Nuclear localization of EGF receptor and its potential new role as a transcription factor

Epidermal growth factor receptor (EGFR) has been detected in the nucleus in many tissues and cell lines. However, the potential functions of nuclear EGFR have largely been overlooked. Here we demonstrate that nuclear EGFR is strongly correlated with highly proliferating activities of tissues. When EGFR was fused to the GAL4 DNA-binding domain, we found that the carboxy terminus of EGFR contained a strong transactivation domain. Moreover, the receptor complex bound and activated AT-rich consensus-sequence-dependent transcription, including the consensus site in cyclin D1 promoter. By using chromatin immunoprecipitation assays, we further demonstrated that nuclear EGFR associated with promoter region of cyclin D1 in vivo. EGFR might therefore function as a transcription factor to activate genes required for highly proliferating activities.

Beta-catenin, a novel prognostic marker for breast cancer: its roles in cyclin D1 expression and cancer progression

Beta-catenin can function as an oncogene when it is translocated to the nucleus, binds to T cell factor or lymphoid enhancer factor family members, and transactivates its target genes. In this study, we demonstrate that cyclin D1 is one of the targets of beta-catenin in breast cancer cells. Transactivation of beta-catenin correlated significantly with cyclin D1 expression both in eight breast cell lines in vitro and in 123 patient samples. More importantly, we found that high beta-catenin activity significantly correlated with poor prognosis of the patients and was a strong and independent prognostic factor in breast cancer. Our studies, therefore, indicated that beta-catenin can be involved in breast cancer formation and/or progression and may serve as a target for breast cancer therapy.

Functional role of high-affinity anandamide transport, as revealed by selective inhibition

Anandamide, an endogenous ligand for central cannabinoid receptors, is released from neurons on depolarization and rapidly inactivated. Anandamide inactivation is not completely understood, but it may occur by transport into cells or by enzymatic hydrolysis. The compound N-(4-hydroxyphenyl)arachidonylamide (AM404) was shown to inhibit high-affinity anandamide accumulation in rat neurons and astrocytes in vitro, an indication that this accumulation resulted from carrier-mediated transport. Although AM404 did not activate cannabinoid receptors or inhibit anandamide hydrolysis, it enhanced receptor-mediated anandamide responses in vitro and in vivo. The data indicate that carrier-mediated transport may be essential for termination of the biological effects of anandamide, and may represent a potential drug target.

Minocycline prevents nigrostriatal dopaminergic neurodegeneration in the MPTP model of Parkinson's disease

Parkinson's disease is a chronic neurodegenerative disorder characterized by the loss of dopamine neurons in the substantia nigra, decreased striatal dopamine levels, and consequent extrapyramidal motor dysfunction. We now report that minocycline, a semisynthetic tetracycline, recently shown to have neuroprotective effects in animal models of stroke/ischemic injury and Huntington's disease, prevents nigrostriatal dopaminergic neurodegeneration in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease. Minocycline treatment also blocked dopamine depletion in the striatum as well as in the nucleus accumbens after MPTP administration. The neuroprotective effect of minocycline is associated with marked reductions in inducible NO synthase (iNOS) and caspase 1 expression. In vitro studies using primary cultures of mesencephalic and cerebellar granule neurons (CGN) and/or glia demonstrate that minocycline inhibits both 1-methyl-4-phenylpyridinium (MPP(+))-mediated iNOS expression and NO-induced neurotoxicity, but MPP(+)-induced neurotoxicity is inhibited only in the presence of glia. Further, minocycline also inhibits NO-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) in CGN and the p38 MAPK inhibitor, SB203580, blocks NO toxicity of CGN. Our results suggest that minocycline blocks MPTP neurotoxicity in vivo by indirectly inhibiting MPTP/MPP(+)-induced glial iNOS expression and/or directly inhibiting NO-induced neurotoxicity, most likely by inhibiting the phosphorylation of p38 MAPK. Thus, NO appears to play an important role in MPTP neurotoxicity. Neuroprotective tetracyclines may be effective in preventing or slowing the progression of Parkinson's and other neurodegenerative diseases.

