Fragile X Gene May Yield Clues About Autism (2/13/2009) Even though the fragile X gene is the cause of only a very small percentage of cases of autism (from 2 to 5 percent), it nonetheless is the cause scientists understand best. As researchers learn more about the faulty gene in fragile X, including possible ways to compensate for it, their discoveries are likely to suggest new ways to look at the more frequent, more devastating disorder of autism. Tiny Fruit Flies Yield Huge Benefits (2/13/2009) Tiny fruit flies contain hundreds of genes that are homologous with genes in humans that can cause disease, from neurological diseases to cancers. That makes the creatures a great way to study what happens when these genes are defective – and how the effects of these genes can be modified. Medicine From Snakes (12/17/2008) The Brazilian pit viper is one of the deadliest snakes of the jungle, but a blood pressure drug made from a protein in its venom has extended the lives of millions of people. Dogs Have Narcolepsy Too (9/18/2008) Dogs with narcolepsy inherit defective versions of the narcolepsy gene from both parents. To create a colony of narcoleptic dogs useful for research on the sleep disorder, researchers kept breeding narcoleptic dogs with each other so their puppies would all have the disorder. Song Learning is a Sign of Sexual Maturity (9/8/2008) In songbirds, the end of song learning coincides with sexual maturity and a change in hormones. Interestingly, song production has a reproductive function in attracting a mate. Also, children lose their ability to learn new languages around puberty, when their hormones change. Nerve Cells That Can Be Seen with the Naked Eye (9/8/2008) Some of the nerve cells of the giant sea slug are so large they can be seen with the naked eye. The large size of the nerve cells, and the small numbers of such cells that control its learning of a simple behavior made the sea slug the ideal animal model to discover the molecular pathway for making memories stick. Female Rats and Humans Have Similar Hormonal Cycles (8/22/2008) Female rats have hormonal cycles (estrus) so closely similar to the cycles of human females (menstruation) that researchers worked with these animals to understand why doctors reported women sometimes recovered better from head injuries than men. Pregnancy Hormones Help Ward Off Head Injuries (8/22/2008) The same hormone that helps protect the fetus during pregnancy can help protect against the devastating effects of head injuries. It's a Two-Way Street (11/9/2006) How does information flow—from DNA to RNA, from RNA to DNA, or in both directions? For years, scientists thought that information could travel only from DNA to RNA, but new discoveries in the early 1970s changed their thinking. An enzyme called reverse transcriptase allows RNA to copy its genome to DNA, a characteristic that aids the cancer-causing properties of RNA viruses. What Was in Mother's Milk (11/9/2006) Through experiments with mice, John Bittner discovered a surprising relationship. Mouse milk carried a virus that caused tumors to grow. Later the virus was identified as an RNA virus—the mouse mammary tumor virus, or MMTV. Was Cancer Caused by Viruses (11/9/2006) Peyton Rous was ahead of his time! Back in 1911, he proposed that a virus could cause cancer. He based his hypothesis on his work with chicken tumors. Most scientists thought his ideas just pertained to chickens, but years later, experiments with mice would prove the scientific community wrong. Uncovering the connection between viruses and cancer opened the door to a new approach to cancer research. Bulging Eyes (11/9/2006) The “bulging eyes” of the leukemic mice turned out to be significant. They meant that leukemia cells had entered the central nervous system, causing a condition known as meningeal leukemia. The problem was solved by injecting chemotherapeutic agents directly into the cerebrospinal fluid as a way to destroy any remaining abnormal cells. One Cancer Cell Significant (11/9/2006) Mouse models provided the key to developing effective chemotherapy for leukemia. Not only did these models help researchers determine how to administer chemotherapy, they also were instrumental in figuring out the reason for recurrences. Pharmacologist Howard Skipper calculated that if even one cancer cell remains after treatment, the disease could begin growing again, pointing to the importance of eradicating cancer cells as thoroughly as possible. Exciting New Animal Model (11/9/2006) Zebrafish (ZF), a small fish found in pet stores, is also an excellent animal model. It has been used successfully to identify genes responsible for developmental disorders and diseases. Easy to breed and maintain, zebrafish larvae are transparent, allowing researchers to observe early development firsthand. Armadillos Are 'Cool' (11/2/2006) The low body temperature of the armadillo is a key reason why it is one of the few animals that can be used as an animal model to study leprosy. The bacilli responsible for the disease thrive in the armadillo’s “cool” body.