The SR protein SRp38 represses splicing in M phase cells

SR proteins constitute a family of pre-mRNA splicing factors that play important roles in both constitutive and regulated splicing. Here, we describe one member of the family, which we call SRp38, with unexpected properties. Unlike other SR proteins, SRp38 cannot activate splicing and is essentially inactive in splicing assays. However, dephosphorylation converts SRp38 to a potent, general repressor that inhibits splicing at an early step. To investigate the cellular function of SRp38, we examined its possible role in cell cycle control. We show first that splicing, like other steps in gene expression, is inhibited in extracts of mitotic cells. Strikingly, SRp38 was found to be dephosphorylated specifically in mitotic cells, and we show that dephosphorylated SRp38 is required for the observed splicing repression.     

Anatomy of the external nasal nerve

After rhinoplasty, many patients report numbness of the nasal tip. This is primarily because of injury to the external nasal nerve. It is imperative that surgeons performing rhinoplasty be familiar with the anatomy and the common variations of this nerve. Therefore, the purpose of this study was to present an anatomical study of the external nasal nerve. Twenty external nasal nerves were examined by dissecting 10 fresh cadaver noses within 48 hours of death. On dissection, the exit of the nerve between the nasal bone and upper lateral cartilage was identified. The distance from the point of exit to the midline of the nose and the size of the nerve were measured. The course and the running plane of the nerve were investigated. The nerve branchings were also classified into three types: type I, only one nerve without any branch; type II, one nerve proximally and then splitting into two main branches at the intercartilaginous junction; and type III, two main branches from the point of exit. The point of exit of the external nasal nerve from the distal nasal bone was located 6.5 to 8.5 mm (7.3 +/- 0.6 mm) lateral to the nasal midline. The average diameter of the nerve at the point of exit was 0.35 +/- 0.036 mm. Most of the nerves (95 percent) passed through the deep fatty layer directly under the nasal superficial musculoaponeurotic layer, all the way down to the alar cartilages. In terms of the branching type, type I was observed in 10 of 20 nerves (50 percent), type II was observed in six of 20 (30 percent), and type III was seen in four of 20 (20 percent). On the basis of the results of this study, the following precautions are suggested during a rhinoplasty to minimize the chance of injury to this nerve. First, it is best to avoid deep intercartilaginous or intracartilaginous incisions so that the deep fatty layer is not invaded and the dissection is maintained directly on the surface of the cartilage (deep to the nasal superficial musculoaponeurotic layer). Second, dissection at the junction of the nasal bone and upper lateral cartilage area of one side should be limited to within 6.5 mm from the midline. Lastly, when the nasal dorsum is augmented by an onlay graft, implants or grafts less than 13 mm wide at the rhinion level should be used.     

Comparative study on high fat diet-induced 4-hydroxy-2E-nonenal adducts in the hippocampal CA1 region of C57BL/6N and C3H/HeN mice

In the present study, we investigated the influences of a high fat diet (HD) fed for 12 weeks, on lipid peroxidation and antioxidant enzyme using 4-hydroxy-2E-nonenal (HNE)-modified proteins (HNE-mp) and Cu,Zn-superoxide dismutase (SOD1) in the hippocampal CA1 region (CA1) in C57BL/6N and C3H/HeN mice. Body weights and body weight gains were significantly higher in HD fed C57BL/6N mice than in low fat diet (LD) fed C57BL/6N and LD or HD fed C3H/HeN mice. In the HD fed C57BL/6N and C3H/HeN mice, HNE-mp immunoreactivity and protein levels were much higher than in the LD fed C57BL/6N or C3H/HeN mice. In particular, HNE-mp immunoreactivity and protein levels in HD fed C57BL/6N mice was higher than that in the HD fed C3H/HeN mice. SOD1 immunoreaction was detected in the non-pyramidal cells of C57BL/6N mice, while in the C3H/HeN mice SOD1 immunoreaction was observed in CA1 pyramidal cells. The SOD1 immunoreactivity in the LD fed C57BL/6N and C3H/HeN mice was slightly, but not significantly decreased compared to that in the HD fed C57BL/6N and C3H/HeN mice, respectively. In addition, ionized calcium-binding adapter molecule 1 (Iba-1) immunoreactive microglia in the HD fed C57BL/6N showed hypertrophy of cytoplasm, which is the characteristics of activated microglia. These results suggest that HD fed C57BL/6N mice are more susceptible to lipid peroxidation in the CA1 than in LD fed C57BL/6N and LD or HD fed C3H/HeN mice without any differences of SOD1 expression. In Koo Hwang and Il Yong Kim have contributed equally to this article.     

Prevalence of putative periodontopathogens in subgingival dental plaques from gingivitis lesions in Korean orthodontic patients

The objective of this study was to detect and compare the presence of periodontopathogens in the subgingival plaques of gingivitis lesions in adults who wore fixed orthodontic appliances, as opposed to adults who did not wear any orthodontic appliances. Thirty-six individuals participated in this study. Nineteen of these subjects did not wear any orthodontic appliances, and these subjects comprised the control group. The other 17 individuals had been wearing fixed orthodontic appliances for at least 3 months each. After a periodontal examination, we collected subgingival plaque samples from the gingivitis lesions of each patient. Using PCR based on 16S rDNA, we detected the presence of 6 putative periodontopathogenic species, Treponema denticola, Porphyromonas gingivalis, Tannerella forsythia (formerly Bacteroides forsythus), Prevotella nigrescens, Prevotella intermedia, and Actinobacillus actinomycetemcomitans. With regard to the presence of individual periodontopathogens, we found that T. forsythia, T. denticola, and P. nigrescens were significantly more common in the samples obtained from the orthodontic patients than in the samples obtained from the non-orthodontic patient controls. Our results indicate that the local changes associated with the wearing of fixed orthodontic appliances may affect the prevalence of periodontopathogens in subgingival dental plaques.     

