The binding of [3H]SCH 23390 has been studied in various brain regions of male mice with the experience of repeated victory (winners) or defeat (losers) gained over 10 (T10) and 20 (T20) days of daily agonistic confrontations. In the frontal cortex, Bmax of [3H]SCH 23390 binding sites was found to be increased in T10 losers and decreased in T20 losers when compared to the control mice. In the striatum, T10 and T20 winners had reduced values of [3H]SCH 23390 binding sites than the ones in the control mice. The Kd was increased in the frontal cortex of T10 losers and T10 winners as well as in the amygdala of T20 losers. Reduced Kd values were found in the striatum of all experimental groups as well as in the amygdala of T20 winners. Thus, both specific changes relating to social behavior patterns and non-specific ones in [3H]SCH 23390 binding were found in the brain regions of mice after 10 and 20 days of intermale confrontations., D. F. Avgustinovich, O. V. Alekseyenko., and Obsahuje bibliografii a bibliografické odkazy
The aim of this study was to evaluate the association of single nucleotide polymorphisms (SNPs) T-786C and G894T in the gene encoding eNOS with blood pressu re variability (BPV) in man. Blood pressure was recorded beat-t o-beat at rest three times in periods of one week (5 min, Finapres, breathing at 0.33 Hz) in 152 subjects (19-24 years). Systolic (SBPV0.1r/SBPV 0.1a) and diastolic (DBPV0.1r/DBPV 0.1a) blood pressure variabilities in relative (r.u.) and absolute (mmHg2/Hz) units were determined by the spectral method as spectral po wer at the frequency of 0.1 Hz. Genotypes of both polymorphisms were detected using polymerase chain reaction and re striction analysis using enzymes Msp I and Ban II. Significant diffe rences were observed in BPV among genotypes of T-786C SNP (p<0.05; Kruskal-Wallis), and among haplotypes of both SNPs (p<0.05; Kruskal-Wallis) as well. In T-786C SNP, carriers of less frequent allele (CC homozygotes and TC heterozygotes) showed significantly greater SBPV0.1r and SBPV0.1a compared to TT homozygote s (Mann-Whitney; p<0.05). The G894T variant showed no sign ificant differences, but, both SNPs were in linkage disequilib rium (D’=0.37; p<0.01). Carriers of haplotype CT/CT (CC homozygotes of -786C/T and TT homozygotes of G894T) displaye d significantly greater SBPV0.1r, SBPV0.1a and DBPV0.1a compared to carriers of other haplotype combinations (Kruskal-Wallis; p=0.015, p=0.048, and p=0.026, respectively). In conclusion, the haplotype formed by less frequent alleles of both eNOS variants was associated with increased systolic and diastolic BPV in this study., M. Jíra ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
1a_It has been known for many years that baroreflex sensitivity is lowered in hypertensive patients. There are several known factors implicating this association, e.g. high blood pressure leads to remodeling of the carotid arterial wall, to its stiffness and to a diminished activation of baroreceptors; leptin released from a fatty tissue activates the sympathetic nervous system etc. On the other hand, low baroreflex sensitivity (BRS, usually quantified in ms/mmHg) can be inborn. Studies on primary hypertension in children and adolescents have brought new information about the role of baroreflex in the development of an early stage of primary hypertension. BRS lower than 3.9 ms/mmHg was found in 5 % of healthy subjects. This value approaches the critical value for the risk of sudden cardiac death in patients after myocardial infarction and corresponds to the value present in hypertensive patients. A decreased BRS and BRSf (baroreflex sensitivity expressed in mHz/mmHg, index independent of the mean cardiac interval), was found not only in children with hypertension, but also in those with white-coat hypertension. This is in accordance with a single interpretation. The decrease of BRS/BRSf precedes a pathological blood pressure increase., 2a_The contribution of obesity and BRS/BRSf to the development of hypertension in adolescents was also compared. Both factors reach a sensitivity and a specificity between 60 % and 65 %, but there is no correlation between the values of the body mass index and BRS either in the group of hypertensive patients or in healthy controls. If a receiver operating curve (sensitivity versus specificity) is plotted for both values together using logistic regression analysis, a sensitivity higher than 70 % and a specificity over 80 % are reached. This means that low baroreflex sensitivity is an independent risk factor for the development of primary hypertension. Studies demonstrate that adolescents with increased blood pressure and with BRS under 7 ms/mmHg should be given care and intensively motivated to change their lifestyle including a change in diet and increase in physical activity., and N. Honzíková, B. Fišer.
V r. 2013 dvě nezávislé skupiny osekvenovaly kompletní genomy obou taxonomicky známých druhů latimérií (Latimeria). Článek krátce shrnuje celou historii jejich objevu, zeměpisné rozšíření a stručně podává přehled vývoji poznatků o jednotlivých částech jejich genomu. Poté komentuje výsledky zmíněných celogenomových studií zejména vzhledem ke dvěma skupinám genů - společné pro paprskoploutvé ryby (Actinopterygii) a latimérii a společné pro latimérii a čtvernožce (Tetrapoda)., Two independent research groups decipher the complete genomes of both taxonomically known species of the genus Latimeria. This note briefly summarizes the discovery and geographic distribution of coelacanth species, and overviews the history of findings dealing with various parts of their genomes. It also comments on the results of both whole genome sequencing studies, especially as regards two gene groups - those present in ray-finned fishes (Actinopterygii) and coelacanth and those present in coelacanth and tetrapods., and Petr Ráb.