Characterization of the structure and function of a new mitogen-activated protein kinase (p38beta)

Mitogen-activated protein (MAP) kinase cascades represent one of the major signal systems used by eukaryotic cells to transduce extracellular signals into cellular responses. Four MAP kinase subgroups have been identified in humans: ERK, JNK (SAPK), ERK5 (BMK), and p38. Here we characterize a new MAP kinase, p38beta. p38beta is a 372-amino acid protein most closely related to p38. It contains a TGY dual phosphorylation site, which is required for its kinase activity. Like p38, p38beta is activated by proinflammatory cytokines and environmental stress. A comparison of events associated with the activation of p38beta and p38 revealed differences, most notably in the preferred activation of p38beta by MAP kinase kinase 6 (MKK6), whereas p38 was activated nearly equally by MKK3, MKK4, and MKK6. Moreover, in vitro and in vivo experiments showed a strong substrate preference by p38beta for activating transcription factor 2 (ATF2). Enhancement of ATF2-dependent gene expression by p38beta was approximately20-fold greater than that of p38 and other MAP kinases tested. The data reported here suggest that while closely related, p38beta and p38 may be regulated by differing mechanisms and may exert their actions on separate downstream targets.

A high-density rice genetic linkage map with 2275 markers using a single F2 population

A 2275-marker genetic map of rice (Oryza sativa L.) covering 1521.6 cM in the Kosambi function has been constructed using 186 F2 plants from a single cross between the japonica variety Nipponbare and the indica variety Kasalath. The map provides the most detailed and informative genetic map of any plant. Centromere locations on 12 linkage groups were determined by dosage analysis of secondary and telotrisomics using > 130 DNA markers located on respective chromosome arms. A limited influence on meiotic recombination inhibition by the centromere in the genetic map was discussed. The main sources of the markers in this map were expressed sequence tag (EST) clones from Nipponbare callus, root, and shoot libraries. We mapped 1455 loci using ESTs; 615 of these loci showed significant similarities to known genes, including single-copy genes, family genes, and isozyme genes. The high-resolution genetic map permitted us to characterize meiotic recombinations in the whole genome. Positive interference of meiotic recombination was detected both by the distribution of recombination number per each chromosome and by the distribution of double crossover interval lengths.

T1/ST2 is preferentially expressed on murine Th2 cells, independent of interleukin 4, interleukin 5, and interleukin 10, and important for Th2 effector function

T helper (Th) cells can be categorized according to their cytokine expression. The differential induction of Th cells expressing Th1 and/or Th2 cytokines is key to the regulation of both protective and pathological immune responses. Cytokines are expressed transiently and there is a lack of stably expressed surface molecules, significant for functionally different types of Th cells. Such molecules are of utmost importance for the analysis and selective functional modulation of Th subsets and will provide new therapeutic strategies for the treatment of allergic or autoimmune diseases. To this end, we have identified potential target genes preferentially expressed in Th2 cells, expressing interleukin (IL)-4, IL-5, and/or IL-10, but not interferon-gamma. One such gene, T1/ST2, is expressed stably on both Th2 clones and Th2-polarized cells activated in vivo or in vitro. T1/ST2 expression is independent of induction by IL-4, IL-5, or IL-10. T1/ST2 plays a critical role in Th2 effector function. Administration of either a mAb against T1/ST2 or recombinant T1/ST2 fusion protein attenuates eosinophilic inflammation of the airways and suppresses IL-4 and IL-5 production in vivo following adoptive transfer of Th2 cells.

