Comparative seed longevity under genebank storage and artificial ageing: a case study in heteromorphic wheat wild relatives

Seed longevity is a complex trait that depends on numerous factors. It varies among species and populations, and within different seed morphs produced by the same plant. Little is known about variation in longevity in different seed morphs or the physiological and molecular basis of these differences. We evaluated the longevity and oxidative stress status in heteromorphic seeds aged in two different storage conditions. We compared controlled ageing tests (seed storage at 45°C and 60% relative humidity; a method of accelerated ageing used to estimate longevity in genebank conditions) with storage in a genebank for up to 40 years (-18°C and 8% seed moisture content). We employed as study species two wild wheats characterized by seed heteromorphism: Aegilops tauschii and Triticum monococcum subsp. aegilopoides. We estimated the ROS content and the expression of genes coding for enzymes related to the H₂ O₂ scavenging pathway. Results confirmed that seed longevity varies between different seed morphs. Different storage environments resulted in different longevity and survival curves. ROS levels, even if with variable patterns, were higher in several aged seed lots. We observed consistency in the expression of two genes (GSR and CAT) related to ROS scavenging in the late phase of pre-germinative metabolism. Differences in seed longevity between morphs were observed for the first time under genebank conditions. Our results suggest also that controlled ageing tests should be used with caution to infer ranks of longevity under cold storage.

The consensus rye microsatellite map with EST-SSRs transferred from wheat

Microsatellite (SSR) markers with known precise intrachromosomal locations are widely used for mapping genes in rye and for the investigation of wheat-rye translocation lines and triticale highly demanded for mapping economically important genes and QTL-analysis. One of the sources of novel SSR markers in rye are microsatellites transferable from the wheat genome. Broadening the list of available SSRs in rye mapped to chromosomes is still needed, since some rye chromosome maps still have just a few microsatellite loci mapped. The goal of the current study was to integrate wheat EST-SSRs into the existing rye genetic maps and to construct a consensus rye microsatellite map. Four rye mapping populations (P87/P105, N6/N2, N7/N2 and N7/N6) were tested with CFE (EST-SSRs) primers. A total of 23 Xcfe loci were mapped on rye chromosomes: Xcfe023, -136 and -266 on chromosome 1R, Xcfe006, -067, -175 and -187 on 2R, Xcfe029 and -282 on 3R, Xcfe004, -100, -152, -224 and -260 on 4R, Xcfe037, -208 and -270 on 5R, Xcfe124, -159 and -277 on 6R, Xcfe010, -143 and -228 on 7R. With the exception of Xcfe159 and Xcfe224, all the Xcfe loci mapped were found in orthologous positions considering multiple evolutionary translocations in the rye genome relative to those of common wheat. The consensus map was constructed using mapping data from the four bi-parental populations. It contains a total of 123 microsatellites, 12 SNPs, 118 RFLPs and 2 isozyme loci.

Hybrid dwarfness in crosses between wheat (Triticum aestivum L.) and rye (Secale cereale L.): a new look at an old phenomenon

The existence of hybrid dwarfs from intraspecific crosses in wheat (Triticum aestivum) was described 100 years ago, and the genetics underlying hybrid dwarfness are well understood. In this study, we report a dwarf phenotype in interspecific hybrids between wheat and rye (Secale cereale). We identified two rye lines that produce hybrid dwarfs with wheat and have none of the hitherto known hybrid dwarfing genes. Genetic analyses revealed that both rye lines carry a single allelic gene responsible for the dwarf phenotype. This gene was designated Hdw-R1 (Hybrid dwarf-R1). Application of gibberellic acid (GA3 ) to both intraspecific (wheat-wheat) and interspecific (wheat-rye) hybrids showed that hybrid dwarfness cannot be overcome by treatment with this phytohormone. Histological analysis of shoot apices showed that wheat-rye hybrids with the dwarf phenotype at 21 and 45 days after germination failed to develop further. Shoot apices of dwarf plants did not elongate, did not form new primordia and had a dome-shaped appearance in the seed. The possible relationship between hybrid dwarfness and the genes responsible for the transition from vegetative to generative growth stage is discussed.