Diapause intensity (DI) is a physiological trait represented by the duration of diapause under given conditions of environment. In many species, it is highly variable, probably being controlled by multiple genes and tends to form a cline in response to the latitudinal gradient of selection pressure. DI clines could be established artificially by crossing between lines of a cricket selected for different levels of DI, indicating the importance of genetic factors in the adaptive variation of DI. However, DI may be modified in response to seasonal cues both before and after the onset of diapause. Polymorphism in the intensity of prolonged diapause may split adults of a single population to emerge in different years. A unimodal distribution of DI may also result in polymodal termination of diapause, if DI variation is so large that chilling in one winter is not enough to terminate diapause for all members of a population. Bimodal termination of diapause after overwintering suggests heterogeneity in the final phase of diapause that requires high temperatures in spring. Polymodal termination of diapause subserves a bet-hedging strategy. Variability in DI thus provides insects with an important means of adaptation to their environments changing in space and time.
Hypertension is a major health problem throughout the world because of its high prevalence and its association with increased risk of cardiovascular disease. Two independent studies discovered a locus conferring susceptibility to essential hypertension on chromosome 2, in the 2p25 region, but the causative gene remains unknown. Grainyhead-like 1 (GRHL1) is one of the genes located in this region. Our experiments determined that the Grhl1-null mice, when fed standard diet, have the same blood pressure as their wild type littermate controls. However, we discovered that blood pressure of these mice increases following high sodium diet and decreases when they are fed low sodium diet, and similar effect s were not observed in the control wild type littermates. This suggests that the Grhl1-null mice are sensitive to the development of salt-sensitive hypertension. Thus it is possible that the GRHL1 gene is involved in the regulation of blood pressure, and it may be the causative gene for the locus of susceptibility to essential hypertension in the 2p25 region., A. Walkowska, M. Pawlak, S. M. Jane, E. Kompanowska-Jezierska, T. Wilanowski., and Obsahuje bibliografii
Genetic predispositions may influence geographical and interethnic differences in COVID-19 prevalence and mortality in affected populations. Of the many genes implicated in COVID-19 progression, a substantial number have no direct functional link on virus transfer/viability or on the host immune system. To address this knowledge deficit, a large number of in silico studies have recently been published. However, the results of these studies often contradict the findings of studies involving real patients. For example, the ACE2 has been shown to play an important role in regulating coronavirus entry into cells, but none of its variations have been directly associated with COVID19 susceptibility or severity. Consistently was reported that increased risk of COVID-19 is associated with blood group A and with the APOE4 allele. Among other genes with potential impacts are the genes for CCR5, IL-10, CD14, TMPRSS2 and angiotensinconverting enzyme. Variants within the protein-coding genes OAS1 and LZTFL1 (transferred to the human genome from Neanderthals) are understood to be among the strongest predictors of disease severity. The intensive research efforts have helped to identify the genes and polymorphisms that contribute to SARS-CoV-2 infection and COVID-19 severity.
Epigenetická regulace aktivity genů může významnou měrou ovlivňovat fenotypovou variabilitu organismů. Vzhledem k tomu, že některá indukovaná epigenetická variabilita může být děděna po mnoho generací, je možné, že epigenetická variabilita ovlivňuje jak ekologii, tak i evoluční trajektorie organismů. V článku popisuji některé poslední poznatky úlohy epigenetické variability v ekologii a evoluci rostlin., Phenotypic variation can be driven by epigenetic regulation of genes' activity. It is possible that induced epigenetic variation can alter the ecology and evolutionary trajectories of organisms because some induced epigenetic variation can be faithfully heritable among several generations. In the article, I discuss some recent information about the role of epigenetic variation in the ecology and evolution of plants., and Vít Latzel.
Apolipoprotein A-V plays an important role in the determination of plasma triglyceride (TG) concentration. We aimed to determine whether polymorphisms -1131T>C (rs662799) and 56C>G (rs3135506) of the APOA5 gene have an impact on the course of postprandial lipemia induced by a fat load and a fat load with added glucose. Thirty healthy male volunteers, seven heterozygous for the -1131C variant and three for the 56G variant (HT) carriers, and 20 wild-type (WT) carriers underwent two 8-hour tests of postprandial lipemia – one after an experimental breakfast consisting of 75 g of fat and second after a breakfast consisting of 75 g of fat and 25 g of glucose. HT carriers had a higher postprandial response after fat load than WT carriers (AUC TG: 14.01±4.27 vs. 9.84±3.32 mmol*h/l,
respectively, p=0.016). Glucose added to the test meal suppressed such a difference. Heterozygous carriers of the variants of APOA5 (-1131C and 56G) display more pronounced postprandial lipemia after pure fat load than WT carriers. This statistically significant difference disappears when glucose is added to a fat load, suggesting that meal composition modulates the effect of these polymorphisms on the magnitude of postprandial lipemia.