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41.
Dinoflagellates are important aquatic primary producers and cause "red tides." The most widespread plastid (photosynthetic organelle) in these algae contains the unique accessory pigment peridinin. This plastid putatively originated via a red algal secondary endosymbiosis and has some remarkable features, the most notable being a genome that is reduced to 1-3 gene minicircles with about 14 genes (out of an original 130-200) remaining in the organelle and a nuclear-encoded proteobacterial Form II Rubisco. The "missing" plastid genes are relocated to the nucleus via a massive transfer unequaled in other photosynthetic eukaryotes. The fate of these characters is unknown in a number of dinoflagellates that have replaced the peridinin plastid through tertiary endosymbiosis. We addressed this issue in the fucoxanthin dinoflagellates (e.g., Karenia brevis) that contain a captured haptophyte plastid. Our multiprotein phylogenetic analyses provide robust support for the haptophyte plastid replacement and are consistent with a red algal origin of the chromalveolate plastid. We then generated an expressed sequence tag (EST) database of 5,138 unique genes from K. brevis and searched for nuclear genes of plastid function. The EST data indicate the loss of the ancestral peridinin plastid characters in K. brevis including the transferred plastid genes and Form II Rubisco. These results underline the remarkable ability of dinoflagellates to remodel their genomes through endosymbiosis and the considerable impact of this process on cell evolution.  相似文献   
42.
The effect of age on 12 chemical element contents in intact prostate of 64 apparently healthy, 13-60-year-old men (mean age 36.5 years) was investigated by inductively coupled plasma atomic emission spectrometry. Mean values (M ± SΕΜ) for mass fraction (milligrams/kilogram, on dry weight basis) of Ba, Ca, Cu, Fe, K, Mg, Na, P, S, Sr, and Zn were: Ba 1.18 ± 0.12, Ca 2,178 ± 160, Cu 10.7 ± 0.9, Fe 122 ± 5, K 12,530 ± 360, Mg 1,100 ± 70, Na 10,470 ± 320, P 7,580 ± 300, S 8,720 ± 180, Sr 1.85 ± 0.28, and Zn 782 ± 97, respectively. The upper limit of mean content of V was ≤0.22 mg/kg. A tendency of age-related increase in Ca, Fe, Na, and Zn mass fraction as well an increase in Zn/Ba, Zn/Ca, Zn/Cu, Zn/Fe, Zn/K, Zn/Mg, Zn/Na, Zn/P, Zn/S, and Zn/Sr ratios in prostate was observed. A significant positive correlation was seen between the prostatic zinc and Ca, Cu, Fe, Mg, Na, and P contents.  相似文献   
43.
Current understanding of the plastid proteome comes almost exclusively from studies of plants and red algae. The proteome in these taxa has a relatively simple origin via integration of proteins from a single cyanobacterial primary endosymbiont and the host. However, the most successful algae in marine environments are the chlorophyll c-containing chromalveolates such as diatoms and dinoflagellates that contain a plastid of red algal origin derived via secondary or tertiary endosymbiosis. Virtually nothing is known about the plastid proteome in these taxa. We analyzed expressed sequence tag data from the toxic "Florida red tide" dinoflagellate Karenia brevis that has undergone a tertiary plastid endosymbiosis. Comparative analyses identified 30 nuclear-encoded plastid-targeted proteins in this chromalveolate that originated via endosymbiotic or horizontal gene transfer (HGT) from multiple different sources. We identify a fundamental divide between plant/red algal and chromalveolate plastid proteomes that reflects a history of mixotrophy in the latter group resulting in a highly chimeric proteome. Loss of phagocytosis in the "red" and "green" clades effectively froze their proteomes, whereas chromalveolate lineages retain the ability to engulf prey allowing them to continually recruit new, potentially adaptive genes through subsequent endosymbioses and HGT. One of these genes is an electron transfer protein (plastocyanin) of green algal origin in K. brevis that likely allows this species to thrive under conditions of iron depletion.  相似文献   
44.
The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.  相似文献   
45.
Administration of 50 micrograms of testosterone propionate to newborn female rats on the 5th day of life provoked a reliable increase in noradrenaline and dopamine concentrations in the hypothalamus of 10-day-old rats. Neonatal administration of aromatase inhibitors on the 5th and 7th days of life prevented testosterone-induced increase in catecholamine concentrations. The data obtained prove the integration of the processes of testosterone aromatization and catecholamine accumulation in androgen-dependent brain differentiation.  相似文献   
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Data on study of action plasma inhibitors on activity of pancreatic proteolytic enzymes (trypsin, chymotrypsin) and plant proteinases (papain, bromelain), included in composition of enzyme mixes, used for orally application are submitted. It is established, that serine proteases are more sensitive to inactivation of plasma inhibitors, than cysteine enzymes. Main inhibitor of the papain and bromelain is alpha-2-macroglobulin in complex with which they preserve significant part of initial activity. A high-sensitivity method of determination of activity enzyme combinations, enabling to detect nanograms of them in presence of plasma inhibitors is offered. It can be used for study pharmacokinetic and optimization of enzyme mixes application in clinical practice.  相似文献   
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