Insulin-like growth factor I correlations to changes of the hormonal status in puberty and age

IGF-I is considered to be one of the most important growth factors during puberty. Information concerning its correlation to thyroid hormones (T3, T4), adrenal and sex steroids is limited to puberty and the elderly. The presented study included 455 subjects (among them 259 children) ranging in age from newborn to 100 years. Serum IGF-I concentrations increase from childhood to the end of puberty (2 years earlier in girls). There are close positive correlations between IGF-I concentrations and age, height and weight and between IGF-I and estradiol or testosterone concentration in girls and boys respectively, and the DHEA-S level in boys during puberty. Correlations also exist with T3, aldosterone and 17 OH-progesterone in boys and girls in the pubertal stages I-V and with T4 in stages I-IV. Compared to 20-30 year-old subjects IGF-I concentrations amounted to 59% after 60 years, 43% in men and 54% in women after 70 years and 29% after 90 years. It is suggested that increasing adrenal DHEA-S concentrations stimulate IGF-I synthesis and by means of gonadal steroidogenesis, increase the pubertal GH secretion and the further pubertal IGF-I increase. The low IGF-I concentrations in patients > 60 years reflect the more catabolic metabolism of the elderly.

Single nucleotide polymorphisms in rye (Secale cereale L.): discovery, frequency, and applications for genome mapping and diversity studies

To elucidate the potential of single nucleotide polymorphism (SNP) markers in rye, a set of 48 barley EST (expressed sequence tag) primer pairs was employed to amplify from DNA prepared from five rye inbred lines. A total of 96 SNPs and 26 indels (insertion-deletions) were defined from the sequences of 14 of the resulting amplicons, giving an estimated frequency of 1 SNP per 58 bp and 1 indel per 214 bp in the rye transcriptome. A mean of 3.4 haplotypes per marker with a mean expected heterozygosity of 0.66 were observed. The nucleotide diversity index (pi) was estimated to be in the range 0.0059-0.0530. To improve assay cost-effectiveness, 12 of the 14 SNPs were converted to a cleaved amplified polymorphic sequence (CAPS) format. The resulting 12 SNP loci mapped to chromosomes 1R, 3R, 4R, 5R, 6R, and 7R, at locations consistent with their known map positions in barley. SNP genotypic data were compared with genomic simple sequence repeat (SSR) and EST-derived SSR genotypic data collected from the same templates. This showed a broad equivalence with respect to genetic diversity between these different data types.

Comparative mapping of genes for glume colouration and pubescence in hexaploid wheat (Triticum aestivum L.)

Microsatellite markers were used to map the major genes Bg (determining black glume colour), Rg1 and Rg3 (red glume), and a locus determining smokey-grey coloured glume to the distal ends of the short arms of the homoeologous group 1 chromosomes, proximally (or closely linked) to Xgwm1223 and distal to Xgwm0033. On this basis, we propose that these genes represent a set of homoeoloci, designated Rg-A1, Rg-B1, and Rg-D1. Rg3 and Bg appear to be variant alleles of Rg-A1. Both Rg3 and Bg are closely linked with the major glume pubescence gene Hg. Similarly, the hexaploid wheat smokey-grey glume gene and Rg2 represent alleles at Rg-D1. The microsatellite markers linked to the Rg genes were used to analyse a phenotypically and genotypically characterized set of Siberian spring wheats. A coincidence between the presence of the 264-bp allele of Xgwm0136 and Rg-A1b (Rg3) was observed; so Xgwm0136 can probably be used as a diagnostic marker for this gene.

[Analysis of the short-stem genes in the genotypes of bread wheat cultivars in Ukraine]

Varieties of winter common wheat widely used in breeding programmes for the period of 1912-2002 in Ukraine were investigated using both the microsatellite Xgwm261 marker linked with the gibberellin-sensitive dwarf gene Rht8 and the biochemical test for the sensitivity of seedlings to gibberellic acid. Allelic characteristics of the locus Xgwm261 have been determined for 97 varieties. Near 98% of the modern varieties of winter common wheat derived from Odessa breeding institute and 50% of the varieties derived from the Mironovka wheat institute possess the allel 192 n.p. and gene Rht8 correspondingly. Estimation of sensitivity of the seedlings to gibberellic acid showed that the majority of the varieteis cultivated in Ukraine until the middle of the seventies are sensitive to gibberellic acid. The insusceptibility to gibberellic acid is predominantly manifested in the varieties derived from the south of Ukraine since the eighties owing to the introduction of the dwarf genes into the genotypes. At the same time the varieties of the Mironovka wheat institute still retain the sensitivity.

