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51.
From 12 to 19 May 1987, during Morspur apple bloom, 21 radioactively labeled (65 Zn) adult plum curculios, Conotrachelus nenuphar (Herbst), were released within a field cage containing four dwarf apple trees and located three times a day. A technique was developed for quickly obtaining (x, y, z)coordinates of location for adults foraging within apple trees. Cyclic patterns of behavior were detected using spectral analysis procedures. Over 70% of plum curculios exhibited diel periodicity with respect to activity and rate of movement, 36% exhibited such periodicity with respect to presence in the trees, and 27% with respect to movements from the center to the periphery of the canopy. Presence in fruit clusters, height in the trees, and movements along east-west and north-south axes showed little or no periodicity. Factors triggering cyclic behavior and practical implications of the results are discussed.  相似文献   
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F Payre  A Vincent 《The EMBO journal》1991,10(9):2533-2541
The closely related Drosophila serendipity (sry) beta (beta) and delta (delta) Cys2-His2 zinc finger proteins show partly overlapping in vitro DNA binding specificities and distinct patterns of binding sites on polytene chromosomes. Using a newly developed procedure, we identified genomic DNA targets for these two proteins. Both the sry beta and delta proteins protect an 18-22 base region from DNase I digestion within each analysed genomic binding site, that includes a 13 bp consensus sequence. The consensus recognition sites sry beta 5'-YCAGAGATGCGCA-3' and sry delta 5'-YTAGAGATGGRAA-3' thus differ by nucleotides at four out of 13 positions. They are determinant for specific binding of the sry beta and delta proteins, respectively, produced in Escherichia coli or present in Drosophila embryos. We further show that sry beta is the major (if not exclusive) Drosophila nuclear protein that specifically binds the 5'-CAGAGTGCGC-3' sequence. The identified sry beta genomic targets are all contained within single-copy DNA in euchromatic regions of the genome. Two out of the five characterized in detail map at cytological positions coincident with binding sites of the native sry beta protein on polytene chromosomes.  相似文献   
54.
We have characterized and genetically mapped new polymorphic DNA markers in the q27-q28 region of the X chromosome. New informative RFLPs have been found for DXS105, DXS115, and DXS152. In particular, heterozygosity at the DXS105 locus has been increased from 25% to 52%. We have shown that DXS105 and DXS152 are contained within a 40-kb region. A multipoint linkage analysis was performed in fragile-X families and in large normal families from the Centre d'Etudes du Polymorphisme Humain (CEPH). This has allowed us to establish the order centromere-DXS144-DXS51-DXS102-F9-DXS105-FRAX A-(F8, DXS15, DXS52, DXS115). DXS102 is close to the hemophilia-B locus (z[theta] = 13.6 at theta = .02) and might thus be used as an alternative probe for diagnosis in Hemophila-B families not informative for intragenic RFLPs. DXS105 is 8% recombination closer to the fragile-X locus than F9 (z[theta] = 14.6 at theta = .08 for the F9-DXS105 linkage) and should thus be a better marker for analysis of fragile-X families. However, the DXS105 locus appears to be still loosely linked to the fragile-X locus in some families. The multipoint estimation for recombination between DXS105 and FRAXA is .16 in our set of data. Our data indicate that the region responsible for the heterogeneity in recombination between F9 and the fragile-X locus is within the DXS105-FRAXA interval.  相似文献   
55.
The effect of adrenalectomy on the formation of cyclooxygenase and lipoxygenase products by activated peritoneal rat macrophages was determined. After isolation, the cells were incubated with [1-14C]arachidonic acid and the calcium ionophore A23187 and the metabolites isolated by HPLC chromatography. The main components formed in the controls are 6-keto-prostaglandin F1 alpha, thromboxane B2 and 12-HETE. One peak represents 5,12-di-HETE. Smaller amounts of prostaglandin F2 alpha, prostaglandin E2, prostaglandin D2, leukotriene B4 and 15-HETE are also present. After adrenalectomy, a considerable increase occurs in the amounts of leukotriene B4, 15-HETE and 12-HETE. The increase in the prostaglandins is smaller. The compounds formed from endogenous arachidonic acid are also determined. In the cells of the controls, 6-keto-prostaglandin F1 alpha and thromboxane B2 are produced in higher amounts than leukotriene B4. After adrenalectomy, the formation of leukotriene B4 is much more increased than that of 6-keto-prostaglandin F1 alpha. These effects are most probably related to a diminished amount or inactivation of lipocortin, a glucocorticosteroid-induced peptide with phospholipase A2 inhibitory activity in adrenalectomized animals.  相似文献   
56.
