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41.
Two different groups of methanol-utilizing bacteria were studied by electron microscopy. Bacteria using the serine pathway for the assimilation of methanol were found to have a thin cell envelope (outer membrane, periplasmic area and cytoplasmic membrane). Those using the assimilatory ribulose monophosphate pathway of formaldehyde fixation had a much thicker cell envelope and in the case ofPseudomonas C protrusions of the outer membrane were found. 相似文献
42.
Abraham A. Hochberg Henryk H. Czosnek Yehudit Reichler Itzhak Ohad Nathan de Groot 《Molecular biology reports》1975,2(4):311-319
The structure of purified fractions of rough, smooth, stripped rough and reconstituted rough membranes have been investigated by the freeze etching technique. Preparations of rough and reconstituted rough membranes, active in protein synthesis, show vesicles whose outer surface is covered with ribosome-like particles. The inner surface of these vesicles contains also numerous particles of the same size. The particles located on the outer surface are largely absent in the stripped rough membrane preparations which, however, retain the particles located on the inner face. Particles were not seen either on the outer nor on the inner face of the smooth membranes. The possibility is considered that the particles located on the inner face are specific to the rough membranes and might play a role in the specific binding of ribosomes to the membranes. 相似文献
43.
R. B. P. Torrecilha M. Milanesi M. Gallana A.-K. Falbo I. M. Reichler P. Hug V. Jagannathan B. B. Trigo S. C. Paulan D. B. Bruno S. D. Garcia N. F. Scaramele F. L. Lopes G. Dolf T. Leeb J. Sölkner J. F. Garcia A. Pieńkowska-Schelling C. Schelling Y. T. Utsunomiya 《Animal genetics》2020,51(1):78-86
In the past two decades, average litter size (ALS) in Entlebucher Mountain dogs decreased by approximately 0.8 puppies. We conducted a GWAS for ALS using the single-step methodology to take advantage of 1632 pedigree records, 892 phenotypes and 372 genotypes (173 662 markers) for which only 12% of the dogs had both phenotypes and genotypes available. Our analysis revealed associations towards the growth differentiation factor 9 gene (GDF9), which is known to regulate oocyte maturation. The trait heritability was estimated at 43.1%, from which approximately 15% was accountable by the GDF9 locus alone. Therefore, markers flanking GDF9 explained approximately 6.5% of the variance in ALS. Analysis of WGSs revealed two missense substitutions in GDF9, one of which (g.11:21147009G>A) affected a highly conserved nucleotide in vertebrates. The derived allele A was validated in 111 dogs and shown to be associated with decreased ALS (−0.75 ± 0.22 puppies per litter). The variant was further predicted to cause a proline to serine substitution. The affected residue was immediately followed by a six-residue deletion that is fixed in the canine species but absent in non-canids. We further confirmed that the deletion is prevalent in the Canidae family by sequencing three species of wild canids. Since canids uniquely ovulate oocytes at the prophase stage of the first meiotic division, requiring maturation in the oviduct, we conjecture that the amino acid substitution and the six-residue deletion of GDF9 may serve as a model for insights into the dynamics of oocyte maturation in canids. 相似文献
44.
M I Evans P G Pryde A Reichler M Bardicef M P Johnson 《The Western journal of medicine》1993,159(3):325-332
Fetal drug therapy encompasses several areas, including the prevention of external genital masculinization in 21-hydroxylase deficiency syndrome (congenital adrenal hyperplasia), biochemical amelioration of methylmalonic acidemia, and biotin-responsive multiple carboxylase deficiency. The correction of cardiac arrhythmias has become relatively commonplace, and a reduction in the risks of neural tube defects is now possible with the use of preconceptual and early conceptual folic acid. Similarly, fetal function can be altered by the induction of fetal lung maturity using a number of agents; corticosteroids are the most common fetal pharmaceutic agent, and a number of other agents have also been tried. The most common route of administering pharmaceutic agents is through the mother and the placenta, although the direct administration of certain agents is becoming more common. 相似文献
45.
1. Aposematic coloration in prey promotes its survival by conspicuously advertising unpalatability to predators. Although classical examples of aposematic signals involve constant presentation of a signal at a distance, some animals suddenly display warning colours only when they are attacked. 2. Characteristics of body parts suddenly displayed, such as conspicuous coloration or eyespot pattern, may increase the survival of the prey by startling the predator, and/or by signalling unpalatability to the predators at the moment of attack. 3. The adaptive value of such colour patterns suddenly displayed by unpalatable prey has not been studied. We experimentally blackened the red patch in the conspicuous red–white–black hindwing pattern displayed by an unpalatable insect Lycorma delicatula White (Hemiptera: Fulgoridae) in response to predator's attack. 4. There was no evidence that the presence of the red patch increased prey survival over several weeks. We hypothesise that predators generalised from the red–white–black patches on the hindwings of unpalatable L. delicatula to any similar wing display as a signal of unpalatability. Because a higher proportion of males than females stay put at their resting sites, displaying their wings in response to repeated attacks by predators, wing damage was more frequent in males than in females. 5. To our knowledge, this is the first experimental test of an adaptive role of aposematic signals presented by unpalatable prey during sudden displays triggered by direct predatory attack. 相似文献
46.
B B Fuks A I Shapoval I Grzhebin IM 《Biulleten' eksperimental'no? biologii i meditsiny》1991,112(7):78-80
We investigated the phenomenon of increased sensitivity of tumor-bearing mice to endotoxin shock. I/V administration of sera from tumor (EL-4, B16, R815, MOPC-315) bearers or tumoral culture media into intact mice caused the increased sensitivity to lethal action of LPS plus GMDP. Production of TNF in above mice was also significantly increased under the influence of LPS plus GMDP. Sensitivity induced factors in tumor bearing mice sera have mol. weight more than 50 kDa. This action was partially abolished by indomethacin. 相似文献