Rationalising germplasm collections: a case study for wheat

In total 70 genebank accessions comprising 50 hexaploid, 12 tetraploid and 8 diploid wheats of the Gatersleben collection were selected based on the screening of the passport data for identical cultivar names or accession numbers of the donor genebanks. Twelve potential duplicate groups consisting of three to nine accessions with identical names/numbers were selected and analysed with DNA markers (microsatellites). A bootstrap approach based on re-sampling of both microsatellite markers and alleles within marker loci was used to test for homogeneity. Although several homogeneous groups were identified it became clear that cultivar name identity alone did not allow the determination of duplicates. A combination of SSR-analysis followed by the bootstrap method and database survey considering the botanical classification and other data (origin, growth habit and donor) available is recommended in order to determine duplicates. A procedure for the identification of duplicates and their further handling in ex situ genebanks is discussed.

Crystal structure of (η4-norborna-2,5-dien)-(1,2-bis((R,R)-2,5-bis- (methoxymethyl)phospholanyl)benzene)rhodium(I) tetrafluoroborate, [Rh(C22H36O4P2)(C7H8)](BF4)

C29H44BF4O4P2Rh, monoclinic, P21 (no. 4), a = 10.119(2) Å, b = 14.125(3) Å, c = 11.542(2) Å, β = 106.87(3)°, V = 1578.7 Å3, Z = 2, Rgt(F) = 0.034, wRref(F2) = 0.090, T = 200 K.

Genetic diversity in cultivated plants-loss or stability?

Human activities like urbanisation, the replacement of traditional agriculture systems by modern industrial methods or the introduction of modern high-yielding varieties may pose a danger to the biological diversity. Using microsatellite markers, we analysed samples of cultivated wheat ( Triticum aestivum L.) collected over an interval of 40-50 years in four comparable geographical regions of Europe and Asia. No significant differences in both the total number of alleles per locus and in the PIC values were detected when the material collected in the repeated collection missions in all four regions were compared. About two-thirds of the alleles were common to both collection periods, while one-third represented collection mission-specific alleles. These findings demonstrate that an allele flow took place during the adaptation of traditional agriculture to modern systems, whereas the level of genetic diversity was not significantly influenced.

The gibberellic-acid insensitive dwarfing gene sdw3 of barley is located on chromosome 2HS in a region that shows high colinearity with rice chromosome 7L

In this study, comparative high resolution genetic mapping of the GA-insensitive dwarfing gene sdw3 of barley revealed highly conserved macrosynteny of the target region on barley chromosome 2HS with rice chromosome 7L. A rice contig covering the sdw3-orthologous region was identified and subsequently exploited for marker saturation of the target interval in barley. This was achieved by (1) mapping of rice markers from the orthologous region of the rice genetic map, (2) mapping of rice ESTs that had been physically localized on the rice contig, or (3) mapping of barley ESTs that show strong sequence similarity to coding sequences present in the rice contig. Finally, the sdw3 gene was mapped to an interval of 0.55 cM in barley, corresponding to a physical distance of about 252 kb in rice, after employing orthologous EST-derived rice markers. Three putative ORFs were identified in this interval in rice, which exhibited significant sequence similarity to known signal regulator genes from different species. These ORFs can serve as starting points for the map-based isolation of the sdw3 gene from barley.

