Identification and mapping of Tril, a homeodomain-leucine zipper gene involved in multicellular trichome initiation in Cucumis sativus.

KEY MESSAGE: Using map-based cloning of Tril gene, we identified a homeodomain-leucine zipper gene involved in the initiation of multicellular trichomes (including the spines of fruit) in cucumber. ABSTRACT: Fruit spines are a special type of trichome that impacts the quality and appearance of cucumber (Cucumis sativus L.) fruit. Scanning electron microscopy revealed that the trichome-less (tril) mutant originating from European greenhouse cucumber has a completely glabrous phenotype on cotyledons, hypocotyls, young leaves, fruits, and fruit stalks. Genetic analysis revealed that tril was inherited as a recessive allele at a single locus. Using 1058 F2 individuals derived from a cross between cucumber tril mutant CGN19839 and the micro-trichome (mict) mutant 06-2, tril was mapped to chromosome 6, and narrowed down to a 37.4 kb genomic region which carries seven predicted genes. Genetic and molecular analyses revealed that gene Cucsa.045360 is a possible candidate gene for the differentiation of epidermal cells to trichomes. It is a member of the class IV homeodomain-leucine zipper (HD-Zip IV) family and encodes homeodomain and START domain, sharing 66.7% predicted amino acid sequence identity to PROTODERMAL FACTOR2 (PDF2) and 35.0% to GLABRA2 (GL2) of Arabidopsis. The homeobox domain had changed amino acid sequence because of an insertion in tril mutant. The results of genetic analysis and transcriptome profiling indicated that the Tril gene had an epistatic effect on the Mict gene in trichome development. Phenotypes of the tril mutant such as glabrous fruits and female flowers at every node could be used in developing new cultivars.

Transcriptome profiling of trichome-less reveals genes associated with multicellular trichome development in Cucumis sativus.

Trichomes on plants, similar to fine hairs on animal and human bodies, play important roles in plant survival and development. They also represent a useful model for the study of cell differentiation. Although the regulatory gene network of unicellular trichome development in Arabidopsis thaliana has been well studied, the genes that regulate multicellular trichome development remain unclear. We confirmed that Cucumis sativus (cucumber) trichomes are multicellular and unbranched, but identified a spontaneous mutant, trichome-less (tril), which presented a completely glabrous phenotype. We compared the transcriptome profilings of the tril mutant and wild type using the Illumina HiSeq 2000 sequencing technology. A total of 991 genes exhibited differential expression: 518 were up-regulated and 473 were down-regulated. We further identified 62 differentially expressed genes that encoded crucial transcription factors and were subdivided into seven categories: homeodomain, MADS, MYB, and WRKY domains, ethylene-responsive, zinc finger, and other transcription factor genes. We further analyzed the tissue-expression profiles of two candidate genes, GLABRA2-like and ATHB51-like, using qRT-PCR and found that these two genes were specifically expressed in the epidermis and trichomes, respectively. These results and the tril mutant provide useful tools to study the molecular networks associated with multicellular trichome development.

Micro-trichome as a class I homeodomain-leucine zipper gene regulates multicellular trichome development in Cucumis sativus.

Plant trichomes serve as a highly suitable model for investigating cell differentiation at the single-cell level. The regulatory genes involved in unicellular trichome development in Arabidopsis thaliana have been intensively studied, but genes regulating multicellular trichome development in plants remain unclear. Here, we characterized Cucumis sativus (cucumber) trichomes as representative multicellular and unbranched structures, and identified Micro-trichome (Mict), using map-based cloning in an F2 segregating population of 7,936 individuals generated from a spontaneous mict mutant. In mict plants, trichomes in both leaves and fruits, are small, poorly developed, and denser than in the wild type. Sequence analysis revealed that a 2,649-bp genomic deletion, spanning the first and second exons, occurred in a plant-specific class I homeodomain-leucine zipper gene. Tissue-specific expression analysis indicated that Mict is strongly expressed in the trichome cells. Transcriptome profiling identified potential targets of Mict including putative homologs of genes known in other systems to regulate trichome development, meristem determinacy, and hormone responsiveness. Phylogenic analysis charted the relationships among putative homologs in angiosperms. Our paper represents initial steps toward understanding the development of multicellular trichomes.

Association study on ADAM33 polymorphisms in mite-sensitized persistent allergic rhinitis in a Chinese population.

