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PubMed1995

Simultaneous mapping of the tricuspid and mitral valve annuli at electrophysiological study.

BACKGROUND: Mapping of the right free wall in patients with accessory pathways is difficult compared with that of the left free wall where the coronary sinus permits stable and accurate location of the electrodes used for endocardial mapping. Furthermore, the sequential roving catheter method is less satisfactory than multiple simultaneous electrode recordings spanning the circumference of the valve annulus. A new method for mapping the tricuspid annulus is described. METHODS: Mapping was performed in nine patients with a suspected right free wall accessory pathway or an atriofascicular connection. The tricuspid annulus was mapped using a specially shaped 1 cm interelectrode 10 pole catheter positioned in the right atrium immediately above the annulus. The coronary sinus was mapped with a 5 mm interelectrode 10 pole catheter and a 2 mm interelectrode 10 pole catheter recorded His bundle activity. Catheter positions were confirmed by multiplane fluoroscopy. Electrograms were digitised and recorded simultaneously using a custom computerised mapping system. The position of the multielectrode catheter around the tricuspid annulus relative to that of the coronary arteries was examined by coronary angiography in three patients. RESULTS: Seven right free wall and two posterior septal accessory pathways, and three atriofascicular connections were detected. Ventricular activation adjacent to both valve annuli was mapped in five patients with pre-excitation. The locations of eight of the nine accessory pathways and the three atriofascicular connections were confirmed at operative mapping. One right free wall accessory pathway in a patient with Ebstein's anomaly was not detected at operative mapping. No additional accessory pathways were found at operative mapping or routine 6 month postoperative electrophysiological study, or during a mean (SD) clinical follow up of 22 (7) months. The tricuspid annulus catheter was located during coronary angiography at a mean (SD) of about 2.5 (0.7) cm above and parallel to the right coronary artery in the right atrioventricular groove. CONCLUSIONS: This new catheter technique permits rapid detailed mapping of atrial and ventricular activation around the tricuspid annulus with a resolution of at least < or = % 1 cm, depending on the number and spacing of electrodes in each catheter. The technique was accurate as judged by mapping at surgery. This method is simple and safe compared with that of others for mapping the right free wall via the right coronary artery. It should facilitate detection and ablation of right free wall accessory pathways and atriofascicular connections.

Adolescent↗
PubMed2006

A two-stage approach for improved prediction of residue contact maps.

BACKGROUND: Protein topology representations such as residue contact maps are an important intermediate step towards ab initio prediction of protein structure. Although improvements have occurred over the last years, the problem of accurately predicting residue contact maps from primary sequences is still largely unsolved. Among the reasons for this are the unbalanced nature of the problem (with far fewer examples of contacts than non-contacts), the formidable challenge of capturing long-range interactions in the maps, the intrinsic difficulty of mapping one-dimensional input sequences into two-dimensional output maps. In order to alleviate these problems and achieve improved contact map predictions, in this paper we split the task into two stages: the prediction of a map's principal eigenvector (PE) from the primary sequence; the reconstruction of the contact map from the PE and primary sequence. Predicting the PE from the primary sequence consists in mapping a vector into a vector. This task is less complex than mapping vectors directly into two-dimensional matrices since the size of the problem is drastically reduced and so is the scale length of interactions that need to be learned. RESULTS: We develop architectures composed of ensembles of two-layered bidirectional recurrent neural networks to classify the components of the PE in 2, 3 and 4 classes from protein primary sequence, predicted secondary structure, and hydrophobicity interaction scales. Our predictor, tested on a non redundant set of 2171 proteins, achieves classification performances of up to 72.6%, 16% above a base-line statistical predictor. We design a system for the prediction of contact maps from the predicted PE. Our results show that predicting maps through the PE yields sizeable gains especially for long-range contacts which are particularly critical for accurate protein 3D reconstruction. The final predictor's accuracy on a non-redundant set of 327 targets is 35.4% and 19.8% for minimum contact separations of 12 and 24, respectively, when the top length/5 contacts are selected. On the 11 CASP6 Novel Fold targets we achieve similar accuracies (36.5% and 19.7%). This favourably compares with the best automated predictors at CASP6. CONCLUSION: Our final system for contact map prediction achieves state-of-the-art performances, and may provide valuable constraints for improved ab initio prediction of protein structures. A suite of predictors of structural features, including the PE, and PE-based contact maps, is available at http://distill.ucd.ie.

