QTL mapping for yield and lodging resistance in an enhanced SSR-based map for tef.

Tef is a cereal crop of cultural and economic importance in Ethiopia. It is grown primarily for its grain though it is also an important source of fodder. Tef suffers from lodging that reduces both grain yield and quality. As a first step toward executing a marker-assisted breeding program for lodging resistance and grain yield improvement, a linkage map was constructed using 151 F(9) recombinant inbred lines obtained by single-seed-descent from a cross between Eragrostis tef and its wild relative Eragrostis pilosa. The map was primarily based on microsatellite (SSR) markers that were developed from SSR-enriched genomic libraries. The map consisted of 30 linkage groups and spanned a total length of 1,277.4 cM (78.7% of the genome) with an average distance of 5.7 cM between markers. This is the most saturated map for tef to date, and for the first time, all of the markers are PCR-based. Using agronomic data from 11 environments and marker data, it was possible to map quantitative trait loci (QTL) controlling lodging, grain yield and 15 other related traits. The positive effects of the QTL identified from the wild parent were mainly for earliness, reduced culm length and lodging resistance. In this population, it is now possible to combine lodging resistance and grain yield using a marker-assisted selection program targeting the QTL identified for both traits. The newly developed SSR markers will play a key role in germplasm organization, fingerprinting and monitoring the success of the hybridization process in intra-specific crosses lacking distinctive morphological markers.

Clinical studies on the hypolipidemic and antioxidant effects of selected natural substances.

BACKGROUND: The average blood levels of cholesterol and triacylglycerol in population are generally considered to be indicators of cardiovascular risk. AIM OF THE STUDY: The aim of our study was to present representative data of selected fractions of blood lipids, and the trend of their levels during the last 35 years in the adult population of Slovakia. RESULTS: This study demonstrates the risk of the elevated average cholesterolaemia and triacylglycerolaemia in men aged 35-39 years and above 60 years, as compared to womens' increased blood level that were detected only in the age group above 60 years. Strong gender differences in HDL-cholesterol were found, women having higher values than men, with these differences fading in the age group above 60 years. The results of two clinical studies present the hypolipemic effects of n-3 polyunsaturated fatty acid in individuals with dyslipidaemia, the hypotriacylglycerolemic effect being dominant (p < 0.001). The hypocholesterolemic effect was less significant (p < 0.05) than in cases when lyophilized powder of the Pleurotus ostreatus was applied (p < 0.01). In both cases, a stabilizing effect on serum HDL-cholesterol had been observed. In case of polyunsaturated fatty acid n-3, its increase was borderline with statistical significance (p = 0.05). CONCLUSION: The study emphasises the necessity of improving the average blood level of lipids in the population of Slovakia and the pertinence of using natural substances with a hypolipemic effect in secondary and even primary prevention of atherosclerosis and its serious complications (Tab. 3, Fig. 4, Ref. 27).

Creutzfeldt-Jakob disease with E200K mutation in Slovakia: characterization and development.

Creutzfeldt-Jakob disease (CJD), the most important human prion disease, occurs in sporadic, iatrogenic and familial form. Except Slovakia and Israel, the recorded familial cases have never exceeded 10-15%. In the Slovak CJD group 95 out of 136 CJD cases (74.2%) carried a CJD-specific mutation in the prion protein gene (PRNP) at codon 200 (mutation E200K). All CJD(E200K) patients carried a heterozygous E200K mutation within the alelle with methionine at codon 129. No more than 53.7% were typical familial cases. The penetrance of the E200K mutation in 1975-2000 was 59.5%. The distribution of codon 129 polymorphism showed 78.6% of methionine-homozygous and 21.4% of methionine/valine-heterozygous patients. Genetic analysis performed on 278 CJD patient relatives demonstrated the E200K mutation in 97 (34.8%) of healthy relatives tested. The E200K mutation carriers were methionine-homozygous in 64% and methionine/valine-heterozygous in 36%. The relatives without the mutation showed a 54.9% methionine homozygosity, 10.4% valine homozygosity and 34.7% methionine/valine heterozygosity. Analysis ofthe E200K carriers provided evidence that the methionine homozygosity is a CJD risk factor, more efficient in CJD patients than in asymptomatic relatives. Th influence of both the E200K mutation and methionine homozygosity at codon 129 was evident in the duration of the clinical stage of CJD and in the immunoreactivity pattern of PrP resistant to proteases (PrP(res)). In the CJD(E200K) methionine-homozygous patients the mean duration ofthe disease was significantly shorter (3.7 +/- 2.0 months) than in the methionine/valine-heterozygous patients (7.84 +/- 7.3 months). Comparison of the PrP(res) positivity in the cerebellum of familial and sporadic CJD using specific polyclonal and monoclonal antibodies (MAbs) to PrP showed less conspicuous immune reaction in CJD(E200K) cases. Methionine-homozygous CJD patients were characteristic mainly by synaptic pattern of staining, while methionine/valine-heterozygous patients by PrP(res) granules and plaque-like structures. Most of numerous plaque-like PrP(res) deposits were found in sporadic valine/valine-homozygous cases. Potential professional risk was excluded in health facility workers. The percentage of professions related to farming was significantly higher in CJD(E200K) (48%) and sporadic CJD (44%) cases as compared to the employed population (9%).

