A simple test for detection of linkage

The paper presents a proposition for detection of linkage of genes responsible for metrical traits. Taking into account the expected means for early generations (F(1), F(2), F(3)) and a population of homozygous lines (in this case doubled haploid lines, DH derived from a cross between two homozygous parents) as well as estimators of genetic parameters m, [d], [i], [h] and [l], the expected values for these parameters in the presence of linkage have been formulated. It was found that when there is no linkage, the expression F(1) - 6F(2) + 8F(3) - 3DH(mean) is equal to zero. Thus, an experiment covering DH lines and F(1), F(2), F(3) hybrids makes it possible to obtain, beside information of interest, also information on presence or absence of linkage.     

Interaction of gene effects with environments for malting quality of barley doubled haploids

Barley doubled haploids covering a wide range of malting quality, along with their parental cultivars and F2, F3 hybrids, were investigated in six environments (three locations, two years) to study the genotype-environment (G x E) interaction structure and the influence of environments on additive, dominance and epistatic gene effects. Grain and malt characters, such as 1000-grain weight, percentage of plump kernels, malt extract yield, protein content, Kolbach index and malt fine-coarse difference (FCD), were measured. Main effects for genetic parameters were estimated and regression analysis was used to explain the interaction of gene effects with environments. The results show that additive effects had the greatest interaction with environments for all the analysed traits, but only for malt characters this interaction was linear. Interaction of dominance effects was much lower and only in the case of 1000-grain weight, protein content and Kolbach index it proved to be significant. The results suggest that effects of heterozygous loci are more stable in contrasting environments than effects of homozygous loci.     

Cellular and cytokine immunoregulation in patients with chronic obstructive pulmonary disease and bronchial asthma

BACKGROUND: Different forms of chronic airway inflammation may involve diverse pathogenic elements. In general, deficient defence response is a feature of chronic obstructive pulmonary disease (COPD), whereas distorted immunoregulatory mechanisms lead to development of asthmatic symptoms. In addition to diverse effector mechanisms, the cellular and humoral elements participating in the development of immune response may appear to be different in COPD and bronchial asthma (BA) patients. AIMS: To evaluate the immunoregulatory properties of T cells and monocytes in cultures of peripheral blood mononuclear cells (PBMC) and to determine the chosen cytokine profiles in COPD and BA patients. METHODS: The microcultures of PBMC from COPD and BA patients were assessed for the T-cell response to mitogens, saturation of interleukin (IL)-2 receptors, T-cell suppressive activity and monokine influence on lymphocyte proliferation. Concomitantly, the cytokine (IL-1beta, interleukin-1 receptor antagonist, tumour necrosis factor-alpha, IL-4, IL-6, IL-8) concentrations were determined in the serum, the broncho-alveolar lavage fluid and in the culture supernatants. RESULTS: The T-lymphocyte reactions (response to phytohaemagglutinin, IL-2 receptor saturation, suppressive activity) were lower in BA patients than in COPD patients. Reversely, the immunogenic activity of monocytes (IL-1beta versus IL-1ra production) was higher in BA patients than in COPD patients. The highest values of cytokine concentrations were found in the culture supernatants. The concentrations of tumour necrosis factor-alpha, IL-4, IL-6 and IL-8 were significantly higher and the concentration of IL-1ra was lower in BA patients than in COPD patients. CONCLUSION: The assessments of cellular immunoregulatory properties and cytokine profiles in the cultures of blood mononuclear cells may prove helpful for diagnostic and therapeutic discrimination between BA and COPD patients.     

