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51.
Fujii T Yokoyama T Ninagi O Kakehashi K Obara Y Nenoi M Ishikawa T Mita K Shimada T Abe H 《Genetica》2007,130(3):267-280
In deletion-mapping of W-specific RAPD (W-RAPD) markers and putative female determinant gene (Fem), we used X-ray irradiation to break the translocation-carrying W chromosome (W
Ze
). We succeeded in obtaining a fragment of the W
Ze
chromosome designated as Ze
W, having 3 of 12 W-RAPD markers (W-Bonsai, W-Yukemuri-S, W-Yukemuri-L). Inheritance of the Ze
W fragment by males indicates that it does not include the Fem gene. On the basis of these results, we determined the relative positions of W-Yukemuri-S and W-Yukemuri-L, and we narrowed
down the region where Fem gene is located. In addition to the Ze
W fragment, the Z chromosome was also broken into a large fragment (Z1) having the +
sch
(1-21.5) and a small fragment (Z2) having the +
od
(1-49.6). Moreover, a new chromosomal fragment (Ze
WZ2) was generated by a fusion event between the Ze
W and the Z2 fragments. We analyzed the genetic behavior of the Z1 fragment and the Ze
WZ2 fragment during male (Z/Z1
Ze
WZ2) and female (Z1
Ze
WZ2/W) meiosis using phenotypic markers. It was observed that the Z1 fragment and the Z or the W chromosomes separate without fail. On the other hand, non-disjunction between the Ze
WZ2 fragment and the Z chromosome and also between the Ze
WZ2 fragment and the W chromosome occurred. Furthermore, the females (2A: Z/Ze
WZ2/W) and males (2A: Z/Z1) resulting from non-disjunction between the Ze
WZ2 fragment and the W chromosome had phenotypic defects: namely, females exhibited abnormal oogenesis and males were flapless
due to abnormal indirect flight muscle structure. These results suggest that Z2 region of the Z chromosome contains dose-sensitive gene(s), which are involved in oogenesis and indirect flight muscle development. 相似文献
52.
Olubukola O. Babalola Abiodun I. Sanni George D. Odhiambo Baldwyn Torto 《World journal of microbiology & biotechnology》2007,23(6):747-752
Summary The use of trap crops such as cowpea could reduce the effects of the root parasitic weed, Striga hermonthica and its subsequent constraints on the growth of cereals. Certain bacteria could augment the trap crop stimulatory effect.
We studied the effect of three bacteria introduced to the rhizosphere of three cowpea varieties at planting. Number of days
to cowpea flowering was noted and at harvest, data were collected on pod characteristics and biomass. Means of data subjected
to ANOVA were compared using Tukey’s Studentized Range Test. We analysed bacterial headspace volatiles for ethylene by gas
chromatography and gas chromatography–mass spectrometry. Bacterial type significantly influenced the cowpea varieties with
better performance over the non-inoculated control. Average pod weight (g) with bacterial treatment was 37.97 for Enterobacter sakazakii 8MR5, 34.38 for Pseudomonas 44MS8 and 27.46 for Pseudomonas 10M3. Non-inoculated control had an average weight of 20.98 g. Bacteria promoted a significant increase in pod weight (≥30.89%),
fresh biomass (≥24.22%), and improved pod number (≥20.54%) and pod wall thickness (≥7.33%) with no deleterious effect on plant
health. Ethylene released by the bacteria ranged from trace concentrations in Pseudomonas sp. to 210 nmoles/108 c. f. u./ml in Ent. sakazakii 8MR5. 相似文献
53.
New metabolites exhibiting antifungal activity were isolated from the culture liquid of Azotobacter vinelandii strain IB 4. The metabolites were characterized by IR and 13C-NMR spectroscopy and defined as sucrose polythiophosphates of tetraamine (α-D-2,3-diaminoglucopyranosyl-β-D-3,4-diaminofructofuranose). 相似文献
54.