Algorithms↗
PubMed1995

Presence and regulation of Raf-1-K (Kinase), MAPK-K, MAP-K, and S6-K in rat nephron segments.

Renal nephron segments are heterogeneous, and receptors for endothelin (ET)-1, ET-3, Angiotensin II (AII), epidermal growth factor (EGF), and insulin-like growth factor I distribute differently along the nephron segments. Recently, growth factors and vasoactive substances are reported to stimulate mitogen-activated protein kinase (MAP-K). In this study, we showed that mRNA and proteins of MEK-K, Raf-1-K, MAPK-K, MAP-K (p42 and p44), and S6-K are expressed ubiquitously in intact nephron segment. We demonstrated that four tiers of a cascade composed of the Raf-1-K, MAP-K, MAP-K, and S6-K are stimulated by ET-1 and ET-3 in rat intact glomeruli (Glm) via primarily B-type ET receptors and PKC. The stimulatory effect of EGF and IGF-I to MAP-K activity is inhibited by a tyrosine kinase inhibitor in Glm. IGF-I significantly stimulates MAP-K activity and EGF and All moderately stimulate MAP-K activity in the proximal convoluted tubule (PCT). EGF significantly increased MAP-K cascades and ET-1 and ET-3 slightly increased MAP-K cascades in the medullary thick ascending limb (MTAL). EGF significantly stimulated MAP-K cascades, and ET-1 and ET-3 moderately stimulate MAP-K cascades in the outer medullary collecting duct (OMCD) and the inner medullary collecting duct (IMCD). MAPK-K and S6-K are similarly stimulated by these agonists in each segment. This study shows that MAP-K cascades are expressed in every nephron segment. ET-1, ET-3, All, EGF, and IGF-I stimulate MAP-K cascades heterogeneously along the nephron segment. It was concluded that MAP-K cascades play an important role in the regulation of renal function.

Animals↗
PubMed2004

Large-scale integration of human genetic and physical maps.

Genetic maps are used routinely in family-based linkage studies to identify the rough location of genes that influence human traits and diseases. Unlike physical maps, genetic maps are based on the amount of recombination occurring between adjacent loci rather than the actual number of bases separating them. Genetic maps are constructed by statistically characterizing the number of crossovers observed in parental meioses leading to the transmission of alleles to their offspring. Considerations such as the number of meioses observed, the heterozygosity and physical distance between the loci studied, and the statistical methods used can impact the construction and reliability of a genetic map. As is well known, poorly constructed genetic maps can have adverse effects on linkage mapping studies. With the availability of sequence-based maps, as well as genetic maps generated by different researchers (such as those generated by the Marshfield and deCODE groups), one can investigate the compatibility and properties of different maps. We have integrated information from the most current human genome sequence data (UCSC genome assembly Human July 2003) as well as 8399 microsatellite markers used in the Marshfield and deCODE maps to reconcile the these maps. Our efforts resulted in updated sex-specific genetic maps.

Chromosome Mapping↗
PubMed2005

Linkage mapping bovine EST-based SNP.

BACKGROUND: Existing linkage maps of the bovine genome primarily contain anonymous microsatellite markers. These maps have proved valuable for mapping quantitative trait loci (QTL) to broad regions of the genome, but more closely spaced markers are needed to fine-map QTL, and markers associated with genes and annotated sequence are needed to identify genes and sequence variation that may explain QTL. RESULTS: Bovine expressed sequence tag (EST) and bacterial artificial chromosome (BAC)sequence data were used to develop 918 single nucleotide polymorphism (SNP) markers to map genes on the bovine linkage map. DNA of sires from the MARC reference population was used to detect SNPs, and progeny and mates of heterozygous sires were genotyped. Chromosome assignments for 861 SNPs were determined by twopoint analysis, and positions for 735 SNPs were established by multipoint analyses. Linkage maps of bovine autosomes with these SNPs represent 4585 markers in 2475 positions spanning 3058 cM. Markers include 3612 microsatellites, 913 SNPs and 60 other markers. Mean separation between marker positions is 1.2 cM. New SNP markers appear in 511 positions, with mean separation of 4.7 cM. Multi-allelic markers, mostly microsatellites, had a mean (maximum) of 216 (366) informative meioses, and a mean 3-lod confidence interval of 3.6 cM Bi-allelic markers, including SNP and other marker types, had a mean (maximum) of 55 (191) informative meioses, and were placed within a mean 8.5 cM 3-lod confidence interval. Homologous human sequences were identified for 1159 markers, including 582 newly developed and mapped SNP. CONCLUSION: Addition of these EST- and BAC-based SNPs to the bovine linkage map not only increases marker density, but provides connections to gene-rich physical maps, including annotated human sequence. The map provides a resource for fine-mapping quantitative trait loci and identification of positional candidate genes, and can be integrated with other data to guide and refine assembly of bovine genome sequence. Even after the bovine genome is completely sequenced, the map will continue to be a useful tool to link observable phenotypes and animal genotypes to underlying genes and molecular mechanisms influencing economically important beef and dairy traits.

