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W Rohde

Publications and source records attributed to W Rohde.

At least 55 records · Page 3Linked to original sources
PubMed1998

An AFLP-based procedure for the efficient mapping of mutations and DNA probes in barley.

A strategy based upon AFLP markers for high-efficiency mapping of morphological mutations and DNA probes to linkage groups in barley is presented. First, 511 AFLP markers were placed on the linkage map derived from the cross Proctor x Nudinka. Second, loci controlling phenotypic traits were assigned to linkage groups by AFLP analysis, using F2 populations consisting of 30-50 mutant plants derived from crosses of the type "mutant x Proctor" and "mutant x Nudinka." To map DNA probes, 67 different wild-type barley lines were selected to generate F2 populations by crossing with Proctor and Nudinka. F2 plants that were polymorphic for a given RFLP fragment were classified into genotypic classes. Linkage of the RFLP polymorphism to 1 of the 511 AFLP loci was indicated by cosegregation. The use of the strategy is exemplified by the mapping of the mutation branched-5 to chromosome 2 and of the DNA probes Bkn2 and BM-7 to chromosomes 5 and 1, respectively. Map expansion and marker order in map regions with dense clustering of markers represented a particular problem. A discussion considering the effect of noncanonical recombinant products on these two parameters is provided.

Alleles↗
PubMed1998

Characterization of cis-acting elements affecting strength and phloem specificity of the coconut foliar decay virus promoter.

During replication in its host plant, coconut foliar decay virus (CFDV) remains restricted to the phloem tissue. Previous in vivo studies on subgenomic CFDV DNA had provided evidence for the phloem specificity of the CFDV promoter. Here, new promoter constructs are described which are distinguished by the presence or absence of various cis-acting signals and which gave rise to a 16-fold higher reporter gene (beta-glucuronidase) activity (reaching 30% of the cauliflower mosaic virus 35S promoter) in tobacco protoplasts, while the phloem specificity in transgenic tobacco plants was conserved. Surprisingly, the CFDV stem-loop structure dramatically influenced transcriptional efficiency. From these studies and sequence comparisons with other phloem-specific promoters, cis-signals involved in CFDV promoter strength and tissue specificity were identified.

Base Sequence↗
PubMed1998

Long-term Effects of Early Postnatally Administered Interleukin-1-beta on the Hypothalamic-Pituitary-Adrenal (HPA) Axis in Rats.

OBJECTIVE: Since perinatal stress events are well known to exert long-term influences on the function of hypothalamic-pituitary-adrenal (HPA) axis in rats, to investigate the consequences of exposure to IL-1, a potent stimulator of this axis, during early postnatal life. METHODS: Wistar rats were treated twice a day with 0.02 ug human recombinant IL-1 from day 1-4 of age, while controls received the vehicle only. RESULTS: IL-1 -treatment had no significant influence on the mortality and body weight. However, at the end of treatment period on the 4th day of life, the thymus weight was decreased in the IL-1 -treated group (P<0.01), while the adrenals were clearly enlarged (P<0.0002). These responses were associated with a nearly 4-fold elevation of the plasma corticosterone (CS) level as compared to vehicle-treated controls (P<0.001). At the age of seven months the stimulated CS levels induced by an acute stress (novel environment) were lower in rats treated neonatally with IL-1 than in controls (P<0.01). This functional disturbance was associated with morphological alterations in the parvicellular part of the paraventricular nucleus (PVN) which is the main hypothalamic regulation centre of the HPA axis. A strong reduction of the numerical density of neurons was found in the neonatally IL-1 -treated rats (P<0.005) while the neuronal nuclei were clearly enlarged (P<0.0005). CONCLUSION: As a part of an infection-induced stress response during critical periods of development, IL-1 might be capable of inducing a permanent structural malorganization of the PVN and, consequently, functional malprogramming of the HPA axis in rats.

Journal Article↗
PubMed1997

In situ localization of the putative movement protein (pr17) from potato leafroll luteovirus (PLRV) in infected and transgenic potato plants.