Insulin restores expression of adenosine kinase in streptozotocin-induced diabetes mellitus rats

The effects of extracellular Mg²⁺ on both dynamic changes of [Ca²⁺]_i and apoptosis rate were analysed. The consequences of spatial and temporal dynamic changes of intracellular Ca²⁺ on apoptosis, in thapsigargin- and the calcium-ionophore 4BrA23187-treated MCF7 cells were first determined. Both 4BrA23187 and thapsigargin induced an instant increase of intracellular Ca²⁺ concentrations ([Ca²⁺]_i) which remained quite elevated (> 150 nM) and lasted for several hours. [Ca²⁺]_i increases were equivalent in the cytosol and the nucleus. The treatments that induced apoptosis in MCF7 cells were systematically associated with high and sustained [Ca²⁺]_i (150 nM) for several hours. The initial [Ca²⁺]_i increase was not determinant in the events triggering apoptosis. Thapsigargin-mediated apoptosis and [Ca²⁺]_i rise were abrogated when cells were pretreated with the calcium chelator BAPTA. The role of the extracellular Mg²⁺ concentration has been studied in thapsigargin treated cells. High (10 mM) extracellular Mg²⁺, caused an increase in basal [Mg²⁺]_i from 0.8 ± 0.3 to 1.6 ± 0.5 mM. As compared to 1.4 mM extracellular Mg²⁺, 1 M thapsigargin induces, in 10 mM Mg²⁺, a reduced percentage from 22 to 11% of fragmented nuclei, a lower sustained [Ca²⁺]_i and a lower Ca²⁺ influx through the plasma membrane. In conclusion, the cell death induced by thapsigargin was dependent on high and sustained [Ca²⁺]_i which was inhibited by high extracellular and intracellular Mg²⁺.     

Assessment of RAPD markers for barley doubled haploid lines resistant and susceptible to Fusarium culmorum at seedling and adult plant growth stages

Thirty doubled haploid (DH) lines of barley derived from F(1) of a cross between the six-rowed cultivar Pomo and two-rowed cultivar Maresi were examined for susceptibility to Fusarium seedling blight (SB) and head blight (FHB), measured by mycotoxin (nivalenol) content of kernels. RAPD (random amplified polymorphic DNA) polymorphism was analysed by using 53 decamer primers. Amplification products (APs) were 200 bp up to 2000 bp in size on average 5.7 per primer and the total number of APs was 284, 51.06% of which were polymorphic. Only 32 APs differentiated the examined DH lines - 19 APs for nivalenol content of kernels and 13 for seedling resistance. DH lines segregated with continuous distribution of resistance to FHB and SB. At the seedling stage all DH lines exhibited lower susceptibility than parental cultivars, but in the adult stage only two lines (MP 2 and MP 7) appeared to be more resistant to FHB, i.e. accumulated in kernels a lower amount of mycotoxin than cultivars Maresi and Pomo.     

Intraspecies variability of Desulfovibrio desulfuricans strains determined by the genetic profiles

Fifteen (soil and intestinal) strains of Desulfovibrio desulfuricans species were typed by PCR method with the use of primers specific for repetitive extragenic palindromic (REP) and enterobacterial repetitive intergenic consensus (ERIC) sequences. As a result, characteristic DNA fingerprints for the strains were obtained. Moreover, the genetic profiles were found to be useful for typing and distinguishing the strains of D. desulfuricans. According to cluster analysis, PCR with primers complementary to the sequences REP appeared to be slightly more discriminatory than PCR with ERIC primers for the investigated strains. Distinct fingerprint patterns of two isolates derived from the same patient pointed to the different origin of both strains.     

Hair copper concentration in healthy children,teenagers, and adults living in Szczecin,Poland

The aim of this study was to assess the hair copper concentration in a population of healthy children, teenagers, and adults living in a specific region of Poland. For this purpose, 840 healthy individuals aged 1–50 yr living in Szczecin, Poland were selected for the study. They were divided into subgroups according to age and sex and the hair was analyzed for copper using a standard atomic absorption spectrometric technique. The level of copper was highest for the group including 11–15 yr old. In the other subgroups, the concentration of copper was lower than the values considered normal, suggesting the possibility of endemic copper deficiency in the inhabitants of this region.     