[A pathological report of three COVID-19 cases by minimal invasive autopsies]

Objective: To investigate the pathological characteristics and the clinical significance of novel coronavirus (2019-nCoV)-infected pneumonia (termed by WHO as coronavirus disease 2019, COVID-19). Methods: Minimally invasive autopsies from lung, heart, kidney, spleen, bone marrow, liver, pancreas, stomach, intestine, thyroid and skin were performed on three patients died of novel coronavirus pneumonia in Chongqing, China. Hematoxylin and eosin staining (HE), transmission electron microcopy, and histochemical staining were performed to investigate the pathological changes of indicated organs or tissues. Immunohistochemical staining was conducted to evaluate the infiltration of immune cells as well as the expression of 2019-nCoV proteins. Real time PCR was carried out to detect the RNA of 2019-nCoV. Results: Various damages were observed in the alveolar structure, with minor serous exudation and fibrin exudation. Hyaline membrane formation was observed in some alveoli. The infiltrated immune cells in alveoli were majorly macrophages and monocytes. Moderate multinucleated giant cells, minimal lymphocytes, eosinophils and neutrophils were also observed. Most of infiltrated lymphocytes were CD4-positive T cells. Significant proliferation of type Ⅱ alveolar epithelia and focal desquamation of alveolar epithelia were also indicated. The blood vessels of alveolar septum were congested, edematous and widened, with modest infiltration of monocytes and lymphocytes. Hyaline thrombi were found in a minority of microvessels. Focal hemorrhage in lung tissue, organization of exudates in some alveolar cavities, and pulmonary interstitial fibrosis were observed. Part of the bronchial epithelia were exfoliated. Coronavirus particles in bronchial mucosal epithelia and type Ⅱ alveolar epithelia were observed under electron microscope. Immunohistochemical staining showed that part of the alveolar epithelia and macrophages were positive for 2019-nCoV antigen. Real time PCR analyses identified positive signals for 2019-nCoV nucleic acid. Decreased numbers of lymphocyte, cell degeneration and necrosis were observed in spleen. Furthermore, degeneration and necrosis of parenchymal cells, formation of hyaline thrombus in small vessels, and pathological changes of chronic diseases were observed in other organs and tissues, while no evidence of coronavirus infection was observed in these organs. Conclusions: The lungs from novel coronavirus pneumonia patients manifest significant pathological lesions, including the alveolar exudative inflammation and interstitial inflammation, alveolar epithelium proliferation and hyaline membrane formation. While the 2019-nCoV is mainly distributed in lung, the infection also involves in the damages of heart, vessels, liver, kidney and other organs. Further studies are warranted to investigate the mechanism underlying pathological changes of this disease.

Dynamics and segregation of cell-matrix adhesions in cultured fibroblasts

Here we use time-lapse microscopy to analyse cell-matrix adhesions in cells expressing one of two different cytoskeletal proteins, paxillin or tensin, tagged with green fluorescent protein (GFP). Use of GFP-paxillin to analyse focal contacts and GFP-tensin to study fibrillar adhesions reveals that both types of major adhesion are highly dynamic. Small focal contacts often translocate, by extending centripetally and contracting peripherally, at a mean rate of 19 micrometers per hour. Fibrillar adhesions arise from the medial ends of stationary focal contacts, contain alpha5beta1 integrin and tensin but not other focal-contact components, and associate with fibronectin fibrils. Fibrillar adhesions translocate centripetally at a mean rate of 18 micrometers per hour in an actomyosin-dependent manner. We propose a dynamic model for the regulation of cell-matrix adhesions and for transitions between focal contacts and fibrillar adhesions, with the ability of the matrix to deform functioning as a mechanical switch.

Schizophrenia after prenatal famine. Further evidence

BACKGROUND

Suggestive findings of an earlier study that prenatal nutritional deficiency was a determinant of schizophrenia prompted us to undertake a second test of the hypothesis using more precise data on both exposure and outcome.

METHODS

Among persons born in the cities of western Netherlands during 1944 through 1946, we compared the risk for schizophrenia in those exposed and unexposed during early gestation to the Dutch Hunger Winter of 1944/1945. The frequency of hospitalized patients with schizophrenia at age 24 to 48 years in the exposed and unexposed birth cohorts was ascertained from a national psychiatric registry.