Substitution analysis of seedling stage copper tolerance in wheat

The relatively copper-tolerant wheat variety Chinese Spring (recipient), the copper-sensitive variety Cappelle Desprez (donor) and their substitution lines were screened for copper tolerance in a soil pot experiment under artificial growth conditions. Chromosomes 5A, 5B, 5D and 7D of Cappelle Desprez significantly decreased the copper tolerance of the recipient variety to varying extents.  By contrast, the 6B and 3D chromosomes significantly increased the copper tolerance of Chinese Spring, suggesting that a wide range of allelic differences could be expected between wheat genotypes for this character. The significant role of homologous group 5 in copper tolerance was confirmed by testing wheat-rye substitution lines. The substitution of rye chromosome 5R (5R/5A substitution line) into a wheat genetic background significantly increased the copper tolerance of the recipient wheat genotype. The results suggest that chromosomes 5R and 5A probably carry major genes or gene complexes responsible for copper tolerance, and that the copper tolerance of wheat can be improved through the substitution of a single chromosome carrying the responsible genes. At the same time, it is also possible that the effect of homologous group 5 is not specific to copper tolerance, but that the genes located on these chromosomes belong to a general stress adaptation (frost, cold, vernalisation requirements, etc.) complex, which has already been detected on this chromosome. To answer this question further studies are needed to determine the real effect of these chromosome regions and loci on copper tolerance.

Molecular studies on genetic integrity of open-pollinating species rye (Secale cereale L.) after long-term genebank maintenance

The genetic integrity of six accessions represented by 14 sub-populations of the open-pollinating species rye ( Secale cereale L.) was investigated. Seeds available from a herbarium collection (first regeneration) and from the cold store (most recent regeneration) were multiplied two to fourteen times and fingerprinted using microsatellite markers. Four accessions had significantly different allele frequencies. These were multiplied seven to thirteen times. Nearly 50% of the alleles discovered in the original samples were not found in the material present in the cold store. However alleles were detected in the most recently propagated sub-populations, that were not observed in the investigated plants of the original one. The change in allele frequencies is a continuous process. Reasons for the occurrence of genetic changes and consequences for managing open pollinating species maintained in ex situ genebanks are discussed.

Mapping of quantitative trait loci determining agronomic important characters in hexaploid wheat ( Triticum aestivum L.)

A set of 114 recombinant inbred lines of the 'International Triticeae Mapping Initiative' mapping population was grown during the seasons 1997, 1998, 1999 and 2000 under several environments. Twenty morphological (glume colour, awn colour, waxiness, leaf erectness, peduncle length), agronomical (ear emergence time, flowering time, grain filling time, ear length, plant height, lodging, grain number, thousand-grain-weight, grain weight per ear, grain protein content, winter hardiness) and disease resistance (powdery mildew, yellow rust, leaf rust, fusarium) traits were studied. Not all traits were scored in each experiment. In total 210 QTLs with a LOD threshold of >2.0 (minor QTLs) were detected of which 64 reached a LOD score of >3.0 (major QTLs). Often QTLs were detected in comparable positions in different experiments. Homologous and homoeologous relationships of the detected QTLs, and already described major genes or QTLs determining the same traits in wheat or other Triticeae members, are discussed.

Assessing genetic diversity of wheat ( Triticum aestivum L.) germplasm using microsatellite markers

A set of 24 wheat microsatellite markers, representing at least one marker from each chromosome, was used for the assessment of genetic diversity in 998 accessions of hexaploid bread wheat ( Triticum aestivum L.) which originated from 68 countries of five continents. A total of 470 alleles were detected with an average allele number of 18.1 per locus. The highest number of alleles per locus was detected in the B genome with 19.9, compared to 17.4 and 16.5 for genomes A and D, respectively. The lowest allele number per locus among the seven homoeologous groups was observed in group 4. Greater genetic variation exists in the non-centromeric regions than in the centromeric regions of chromosomes. Allele numbers increased with the repeat number of the microsatellites used and their relative distance from the centromere, and was not dependent on the motif of microsatellites. Gene diversity was correlated with the number of alleles. Gene diversity according to Nei for the 26 microsatellite loci varied from 0.43 to 0.94 with an average of 0.77, and was 0.78, 0.81 and 0.73 for three genomes A, B and D, respectively. Alleles for each locus were present in regular two or three base-pair steps, indicating that the genetic variation during the wheat evolution occurred step by step in a continuous manner. In most cases, allele frequencies showed a normal distribution. Comparative analysis of microsatellite diversity among the eight geographical regions revealed that the accessions from the Near East and the Middle East exhibited more genetic diversity than those from the other regions. Greater diversity was found in Southeast Europe than in North and Southwest Europe. The present study also indicates that microsatellite markers permit the fast and high throughput fingerprinting of large numbers of accessions from a germplasm collection in order to assess genetic diversity.