Meremyanin AV Eronina TB Chebotareva NA Kleimenov SY Yudin IK Muranov KO Ostrovsky MA Kurganov BI 《Biochemistry. Biokhimii?a》2007,72(5):518-528
Thermal aggregation of rabbit skeletal muscle glycogen phosphorylase b (Phb) has been investigated using dynamic light scattering under conditions of a constant rate of temperature increase (1 K/min). The linear behavior of the dependence of the hydrodynamic radius on temperature for Phb aggregation is consistent with the idea that thermal aggregation of proteins proceeds in the kinetic regime wherein the rate of aggregation is limited by diffusion of the interacting particles (the regime of "diffusion-limited cluster-cluster aggregation"). In the presence of alpha-crystallin, a protein exhibiting chaperone-like activity, the dependence of the hydrodynamic radius on temperature follows the exponential law; this suggests that the aggregation process proceeds in the kinetic regime where the sticking probability for colliding particles becomes lower than unity (the regime of "reaction-limited cluster-cluster aggregation"). Based on analysis of the ratio between the light scattering intensity and the hydrodynamic radius of Phb aggregates, it has been concluded that the addition of alpha-crystallin results in formation of smaller size starting aggregates. The data on differential scanning calorimetry indicate that alpha-crystallin interacts with the intermediates of the unfolding process of the Phb molecule. The proposed scheme of thermal denaturation and aggregation of Phb includes the stage of reversible dissociation of dimers of Phb into monomers, the stage of the formation of the starting aggregates from the denatured monomers of Phb, and the stage of the sticking of the starting aggregates and higher order aggregates. Dissociation of Phb dimer into monomers at elevated temperatures has been confirmed by analytical ultracentrifugation. 相似文献
55.
Induced defence responses are elicited when plants are exposed to biotic stresses such as attack by herbivores or pathogens. In nature, plants are often subjected to attack by more than one organism, and defence responses elicited by one organism can thereby be modified by the presence of another. Below-ground attack can influence responses to above-ground attack and vice versa, due to systemic induction of defence metabolism. In some interactions defence is enhanced through prior attack by another organism, whereas in others there are conflicting signals. Recent research has shown how plants integrate these signals to coordinate defence by regulation of key metabolic pathways, although there is still much to be learnt. 相似文献
56.
Berit M. Mortensen Hanne W. Lund Greg Jablonski Ruth H. Paulssen Jan O. Gordeladze 《Bioscience reports》1995,15(3):135-150
In normal rats treated with 1,25(OH)2D3 or 24,25(OH)2D3, serum Ca2+, ALP, PRL and GH are significantly altered. In order to study the primary effect of vitamin D3 analogues on target organ function, rat UMR 106 osteosarcoma and GH3 pituitary adenoma cells in monolayer culture were exposed accordingly.Surprisingly, prolonged exposure of these cell lines to physiological levels of either 1,25(OH)2D3 or 24,25(OH)2D3 did not significantly affect the secretory parameters (ALP, PRL or GH) tested. However, 1,25(OH)2D3 exposure significantly reduced PTH- and Gpp(NH)p-elicited AC as well as Gpp(NH)p-stimulated PLC activities in the UMR 106 cells. These changes were accompanied by an increase and decrease in the membrane contents of the G-protein subunits G36 and Gq/11, respectively. In contrast, 24,25(OH)2D3 remained without significant biological effect on these signalling systems despite concomitantly augmented levels of G36. TRH- and Gpp(NH)p-elicited PLC activities in the GH3 cells were significantly reduced by 1,25(OH)2D3 with a concurrent reduction in cellular amounts of Gq/11, however, 24,25(OH)2D3 did not significantly alter any signalling systems nor G-proteins analyzed.It is concluded that the osteoblastic and pituitary cell secretion of ALP, PRL and GH remain unaffected by the presence of 1,25(OH)2D3 and 24,25(OH)2D3, despite distinct alterations in components of G-protein mediated signalling pathways. Hence, other factors like ambient Ca2+ may be responsible for the perturbed secretory patterns of ALP and PRL seen in vitamin D3 treated rats.Abbreviations AC
adenylate cyclase
- ALP
alkaline phosphatase
- BGP
osteocalcin
- BSA
bovine serum albumin
- DA
dopamine
- DAG
diacylglycerol
- GH
growth hormone
- GHRH
growth hormone releasing hormone
- Gpp(NH)p
guanosine 5-[-imido]triphosphate
- G-protein
guanine nucleotide-binding regulatory protein
- Gs etc.
Gs protein -subunit
- IP3
inositol 1,4,5 trisphosphate
- OAF
osteoclast activating factor
- PGE2
prostaglandin E2
- PKA & PKC
protein kinase A & C
- PLC
phospholipase C
- PRL
prolactin
- PTH
parathyroid hormone
- SRIF
somatostatin
- TRH
thyrotropin releasing hormone
- VIP
vasoactive intestinal peptide
- 25(OH)D3
25 hydroxy vitamin D3
- 1,25(OH)2D3
1·25 dihydroxy vitamin D3
- 24,25(OH)2D3
24,25 dihydroxy vitamin D3 相似文献
57.