RESULTS

The most exposed birth cohort, conceived at the height of the famine, showed a twofold and statistically significant increase in the risk for schizophrenia (relative risk [RR] = 2.0; 95% confidence interval [CI] = 1.2 to 3.4; P < .01) in both men (RR = 1.9; 95% CI = 1.0 to 3.7; P = .05) and women (RR = 2.2; 95% CI = 1.0 to 4.7; P = .04). Among all birth cohorts of 1944 through 1946, the risk for schizophrenia clearly peaked in this exposed cohort.

CONCLUSION

Prenatal nutritional deficiency may play a role in the origin of some cases of schizophrenia.

Development of high fat diet-induced obesity and leptin resistance in C57Bl/6J mice

OBJECTIVE

To investigate the development of high fat diet-induced obesity and leptin resistance.

DESIGN

Two experiments were carried out in this study. Firstly, we fed the mice with a high- or low-fat diet for up to 19 weeks to examine a progressive development of high fat diet-induced obesity. Secondly, we examined peripheral and central exogenous leptin sensitivity in mice fed high- or low-fat diets for 1, 8 or 19 weeks.

SUBJECTS

A total of 168 C57BL/6J mice (3 weeks old) were used in this study.

MEASUREMENTS

In the first experiment, we measured the body weight, energy intake, adipose tissue mass, tibia bone length, and plasma leptin in mice fed either a high- or low-fat diet for 1, 8, 15 and 19 weeks. In the second experiment, body weight change and cumulative energy intake were measured at 6 h intervals for 72 h after leptin injection in mice fed a high- or low-fat diet for 1, 8 or 19 weeks.

RESULTS

The results from the first experiment suggested that the development of high fat diet-induced obesity in mice could be divided into early, middle and late stages. Compared with the mice fed a low-fat diet, the mice fed a high-fat diet showed a gradually increased body weight (+5.2%), fat storage (epididymal plus perirenal; +6.7%) and plasma leptin (+18%) at 1 week; +11.4%, +68.1%, and +223%, respectively, at 8 weeks; and +30.5%, +141%, and +458%, respectively, at 19 weeks. Energy intake of high fat diet-fed mice was equal to that of low fat diet-fed controls for the first 3 weeks; it fell below control levels over the next 5 week period, but began to increase gradually after 8 weeks of high-fat diet feeding and then increased dramatically from 15 weeks to be 14% higher than that of controls after 19 weeks. The results from our second experiment showed that: (1) after 1 week of feeding, the mice fed a high-fat diet were sensitive to a 2 microg/g (body weight) intraperitoneal (i. p.) injection of leptin, with no differences in body weight change or cumulative energy intake post-injection; (2) after 8 weeks of feeding, the mice fed a high-fat diet were insensitive to 2 microg/g (body weight) i.p. leptin, but were sensitive to a 0.1 microg intracerebroventricular (i.c.v.) injection of leptin; (3) after 19 weeks of feeding, the mice fed a high-fat diet were insensitive to 0. 1 microg i.c.v. leptin, but were sensitive to a high dose of 2 microg i.c.v. leptin.

CONCLUSIONS

The present study demonstrated that the development of high fat diet-induced obesity (19 weeks) in C57 B1/6J mice could be divided into three stages: (1) an early stage in response to high-fat diet that mice were sensitive to exogenous leptin; (2) a reduced food intake stage when mice had an increase in leptin production and still retained central leptin sensitivity; and (3) an increased food intake stage, accompanied by a reduction of central leptin sensitivity.

The cellular metabolism and systemic toxicity of arsenic

Although it has been known for decades that humans and many other species convert inorganic arsenic to mono- and dimethylated metabolites, relatively little attention has been given to the biological effects of these methylated products. It has been widely held that inorganic arsenicals were the species that accounted for the toxic and carcinogenic effects of this metalloid and that methylation was properly regarded as a mechanism for detoxification of arsenic. Elucidation of the metabolic pathway for arsenic has changed our understanding of the significance of methylation. Both methylated and dimethylated arsenicals that contain arsenic in the trivalent oxidation state have been identified as intermediates in the metabolic pathway. These compounds have been detected in human cells cultured in the presence of inorganic arsenic and in urine of individuals who were chronically exposed to inorganic arsenic. Methylated and dimethylated arsenicals that contain arsenic in the trivalent oxidation state are more cytotoxic, more genotoxic, and more potent inhibitors of the activities of some enzymes than are inorganic arsenicals that contain arsenic in the trivalent oxidation state. Hence, it is reasonable to describe the methylation of arsenic as a pathway for its activation, not as a mode of detoxification. This review summarizes the current knowledge of the processes that control the formation and fate of the methylated metabolites of arsenic and of the biological effects of these compounds. Given the considerable interest in the dose-response relationships for arsenic as a toxin and a carcinogen, understanding the metabolism of arsenic may be critical to assessing the risk associated with chronic exposure to this element.