The potato leafroll virus (PLRV) 17-kDa protein (pr17), the putative movement protein for this phloem-limited luteovirus, was localized on ultrathin sections of leaves from PLRV-infected and transgenic potato plants. The transgenic plants expressed the entire viral genome from a full-length cDNA copy (PLRVfl) or only the gene encoding pr17 (ORF4) under the control of the cauliflower mosaic virus 35S promoter. Virus-infected and PLRVfl-transgenic plants developed symptoms typical of virus infection, whereas pr17-transgenic plants did not display symptoms or ultrastructural alterations. Immunogold electron microscopy using an anti-pr17-serum detected pr17 in plasmodesmata, in virus-induced vesicles, in mitochondria, and in chloroplasts of phloem cells, in PLRV-infected as well as PLRVfl-transgenic plants. In addition, in transgenic plants, pr17 was expressed in mesophyll cells (which are not infected by PLRV under natural conditions) and localized to the same sites as in phloem cells, except in plasmodesmata. In contrast, in pr17-transgenic plants the protein was never observed on organelles, but was almost exclusively associated with plasmodesmata of all leaf cell types, indicating that the targeting of pr17 to plasmodesmata is an intrinsic property of the protein. These results support the role of pr17 in PLRV movement.

Carrier Proteins↗
PubMed1997

[The long-term therapy of hypothalamic-hypophyseal Cushing's syndrome with mitotane (o,p'-DDD)].

BACKGROUND AND OBJECTIVE: Drug treatment of hypothalamic-pituitary Cushing's syndrome is indicated if standard surgical intervention is not possible or has failed. The question arises whether, after unsatisfactory treatment with various adrenostatic drugs, mitotane (o,p'-DDD), used against adrenal cortical cancer, is efficacious and free of significant side effects when used long-term. PATIENTS AND METHODS: The results of long-term administration of mitotane to six patients, including one pregnant woman, were analysed retrospectively. After a moderate initial dosage of 3.0 g daily a maintenance dose of minimally 0.5 g per week was given or the treatment temporarily interrupted. The concentration of urinary free cortisol served as the main criterion of efficaciousness, together with the clinical course. The plasma concentrations of cortisol, aldosterone and ACTH were also determined, as well as routine clinicochemical parameters. RESULTS: Cortisol excretion became normal in all patients between the 2nd and 10th treatment month, falling from 919 +/- 621.3 nmol daily in the six months before treatment to 162 +/- 93.0 nmol daily in the third six-month treatment period (mean +/- standard deviation). Normal cortisol excretion and regression of symptoms was noted, dose-dependent, as long as the 12th year after start of treatment. Adrenocortical insufficiency occurred in one patient and at times required hormone substitution, followed by lasting remission without special treatment. Significant side effects were not observed other than a reversible increase in gamma-glutamyl transpeptidase. CONCLUSION: Mitotane proved to be an efficacious drug which in exceptional cases can be used without significant side effects in low dosage for the long-term treatment of hypothalamic-pituitary Cushing disease.

Adult↗
PubMed1997

In vivo expression of a full-length cDNA copy of potato leafroll virus (PLRV) in protoplasts and transgenic plants.

A full-length cDNA copy (PLRVfl) of potato leafroll virus (PLRV) was constructed and examined in vivo for its biological activities by transient expression experiments with plasmid DNA or in vitro transcribed RNA. In addition, PLRVfl cDNA was stably introduced into the genome of potato plants by Agrobacterium-mediated leaf disc transformation. Both transient and stable expression of PLRVfl resulted in the synthesis of genomic and subgenomic PLRV RNAs. Transgenic plants accumulated the 17-kDa movement protein and displayed the typical symptoms of PLRV infection. This is the first example of the constitutive expression of a phloem-limited virus in planta.

Agrobacterium tumefaciens↗
PubMed1997

The potato leafroll virus 17K movement protein is phosphorylated by a membrane-associated protein kinase from potato with biochemical features of protein kinase C.

The 17 kDa protein (pr17), the phloem-limited movement protein (MP) of potato leafroll luteovirus (PLRV), is associated with membranous structures and localized to plasmodesmata [Tacke et al. (1993) Virology 197, 274-282; Schmitz, J. (1995) Ph.D. Thesis, University of Cologne]. In planta the protein is predominantly present in its phosphorylated form, but it is rapidly dephosphorylated during isolation under native conditions. In an effort to examine the nature of the protein kinase(s) involved in the phosphorylation reaction, pr17 deletion mutants were expressed as fusion proteins in a bacterial expression vector system and tested for their ability to be phosphorylated by potato membrane preparations as well as by commercially available kinases. A fusion protein containing the nucleic acid-binding, basic, C-proximal domain (pr17C1) was identified to be phosphorylated by a Ca2+- and phospholipid-dependent, membrane-associated protein kinase. This protein kinase activity was inhibited by the addition of (19-36) protein kinase C (PKC) inhibitory peptide, known to be a highly specific inhibitor of mammalian PKC. Moreover, also the mammalian PKC from rat was able to phosphorylate pr17 in vitro. The results suggest that phosphorylation of pr17 takes place at membranous structures, possibly at the deltoid plasmodesmata connecting the sieve cell-companion cell complex of the phloem, by the activity of PKC-related, membrane-associated protein kinase activity.