Interrelationships between production of progesterone (P4), prostaglandin (PG) E2 and PGF2 alpha, and collagenase by periovulatory ovine follicles and their possible involvements in the ovulatory process were investigated. Follicles were isolated from ovaries at intervals (0 to 24 h) after the initiation of the preovulatory surge of luteinizing hormone (LH). Progesterone and PGs within follicles were determined by radioimmunoassay. Digestion of radioactive collagen during coincubation with tissue homogenates was used to assess the production of a bioactive follicular collagenase(s). Follicular accumulation of PGs and P4 increased at 12 and 16 h, respectively, after the onset of the surge of LH; PGE2 then decreased at 20 h. Collagenolytic activity of follicular tissue increased at 20 h and was maximal at 24 h (during the time of follicular rupture). An inhibitor of synthesis of P4 (isoxazol) or PGs (indomethacin) was injected into the follicular antrum at 8 h. Isoxazol did not prevent the initial rise in PGs, but inhibited synthesis of PGF2 alpha at 16 h and therafter. Isoxazol negated the decline in PGE2 and increase in collagenolysis. Indomethacin did not influence synthesis of P4; however, it suppressed collagenolytic activity of follicular tissue. Ovaries with treated follicles were left in situ and observed for an ovulation point at 30 h. Isoxazol or indomethacin was a potent inhibitor of ovulation. The blockade of ovulation by isoxazol was reversed by systemic administration of P4 or PGF2 alpha, but not by PGE2. Reversal of the blockade by indomethacin was accomplished with PGE2 or PGF2 alpha. Collagenolytic activity of follicular tissue was likewise restored by such treatments.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
57.
Either testosterone or follicle-stimulating hormone (FSH) stimulates progesterone secretion by granulosa cells from rats but the combination of the two hormones increases progesterone production in a synergistic manner. We have investigated the effects of graded doses of prolactin (0, 0.02, 0.2, 2, or 10 micrograms/ml) alone or in combination with testosterone (0.5 microM), FSH (300 ng/ml), or FSH + testosterone on progesterone secretion by granulosa cells at two stages of differentiation. Relatively undifferentiated granulosa cells from immature, diethylstilbestrol-treated, hypophysectomized (HPX) rats were cultured in defined (serum-free) medium for 3 days. More highly differentiated granulosa cells were obtained on the morning of proestrus from the preovulatory follicles of 30-day-old rats induced to undergo an estrous cycle by injection with 4 IU pregnant mare's serum gonadotropin; these cells were cultured in medium containing 10% fetal bovine serum. Prolactin alone did not enhance the negligible secretion of progesterone by cells from HPX rats, but increased progesterone secretion by cells from proestrous rats. Prolactin significantly enhanced the stimulatory effects of testosterone or FSH alone on cells from both HPX and proestrous rats. When cultures containing both FSH + testosterone were treated with prolactin, progesterone secretion by cells from proestrous rats was significantly enhanced, whereas secretion by cells from HPX rats was significantly depressed. Therefore when cells from HPX rats were cultured with both FSH and testosterone, the direction of the effect of prolactin was reversed from that observed with prolactin + FSH or testosterone alone, and from that observed when cells from proestrous rats were cultured with prolactin + FSH + testosterone.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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59.
Twenty isolates of the dimorphic, pathogenic fungus Histoplasma capsulatum were divided into three classes based on comparisons of restriction enzyme digests of their mitochondrial DNA and rDNA. The majority of isolates, including most North American strains and the African H. capsulatum var. duboisii variants, belong to class 2. Isolates from Central America and South America make up class 3. The attenuated Downs strain is the only member of class 1.  相似文献   
60.
The role of progesterone in regulation of uteroovarian venous concentrations of prostaglandins F2 α (PGF2α) and E2 (PGE2) during days 13 to 16 of the ovine estrous cycle or early pregancy was examined. At estrus, ewes were either mated to a fertile ram or unmated. On day 12 postesturus, ewes were laparotomized and a catheter was inserted into a uteroovarian vein. Six mated and 7 unmated ewes received no further treatment. Fifteen mated and 13 unmated ewes were ovariectomized on day 12 and of these, 7 mated and 5 unmated ewes were given 10 mg progesteron sc and an intravaginal pessary containing 30 mg of progesterone. Uteroovarian venous samples were collected every 15 min for 3 h on days 13 to 16 postestrus. Mating resulted in higher mean daily concentrations of PGE2 in the uterovarian vein than in unmated ewes. Ovariectomy prevented the rise in PGE2 with day in mated ewes but had no effect in unmated ewes. Progesterone treatment restored PGE2 in ovariectomized, mated ewes with intact embros. Mating had no effect on mean daily concentrations of PGF2α or the patterns of the natural logarithm (ln) of the invariance of PGF2α. Ovariectomy resulted in higher mean concentrations and ln invariances of PGF2α on day 13 and lower mean concentrations and ln invariances of PGF2α on days 15 and 16. Replacement with progesterone prevented these changes in patters of mean concentrations and ln variances of PGF2α following ovariectomy. It is concluded that progesterone regulates the release of PGF2α from the uterus, maintaining high concentrations while also preventing the occurrence of the final peaks of PGF2α which are seen with falling concentrations of progesterone. This occurs in both pregnant and non-pregnant ewes. Progesterone is also needed to maintain increasing concentrations of PGE2 in mated ewes.  相似文献   
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