HuR regulates cyclin A and cyclin B1 mRNA stability during cell proliferation

Colorectal carcinoma RKO cells expressing reduced levels of the RNA-binding protein HuR (ASHuR) displayed markedly reduced growth. In synchronous RKO populations, HuR was almost exclusively nuclear during early G(1), increasing in the cytoplasm during late G(1), S and G(2). The expression and half-life of mRNAs encoding cyclins A and B1 similarly increased during S and G(2), then declined, indicating that mRNA stabilization contributed to their cell cycle-regulated expression. In gel-shift assays using radiolabeled cyclin RNA transcripts and RKO protein extracts, only those transcripts corresponding to the 3'-untranslated regions of cyclins A and B1 formed RNA-protein complexes in a cell cycle-dependent fashion. HuR directly bound mRNAs encoding cyclins A and B1, as anti-HuR antibodies supershifted such RNA-protein complexes. Importantly, the expression and half-life of mRNAs encoding cyclins A and B1 were reduced in ASHuR RKO cells. Our results indicate that HuR may play a critical role in cell proliferation, at least in part by mediating cell cycle-dependent stabilization of mRNAs encoding cyclins A and B1.

Structure-activity relationships of pyrazole derivatives as cannabinoid receptor antagonists

As a potent, specific antagonist for the brain cannabinoid receptor (CB1), the biarylpyrazole N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2, 4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (SR141716A; 1) was the lead compound for initiating studies designed to examine the structure-activity relationships of related compounds and to search for more selective and potent cannabimimetic ligands. A series of pyrazole derivatives was designed and synthesized to aid in the characterization of the cannabinoid receptor binding sites and also to serve as potentially useful pharmacological probes. Therapeutically, such compounds may have the ability to antagonize harmful side effects of cannabinoids and cannabimimetic agents. Structural requirements for potent and selective brain cannabinoid CB1 receptor antagonistic activity included (a) a para-substituted phenyl ring at the 5-position, (b) a carboxamido group at the 3-position, and (c) a 2,4-dichlorophenyl substituent at the 1-position of the pyrazole ring. The most potent compound of this series contained a p-iodophenyl group at the 5-position, a piperidinyl carboxamide at the 3-position, and a 2,4-dichlorophenyl group at the 1-position of the pyrazole ring. The iodinated nature of this compound offers additional utility as a gamma-enriching SPECT (single photon emission computed tomography) ligand that may be useful in characterizing brain CB1 receptor binding in vivo.

Phosphatidylinositol-3,4,5-trisphosphate (PtdIns-3,4,5-P3)/Tec kinase-dependent calcium signaling pathway: a target for SHIP-mediated inhibitory signals

Tec family non-receptor tyrosine kinases have been implicated in signal transduction events initiated by cell surface receptors from a broad range of cell types, including an essential role in B-cell development. A unique feature of several Tec members among known tyrosine kinases is the presence of an N-terminal pleckstrin homology (PH) domain. We directly demonstrate that phosphatidylinositol-3,4,5-trisphosphate (PtdIns-3,4,5-P3) interacting with the PH domain acts as an upstream activation signal for Tec kinases, resulting in Tec kinase-dependent phospholipase Cgamma (PLCgamma) tyrosine phosphorylation and inositol trisphosphate production. In addition, we show that this pathway is blocked when an SH2-containing inositol phosphatase (SHIP)-dependent inhibitory receptor is engaged. Together, our results suggest a general mechanism whereby PtdIns-3,4,5-P3 regulates receptor-dependent calcium signals through the function of Tec kinases.