BACKGROUND: The ADAM33 gene has been identified as a potentially important asthma candidate gene and polymorphisms in this gene have been shown to be associated with asthma and seasonal allergic rhinitis. OBJECTIVE: To assess whether the ADAM33 polymorphisms are associated with persistent allergic rhinitis (PER) due to house dust mites in a Chinese population. METHODS: In a hospital-based case-control study of 515 patients with mite-sensitized PER and 495 healthy controls, we genotyped seven single nucleotide polymorphisms (SNPs) in ADAM33. Serum levels of eosinophil cationic protein, total IgE and allergen-specific IgE against Dermatophagoides pteronyssinus and Dermatophagoides farinae were measured by the ImmunoCAP assays. RESULTS: In the single-locus analysis, three polymorphisms, rs3918392 (F1), rs528557 (S2) and rs2787093, were significantly associated with mite-sensitized PER. SNP S2 was associated with significantly increased risk both of asthmatic and nonasthmatic mite-sensitized PER. In the combined genotypes analysis, individuals with 2-4 risk alleles had a significantly higher risk of mite-sensitized PER (adjusted OR = 1.99, 95% CI = 1.50-2.62) than those with 0-1 risk alleles. Haplotype-based association analysis revealed that the ACAGCCT haplotype might have potential to protect against mite-sensitized PER (adjusted OR = 0.67; 95% CI = 0.49-0.90). CONCLUSIONS: Polymorphisms in the ADAM33 gene may contribute to susceptibility of mite-sensitized PER in this Chinese population.

[Comparison of clinical characteristics between patients with non-allergic and allergic rhinitis].

OBJECTIVE: To analyze and compare the differences of clinical characteristics and comorbidities between patients with non-allergic rhinitis (NAR) and allergic rhinitis (AR). METHODS: A total of 556 out-patients were enrolled from January 2010 to June 2011. The chief complaints of the patients included at least two of the following nasal symptoms: nasal congestion, rhinorrhea, sneezing, and nasal itching. Based on the results of the disease history, physical examination and allergen skin prick test, the patients were classified into NAR group (n = 206) and AR group (n = 350). Detailed information including general data, nasal symptoms and signs, accompanied symptoms and comorbidities were obtained by questionnaires. A scoring was adopted to estimate the severity of disease. SPSS 13.0 software was applied for statistical analysis. RESULTS: The mean age of NAR patients (31.8 ± 16.7) was older than that of AR patients (26.3 ± 14.8), and the difference was significant (t = 4.01, P = 0.0001). While there was no significant difference on gender distribution between two groups (χ² = 0.12, P = 0.73). The percentage of nasal congestion was not significantly different between NAR and AR patients (89.8% and 92.0%, respectively; χ² = 0.26, P = 0.611). However, the symptoms of rhinorrhea, sneezing, nasal itching, eyes itching, lachrymation, wheeze and cough were more popular in AR patients than those in NAR patients (all P < 0.05). Moreover, above symptoms (except cough) were more serious in AR patients, and the symptom scores were significantly higher than those in NAR patients (all P < 0.05). Most of patients with NAR (67.0%) and AR (62.9%) were moderate-severe persistent (χ² = 1.25, P = 0.264). Accompanied asthma were more common in patients with AR (12.6%) compared with NAR (2.4%), while hypertension were more common in patients with NAR (7.3%) compared with AR (1.7%), and the differences were significant (both P < 0.05). CONCLUSION: NAR and AR are two different disease entities, which have different clinical characteristics, as well as different comorbidities. Further clinical study should be done on the rhinitis phenotypes.

[Evaluation of exposure and sensitization to house dust mites among rhinitis patients in the steppe environment of Inner Mongolia].

OBJECTIVE: To evaluate the correlation of exposure and sensitization to house dust mites among rhinitis patients, and the consistency of skin prick test (SPT) and serum specific IgE (sIgE) in the detection of sensitization in a steppe environment of inner Mongolia. METHODS: Three hundreds and fourteen patients with rhinitis symptoms were recruited in this study in a hospital setting at Xilinhot City, inner Mongolia. All patients underwent medical history investigation, anterior rhinoscopy, and allergen tests in vivo (SPT) and in vitro (sIgE). Dust samples were collected from mattresses in patient's bedroom. The concentrations of group I major allergen of Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f) were measured by enzyme linked immunosorbent assay (ELISA). Statistical analysis was performed using a SPSS 17.0 software (t test, χ(2) test and so on). RESULTS: Among a total of 314 patients, the prevalence of positive SPT for Der p and Der f was 5.7% and 22.0%, respectively; and the prevalence of positive sIgE for Der p and Der f was 9.2% and 7.6%, respectively. Sensitization rates for house dust mites (Der p and/or Der f) were lower than those of pollens. The pollen allergen with the highest positive rate was mugwort (SPT, 51.9%; sIgE, 47.1%). Diagnostic tests using SPT as the gold standard for sensitization showed that the positive likelihood ratio of sIgE was 4.27 for Der p and 10.64 for Der f, and the Kappa value was 0.20 for Der p and 0.35 for Der f, respectively. A total of 276 dust samples collected from patient's mattresses were measured. The concentrations of Der p 1 and Der f1 were detectable in 2 (0.7%) and 4 (1.4%) mattress samples, respectively. There was positive correlation between the exposure levels of Derp 1 and the SPT positive reaction to Der p (r(s) = 0.156, P = 0.01), but no significant correlation was found between the exposure levels of Der p 1 and the sIgE positive reaction to Der p (r(s) = 0.116, P = 0.055). There was no significant correlation between the exposure levels of Der f 1 and the SPT as well as sIgE positive reaction to Der f 1(r(s) = 0.05, P = 0.931; r(s) = 0.07, P = 0.245). CONCLUSIONS: In the steppe environment of inner Mongolia, exposure to house dust mites are very low, and the Der p and Der f are not the major allergens in patients with allergic rhinitis. Also, it was not a simple dose-response relationship between exposure and sensitization to house dust mites. In such a specific environment, there is lower consistency between the results of SPT and sIgE in the detection of sensitization to house dust mites. Therefore, it is recommended that the allergen testing in vivo and in vitro should be combined for clinical diagnosis.

