as possible. What is the difference between a hereditary disease and an infectious disease?
4. Variants of genes do not always cause disease. Find two examples of genes that have variants that simply make people or cat bodies look or work differently.
5. Choose one of the possible applications in this final paragraph. Find out as much as possible about this application and prepare a presentation on it to the class.

Tips for science class discussions and groupwork

No 63

It is a shame that more scientists don't read the education literature, for they would be aware of the quiet revolution taking place in teaching....

Put students into small interactive groups of four or five, give them projects, problems, tests, or case studies to analyze, and they will learn more effectively. Unlike many fads in education, which are enthusiastically touted but poorly investigated, cooperative learning may be the most thoroughly studied educational technique ever utilized. ...

Cooperative learning promoted higher individual knowledge than did competitive and individualistic learning, whether the task required verbal, mathematical, or physical skills. Most important the retention of knowledge was greater. Cooperative learning has striking additional benefits..."

Herreid, C.F. (2007) Start with a Story: The Case Study Method of Teaching College Science. Arlington, Virginia: NSTA Press