The 200-MeV proton therapy project at the Paul Scherrer Institute: conceptual design and practical realization

The new proton therapy facility is being assembled at the Paul Scherrer Institute (PSI). The beam delivered by the PSI sector cyclotron can be split and brought into a new hall where it is degraded from 590 MeV down to an energy in the range of 85-270 MeV. A new beam line following the degrader is used to clean the low-energetic beam in phase space and momentum band. The analyzed beam is then injected into a compact isocentric gantry, where it is applied to the patient using a new dynamic treatment modality, the so-called spot-scanning technique. This technique will permit full three-dimensional conformation of the dose to the target volume to be realized in a routine way without the need for individualized patient hardware like collimators and compensators. By combining the scanning of the focused pencil beam within the beam optics of the gantry and by mounting the patient table eccentrically on the gantry, the diameter of the rotating structure has been reduced to only 4 m. In the article the degrees of freedom available on the gantry to apply the beam to the patient (with two rotations for head treatments) are also discussed. The devices for the positioning of the patient on the gantry (x rays and proton radiography) and outside the treatment room (the patient transporter system and the modified mechanics of the computer tomograph unit) are briefly presented. The status of the facility and first experimental results are introduced for later reference.

Biphasic calcium phosphate bioceramics: preparation, properties and applications

Biphasic calcium phosphate (BCP) bioceramics belong to a group of bone substitute biomaterials that consist of an intimate mixture of hydroxyapatite (HA), Ca(10)(PO(4))(6)(OH)(2), and beta-tricalcium phosphate (beta-TCP), Ca(3)(PO(4))(2), of varying HA/beta-TCP ratios. BCP is obtained when a synthetic or biologic calcium-deficient apatite is sintered at temperatures at and above 700 degrees C. Calcium deficiency depends on the method of preparation (precipitation, hydrolysis or mechanical mixture) including reaction pH and temperature. The HA/beta-TCP ratio is determined by the calcium deficiency of the unsintered apatite (the higher the deficiency, the lower the ratio) and the sintering temperature. Properties of BCP bioceramics relating to their medical applications include: macroporosity, microporosity, compressive strength, bioreactivity (associated with formation of carbonate hydroxyapatite on ceramic surfaces in vitro and in vivo), dissolution, and osteoconductivity. Due to the preferential dissolution of the beta-TCP component, the bioreactivity is inversely proportional to the HA/beta-TCP ratio. Hence, the bioreactivity of BCP bioceramics can be controlled by manipulating the composition (HA/beta-TCP ratio) and/or the crystallinity of the BCP. Currently, BCP bioceramics is recommended for use as an alternative or additive to autogeneous bone for orthopedic and dental applications. It is available in the form of particulates, blocks, customized designs for specific applications and as an injectible biomaterial in a polymer carrier. BCP ceramic can be used also as grit-blasting abrasive for grit-blasting to modify implant substrate surfaces. Exploratory studies demonstrate the potential uses of BCP ceramic as scaffold for tissue engineering, drug delivery system and carrier of growth factors.

Activation of BTK by a phosphorylation mechanism initiated by SRC family kinases

Bruton's tyrosine kinase (BTK) is pivotal in B cell activation and development through its participation in the signaling pathways of multiple hematopoietic receptors. The mechanisms controlling BTK activation were studied here by examination of the biochemical consequences of an interaction between BTK and SRC family kinases. This interaction of BTK with SRC kinases transphosphorylated BTK on tyrosine at residue 551, which led to BTK activation. BTK then autophosphorylated at a second site. The same two sites were phosphorylated upon B cell antigen receptor cross-linking. The activated BTK was predominantly membrane-associated, which suggests that BTK integrates distinct receptor signals resulting in SRC kinase activation and BTK membrane targeting.