Animals↗
PubMed1997

Glucose tolerance and insulin secretion in children of mothers with pregestational IDDM or gestational diabetes.

The offspring of mother's with diabetes mellitus during pregnancy are presumed to develop altered glucose homeostasis. We analysed metabolic parameters at birth and glucose tolerance and insulin secretion during oral glucose tolerance tests at 1-9 years of age in 129 children born to mothers with pregestational insulin-dependent diabetes (IDDM) and 69 infants of gestational diabetic mothers. Newborns of IDDM mothers displayed higher insulin (p < 0.001), glucose (p < 0.05), and insulin/glucose ratios (p < 0.002) than newborns of gestational diabetic mothers. During childhood, frequencies of impaired glucose tolerance (IGT) rose in infants of IDDM mothers from 9.4% at 1-4 years to 17.4% at 5-9 years of age, while in children of gestational diabetic mothers an increase from 11.1% up to 20.0% was observed. Offspring of gestational diabetic mothers displayed higher stimulated blood glucose (p < 0.025) than infants of IDDM mothers, while children of IDDM mothers showed higher stimulated insulin (p < 0.025), accompanied by increased fasting and stimulated insulin/glucose ratios (p < 0.05 and p < 0.02, respectively). Stimulated insulin in childhood was positively correlated to insulin at birth (p < 0.05). Furthermore, insulin/glucose ratio in childhood showed a positive correlation to insulin (p < 0.01) and insulin/glucose ratio at birth (p < 0.005). In conclusion, a pathogenetic role of fetal and neonatal hyperinsulinism for the development of IGT in both groups of infants of diabetic mothers is suggested, in particular for early induction of insulin resistance in the offspring of mothers with pregestational IDDM.

Birth Weight↗
PubMed1997

Overweight and obesity in infants of mothers with long-term insulin-dependent diabetes or gestational diabetes.

OBJECTIVES: To analyse the development of body weight and frequencies of overweight and obesity in infants of long-term insulin-dependent diabetic mothers as compared to those of gestational diabetic mothers. DESIGN: Retrospective study. SUBJECTS: Two hundred infants of mothers with pregestational insulin-dependent diabetes mellitus (IDM) and 117 infants of gestational diabetic mothers (IGDM) born between 1980 and 1990 at the Clinic of Obstetrics and Gynaecology, Berlin-Kaulsdorf, Germany. MEASUREMENTS: Birth weight, birth length, plasma insulin, interscapular skinfold, symmetry index (SI) and body mass index (BMI) at birth; SI and BMI in childhood (1-9y of age). RESULTS: Neonatally, mean relative weight (SI) was found to be increased in both groups of infants. It was positively correlated to interscapular skinfold (P < 0.001) and insulin (P < 0.005). However, IDM had higher insulin levels (P < 0.001) and a higher frequency of obesity (P < 0.05) than IGDM at birth. Throughout childhood frequencies of overweight (SI > 1.1) were elevated in both IDM as well as IGDM. In IDM the percentage of obesity (SI > 1.2) displayed a significant increase from 11.2% in children 1-4y old up to 25.8% at 5-9y (P < 0.05). Similar frequencies and a highly significant increase of overweight during childhood of IDM (P < 0.005) were observed when BMI > or = 95th percentile was used to determine overweight. Relative weight in childhood was positively correlated to relative weight at birth (P < 0.05). Large-for-gestational-age infants displayed a significantly higher percentage of overweight (SI > 1.1) in childhood than appropriate-for-gestational-age infants (P < 0.05). CONCLUSIONS: Infants of mothers with diabetes during pregnancy are predisposed to develop overweight and obesity during childhood. These alterations seem to be related to insulin and relative body weight at birth. Pathophysiological mechanisms which might be involved into the development of these changes are discussed. Prophylactic measures are recommended to reduce morbidity in infants of diabetic mothers.