Alleles↗
PubMed1999

Optical mapping of Plasmodium falciparum chromosome 2.

Detailed restriction maps of microbial genomes are a valuable resource in genome sequencing studies but are toilsome to construct by contig construction of maps derived from cloned DNA. Analysis of genomic DNA enables large stretches of the genome to be mapped and circumvents library construction and associated cloning artifacts. We used pulsed-field gel electrophoresis purified Plasmodium falciparum chromosome 2 DNA as the starting material for optical mapping, a system for making ordered restriction maps from ensembles of individual DNA molecules. DNA molecules were bound to derivatized glass surfaces, cleaved with NheI or BamHI, and imaged by digital fluorescence microscopy. Large pieces of the chromosome containing ordered DNA restriction fragments were mapped. Maps were assembled from 50 molecules producing an average contig depth of 15 molecules and high-resolution restriction maps covering the entire chromosome. Chromosome 2 was found to be 976 kb by optical mapping with NheI, and 946 kb with BamHI, which compares closely to the published size of 947 kb from large-scale sequencing. The maps were used to further verify assemblies from the plasmid library used for sequencing. Maps generated in silico from the sequence data were compared to the optical mapping data, and good correspondence was found. Such high-resolution restriction maps may become an indispensable resource for large-scale genome sequencing projects.

Animals↗
PubMed2005

[Patterns of body surface isointegral maps for anteroseptal and inferior myocardial infarction].

A goal of the present paper was to determine the patterns of the QRS isointegral maps for the two location of myocardial infarction: anteroseptal (aMI) and inferior (iMI), using a method of body surface potential mapping (BSPM) with a 87-electrode Fukuda Denshi system. The maps were recorded in the two groups of the patients with previous (6-12 month earlier), clinically documented, Q-wave myocardial infarction. The examined group comprised 36 patients with aMI and 32 patients with iMI. The analysis concerned the isointegral maps of the assigned seven time intervals within the QRS complex (the A-G maps), rendering the patterns of positive and negative potential distribution, likewise the group-mean values of minima and maxima for each of the analyzed maps. The increased area of negative potential, as compared with the corresponding control maps, was observed in the maps of the A, B and D intervals in the aMI group. Contrary, in the iMI group a pathological negative potential was found only in the E maps (the second half of the QRS complex). The comparative analysis of the potential extremes revealed in the aMI group the significantly more negative minima in the A, B, D and E maps and lower maxima in the A and B maps. However, in the iMI group the only statistically significant difference were the lower minima for the E maps. The investigations resulted in creating the patterns of the pathological distribution of the negative potential and the minimum values in the isointegral QRS maps, which are specific for the anteroseptal and inferior myocardial infarction.

Adult↗
PubMed2001

Calcium-mediated inactivation of the MAP kinase pathway in sea urchin eggs at fertilization.