Development of a set of Triticum aestivum-Aegilops tauschii introgression lines

New wheat introgression lines were obtained which contain different segments of individual chromosomes of Aegilops tauschii in the Triticum aestivum cv. 'Chinese Spring' background. The introgression lines were developed to examine various subsets of alleles from the wild grass in the genetic background of common wheat. As starting point substitution lines of 'Chinese Spring' in which single chromosomes of the D genome had been replaced by homologous chromosomes of a synthetic wheat were used. Synthetic wheat had been obtained earlier from a cross between the tetraploid emmer (genomes AABB) and wild grass Aegilops tauschii (genome DD). The seven wheat chromosome substitution lines carrying different chromosomes of Ae. tauschii were crossed twice to T. aestivum cv. 'Chinese Spring' and 259 BC1-progeny plants were analysed. Phenotypic evaluation was carried out for different traits such as plant height, spikelet number, peduncle length, flowering time, spike length, tiller number, grain weight per ear, fertility and thousand kernel weight. Genotypic analysis was performed using a set of 65 microsatellite markers previously mapped on the chromosomes of the D genome of wheat. During this analysis recombinant lines carrying different segments of Ae. tauschii chromosomes were detected. Plants containing small introgressions of the alien genetic material were selfed to get homozygous lines and plants carrying large pieces of the donor chromosome were backcrossed again to get smaller introgressions. Further microsatellite analysis of selected BC1F2-progeny plants resulted in detection of a first set of 36 homozygous lines carrying different pieces of Ae. tauschii genome.

Molecular mapping, phenotypic expression and geographical distribution of genes determining anthocyanin pigmentation of coleoptiles in wheat ( Triticum aestivumL.)

Three major gene loci determining the anthocyanin pigmentation of coleoptiles were mapped on the short arms of chromosomes 7A, 7B and 7D, respectively. All three genes map about 15 to 20 cM distal from the centromere and, therefore, it may be concluded that they are members of a homoeologous series and should be designated Rc-A1, Rc-B1 and Rc-D1, respectively. Further homoeologous loci exist in Triticum durum, Triticum tauschii, and most probably in Secale cereale and Hordeum vulgare. By analyzing a syntheticxcultivated wheat cross (ITMI mapping population) under different environmental conditions it was shown that the expression of the genes determining anthocyanin pigmentation of the coleoptiles varies. One additional locus was detected on chromosome 4BL. Beside the mapping data, results of a screening for red coleoptile color genes in 468 mainly European wheat varieties are presented.

Biomimetic asymmetric hydrogenation

Enzymes and synthetic organometallic catalysts utilize different approaches for the creation of chiral centers in prochiral substrates. While chiral organometallic catalysts realize the transfer of chirality mainly by repulsive interactions, several enzymes use preferentially stereodiscriminating hydrogen bonding. To investigate if hydrogen bonding within the catalyst-substrate assembly can also have a benefit on the rhodium diphosphine-catalyzed asymmetric hydrogenation, some model metal complexes and substrates were investigated. As 'biomimetically acting' functionalities, hydroxy groups were incorporated in the chiral ligand. Three secondary interactions could be identified by different analytical methods which influence rate and enantioselectivity of the catalytic reaction: 1) HO/Rh-interactions, 2) HO/HO-interactions within the backbone of the ligand, and 3) hydrogen bonding between HO-groups of the ligand and functional groups of an appropriate substrate. Due to the effect of the additional hydroxy groups, enantioselectivities by up to 99% ee could be induced in the hydrogenation product even with water as solvent.

