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141.
142.
Cannibalism in teleost fish 总被引:1,自引:0,他引:1
1. | Cannibalistic behaviour in fish is reviewed here for the first time. |
2. | Cannibalism has been recorded in 36 out of 410 teleost families according to the published literature, but is considered to be more widespread than this. Finding examples of cannibalism is not difficult, and it may be more interesting to look for taxa in which the behaviour does not take place. |
3. | The families that have provided the most information include the Engraulididae, Esocidae, Poeciliidae, Gasterosteidae, Percidae and Cichlidae. |
4. | Cannibalism has been classified into seven types, depending on life-history stage, age difference between cannibal and prey, and whether or not they are related. |
5. | Although in captive populations, cannibalism tends to increase with increasing density and decreasing food availability, its role in population regulation has not been unequivocally demonstrated in any wild population, and obtaining the necessary data presents a formidable challenge to fish ecologists. |
6. | Cannibalism is of some economic importance in aquaculture, but its impact can be reduced relatively easily, by frequent grading to reduce size variability. |
7. | The main proximate advantage conferred by cannibalism is assumed to be nutritional. In an ultimate sense the behaviour may have evolved as a particularly effective competitive strategy. |
8. | Finally, it is considered that cannibalism deserves more attention from fish biologists. Investigations, however, should recognize the different types of cannibalistic interaction, and, in particular, should explore the different implications of kin and nonkin cannibalism |
143.
Carl E. Hilliker Martine I. Darville Magdy S. Aly Mohamed Chikri Claude Szpirer Peter Marynen Guy G. Rousseau Jean-Jacques Cassiman 《Genomics》1991,10(4)
Two genes encoding 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase were localized in human and rat chromosomes. PFKFB1 (previously PFRX), which encodes the liver and muscle isozymes, was assigned to Xq22-q31 in the rat and to Xq27–q28 in the human by in situ hybridization using probes generated by the polymerase chain reaction. PFKFB2, which encodes the heart isozyme of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase, was assigned to chromosome 13 in the rat and to chromosome 1 in the human by hybridization of DNA from somatic cell hybrids. By in situ hybridization, this gene was localized to the regions 13q24–25 in the rat and 1q31 in the human. 相似文献
144.
The zebrafish is rapidly increasing in popularity with developmental biologists. Driving this interest are the elegant methods for in vivo observations and recovery of early developmental mutations. The past year has seen the introduction of additional methods for in vivo manipulation of identified cells and the application of these methods to mutant analysis. 相似文献
145.
Charles D. Hébert Sumiyo Endo Kenneth S. Korach Jeff Boyd J. Carl Barrett John A. Mclachlan Retha R. Newbold 《In vitro cellular & developmental biology. Animal》1992,28(5):327-336
Neonatal treatment with estrogens is associated with development of uterine adenocarcinomas in CD-1 mice. Treatment with the
synthetic estrogen diethylstilbestrol (DES) on Days 1 to 5 after birth results in 90% incidence of these hormonedependent
lesions in 18-mo.-old mice. Three cell lines were established from these DES-associated tumors. Each of these cell lines exhibited
morphologic and ultrastructural characteristics of transformed epithelial cells, including an increased nuclear:ytoplasmic
ratio, enlarged and irregular nuclei with multiple nucleoli and areas of chromatin condensation, positive staining for cytokeratin,
desmosomes, and microvilli. After subcutaneous injection into nude mice, all three cell lines formed solid tumors within 4
wk. Although the primary uterine tumors and tumor transplants in nude mice had been shown to be estrogen-dependent and estrogen-receptor
positive, neither the monolayer growth nor the tumorigenicity of any of the three cell lines in this study was enhanced by
or dependent on estrogen. Estrogen receptor levels were low in early and intermediate passage cells. Allele-specific oligonucleotide
hybridization analysis of PCR-amplified cell line DNA revealed no point mutations in the 12th, 13th, or 61st codons of the
K-ras or H-ras protooncogenes. Southern analysis revealed no changes in genomic organization of the putative tumor suppressor
gene DCC, but demonstrated a three-to four-fold amplification of the c-myc gene in one cell line. Expression of c-myc RNA
was concomitantly increased in the same cell line. These three transformed cell lines represent the end point in the process
of hormone-associated tumorigenesis and as such should prove useful in investigating the molecular changes and the mechanisms
involved in hormonal carcinogenesis. 相似文献
146.