[The comparative study of effect of a modified open door laminoplasty using anchor method on axial symptoms and cervical curvature].

OBJECTIVE: To evaluate the effect of a modified open door laminoplasty using anchor method on reducing the occurrence of axial symptoms and loss of cervical curvature. METHODS: From October 2004 to May 2007,56 patients with cervical spondylotic myelopathy underwent this procedure and been followed up (group A). Another 50 patients who underwent conventional unilaterally open-door laminoplasty served as control (group B). The operation time, blood loss, JOA scores and the incidence of newly developed or deteriorated axial symptoms were recorded. Preoperative and postoperative curvature angle which was presented on the tangent of posterior vertebral body margins of C2 and C7 in the cervical spine were measured on cervical radiographs. RESULTS: The operative time was (116 +/- 27.9) min in group A and (120 +/- 18.9) min in group B,showing no statistically significant difference (P > 0.05). The operative blood loss was (148 +/- 68.3) ml in group A and (152 +/- 63.4) ml in group B (P > 0.05). According to JOA scores, the average recovery rates were (61.1 +/- 24.5)% in group A and(53.3 +/- 23.3)% in group B (P < 0.05). Postoperative development or deterioration of axial symptoms occurred in 41.1% of patients in group A and 76.0% of patients in group B,showing statistically significant difference (P < 0.05). There was no significant difference between preoperative (6.3 degrees +/- 5.1 degrees) and postoperative (6.6 degrees +/-4.5 degrees) cervical curvature angle in group A,whereas the mean value of postoperative angle(4.8 degrees +/- 3.5 degrees) was significantly smaller than that of preoperative one(5.9 degrees +/- 5.1 degrees) in group B (P < 0.05). CONCLUSION: The modified open door laminoplasty using anchor method was effective on reducing the occurrence of axial symptoms and loss of cervical curvature and to the benefit of early functional training.

[Inhibitory effect of soman on stress induced hyperthermia in rats and the influence of central and peripheral cholinergic antagonists].

AIM: To determine the effect of soman on stress induced hyperthermia and the influence of central and peripheral cholinergic antagonists. METHODS: Effects of subcutaneous injection of soman, scopolamine, methylscopolamine and pyridostigmine on stress-induced hyperthermia were observed in rats by radio telemetry in an open-field environment. Plasma cholinesterase (ChE) activity was measured by a spectrophotometry. RESULTS: (1) Core temperature of the control group increased by 0.96 degrees C when exposed to open-field, whereas core temperature only increased by 0.55 degrees C in soman treated animals. Scopolamine, a central cholinergic antagonist, nearly abolished inhibitory effects of soman on core temperature when exposed to open-field. Methylscopolamine, a peripheral cholinergic antagonist, coadministered with soman reduced significantly the hyperthermic response to open-field exposure compared with rats dosed with soman. (2) Pyridostigmine, a peripheral anti-ChE agent that caused a 52% decrease in plasma ChE activity led to a significant enhancement of the hyperthermic response to open-field exposure. Methyl scopolamine nearly abolished the effects of pyridostigmine on stress-induced hyperthermia response. CONCLUSION: Inhibitory effect of soman on the open field hyperthermia suggested that soman treatment hampered the ability of the rat to develop a normal hyperthermic response when placed in the open-field environment. Its inhibitory effects were mediated primarily through a central muscarinic pathway. In addition, peripheral cholinergic nerve was involved in the control of stress hyperthermic response.

[Correlation and influences of inflammatory mediators on permeability of the blood-brain barrier at high altitude exposure].

AIM: To investigate the influences of inflammatory mediator on permeability of the blood-brain barrier(BBB) at high altitude environmental exposure as well as relationship and water content in brain. METHODS: Wistar rats were exposed to different altitude gradients, then brain tissue homogenate was prepared, and the activities of tumor necrosis factor-alpha (TNFalpha) and endothelin (ET) in brain tissue homogenate were measured by radioimmunoassay methods. The activities of nitric oxide (NO) in brain tissue homogenate were measured by chemical methods. The evans blue (EB) content in brain tissue was determined by colorimetry and the wet weight/dry weight ratio (W/D) was used to express the water content in brain. RESULTS: With altitude going up, the activities of TNFalpha, NO and ET in the brain of rats rose, and they also rose gradually with time prolonging under high altitude hypoxia exposure. Their most obvious rise was seen during 9 days after ascending 5 000 m high altitude regions. At the same time, the EB and water content in the brain of mice showed the same change trends. Therefore, the inflammatory mediator activity and EB content as well as water content in brain showed an evidently linear relationship. CONCLUSION: The inflammatory mediator plays an important role in the change of permeability of BBB. It's a critical inducing factor in the change of permeability of BBB under high altitude exposure.