Uncoupling protein-2 prevents neuronal death and diminishes brain dysfunction after stroke and brain trauma

Whereas uncoupling protein 1 (UCP-1) is clearly involved in thermogenesis, the role of UCP-2 is less clear. Using hybridization, cloning techniques and cDNA array analysis to identify inducible neuroprotective genes, we found that neuronal survival correlates with increased expression of Ucp2. In mice overexpressing human UCP-2, brain damage was diminished after experimental stroke and traumatic brain injury, and neurological recovery was enhanced. In cultured cortical neurons, UCP-2 reduced cell death and inhibited caspase-3 activation induced by oxygen and glucose deprivation. Mild mitochondrial uncoupling by 2,4-dinitrophenol (DNP) reduced neuronal death, and UCP-2 activity was enhanced by palmitic acid in isolated mitochondria. Also in isolated mitochondria, UCP-2 shifted the release of reactive oxygen species from the mitochondrial matrix to the extramitochondrial space. We propose that UCP-2 is an inducible protein that is neuroprotective by activating cellular redox signaling or by inducing mild mitochondrial uncoupling that prevents the release of apoptogenic proteins.     

Age-dependent response of maize leaf segments to cadmium treatment: effect on chlorophyll fluorescence and phytochelatin accumulation

The relationship between the age of leaf tissue and response of the photosynthetic apparatus and phytochelatin accumulation to Cd treatment was studied. Studies were carried out with seedlings of Zea mays L. cv. Hidosil grown in the presence of 100-200 mumol/L Cd for 14 days under low light conditions. The third leaf was divided into 3 segments of equal length differing in the stage of tissue maturity and used for measurements of chlorophyll content, chlorophyll fluorescence, glutathione and phytochelatin content and Cd accumulation. A close relationship between the age of leaf tissue and response of the photosynthetic apparatus to Cd was shown. Cadmium (200 mumol/L) reduced photochemical processes more in older than younger leaf segments as seen in the Chl fluorescence parameters Fv/F0, and t1/2, while the chlorophyll fluorescence decrease ratio (Rfd) was inhibited more strongly in younger ones. Fv/Fm was slightly affected. Cd-induced enhancement of GSH content was correlated with higher phytochelatin accumulation to a greater extent in younger than in older leaf segments. Phytochelatin level corresponded to changes of photochemical processes in older leaves. The peptide thiol:Cd molar ratio for the phytochelatins varied depending on Cd concentration and age of leaf segments. The protective role of phytochelatins for the photosynthetic apparatus is discussed.     

Responses of benthic community metabolism to abiotic factors in a mountain river in southern Poland

Seasonal and longitudinal metabolic trends in benthic communities were studied in the five orders of a natural mountain river (the Stradomka) in southern Poland. The method of oxygen change of rocky substrata in chambers was applied. Metabolic data were compared with abiotic (light regime, channel geomorphology and stream hydrology), and water chemical variables. A tendency of downstream increase in gross production and community respiration was observed between 1st and 4th stream orders. The highest values of GP (0.94 g C m^-2 24 h ^-1) and CR (1.12 g C m^-2 24 h ^-1) were observed in the middle Stradomka course (3–4 orders) in spring. A distinct negative NDM (heterotrophy) of the benthic community was measured in autumn and spring. During winter NDM was almost constant and oscillated around zero. The P/R ratio changed according to season and fluctuated between heterotrophy (P/R < 1) and autotrophy (P/R > 1). In general, heterotrophy prevailed in the study system (except 5th order). A marked shift in P/R between 4th and 5th stream orders confirms the prediction included in the RCC. Water temperature and PAR accounted for 56% in GP variability, whereas CR and NDM were not related to these variables. The combined variables (PAR and PO₄–P) attributed to 69% in GP variability. The set of chemical factors was less related to Stradomka metabolic data. These results suggest that metabolic processes in this mountain river remarkably depend on physical variables (solar radiation, altitude, water temperature and conductivity). Metabolic parameters were similar to other geographical mountain systems. This revised version was published online in July 2006 with corrections to the Cover Date.