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81.
W. A. Schroeder Darleen Powars Joan B. Shelton J. Roger Shelton J. B. Wilson T. H. J. Huisman Antranik A. Bedros 《Biochemical genetics》1982,20(11-12):1175-1187
After a boy of Mexican-American descent became jaundiced during treatment of a serious urinary tract infection with an oxidant drug, an extensive hematological examination was made. The important finding was the presence of Hb-Leiden to the extent of less than 3% or about a tenth of the usual percentage. Although inclusion bodies are present in the erythrocytes at all times, his hematological parameters have remained normal. The genetic basis for the unusually small amount of Hb-Leiden in the propositus may be due to the Hb-Leiden gene in an anti-Lepore configuration, that is, and Hb-Leiden gene in cis to the normal β and δ genes. 相似文献
82.
Genetic and developmental evidence for a repressed genital primordium in Drosophila melanogaster 总被引:5,自引:0,他引:5
Lee Engstrom Joan H. Caulton Eileen M. Underwood Anthony P. Mahowald 《Developmental biology》1982,94(1):163-175
Agametic, a maternal-effect mutation, causes the absence of germ cells in approximately 40% of the gonads of flies derived from homozygous females. The nature of the deficiency in the eggs produced by these flies was examined. Ultrastructural abnormalities were seen in the polar granules of some eggs shortly after fertilization. Although a normal number of pole cells form, some are abnormal with degenerating polar granules and nuclear bodies and they contain myeloid bodies. The pole cells reach the gonads and at 14 hr of development all the gonads contain germ cells. However, in 40% of the gonads the germ cells become necrotic and disappear. Thus, the source of agametic gonads in the adult is embryonic death of pole cells in some gonads. To test whether this gonadal death is an autonomous deficiency of the mutant pole cells, mosaic pole cell populations were produced by reciprocal pole cell transplantation. In both types of transplants, the mutant pole cells died autonomously. In eight instances gonads containing only donor pole cells were obtained. Since mutant pole cells die when wild-type pole cells normally begin dividing, we suggest that the lesion affects the ability of these mutant pole cells to reenter the cell cycle. 相似文献
83.
Females of the social wasp, Polistes annularis, nest in largeaggregations onriverside cliffs in central Texas. Aggregationsoccur where there is an overhang under which wasps build theirnests. Colony aggregations appear to occur partly because individualfemales do notdisperse far from the natal site where most coloniesare successful. In most taxa greater reproductive success nearthe natal nest site is related to unique physical features orto advantages ofbeing in a group. In P. annularis, the physicalfactors and not the social factors appear to be most important.Advantages to remaining near the natal nest site include protectionprovided by the cliff overhang from rain and afternoon sun.Central colonies are as likely to suffer predation as are peripheralcolonies, which indicates an absence of selfish herd advantagesto being in the center of the group. A cost of being in a denseaggregation is often increased reproductive competition, andthis is the case for P. annularis. Colonies in the center ofthe aggregation suffer high usurpation rates by unrelated femalesand in 1 of 3 years produced fewer reproductives than edge colonies. 相似文献
84.
Directed excision of a transgene from the plant genome 总被引:40,自引:0,他引:40
Sandra H. Russell Joyce L. Hoopes Joan T. Odell 《Molecular & general genetics : MGG》1992,234(1):49-59
Summary The effectiveness of loxP-Cre directed excision of a transgene was examined using phenotypic and molecular analyses. Two methods of combining the elements of this system, re-transformation and cross pollination, were found to produce different degrees of excision in the resulting plants. Two linked traits, -glucuronidase (GUS) and a gene encoding sulfonylurea-resistant acetolactate synthase (ALSr), were integrated into the genome of tobacco and Arabidopsis. The ALSr gene, bounded by loxP sites, was used as the selectable marker for transformation. The directed loss of the ALST gene through Cre-mediated excision was demonstrated by the loss of resistance to sulfonylurea herbicides and by Southern blot analysis. The -glucuronidase gene remained active. The excision efficiency varied in F1 progeny of different lox and Cre parents and was correlated with the Cre parent. Many of the lox × Cre F1 progeny were chimeric and some F2 progeny retained resistance to sulfonylureas. Re-transformation of lox/ALS/lox/GUS tobacco plants with cre led to much higher efficiency of excision. Lines of tobacco transformants carrying the GUS gene but producing only sulfonylurea-sensitive progeny were obtained using both approaches for introducing cre. Similarly, Arabidopsis lines with GUS activity but no sulfonylurea resistance were generated using cross pollinations. 相似文献
85.
Joan Sloan Tracy A. Warner Paul T. Scott Trudi L. Bannam David I. Berryman Julian I. Rood 《Plasmid》1992,27(3)
A newClostridium perfringens-Escherichia coli shuttle plasmid has been constructed and its complete DNA sequence compiled. The vector, pJIR418, contains the replication regions from theC. perfringens replicon pIP404 and theE. coli vector pUC18. The multiple cloning site and lacZ gene from pUC18 are also present, which means that X-gal screening can be used to select recombinants inE. coli. Both chloramphenicol and erythromycin resistance can be selected inC. perfringens andE. coli since pJIR418 carries theC. perfringens catP and ermBP genes. Insertional inactivation of either the catP or ermBP genes can also be used to directly screen recombinants in both organisms. The versatility of pJIR418 and its applicability for the cloning of toxin genes fromC. perfringens have been demonstrated by the manipulation of a cloned gene encoding the production of phospholipase C. 相似文献
86.