We have evaluated the regulation of a 43-kDa MAP kinase in sea urchin eggs. Both MAP kinase and MEK (MAP kinase kinase) are phosphorylated and active in unfertilized eggs while both are dephosphorylated and inactivated after fertilization, although with distinct kinetics. Reactivation of MEK or the 43-kDa MAP kinase prior to or during the first cell division was not detected. Confocal immunolocalization microscopy revealed that phosphorylated (active) MAP kinase is present primarily in the nucleus of the unfertilized egg, with some of the phosphorylated form in the cytoplasm as well. Incubation of unfertilized eggs in the MEK inhibitor U0126 (0.5 microM) resulted in the inactivation of MEK and MAP kinase within 30 min. Incubation in low concentrations of U0126 (sufficient to inactivate MEK and MAP kinase) after fertilization had no effect on progression through the embryonic cell cycle. Microinjection of active mammalian MAP kinase phosphatase (MKP-3) resulted in inactivation of MAP kinase in unfertilized eggs, as did addition of MKP-3 to lysates of unfertilized eggs. Incubation of unfertilized eggs in the Ca(2+) ionophore A23187 led to inactivation of MEK and MAP kinase with the same kinetics as observed with sperm-induced egg activation. This suggests that calcium may be deactivating MEK and/or activating a MAP kinase-directed phosphatase. A cell-free system was used to evaluate the activation of phosphatase separately from MEK inactivation. Unfertilized egg lysates were treated with U0126 to inactivate MEK and then Ca(2+) was added. This resulted in increased MAP kinase phosphatase activity. Therefore, MAP kinase inactivation at fertilization in sea urchin eggs likely is the result of a combination of MEK inactivation and phosphatase activation that are directly or indirectly responsive to Ca(2+).

Animals↗
PubMed1997

An integrated transcript map of human chromosome 1p35-p36.

The distal short arm of human chromosome 1 (1p) is rearranged in a variety of malignancies, and several genetic diseases also map to this region. We have constructed an integrated transcript map to precisely define the positions of genes and expressed sequence tags (ESTs) previously mapped to 1p35-p36, a region spanning approximately 40 Mb. To anchor the integrated map, a framework genetic map was constructed with 24 genetic markers and a marker order of 1000:1 odds, yielding an average resolution of 2.8 cM. An additional 106 genetic markers were localized relative to the framework genetic map. To place markers more precisely within 1p35-p36, a chromosome 1-specific, radiation-reduced hybrid (RH) panel was created. Individual DNA fragments of the RH panel were identified and ordered by PCR with the framework genetic map. A total of 250 markers, including 142 genes and ESTs, were mapped by PCR against the RH panel. The map has an observed resolution of 800 kb, and the results closely match and more precisely define previous mapping information for most markers. This map will help to identify candidate genes for genetic diseases mapping to distal 1p and is fully integrated with existing genetic and RH maps of the human genome.

Animals↗
PubMed1995

The PiGMaP consortium linkage map of the pig (Sus scrofa).

A linkage map of the porcine genome has been developed by segregation analysis of 239 genetic markers. Eighty-one of these markers correspond to known genes. Linkage groups have been assigned to all 18 autosomes plus the X Chromosome (Chr). As 69 of the markers on the linkage map have also been mapped physically (by others), there is significant integration of linkage and physical map data. Six informative markers failed to show linkage to these maps. As in other species, the genetic map of the heterogametic sex (male) was significantly shorter (approximately 16.5 Morgans) than the genetic map of the homogametic sex (female) (approximately 21.5 Morgans). The sex-averaged genetic map of the pig was estimated to be approximately 18 Morgans in length. Mapping information for 61 Type I loci (genes) enhances the contribution of the pig gene map to comparative gene mapping. Because the linkage map incorporates both highly polymorphic Type II loci, predominantly microsatellites, and Type I loci, it will be useful both for large experiments to map quantitative trait loci and for the subsequent isolation of trait genes following a comparative and candidate gene approach.

Animals↗
PubMed2005

Simple-sequence repeat markers used in merging linkage maps of melon (Cucumis melo L.).

A set of 118 simple sequence repeat (SSR) markers has been developed in melon from two different sources: genomic libraries (gSSR) and expressed sequence-tag (EST) databases (EST-SSR). Forty-nine percent of the markers showed polymorphism between the 'Piel de Sapo' (PS) and PI161375 melon genotypes used as parents for the mapping populations. Similar polymorphism levels were found in gSSR (51.2%) and EST-SSR (45.5%). Two populations, F2 and a set of double haploid lines (DHLs), developed from the same parent genotypes were used for map construction. Twenty-three SSRs and 79 restriction fragment length polymorphisms (RFLPs), evenly distributed through the melon genome, were used to anchor the maps of both populations. Ten cucumber SSRs, 41 gSSRs, 16 EST-SSR, three single nucleotide polymorphism (SNP) markers, and the Nsv locus were added in the DHL population. The maps developed in the F2 and DHL populations were co-linear, with similar lengths, except in linkage groups G1, G9, and G10. There was segregation distortion in a higher proportion of markers in the DHL population compared with the F2, probably caused by selection during the construction of DHLs through in vitro culture. After map merging, a composite genetic map was obtained including 327 transferable markers: 226 RFLPs, 97 SSRs, three SNPs, and the Nsv locus. The map length is 1,021 cM, distributed in 12 linkage groups, and map density is 3.11 cM/marker. SSR markers alone cover nearly 80% of the map length. This map is proposed as a basis for a framework melon map to be merged with other maps and as an anchor point for map comparison between species of the Cucurbitaceae family.

