Cellular transforming genes   总被引：65，自引：0，他引：65  

G M Cooper 《Science (New York, N.Y.)》1982,217(4562):801-806

Cellular genes potentially capable of inducing oncogenic transformation have been identified by homology to the transforming genes of retroviruses and by the biological activity of cellular DNA's in transfection assays. DNA's of various tumors induce transformation with high efficiencies, indicating that oncogenesis can involve dominant genetic alterations resulting in activation of cellular transforming genes. The identification and characterization of cellular transforming genes and their possible involvement in naturally occurring cancers, is discussed.  相似文献   

Multimodal signals: enhancement and constraint of song motor patterns by visual display     

Cooper BG  Goller F 《Science (New York, N.Y.)》2004,303(5657):544-546

Many birds perform visual signals during their learned songs, but little is known about the interrelationship between visual and vocal displays. We show here that male brown-headed cowbirds (Molothrus ater) synchronize the most elaborate wing movements of their display with atypically long silent periods in their song, potentially avoiding adverse biomechanical effects on sound production. Furthermore, expiratory effort for song is significantly reduced when cowbirds perform their wing display. These results show a close integration between vocal and visual displays and suggest that constraints and synergistic interactions between the motor patterns of multimodal signals influence the evolution of birdsong.  相似文献   

THE GOLDEN HAMSTER (CRICETUS AURATUS) AS A TEST ANIMAL FOR THE DIAGNOSIS OF LEPTOSPIROSIS     

Randall R  Cooper HK 《Science (New York, N.Y.)》1944,100(2589):133-134

There is evidence that the golden hamster (Cricetus auratus) is the animal of choice for the isolation of leptospirae, especially of the Leptospira canicola type since young guinea pigs and mice are resistant to infection and rats are entirely refractory. Both the classical strain, L. icterohaemorrhagiae and L. canicola on isolation have been found to produce a fatal infection in hamsters. The present report deals with the isolation of L. canicola in two instances by the injection intraperitoneally into hamsters of urine obtained from dogs ill with suspected leptospirosis. Each of the dogs was apparently the source of infection for a human case of Canicola leptospirosis. The classical strain L. icterohaemorrhagiae was isolated from the dog for the first time in the United States. In this instance the organism was isolated by injecting both whole blood and urine from the patient intraperitoneally into young hamsters. The injection into hamsters of suitable material from patients infected with L. canicola and L. icterohaemorrhagiae is followed by a fatal leptospirosis in the test animal.  相似文献   

Defect in vitamin B12 release from lysosomes: newly described inborn error of vitamin B12 metabolism   总被引：5，自引：0，他引：5  

D S Rosenblatt  A Hosack  N V Matiaszuk  B A Cooper  R Laframboise 《Science (New York, N.Y.)》1985,228(4705):1319-1321

Cultured diploid fibroblasts from a patient with a previously undescribed inborn error of cobalamin metabolism accumulate unmetabolized, nonprotein-bound vitamin B12 in lysosomes. These cells are able to endocytose the transcobalamin II-B12 complex and to release B12 from transcobalamin II. The freed vitamin B12 is not released from lysosomes into the cytoplasm of the cell. This suggests that there is a specific lysosomal transport mechanism for vitamin B12 in the human.  相似文献   

The cost of R & d living     

Berger M  Cooper MJ 《Science (New York, N.Y.)》1979,204(4400):1369

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Climate. Society and sea level rise     

Pilkey OH  Cooper JA 《Science (New York, N.Y.)》2004,303(5665):1781-1782

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Isoprenoid acids in recent sediments     

Blumer M  Cooper WJ 《Science (New York, N.Y.)》1967,158(3807):1463-1464

Phytanic acid, pristanic acid, and 4,8,12-trimethyltridecanoic acid have been isolated from three recent marine sediments. The ratio of palmitic to pristanic acid is similar to that encountered in typical marine lipids. This suggests a biochemical origin of these sedimentary acids; phytol is their presumed biochemical precursor. Other isoprenoid acids between C(11) and C(22) which are common in ancient sediments have not been found. They are probably geochemical products formed slowly and at a greater depth.  相似文献   

Genetic effects of captive breeding cause a rapid, cumulative fitness decline in the wild     

Araki H  Cooper B  Blouin MS 《Science (New York, N.Y.)》2007,318(5847):100-103

Captive breeding is used to supplement populations of many species that are declining in the wild. The suitability of and long-term species survival from such programs remain largely untested, however. We measured lifetime reproductive success of the first two generations of steelhead trout that were reared in captivity and bred in the wild after they were released. By reconstructing a three-generation pedigree with microsatellite markers, we show that genetic effects of domestication reduce subsequent reproductive capabilities by approximately 40% per captive-reared generation when fish are moved to natural environments. These results suggest that even a few generations of domestication may have negative effects on natural reproduction in the wild and that the repeated use of captive-reared parents to supplement wild populations should be carefully reconsidered.  相似文献   

ACDA Staffing     

Cooper HF 《Science (New York, N.Y.)》1983,220(4592):6

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Rise and fall of species occupancy in Cenozoic fossil mollusks     

Foote M  Crampton JS  Beu AG  Marshall BA  Cooper RA  Maxwell PA  Matcham I 《Science (New York, N.Y.)》2007,318(5853):1131-1134

In the time between speciation and extinction, a species' ecological and biogeographic footprint-its occupancy-will vary in response to macroecological drivers and historical contingencies. Despite their importance for understanding macroecological processes, general patterns of long-term species occupancy remain largely unknown. We documented the occupancy histories of Cenozoic marine mollusks from New Zealand. For both genera and species, these show a distinct pattern of increase to relatively short-lived peak occupancy at mid-duration, followed by a decline toward extinction. Thus, species at greatest risk for extinction are those that have already been in decline for a substantial period of time. This pattern of protracted rise and fall stands in contrast to that of incumbency, insofar as species show no general tendency to stay near maximal occupancy once established.  相似文献