Pablo Collazo Lluís Montoliu Pere Puigdomènech Joan Rigau 《Plant molecular biology》1992,20(5):857-867
The isolation and characterization of cDNA and homologous genomic clones encoding the lignin O-methyltransferase (OMT) from maize is reported. The cDNA clone has been isolated by differential screening of maize root cDNA library. Southern analysis indicates that a single gene codes for this protein. The genomic sequence contains a single 916 bp intron. The deduced protein sequence from DNA shares significant homology with the recently reported lignin-bispecific caffeic acid/5-hydroxyferulic OMTs from alfalfa and aspen. It also shares homology with OMTs from bovine pineal glands and a purple non-sulfur photosynthetic bacterium. The mRNA of this gene is present at different levels in distinct organs of the plant with the highest accumulation detected in the elongation zone of roots. Bacterial extracts from clones containing the maize OMT cDNA show an activity in methylation of caffeic acid to ferulic acid comparable to that existing in the plant extracts. These results indicate that the described gene encodes the caffeic acid 3-O-methyltransferase (COMT) involved in the lignin biosynthesis of maize. 相似文献
87.
I.-Wu Chen Juinn H. Lin Joan Dorley 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1992,576(2)
A high-performance liquid chromatographic (HPLC) procedure has been developed for the quantification of L-365,260 (I), a cholecystokinin and gastrin receptor antagonist, in dog and rat plasma. The method involves liquid—liquid extraction and HPLC with ultraviolet detection. Standard curves were linear over the range 7.5–2000 ng/ml for rat and dog plasma. The method is reproducible and reliable with a detection limit of 7.5 ng/ml in biological fluids. The mean coefficients of variation for concentrations within the range of the standard curve range were 3.84 and 2.56%, respectively, for intra-day analysis and 4.48 and 4.26%, respectively, for inter-day analysis. Application of the development was successfully demonstrated by quantifying the concentration of I in both dog and rat plasma samples following an intravenous or oral dose of 5 mg/kg I. 相似文献
88.
Scott K. Davis Joan E. Strassmann Colin Hughes L. Susan Pletscher Alan R. Templeton 《Evolution; international journal of organic evolution》1990,44(5):1242-1253
Six variable protein loci and one variable ribosomal DNA restriction site were used for an analysis of population structure in five species of Polistes from Texas. A sample-reuse algorithm was developed that estimated FST, FIS, and ø (the coefficient of kinship) from probabilities of identity. Of the four species analyzed in detail only one, Polistes exclamans, had statistically significant values of FST. These values may reflect natural constraints on successful nesting for migrants of this species. Three of the four species had significant values of FIS and three of the four species had significant values of ø. In many cases ø also differed from the expected value under haplodiploidy and random mating. Values of ø did not differ from expectations under haplodiploidy and local inbreeding. These results emphasize that theories of social behavior and evolution based on coefficients of kinship should include some explicit consideration of population structure. 相似文献
89.
A TLC procedure which resolves two molecular species of ethanolamine plasmalogen, Pl-PE-1 and Pl-PE-2, was used to compare the ratio of these two species in myelin isolated from normal appearing white matter from brains of 17 multiple sclerosis (MS) patients, 17 normal (N) individuals, 1 patient with subacute sclerosing panencepha itis (SSPE) and 1 patient with a non-demyelinating neurological disease (OND). One of these species (Pl-PE-2) has been reported to be unique to myelin and has primarily 181 in both the 1 and 2 positions of glycerol. The other species (Pl-PE-1) is also present in other membranes and has primarily a saturated chain in the 1 position and a polyunsaturated chain in the 2 position. The Pl-PE-1 to Pl-PE-2 ratio was quantitated by scanning the plates with a densitometer. The ratio was similar to normal in most of the MS samples, 0.88±0.09, but was much less than normal in 4 of the MS samples and the SSPE sample. This is attributed to increased decomposition or hydrolysis of Pl-PE-1 relative to Pl-PE-2 at some stage, either during the disease process or due to post-mortem decomposition. Although the reason for the enhanced decomposition of Pl-PE-1 is not known it suggests that Pl-PE-2 is more stable chemically. This may be related to the unique occurrence of Pl-PE-2 in myelin. 相似文献
90.
Implications of a revised United States American Indian nadir population and the pattern of decline leading to it are examined. Substituting the new nadir for that used by Dobyns (1966) lowers by several million his estimates of Indian population for the United States (and Canada) area. These estimates then become more compatible with ones currently being suggested by other scholars. The nineteenth century decline leading to this nadir is found to be remarkably linear. Assuming linearity in decline from initial European contact through the eighteenth century, an aboriginal population estimate of 1,845,183 for the United States area may be extrapolated, along with estimates for intervening years. The nineteenth century decline is then graphed with the data extrapolated to 1492. The resulting pattern of population decline is quite different from the ones suggested by Mooney (1928) and Dobyns (1966). 相似文献