Chromosome Mapping↗
PubMed2005

A composite linkage map from two crosses for the species complex Picea mariana x Picea rubens and analysis of synteny with other Pinaceae.

Four individual linkage maps were constructed from two crosses for the species complex Picea mariana (Mill.) B.S.P. x Picea rubens Sarg in order to integrate their information into a composite map and to compare with other Pinaceae. For all individual linkage maps, 12 major linkage groups were recovered with 306 markers per map on average. Before building the composite linkage map, the common male parent between the two crosses made it possible to construct a reference linkage map to validate the relative position of homologous markers. The final composite map had a length of 2,319 cM (Haldane) and contained a total of 1,124 positioned markers, including 1,014 AFLPs, 3 RAPDs, 53 SSRs, and 54 ESTPs, assembled into 12 major linkage groups. Marker density of the composite map was statistically homogenous and was much higher (one marker every 2.1 cM) than that of the individual linkage maps (one marker every 5.7 to 7.1 cM). Synteny was well conserved between individual, reference, and composite linkage maps and 94% of homologous markers were colinear between the reference and composite maps. The combined information from the two crosses increased by about 24% the number of anchor markers compared to the information from any single cross. With a total number of 107 anchor markers (SSRs and ESTPs), the composite linkage map is a useful starting point for large-scale genome comparisons at the intergeneric level in the Pinaceae. Comparisons of this map with those in Pinus and Pseudotsuga allowed the identification of one breakdown in synteny where one linkage group homologous to both Picea and Pinus corresponded to two linkage groups in Pseudotsuga. Implications for the evolution of the Pinaceae genome are discussed.

Chromosome Mapping↗
PubMed2002

A bovine whole-genome radiation hybrid panel and outline map.

A 3000-rad radiation hybrid panel was constructed for cattle and used to build outline RH maps for all 29 autosomes and the X and Y chromosomes. These outline maps contain about 1200 markers, most of which are anonymous microsatellite loci. Comparisons between the RH chromosome maps, other published RH maps, and linkage maps allow regions of chromosomes that are poorly mapped or that have sparse marker coverage to be identified. In some cases, mapping ambiguities can be resolved. The RH maps presented here are the starting point for mapping additional loci, in particular genes and ESTs that will allow detailed comparative maps between cattle and other species to be constructed. Radiation hybrid cell panels allow high-density genetic maps to be constructed, with the advantage over linkage mapping that markers do not need to be polymorphic. A large quantity of DNA has been prepared from the cells forming the RH panel reported here and is publicly available for mapping large numbers of loci.

Animals↗
PubMed1992

Isolation and high-resolution mapping of new DNA markers from the pericentromeric region of chromosome 10.

The gene responsible for multiple endocrine neoplasia type 2A (MEN 2A) has been localized to the pericentromeric region of chromosome 10. Several markers that fail to recombine with MEN2A have been identified, including D10Z1, D10S94, D10S97, and D10S102. Meiotic mapping in the MEN2A region is limited by the paucity of critical crossovers identified and by the dramatically reduced rates of recombination in males. Additional approaches to mapping loci in the pericentromeric region of chromosome 10 are required. We have undertaken the generation of a detailed physical map by radiation hybrid mapping. Here we report the development of a radiation hybrid panel and its use in the mapping of new DNA markers in pericentromeric chromosome 10. The radiation-reduced hybrids used for mapping studies all retain small subchromosomal fragments that include both D10S94 and D10Z1. One hybrid was selected as the source of DNA for cloning. One hundred five human recombinant clones were isolated from a lambda library made with pp11A DNA. We have completed regional mapping of 22 of those clones using our radiation hybrid mapping panel. Seven markers have been identified and, when taken together with previously meiotically mapped markers, define eight radiation hybrid map intervals between D10S34 and RBP3. The identical order is found for a number of these using either the radiation hybrid mapping panel or the meiotic mapping panel. We believe that this combination cloning and mapping approach will facilitate the precise positioning of new markers in pericentromeric chromosome 10 and will help in refining further the localization of MEN2A.

