Unit one

I. Pre-reading Activities.

A. Practice the pronunciation of the following words and memorize them.

• feline /ˈfiːlaɪn/ • lesion /ˈliːʒən/

• diabetes /ˌdaɪəˈbiːtiːz/ • herpes /ˈhɜːpiːz/

• hemophilia /ˌhiːməˈfɪliə/ • syndrome /ˈsɪndrəum/

• anthrax /ˈænθræks/ • immunodeficiency /ˌɪmjunəudɪˈfɪʃənsi/

• lupus /ˈluːpəs/ • canine /ˈkeɪnaɪn/

• leukemia /luːˈkiːmiə/

B. Read and discuss the questions.

→ What is gene mapping?

→ What do you know about gene mapping in Russia?

→ Have you ever heard about gene mapping of domestic animals?

→ What are the benefits of gene mapping?

→ Do you think that gene mapping is important for science? Prove it.

C. Match the following words with their definitions.

1. unravel A. to devote

2. dedicate B. to cut into pieces

3. chop up C. to probe and solve (a mystery, etc.)

4. lineage D. to be analogous or similar to

5. afflict E. of, relating to, or affecting cats or the cat family

6. correspond to F. resemblance in structure between animals, plants, or languages

7. feline G. to receive an advantage or gain

8. string (v) H. descent in a line from a common progenitor

9. benefit (v ) I. to cause great unhappiness for; distress

10. affinity J. to arrange in a long line

II. Reading Activities.

A. Read the text below using a dictionary.

By Mapping Cat’s Genes, Mysteries of Genetic Illnesses May Unravel

The New York Times,

By NICHOLAS BAKALAR

Genetically speaking, every dog has already had its moment as the center of attention. In 2003 a poodle named Shadow became the first canine to have his genome mapped, and in 2004 a boxer, Tasha, became the second.

Now scientists are turning their attention to the genome of the do­mestic cat, and it is a cat named Cinnamon's turn to donate a blood sample. Cinnamon comes from a carefully bred colony at the University of Missouri, and her lineage can be traced back for de­cades. Scientists therefore know exactly what they are getting when they look at her DNA.

Researchers hope to have the cat genome mapped by the end of the year and when the job is done, humans will be the ones to benefit.

Americans own more than 60 million cats, spend over $4 bil­lion a year on cat food and are so dedicated to feline health care that their veterinarians have identified more than 250 genetic diseases and hundreds of infectious agents that afflict them. The genome will contribute to knowledge with immediate practical application, not only for veterinarians and cat owners, but for geneticists, zoologists and conservationists.

When the National Human Ge­nome Research Institute, part of the National Institutes of Health in the United States, chose the cat as one of the select group of species to have their genomes mapped, it was no small honor. It will cost $5.5 million to do the job, said a spokes­man for the health institutes.

The sequencing is carried out un­der contract with Agencourt Bioscience Corporation, a biotechnology firm in Beverly, Massachusetts, which was started five years ago by scientists originally involved in the Human Genome Project.

Chopping up the DNA into tiny usable pieces in a process called library construction, and then putting it all back together creates the map.

The cat was chosen, among oth­er reasons, for its importance as a medical model in studying human disease.

"The genes on the cat chromo­some and the human chromosome correspond to each other like two strings of beads made of differ­ent colors," said Dr. Stephen J. O'Brien, chief of the Laboratory of Genomic Diversity of the National Cancer Institute, adding that cats have "the same genes, one after another, strung together across every chromosome.''

This resemblance means that many of the cat's genetic diseases are inherited exactly the same way as genetic illnesses in hu­mans. Diabetes, hemophilia and lupus, for example, have precise genetic homologues in cats.

Cat retroviruses, like those that cause feline leukemia and feline sarcoma, although slightly differ­ent in their gene structure from the human versions, produce le­sions that look almost identical to human cancers.

Feline immunodeficiency vi­rus, or F.I.V., resembles H.I.V. so closely that it follows the same progression that, untreated, leads to the wasting syndrome of AIDS in humans.

Cats also get feline versions of many other human infectious dis­eases, including rotavirus, poxvirus, herpes, Q-fever and dozens more. They are resis­tant to anthrax infection. Once the genome is mapped, said Dr. O'Brien, "research on feline stem cells will blossom, along with gene therapy applications."

"At least from a genomic per­spective," he added, "cats share a striking ancient affinity with hu­mankind."

B. Look through the text again and translate the following parts from English into Russian:

― genetically speaking

― scientists are turning their attention to

― carefully bred

― the genome will contribute to knowledge with immediate practical application

― the cat was chosen for its importance

― the genes on the cat chromo­some and the human chromosome correspond to each other like two strings of beads made of differ­ent colors

― look almost identical to human cancers

― Once the genome is mapped, research on feline stem cells will blossom, along with gene therapy applications.

C. Read the text again and answer the following questions in your own words.

1. What is the mapping mechanism according to the text?

2. Why have the scientists chosen cats for gene mapping?

3. Why have the scientists chosen the cat called Cinnamon rather than some other cat?

4. What is similar in cats and humans according to the text?

5. How do you understand the first paragraph of the text, in particular, its first sentence? Could you explain it in your own way giving an example?

D. The text below has been jumbled. Arrange the paragraphs in the correct order to make a full story.

(1) Genome mapping is the creation of a genetic map assigning DNA fragments to chromosomes.

(2) When a genome is first investigated, this map is nonexistent. The map improves with the scientific progress and is perfect when the genomic DNA sequencing of the species has been completed. During this process, and for the investigation of differences in strain, the fragments are identified by small tags. These may be genetic markers (PCR products) or the unique sequence-dependent pattern of DNA-cutting enzymes. The ordering is derived from genetic observations (recombinant frequency) for these markers or in the second case from a computational integration of the fingerprinting data. The term "mapping" is used in two different but related contexts.

(3) Two different ways of mapping are distinguished. Genetic mapping uses classical genetic techniques (e.g. pedigree analysis or breeding experiments) to determine sequence features within a genome. Using modern molecular biology techniques for the same purpose is usually referred to as physical mapping.

(4) In physical mapping, the DNA is cut by a restriction enzyme. Once cut, the DNA fragments are separated by electrophoresis. The resulting pattern of DNA migration is used to identify what stretch of DNA is in the clone. By analyzing the fingerprints,  contigs are assembled by automated (FPC) or manual means (Pathfinders) into overlapping DNA stretches. Now a good choice of clones can be made to efficiently sequence the clones to determine the DNA sequence of the organism under study (seed picking).

(5) Macro restriction is a type of physical mapping wherein the high molecular weight DNA is digested with a restriction enzyme having a low number of restriction sites.

(6) There are alternative ways to determine how DNA in a group of clones overlap without completely sequencing the clones. Once the map is determined, the clones can be used as a resource to efficiently contain large stretches of the genome. This type of mapping is more accurate than genetic maps.

(7) Genes can be mapped prior to the complete sequencing by independent approaches like in situ hybridization.