147.
Carl R. Woese Paul Blanz Robert B. Hespell Christine M. Hahn 《Current microbiology》1982,7(2):119-124
Helical bacteria from the generaSpirillum, Oceanospirillum, Aquaspirillum, andAzospirillum—as well asSerpens flexibilis—were characterized by oligonucleotide cataloging of 16S rRNA in order to establish their phylogenetic relationships to one another and to Gramnegative bacteria in general. The various genera of helical bacteria are not specifically related to one another (to the exclusion of nonhelical bacteria) and, where tested, the individual genera as presently constituted are not phylogenetically coherent (with the possible exception ofOceanospirillum, which may form a deep grouping). 相似文献
148.
Harvey B. Pollard Samuel S. Stopak Christopher J. Pazoles Carl E. Creutz 《Analytical biochemistry》1981,110(2)
Glucose utilization by cells and tissues can be followed by measuring the release of [3H]H2O from added
-[5-3H]glucose, and we have developed a method whereby the whole reaction and assay can be performed in a single scintillation vial. The basic principle behind our new assay is that the released tritiated hydrogen ion in water can be quantitatively exchanged with the hydroxyl proton of simple alcohols such as isoamyl alcohol. The radiolabeled alcohol can then be extracted into an organic solvent to which 2,5-diphenyloxazole and p-bis[2-(5-phenyloxazoyl)]benzene have been previously added. Using this new assay we studied isolated chromaffin cells and found them to utilize glucose at a linear rate for at least 30 min. The assay was precise and reproducible enough to allow detailed analysis of various inhibitors of glycolysis and of oxidative phosphorylation. The new method is simple and rapid, can be done in open test tubes, requires no complex equipment, and is intrinsically highly accurate. 相似文献
149.
The complex sterol mixture isolated from was found to contain a low level of Δ4-3-keto steroids, 5β-stanols and 4α-methyl sterols in addition to regular (4-demethyl) sterols. The following new marine sterols were isolated and identified using MS and 360 MHz NMR: 5β-cholest-22E-en-3β-ol, 24S-methyl-5β-cholest-22E-en-3β-ol, 24-methylene-5β-cholestan-3β-ol, both epimers at C-24 of 4α-methyl-24-ethyl-5α-cholest-22E-en-3β-ol, 4α, 22ξ, 23ξ-(or 24ξ-)trimethyl-5α-cholest-8(14)-en-3β-ol and (22S, 23S, 24S)-4α-24-dimethyl-22, 23-methylene-5α-cholestan-3β-ol. The latter sterol and 23-demethylgorqosterol have opposite configurations at C-22, C-23, and C-24; the Δ8(14) sterol has an unprecedented side chain. 相似文献
150.
Peter Sarnow Patrick Hearing Carl W. Anderson Nancy Reich Arnold J. Levine 《Journal of molecular biology》1982,162(3):565-583
Antisera from some hamsters bearing adenovirus-induced tumors contain antibodies to an 11,000 Mr adenovirus-induced protein. In adenovirus-infected HeLa cells, this early viral protein was specifically associated with the nuclear matrix fraction. After two-dimensional gel electrophoresis, two forms of the 11,000 Mr protein at pI 5.6 and pI 5.4 were found. Only the pI 5.4 form of this protein was associated with the nuclear matrix fraction. Adenoviruses from groups A, B, C, D and E all produced an early viral protein (10,000 to 12,000 Mr) that reacted with group C antibody to the 11,000 Mr protein. To date, this is the only known early viral protein that is immunologically conserved in all of the human adenovirus groups.The positions of two methionine and seven leucine residues were determined by sequencing the first 35 amino acids from the N terminus of the adenovirus serotype 2 group C 11,000 Mr protein. The positions of these amino acid residues were compared to the adenovirus serotype 2 nucleotide sequence, which uniquely localized the structural gene of the 11,000 Mr protein to region E4, subregion 3 in type 2 adenovirus. A frameshift mutant, which contained a deletion of one base-pair in the structural gene of the 11,000 Mr protein, was isolated and mapped by marker rescue and nucleotide sequence analysis. This mutant failed to produce immunologically detectable 11,000 Mr protein. The mutant had a viable phenotype, producing normal levels of infectious virus in both HeLa cells and WI38 cells in culture. These experiments identify the first adenovirus early region 4 protein detected in virus-infected cells. 相似文献