Centromere↗
PubMed1992

Closure of a genetic linkage map of human chromosome 7q with centromere and telomere polymorphisms.

We have constructed a 2.4-cM resolution genetic linkage map for chromosome 7q that is bounded by centromere and telomere polymorphisms and contains 66 loci (88 polymorphic systems), 38 of which are uniquely placed with odds for order of at least 1000:1. Ten genes are included in the map and 11 markers have heterozygosities of at least 70%. This map is the first to incorporate several highly informative markers derived from a telomere YAC clone HTY146 (locus D7S427), including HTY146c3 (HET 92%). The telomere locus markers span at least 200 kb of the 7q terminus and no crossovers within the physical confines of the locus were observed in approximately 240 jointly informative meioses. The sex-equal map length is 158 cM and the largest genetic interval between uniquely localized markers in this map is 11 cM. The female and male map lengths are 181 and 133 cM, respectively. The map is based on the CEPH reference pedigrees and includes over 4000 new genotypes, our previously reported data plus 29 allele systems from the published CEPH version 5 database, and was constructed using the program package CRI-MAP. This genetic linkage map can be considered a baseline map for 7q, and will be useful for defining the extent of chromosome deletions previously reported for breast and prostate cancers, for developing additional genetic maps such as index marker and 1-cM maps, and ultimately for developing a fully integrated genetic and physical map for this chromosome.

Centromere↗
PubMed1996

Tyrosine phosphorylation and activation of a new mitogen-activated protein (MAP)-kinase cascade in human neutrophils stimulated with various agonists.

The presence of a novel 38 kDa protein that is tyrosine phosphorylated in human neutrophils, a terminally differentiated cell, upon stimulation of these cells with low concentrations of lipopolysaccharide (LPS) in combination with serum has been demonstrated. This 38 kDa protein was identified as the mammalian homologue of HOG1 in yeast, the p38 mitogen-activated protein (MAP) kinase. This conclusion is based on the experimental findings that anti-phosphotyrosine (anti-PY) antibody immunoprecipitates a 38 kDa protein that is recognized by anti-p38 MAP kinase antibody, and conversely, anti-p38 MAP kinase antibody immunoprecipitates a 38 kDa protein that can be recognized by anti-PY antibody. Moreover, this tyrosine phosphorylated protein is found associated entirely with the cytosol. It was also found that this p38 MAP kinase is activated following stimulation of these cells with low concentrations of LPS in combination with serum. This conclusion is based on three experimental findings. First, soluble fractions isolated from LPS-stimulated cells phosphorylate heat shock protein 27 (hsp27) in an in vitro assay, and this effect is not inhibited by protein kinase C and protein kinase A inhibitor peptides. This effect is similar to the effect produced by the commercially available phosphorylated and activated MAPKAP kinase-2 (MAP kinase activated protein kinase-2). Secondly, a 27 kDa protein that aligns with a protein recognized by anti-hsp27 antibody is phosphorylated upon LPS stimulation of intact human neutrophils prelabelled with radioactive phosphate. Lastly, immune complex protein kinase assays, using [gamma-32P]ATP and activating transcription factor 2 (ATF2) as substrates, showed increased p38 MAP kinase activity from LPS-stimulated human neutrophils. The phosphorylation and activation of this p38 MAP kinase can be affected by both G-protein-coupled receptors such as platelet-activating factor (PAF) and non-G-protein-coupled receptors such as the cytokine-coupled receptors for granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumour necrosis factor alpha (TNF-alpha). The effect of low concentrations of PAF is greatly increased in cells pretreated with LPS. The tyrosine phosphorylation of the p38 MAP kinase is not restricted to stimuli that mediate their actions through membrane-associated receptors, but it can be affected by agents that bypass membrane-associated receptors such as the protein translation blocker anisomycin. While anisomycin is known to increase the tyrosine phosphorylation of the 54 kDa SAPK (stress-activated protein kinase), this is the first report that shows that anisomycin also tyrosine phosphorylates the p38 MAP kinase. Cytokine receptors that increase the tyrosine phosphorylation and activation of the erk1 and erk2 MAP kinases have less effect on this p38 MAP kinase than those that do not affect the erk1 and erk2 MAP kinases. The possible role of the p38 MAP kinase in the phosphorylation of cytosolic phospholipase A2 is discussed.