Serum concentrations of iodine, thyroxine (T4), triiodothyronine (T3), thyrotropin (TSH) and insulin-like growth factor 1 (IGF-1) during the last trimester of pregnancy, during labour, and in early puerperium of women with normal pregnancy or with in

In women with intrauterine growth retardation (IUGR), insulin-like growth factor 1 (IGF-1) concentrations tended to reduce during the last trimester of pregnancy. Parameters of thyroid function in maternal serum were not distinctly influenced by IUGR, except for high concentrations of iodine. Triiodothyronine (T3) concentrations in cord blood of normal pregnancies was significantly lower than maternal concentrations, but was relatively high when the fetus was growth retarded. The results are discussed in connection with changes of thyroid function and changes of IGF-1 during pregnancy.

Predictive value of S-100beta and neuron-specific enolase serum levels for adverse neurologic outcome after cardiac surgery

OBJECTIVES

The aim of this study was to evaluate the time course of S-100beta and neuron-specific enolase serum levels after cardiac surgery and their clinical relevance in predicting postoperative adverse neurologic outcomes; the 2 proteins are only released in peripheral blood in association with nervous system lesions.

METHODS

We neurologically assessed 190 consecutive patients undergoing elective cardiac operations for coronary artery bypass (n = 147), valve replacement (n = 29), or both (n = 14), before as well as after the operation. Postoperative outcome was classified as type I (uncomplicated), type II (confusion, agitation, disorientation, or epileptic seizures), or type III (stroke, stupor, or coma). Levels of S-100beta and neuron-specific enolase were evaluated in venous blood samples drawn preoperatively and then daily in the first 5 postoperative days.

RESULTS

Levels of S-100beta and neuron-specific enolase differed significantly among the 3 groups (type III > type II > type I) throughout the postoperative period and had a diagnostic specificity and specificity of 89% and 79%, respectively, in identifying patients with type III outcome. S-100beta (but not neuron-specific enolase) levels were identified as significant independent predictors for type II and III outcomes (odds ratio 16.2, P <.0004). The same was true for duration of cardiopulmonary bypass (odds ratio 1.02, P <.006).

CONCLUSIONS

Serum levels of S-100beta are reliable markers for adverse neurologic outcomes after cardiac surgery.

Comparison of biochemical markers for the detection of minimal myocardial injury: superior sensitivity of cardiac troponin--T ELISA

OBJECTIVES

Patients with minimal myocardial injuries who present clinically with unstable angina, early stages of myocardial infarction or myocarditis require different therapy strategies to those without. The newer diagnostic assays for detecting myocardial lesions (cardiac Troponin T and cardiac Troponin I [cTnT, cTnI], glycogenphosphorylase - BB [GPBB]) are reported to be more sensitive and specific than common biochemical markers such as CK and myoglobin. Our study tested whether the recently developed four assays cTnT-ELISA (in vitro), cTnT rapid bedside assay, cTnI rapid bedside assay, and GPBB (Immunoenzymetric assay) are effective in detecting minimal myocardial injuries caused by endomyocardial biopsy. We compared them with CK activity (CK-cat), CK-MB activity (CK-MBcat), CK-MB-concentration (CK-MB-mass) and Myoglobin concentration (Myo-conc.).

PATIENTS AND METHODS

Twenty-four patients [six female, 18 male, age (mean): 47 years (20-65)] underwent diagnostic endomyocardial biopsy. Between four and six biopsies were taken from the mid-right ventricular aspect of the interventricular septum of the heart. Blood was drawn before catheterization (baseline), 10 min after the biopsy, in the next morning, and in the morning of the second day after (days 1 and 2).

RESULTS AND CONCLUSION

Because of very low CKcat it was not possible to analyse CK-MBcat with reliable precision. The assay for GPBB and cTnI rapid bedside assay did not indicate this minimal myocardial injury. The CK cat, CK-MB mass, and myoglobin assays indicated significant increase at 10 min after biopsy but remained within reference range. cTnT rapid bedside assay indicated this minimal myocardial injury in 50% (P < 0.05). cTnT-ELISA (in vitro) was increased above the reference limit in 54%. This increase was 3. 6-fold the upper reference limit (P < 0.01). In our study, due to superior discriminating power, cTnT-ELISA (in vitro) was the most sensitive assay for minimal myocardial injuries.