Adedayo O. Javadpour S. Taylor C. Anderson W.A. Moo-Young M. 《World journal of microbiology & biotechnology》2004,20(6):545-550
Bacterial cultures from a wastewater treatment plant degraded a toxic azo dye (methyl red) by decolourization. Complete decolourization
using a mixed-culture was achieved at pH 6, 30 °C within 6 h at 5 mg/l methyl red concentration, and 16 h at 20—30 mg/l. Four
bacterial species were isolated that were capable of growth on methyl red as the sole carbon source, and two were identified,
namely Vibrio logei and Pseudomonas nitroreducens. The Vibrio species showed the highest methyl red degradation activity at the optimum conditions of pH 6--7, and 30—35 °C. Analysis by
NMR showed that previously reported degradation products 2-aminobenzoic acid and N,N-dimethyl-1,4-phenylenediamine were not
observed. The decolourized dye was not toxic to a monkey kidney cell line (COS-7) at a concentration of 250 μM.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
58.
At thoracic and lumbar levels the spinal dorsal gray of young specimens of the turtle Chrysemys d'orbigny consists of a cell-free neuropil and an aggregation of perikarya termed here the lateral column of the dorsal horn (LCDH). Nerve cell clusters also occur in the dorsal commissure. The main neuropil area can be divided into a thin superficial layer containing some myelinated fibers (neuropil area Ib) and a compact core composed of unmyelinated axon terminals, dendritic branches, and thin glial processes (neuropil area II). A looser neuropil area is located at the horn base (neuropil area III). The so-called marginal zone of de Lange represents a fourth synaptic field termed here neuropil area Ia. The LCDH consists of neurons of different size and shape. Two peculiar nerve cell types have been recognized in the dorsal horn: giant and bitufted neurons. The former exhibits a large dendritic arbor, which after passing through neuropil areas II and Ib projects into neuropil area Ia and the adjacent white matter. Most frequently Golgi-stained giant neurons have perikarya and dendritic domains on the same side (ipsilateral giant neurons). There are also heterolateral giant neurons whose dendritic branches invade the opposite horn. Bitufted neurons are characterized by the presence of two main dendritic shafts connecting neuropil area II of both dorsal horns. At neuropil levels the major dendritic branches ramify profusely giving rise to short tortuous terminal processes. Perikarya of bitufted neurons occur in the dorsal commissure. The LCDH also contains many small and medium-sized neurons. These are oriented in two main directions: parallel or radial with respect to the dorsal horn surface. The population of horizontally oriented neurons comprises two subtypes termed here alpha and beta. Radially oriented neurons are pleomorphic, defying precise, unequivocal classification. 相似文献
59.
Thomas A. Edsall Bruce A. Manny Donald W. Schloesser Susan J. Nichols Anthony M. Frank 《Hydrobiologia》1991,219(1):353-361
In April through October 1986, we sampled sediments and populations of nymphs of the burrowing mayfly, Hexagenia limbata (Serville), at 11 locations throughout the connecting channels of the upper Great Lakes, to determine if sediment contaminants adversely affected nymph production. Production over this period was high (980 to 9231 mg dry wt m-2) at the five locations where measured sediment levels of oil, cyanide, and six metals were below the threshold criteria of the U.S. Environmental Protection Agency and the Ontario Ministry of Environment for contaminated or polluted sediments, and also where the criterion for visible oil given in the Water Quality Agreement between the U.S.A. and Canada for connecting waters of the Great Lakes was not exceeded. At the other six locations where sediments were polluted, production was markedly lower (359 to 872 mg dry wt m-2). This finding is significant because it indicates that existing sediment quality criteria can be applied to protect H. limbata from oil, cyanide, and metals in the Great Lakes and connecting channels where the species fulfills a major role in secondary production and trophic transfer of energy.Contribution 733, of the National Fisheries Research Center-Great Lakes, U.S. Fish and Wildlife Service, 1451 Green Road, Ann Arbor, MI 48105. 相似文献
60.
AB toxins deliver their enzymatically active A domain to the cytosol. Some AB-toxins are able to penetrate cellular membranes from endosomes where the low pH triggers their translocation. One such toxin is diphtheria toxin and important features of its translocation mechanism have been unraveled during the last year. Other toxins depend on retrograde transport through the secretory pathway to the ER before translocation, and recent findings suggest that these toxins take advantage of the ER translocation machinery normally used for transport of cellular proteins. In addition, the intracellular targets of many of these toxins have been identified recently. 相似文献