Anisomycin↗
PubMed2002

MAP kinase cascades are activated in astrocytes and preadipocytes by 15-deoxy-Delta(12-14)-prostaglandin J(2) and the thiazolidinedione ciglitazone through peroxisome proliferator activator receptor gamma-independent mechanisms involving reactive oxygenated species.

15-Deoxy-Delta(12-14)-prostaglandin J(2) (dPGJ2) and thiazolidinediones are known as ligands for the peroxisome proliferator activator receptor gamma (PPAR gamma) a member of the nuclear receptor superfamily. Herein, we show that dPGJ2 activates, in cultured primary astrocytes, Erk, Jnk, p38 MAP kinase, and ASK1, a MAP kinase kinase kinase, which can be involved in the activation of Jnk and p38 MAP kinase. The activation kinetic is similar for the three MAP kinase. The activation of the MAP kinases is detectable around 0.5 h. The activation increases with dPGJ2 in a dose dependent manner (0-15 microm). A scavenger of reactive oxygenated species (ROS), N-acetylcysteine (NAC) at 20 mm, completely suppresses the activation of MAP kinases and ASK1, suggesting a role for oxidative stress in the activation mechanism. Other prostaglandin cyclopentenones than dPGJ2, A(2), and to a lesser degree, A(1) also stimulate the MAP kinases, although they do not bind to PPAR gamma. Ciglitazone (20 microm), a thiazolidinedione that mimics several effects of dPGJ2 in different cell types, also activates the three MAP kinase families and ASK1 in cultured astrocytes. However the activation is more rapid (it is detectable at 0.25 h) and more sustained (it is still strong after 4 h). NAC prevents the activation of the three MAP kinase families by ciglitazone. Another thiazolidinedione that binds to PPAR gamma, rosiglitazone, does not activate MAP kinases, indicating that the effect of ciglitazone on MAP kinases is independent of PPAR gamma. Ciglitazone and less strongly dPGJ2 activate Erk in undifferentiated cells of the adipocyte cell line 1B8. Ciglitazone also activates Jnk and p38 MAP kinase in these preadipocytes. Our findings suggest that a part of the biological effects of dPGJ2 and ciglitazone involve the activation of the three MAP kinase families probably through PPAR gamma-independent mechanisms involving ROS.

Adipocytes↗
PubMed1994

Saturated molecular map of the rice genome based on an interspecific backcross population.

A molecular map has been constructed for the rice genome comprised of 726 markers (mainly restriction fragment length polymorphisms; RFLPs). The mapping population was derived from a backcross between cultivated rice, Oryza sativa, and its wild African relative, Oryza longistaminata. The very high level of polymorphism between these species, combined with the use of polymerase chain reaction-amplified cDNA libraries, contributed to mapping efficiency. A subset of the probes used in this study was previously used to construct an RFLP map derived from an inter subspecific cross, providing a basis for comparison of the two maps and of the relative mapping efficiencies in the two crosses. In addition to the previously described PstI genomic rice library, three cDNA libraries from rice (Oryza), oat (Avena) and barley (Hordeum) were used in this mapping project. Levels of polymorphism detected by each and the frequency of identifying heterologous sequences for use in rice mapping are discussed. Though strong reproductive barriers isolate O. sativa from O. longistaminata, the percentage of markers showing distorted segregation in this backcross population was not significantly different than that observed in an intraspecific F2 population previously used for mapping. The map contains 1491 cM with an average interval size of 4.0 cM on the framework map, and 2.0 cM overall. A total of 238 markers from the previously described PstI genomic rice library, 250 markers from a cDNA library of rice (Oryza), 112 cDNA markers from oat (Avena), and 20 cDNA markers from a barley (Hordeum) library, two genomic clones from maize (Zea), 11 microsatellite markers, three telomere markers, eleven isozymes, 26 cloned genes, six RAPD, and 47 mutant phenotypes were used in this mapping project. Applications of a molecular map for plant improvement are discussed.

Avena↗