RFLP mapping of a gene for hairy leaf sheath using a recombinant line from Hordeum vulgare L. ×Hordeum bulbosum L. cross

A gene conditioning hairy leaf sheath character, which was derived from Hordeum bulbosum and designated Hsb, was mapped using a cross between Hordeum vulgare and a H. vulgare/H. bulbosum recombinant line. The Hsb locus was tagged relative to eight RFLP markers detecting three loci on the distal part of chromosome 4HL. The map position suggests that Hsb of H. bulbosum is homoeologous to the gene Hp1 of rye (Secale cereale), which pleiotropically governs the traits hairy leaf sheath and hairy peduncle. It is proposed that the recombination break point between H. vulgare and H. bulbosum chromosomes occured at a position homoeologous compared with the 4L/5L translocation in Triticeae genomes, and may reflect a hot spot for chromosome breakage.Key words: Hordeum vulgare, Hordeum bulbosum, comparative mapping, hairy leaf sheath, RFLP.

Molecular mapping of two dwarfing genes differing in their GA response on chromosome 2H of barley

The two recessive dwarfing mutants gai (GA-ins) and gal (GA-less), differing in their response to exogenously applied gibberellic acid (GA(3)), were mapped in the centromere region and on the long arm, respectively, of the barley chromosome 2H. The gene gai, which determines reduced plant height and GA insensitivity pleiotropically, was found to co-segregate with the two RFLP markers Xmwg2058 and Xmwg2287. Both markers are known to map close to the centromere. The GA-sensitive dwarfing gene gal was found to be linked to the three co-segregating RFLP markers Xmwg581, Xmwg882 and Xmwg2212 (proximal) and XksuG5 (distal) by 3.6 and 9.5. cM, respectively. The distance between the two mutant loci was estimated to be about 55 cM. Homoeologous relationships between the dwarfing genes within the Triticeae are discussed.

Pharmacokinetics of orally administered estradiol valerate. Results of a single-dose cross-over bioequivalence study in postmenopausal women

A randomized, single-dose cross-over study in 32 postmenopausal women was performed to demonstrate bioequivalence of two estradiol valerate containing formulations (first sequence of Klimonorm as test preparation). The serum levels of estradiol, free and conjugated estrone were measured until 48 h after an oral dosage of 4 mg estradiol valerate (CAS 979-32-8). The mean AUC(0-48) of estradiol was calculated as 1006.6 +/- 479.4 h x pg x ml-1 (Test) and 1015.2 +/- 555.2 h x pg x ml-1 (Reference). The corresponding (AUC(0-48) of the active metabolite, free estrone, exceeded that of estradiol at 3578.3 h x pg x ml-1 (Test) and 3485.1 h x pg x ml-1 (Reference). Much higher was the AUC(0-48) for conjugated estrone at 132.4 h x ng x ml-1 (Test) and 133.6 h x ng x ml-1 (Reference). Mean estradiol Cmax values of 39.8 +/- 17.7 pg/ml (Test) and 42.9 +/- 21.0 pg/ml (Reference) were attained 8.2 +/- 4.5 h (Test) and 10.0 +/- 5.9 h (Reference) after the administration of 4 mg estradiol valerate. Maximal free estrone concentrations of 163 pg/ml (Test) and 174.3 pg/ml (Reference) were reached after 7.2 h (Test) and 7.5 h (Reference). Maximal conjugated estrone concentrations of 15.5 ng/ml (Test) and 16.2 ng/ml (Reference) were reached after 2.4 h (Test) and 2.0 h (Reference). The terminal elimination half-life of estradiol was calculated at 16.9 +/- 6.0 h (Test) and 15.0 +/- 4.8 h (Reference), that of free estrone at 16.3 h (Test) and 13.5 h (Reference), that of conjugated estrone at 11.8 h (Test) and 10.6 h (Reference). After logarithmic transformation, the 90% confidence intervals of the AUC(0-48) and Cmax ratios for estradiol and also for the metabolites (free and conjugated estrone) were within the acceptance ranges for bioequivalence. Therefore the test preparation and the reference preparation are bioequivalent.