Agonists induce conformational changes in transmembrane domains III and VI of the beta2 adrenoceptor

Agonist binding to G protein-coupled receptors is believed to promote a conformational change that leads to the formation of the active receptor state. However, the character of this conformational change which provides the important link between agonist binding and G protein coupling is not known. Here we report evidence that agonist binding to the beta2 adrenoceptor induces a conformational change around 125Cys in transmembrane domain (TM) III and around 285Cys in TM VI. A series of mutant beta2 adrenoceptors with a limited number of cysteines available for chemical derivatization were purified, site-selectively labeled with the conformationally sensitive, cysteine-reactive fluorophore IANBD and analyzed by fluorescence spectroscopy. Like the wild-type receptor, mutant receptors containing 125Cys and/or 285Cys showed an agonist-induced decrease in fluorescence, while no agonist-induced response was observed in a receptor where these two cysteines were mutated. These data suggest that IANBD bound to 125Cys and 285Cys are exposed to a more polar environment upon agonist binding, and indicate that movements of transmembrane segments III and VI are involved in activation of G protein-coupled receptors.

A 300 kilobase interval genetic map of rice including 883 expressed sequences

We have constructed a high resolution rice genetic map containing 1,383 DNA markers at an average interval of 300 kilobases (kb). The markers, distributed along 1,575 cM on 12 linkage groups, comprise 883 cDNAs, 265 genomic DNAs, 147 randomly amplified polymorphic DNAs (RAPD) and 88 other DNAs. cDNAs were derived from rice root and callus, analysed by single-run sequencing and searched for similarities with known proteins. Nearly 260 rice genes are newly identified and mapped, and genomic DNA and cloned RAPD fragments were also sequenced to generate STSs. Our map is the first significant gene expression map in plants. It is also the densest genetic map available in plants and the first to be backed up comprehensively by clone sequence data.

Zebrafish pigmentation mutations and the processes of neural crest development

Neural crest development involves cell-fate specification, proliferation, patterned cell migration, survival and differentiation. Zebrafish neural crest derivatives include three distinct chromatophores, which are well-suited to genetic analysis of their development. As part of a large-scale mutagenesis screen for embryonic/early larval mutations, we have isolated 285 mutations affecting all aspects of zebrafish larval pigmentation. By complementation analysis, we define 94 genes. We show here that comparison of their phenotypes permits classification of these mutations according to the types of defects they cause, and these suggest which process of neural crest development is probably affected. Mutations in eight genes affect the number of chromatophores: these include strong candidates for genes necessary for the processes of pigment cell specification and proliferation. Mutations in five genes remove part of the wild-type pigment pattern, and suggest a role in larval pigment pattern formation. Mutations in five genes show ectopic chromatophores in distinct sites, and may have implications for chromatophore patterning and proliferation. 76 genes affect pigment or morphology of one or more chromatophore types: these mutations include strong candidates for genes important in various aspects of chromatophore differentiation and survival. In combination with the embryological advantages of zebrafish, these mutations should permit cellular and molecular dissection of many aspects of neural crest development.

Crucial role of the interleukin 1 receptor family member T1/ST2 in T helper cell type 2-mediated lung mucosal immune responses

T1/ST2 is an orphan receptor of unknown function that is expressed on the surface of murine T helper cell type 2 (Th2), but not Th1 effector cells. In vitro blockade of T1/ST2 signaling with an immunoglobulin (Ig) fusion protein suppresses both differentiation to and activation of Th2, but not Th1 effector populations. In a nascent Th2-dominated response, anti-T1/ST2 monoclonal antibody (mAb) inhibited eosinophil infiltration, interleukin 5 secretion, and IgE production. To determine if these effects were mediated by a direct effect on Th2 cells, we next used a murine adoptive transfer model of Th1- and Th2-mediated lung mucosal immune responses. Administration of either T1/ST2 mAb or T1/ST2-Ig abrogated Th2 cytokine production in vivo and the induction of an eosinophilic inflammatory response, but failed to modify Th1-mediated inflammation. Taken together, our data demonstrate an important role of T1/ST2 in Th2-mediated inflammatory responses and suggest that T1/ST2 may prove to be a novel target for the selective suppression of Th2 immune responses.