Birth Weight↗
PubMed1997

Expression of a luteoviral movement protein in transgenic plants leads to carbohydrate accumulation and reduced photosynthetic capacity in source leaves.

Elucidating the role of viral genes in transgenic plants revealed that the movement protein (MP) from tobacco mosaic virus is responsible for altered carbohydrate allocation in tobacco and potato plants. To study whether this is a general feature of viral MPs, the movement protein MP17 of potato leafroll virus (PLRV), a phloem-restricted luteovirus, was constitutively expressed in tobacco plants. Transgenic lines were strongly reduced in height and developed bleached and sometimes even necrotic areas on their source leaves. Levels of soluble sugars and starch were significantly increased in source leaves. Yet, in leaf laminae the hexose-phosphate content was unaltered and ATP reduced to only a small extent, indicating that these leaves were able to maintain homeostatic conditions by compartmentalization of soluble sugars, probably in the vacuole. On the contrary, midribs contained lower levels of soluble sugars, ATP, hexose-phosphates and UDP-glucose supporting the concept of limited uptake and catabolism of sucrose in the phloem. The accumulation of carbohydrates led to a decreased photosynthetic capacity and carboxylation efficiency of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) probably owing to decreased expression of photosynthetic proteins. In parallel, levels of pathogenesis-related proteins were elevated which may be the reason for the obtained limited resistance against the unrelated potato virus Y (PVY)N in the transgenic tobacco plants. Ultrathin sections of affected leaves harvested from 2-week-old plants revealed plasmodesmal alterations in the phloem tissue while plasmodesmata between mesophyll cells were indistinguishable from wild-type. These data favour the phloem tissue to be the primary site of PLRV MP17 action in altering carbohydrate metabolism.

Carbohydrate Metabolism↗
PubMed1996

Non-canonical translation mechanisms in plants: efficient in vitro and in planta initiation at AUU codons of the tobacco mosaic virus enhancer sequence.

The 5' untranslated leader (Omega sequence) of tobacco mosaic virus (TMV) genomic RNA was utilized as a translational enhancer sequence in expression of the 17 kDa putative movement protein (pr17) of potato leaf roll luteovirus (PLRV). In vitro translation of RNAs transcribed from appropriate chimeric constructs, as well as their expression in transgenic potato plants, resulted in the expected wild-type pr17 protein, as well as in larger translational products recognized by pr17-specific antisera. Mutational analyses revealed that the extra proteins were translated by non-canonical initiation at AUU codons present in the wild-type Omega sequence. In the plant system translation initiated predominantly at the AUU codon at positions 63-65 of the Omega sequence. Additional AUU codons in a different reading frame of the Omega sequence also showed the capacity for efficient translation initiation in vitro. These results extend the previously noted activity of the TMV 5' leader sequence in ribosome binding and translation enhancement in that the TMV translation enhancer can mediate non-canonical translation initiation in vitro and in vivo.

Base Sequence↗
PubMed1996

Genetic engineering of potato for broad-spectrum protection against virus infection.

Transgenic potato plants expressing mutant alleles of PLRV ORF4, the gene for the movement protein pr17 of this luteovirus, were generated for broad-range protection against virus infection. When tested for protection against infection by PLRV, all transgenic lines showed a significant reduction of virus antigen. Potato lines accumulating N- or C-terminally extended PLRV pr17 mutant proteins were resistant to infection by the unrelated potato viruses PVY and PVX. Transgenic lines that did not express protein despite high transcript levels failed to exhibit virus resistance.

Alleles↗
PubMed1996

Infections with various types of organisms stimulate transcription from a short promoter fragment of the potato gst1 gene.

By histochemical GUS staining, we demonstrate that transcription from a short promoter fragment of the potato gst1 gene is locally induced after infection of a host plant with various types of pathogenic or symbiotic organisms. This regulatory unit is not active in noninfected tissues, except root apices and senescing leaves. Measuring the expression of a fusion between the promoter fragment and the gus gene in transgenic plants, therefore, allows comparison of the induction of defense reactions in different types of plant-microbe interactions, in one and the same plant.

Animals↗
PubMed1996

[Pregnancy in hyperprolactinemic patients].