Chromosomal location of three wheat sequences with homology to pollen allergen encoding, DNA replication regulating, and DNA (cytosine-5)-methyltransferase genes in wheat and rye

Three wheat sequences, shown to be homologous to pollen allergen encoding, DNA replication regulating, and DNA (cytosine-5)-methyltransferase genes were localized on chromosomes using nullisomic-tetrasomic wheat ('Chinese Spring') and wheat-rye ('Chinese Spring'/'Imperial') addition lines. Whereas the loci for the pollen allergen encoding sequence (Tri a III) were shown to be located on homoeologous group 4, the DNA replication regulating (Rep) and DNA (cytosine-5)-methyltransferase (Mtase) genes were located to homoeologous groups 1 and 7, respectively, of Triticeae. Chromosomal rearrangements in wheat and rye relative to each other are discussed.

RFLP mapping of the dwarfing (Ddw1) and hairy peduncle (Hp) genes on chromosome 5 of rye (Secale cereale L.)

An F2 population was established for mapping the two dominant genes for dwarfness (Ddw1) and hairy peduncle (Hp) on chromosome 5R. The location of both genes was shown to be on the segment of chromosome 5RL which was ancestrally translocated and is homoeologous to Triticeae 4L. Hp cosegregated with the wheat gDNA probe WG199, localised in wheat on chromosomes 5AL, 4BL and 4DL. No segregation was observed between the traits hairy peduncle and hairy leaf sheath. The locus for Ddw1 was found to map distally to Hp/Xwg199 but proximal to the isozyme marker β-amy-R1. The genetical distances were 5.6 cM between Hp/Xwg199 and Ddw1 and ll.ScM between Ddw1 and β-amy-R1, respectively. The map position of Ddw1 suggests that it is homoeologous to the wheat dominant dwarfing gene Rht12, present on chromosome 5AL and linked to β-amy-A1.

Can grapefruit juice influence ethinylestradiol bioavailability?

The effects of grapefruit juice on the bioavailability of 17 alpha-ethinylestradiol (EE2) after a single oral administration of 50 micrograms EE2 have been investigated. The pharmacokinetics of EE2 were studied in an open, randomized, cross-over study in which 13 healthy volunteers were administered the drug with herbal tea or grapefruit juice (naringin, 887 mg/ml). In contrast to herbal tea, grapefruit juice increased the peak plasma concentration (Cmax) significantly to 137% (mean; range 64% to 214%, p = 0.0088) and increased the area under plasma concentration-time curve from 0 to 8 hours (AUC0-8) to 128% (mean; range 81% to 180%, p = 0.0186). This study shows that grapefruit juice increases the bioavailable amount of EE2. A possible explanation may be that grapefruit juice inhibits the metabolic degradation of EE2. Whether the increased bioavailability of EE2 following grapefruit juice administration is of clinical importance should be investigated in long-term studies.

Influence of ethinylestradiol-containing combination oral contraceptives with gestodene or levonorgestrel on caffeine elimination

In a controlled clinical trial, the elimination of caffeine was examined in 20 healthy women prior to and during one cycle of treatment with either of two oral contraceptive formulations, one containing 0.075 mg gestodene and 0.03 mg ethinylestradiol and one containing 0.125 mg levonorgestrel and 0.03 mg ethinylestradiol. In addition, caffeine clearance was determined 1 month after the last intake of the oral contraceptives. Compared with pretreatment values, the clearance of caffeine was reduced by about 54% and 55% after one treatment cycle with gestodene- and the levonorgestrel-containing oral contraceptive, respectively. Other pharmacokinetic parameters of caffeine, such as tmax and Cmax, were not affected. Clearance values returned to pretreatment values 1 month after the last administration of the oral contraceptives. There was no difference in the reduction of caffeine clearance between contraceptive formulations. A small, but significant difference in the AUC(0-24 h) values of ethinylestradiol was noted between both preparations. There was no correlation between the AUC(model) values of caffeine and the AUC(0-24 h) values of ethinylestradiol. In the present study, a somewhat more pronounced effect on the elimination of caffeine was observed than in previous investigations, where several contraceptive steroids were administered only for a period of 2 weeks.