Creutzfeldt-Jakob disease risk in Slovak recipients of human pituitary growth hormone.

UNLABELLED: Creutzfeldt-Jakob disease (CJD) is a transmissible, fatal degenerative disorder of the CNS. CJD is known in a sporadic, familial and iatrogenic form. Iatrogenic form has been accidentally induced through corneal and dura mater transplantation or surgical procedures. The largest number of iatrogenic CJD developed in patients who had received human growth hormone (hGH). The minimal incubation period appears to be 4-15 years, the maximal 21-30 years after receiving hGh treatment. An increasing number of new CJD cases in hGH recipients in France, providing evidence of unusually long incubation period and an occurrence of genetically controlled (mutation E200K carrier) CJD-risk group in Slovak population induced this second investigation of hGh treated patients. The aim of this study is to verify whether the absence of CJD in hGH recipients in Slovakia reflects the actual epidemiological situation or a lack of informations. The objective of the study was to investigate signs of clinical manifestation of CJD and to perform molecular genetic study on prion protein (PrP) gene in hGh recipients. PATIENTS AND METHODS: 32 hGH treated patients (23 men and 9 women) at the age of 17-38 years were investigated. The occurrence of codon 200 (E200K) mutation and polymorphism at codon 129 of PrP gene was studied. RESULTS: Neurological, including cerebellar signs of CJD, intellectual or psychological changes were not observed in investigated patients. The shortest duration of hGH treatment was 2 years, the longest 9 years. The time interval since the beginning of hGH administration was 12-19 years. Restriction endonuclease analysis of the PrP gene revealed one patient with E200K mutation, 8 patients homozygous for methionin, 2 patients homozygous for valin and 16 heterozygous patients at codon 129. CONCLUSION: No evidence of CJD has been observed in investigated group of hGH recipients. Considering the long incubation period of hGH-induced CJD and the obtained results, clinical and genetic investigation on the whole relatively small group of Slovak hGH recipients is recommended. (Tab. 2, Fig. 1, Ref. 22.)

Creutzfeldt-Jakob disease in health professionals in Slovakia.

Creutzfeldt-Jakob disease (CJD) is the most important human transmissible spongiform encephalopathy (prion disease), recognised in sporadic, genetic but also iatrogenic forms. The identification of 8 health care workers in a group of 114 definitive CJD patients in Slovakia suggested the possibility of professionally acquired CJD and induced the investigation of potential endo- and exogenous risk factors. In CJD-affected health professionals special attention was paid to a detailed occupational history, including a possible professional contact with CJD patient and to the findings characteristic for iatrogenic CJD: early cerebellar symptomatology, long duration of the disease, absence of typical EEG finding and homozygosity of PRNP gene at codon 129. Analysis of epidemiological, clinical and molecular biological data in investigated group of CJD-affected health professionals gave no evidence of an occupational risk for CJD.

Relationships among tetraploid wheat (Triticum turgidum L.) landrace populations revealed by isozyme markers and agronomic traits.

Diversity and relationships among ten tetraploid wheat landrace populations, collected from different localities in the central highlands of Ethiopia, were studied using isozyme markers and agronomic traits. This type of analysis in crop species is fundamental for designing optimal germ plasm collection, management practices and for developing an index for parental selection. The populations differed in allelic frequencies. Gene-diversity estimates showed that the populations encompass an appreciable amount of variation. However, differentiation between them was low, as was also confirmed by the presence of gene flow. Much of the diversity (85%), was attributable to the within-population level. The genetic distances were mostly small with the exception of those between a few pairs of populations. Thus, the relationships discerned among the populations were more of a similarity nature which could be ascribed to sharing a common ancestral population and/or adaptation to similar climatic conditions. The pattern of genetic divergence appeared to be independent of geographic distance. Considerable divergence in the agronomic traits was observed for certain populations. Cluster analyses of the isozyme and agronomic data produced different patterns and memberships of groupings. This lack of agreement could be ascribed to the different forces of evolution acting on isozyme markers and agronomic traits since agronomic traits, are the prime target of artificial selection. The clustering based on agronomic traits resulted in grouping together populations with similar agronomic performance. The results of this study suggest that taking more samples within a locality or population would be a better approach to capture the range of variation in the landrace populations of the central highlands of Ethiopia.