Cell & molecular biology. (Science News of the year: the weekly newsmagazine of science).Malaria milestones Biologists deciphered the DNA sequences of a key malaria-causing parasite and of the mosquito that usually carries it, findings that suggest new ways to combat the deadly disease (162: 211 *). Hunger hormone The stomach makes a hormone called ghrelin that, in the brain, triggers hunger. Dieting, gastric-bypass surgery, and genetic mutations appeared to disturb the hormone's production (161: 107 *, 366; 162: 14). Rice twice Two research groups independently described the entire genetic sequence office, a first for a crop plant (161: 211 *). Cloning consensus A national advisory panel recommended outlawing cloning aimed at creating a child but suggested allowing medical experiments with cloned human cells (161: 52). Stem cell stem cell In living organisms, an undifferentiated cell that can produce other cells that eventually make up specialized tissues and organs. There are two major types of stem cells, embryonic and adult. stir Generating controversy over the potential of similar work in people, scientists showed that stem cells stem cells, unspecialized human or animal cells that can produce mature specialized body cells and at the same time replicate themselves. Embryonic stem cells are derived from a blastocyst (the blastula typical of placental mammals; see embryo), which is very young derived from cloned mouse and cow embryos can cure some animal diseases and create organs such as kidneys (161: 163 *, 356 *). Offering an alternative source for similar human cells, researchers showed that bone marrow from adults contains cells that can mature into many specialized types (161: 390). Monkey business Scientists obtained long-lived stem cells from monkey eggs stimulated to develop without being fertilized fer·til·ize v. fer·til·ized, fer·til·iz·ing, fer·til·iz·es v.tr. 1. To cause the fertilization of (an ovum, for example). 2. by sperm (161: 94). Viral threat Stoking bioterrorism fears, scientists proved they could build the poliovirus poliovirus /po·lio·vi·rus/ (pol´-e-o-vi?rus) the causative agent of poliomyelitis, separable, on the basis of specificity of neutralizing antibody, into three serotypes designated types 1, 2, and 3. from scratch, using the widely known genetic sequence and available chemicals (162: 22). RNA RNA: see nucleic acid. RNA in full ribonucleic acid One of the two main types of nucleic acid (the other being DNA), which functions in cellular protein synthesis in all living cells and replaces DNA as the carrier of genetic world An unexpectedly large number of genes encode RNA strands instead of proteins (161: 24 *). Scientists started using short RNA strands to inhibit viruses and cancer growth (162: 93, 189). Small wonder A microbe microbe /mi·crobe/ (mi´krob) a microorganism, especially a pathogenic one such as a bacterium, protozoan, or fungus.micro´bialmicro´bic mi·crobe n. plucked from a volcanically heated ocean bed has the smallest number of genes of any living organism studied (161: 275). Sleepy head Two common general anesthetics produce their sedative sedative, any of a variety of drugs that relieve anxiety. Most sedatives act as mild depressants of the nervous system, lessening general nervous activity or reducing the irritability or activity of a specific organ. effects by triggering the brain's natural sleep circuits (162: 132 *). Gender gap Parasites infect male mammals more often than females, possibly contributing to the tendency for male mammals to die earlier than females (162:182). Spark of life Spark of Life is the eighteenth episode in the of the popular American crime drama , set in Las Vegas, Nevada. Summary Grissom, Sara and Greg work a case where a bushfire kills a man and burns a woman, who survived. Biologists identified the enzyme in mammalian sperm that triggers development of a fertilized egg (162: 189) and found that sperm contain an unexpected payload of RNA (162: 216). Longevity gene Variations in a gene called klotho may influence the length of a person's life (161: 36 *). Muscled out A study in worms suggested that during aging, the nervous system stays intact but muscles degenerate (162: 260). Showing off a growing ability to guide the growth of lab-grown tissues, Salt Lake City scientists created this image of the Olympic rings from live nerve cells (161: 61). * An asterisk indicates that the text of the item is available free on SCIENCE NEWS ONLINE (http://www.sciencenews.org). |
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