In a retrospective study we analysed the outcome of 27 pregnancies in 17 hyperprolactinaemic patients. Cranial CT or MRI scans showed a microadenoma in 9, a macroadenoma in 7 and no change in 1 case. In 5 patients macroadenomas were surgically removed but a residual hyperprolactinaemia remained. In 2 patients with selectively removed microadenomas through the transsphenoidal route only in one case normal prolactin levels could be achieved. This patient became two times pregnant. In 24 patients pregnancy was induced by dopaminergic treatment whereas another patient with microadenoma became spontaneously pregnant after surgery and treatment with bromocriptine. The treatment was discontinued as soon as the pregnancy was recognised. 19 pregnancies were finished by spontaneous delivery and 3 by Caesarean section. Termination of pregnancy was artificially induced in 3 patients. One miscarriage was observed. Another patient was suffering from an extrauterine pregnancy. During pregnancy prolactin levels increased in comparison to basal levels. After delivery and lactation the same prolactin level was found compared to basal levels in patients with microprolactinomas. In patients suffering from macroadenomas prolactin levels decreased in comparison to basal levels. CT of MRI scan evaluations performed after delivery revealed a clinical not relevant increase as well as a decrease of tumor size in 2 cases, respectively. During pregnancy there was no complication due to tumor found in treated patients for hyperprolactinaemia. Only about one half of mothers were able to perform regular breast feeding.

Adult↗
PubMed1995

The barley Hooded mutation caused by a duplication in a homeobox gene intron.

In barley (Hordeum vulgare L.) the unit of inflorescence is the spikelet, which bears a fertile bract, the lemma, and the floret consisting of palea, two lodicules, three stamens and the pistil. The Hooded mutation causes the appearance of an extra flower of inverse polarity on the lemma. This phenotype is governed by the single dominant genetic locus K3. Here we show that the homeobox gene Knox3 represents this locus. Ectopic Knox3 gene expression in the primordium of the extra floret is caused by a 305-base pair duplication in intron 4, and phenocopies of the mutation are obtained in the heterologous tobacco system by Knox3 overexpression. It is concluded that homeotic genes of the Knox gene family are involved in floral evocation. Furthermore, the study of polarity of reproductive organs in K and related mutants can now focus on homeobox genes.

Amino Acid Sequence↗
PubMed1995

The promoter of coconut foliar decay-associated circular single-stranded DNA directs phloem-specific reporter gene expression in transgenic tobacco.

A full-length double-stranded DNA copy of the single-stranded circular DNA associated with coconut foliar decay virus (CFDV) was constructed. Full-length CFDV DNA and smaller fragments were transcriptionally fused to the beta-glucuronidase reporter gene and examined for promoter activity in vivo. In stably transformed tobacco plants, the CFDV DNA promoter confered a tissue-specific expression pattern in that the reporter gene was specifically expressed in the phloem tissue of the vascular system in stem, leaves and flower. These results are in agreement with the previously reported association of CFDV DNA with the phloem of its coconut host plant.

Base Sequence↗
PubMed1994

The nucleic acid-binding zinc finger protein of potato virus M is translated by internal initiation as well as by ribosomal frameshifting involving a shifty stop codon and a novel mechanism of P-site slippage.

The genes for the capsid protein CP and the nucleic acid-binding 12K protein (pr12) of potato virus M (PVM) constitute the 3' terminal gene cluster of the PVM RNA genome. Both proteins are presumably translated from a single subgenomic RNA. We have identified two translational strategies operating in pr12 gene expression. Internal initiation at the first and the second AUG codon of the pr12 coding sequence results in the synthesis of the 12K protein. In addition the protein is produced as a CP/12K transframe protein by ribosomal frameshifting. For these studies parts of the CP and pr12 coding sequences including the putative frameshift region were introduced into an internal position of the beta-glucuronidase gene. Mutational analyses in conjunction with in vitro translation experiments identified a homopolymeric string of four adenosine nucleotides which together with a 3' flanking UGA stop codon were required for efficient frameshifting. The signal AAAAUGA is the first frameshift signal with a shifty stop codon to be analyzed in the eukaryotic system. Substitution of the four consecutive adenosine nucleotides by UUUU increased the efficiency of frameshifting, while substitution by GGGG or CCCC dramatically reduced the synthesis of the transframe protein. Also, UAA and UAG could replace the opal stop codon without effect on the frameshifting event, but mutation of UGA to the sense codon UGG inhibited transframe protein formation. These findings suggest that the mechanism of ribosomal frameshifting at the PVM signal is different from the one described by the 'simultaneous slippage' model in that only the string of four adenosine nucleotides represents the slippery sequence involved in a -1 P-site slippage.

Base Sequence↗