Crystal structures of cyclomaltohexaose (α-cyclodextrin) complexes with p-chlorophenol and p-cresol

Crystal structures of cyclomaltohexaose (α-cyclodextrin) complexes with p-chlorophenol and p-cresol have been determined by single-crystal X-ray diffraction studies. The space group of the α-cyclodextrin–p-chlorophenol complex is P2₁2₁2₁ with unit cell dimensions of a=15.299(3), b=24.795(5), c=13.447(5) Å, and that of the α-cyclodextrin–p-cresol complex is P2₁ with unit cell dimensions of a=7.927(7), b=13.568(7), c=24.54(1) Å, β=90.41(8)°. In spite of the similar structures of guest molecules, both complexes have different inclusion modes and packing structures.     

Detection of IgG and IgM antibodies with ELISA technique in human trichomoniasis

The direct wet mount examination of vaginal secretion, widely applied for the diagnosis of Trichomonas vaginalis infection in woman patients, is rapid and economical, however, the sensitivity of this technique is not so high. In this study enzyme-linked immunosorbent assay (ELISA) was employed for the detection of serum anti-T. vaginalis IgG and IgM antibodies from 30 vaginal trichomoniasis patients and 30 non-infected healthy persons. The results were as follows: 1. Serum ELISA-IgG value was 0.37 +/- 0.134 (Mean +/- S.D.) in vaginal trichomoniasis patients and 0.21 +/- 0.054 in healthy controls (p less than 0.005), and the sensitivity and specificity of ELISA for serum IgG antibody were 70.0% and 96.7%, respectively. 2. Serum ELISA-IgM value was 0.33 +/- 0.177 (Mean +/- S.D.) in vaginal trichomoniasis patients and 0.11 +/- 0.051 in healthy controls (p less than 0.005), and the sensitivity and specificity of ELISA for serum IgM antibody were 70.0% and 96.7%, respectively. 3. The ELISA-IgG values showed a significant correlation with ELISA-IgM values (r = 0.77, p less than 0.005). With above results, it is assumed that ELISA is a reliable method for the diagnosis of T. vaginalis infection and simultaneous measurement of serum IgG and IgM with this technique is recommended.     

MUN (MERISTEM UNSTRUCTURED), encoding a SPC24 homolog of NDC80 kinetochore complex,affects development through cell division in Arabidopsis thaliana

Kinetochore, a protein super‐complex on the centromere of chromosomes, mediates chromosome segregation during cell division by providing attachment sites for spindle microtubules. The NDC80 complex, composed of four proteins, NDC80, NUF2, SPC24 and SPC25, is localized at the outer kinetochore and connects spindle fibers to the kinetochore. Although it is conserved across species, functional studies of this complex are rare in Arabidopsis. Here, we characterize a recessive mutant, meristem unstructured‐1 (mun‐1), exhibiting an abnormal phenotype with unstructured shoot apical meristem caused by ectopic expression of the WUSCHEL gene in unexpected tissues. mun‐1 is a weak allele because of the insertion of T‐DNA in the promoter region of the SPC24 homolog. The mutant exhibits stunted growth, embryo arrest, DNA aneuploidy, and defects in chromosome segregation with a low cell division rate. Null mutants of MUN from TALEN and CRISPR/Cas9‐mediated mutagenesis showed zygotic embryonic lethality similar to nuf2‐1; however, the null mutations were fully transmissible via pollen and ovules. Interactions among the components of the NDC80 complex were confirmed in a yeast two‐hybrid assay and in planta co‐immunoprecipitation. MUN is co‐localized at the centromere with HTR12/CENH3, which is a centromere‐specific histone variant, but MUN is not required to recruit HTR12/CENH3 to the kinetochore. Our results support that MUN is a functional homolog of SPC24 in Arabidopsis, which is required for proper cell division. In addition, we report the ectopic generations of stem cell niches by the malfunction of kinetochore components.     

Maternal care in the red-headed spruce web-spinning sawfly,Cephalcia isshikii (Hymenoptera: Pamphiliidae)

We describe oviposition and maternal behavior in the sawfly Cephalcia isshikiiand examine the adaptive significance of this behavior. Females deposited eggs in a single but loose cluster on needles of terminal twigs of spruces, Piceaspp., and remained with the eggs usually on the underside of the twig facing toward the tip. The female attended her eggs until death without taking food but did not follow the first-instar larvae that moved from natal needles even if she survived until then. When the female was disturbed, she usually moved toward the source and attempted to bite it. Though at much lower frequencies, this aggressive behavior was also observed in gravid females and even in males. Field observations and female removal experiments indicated that the female enhanced the survival of the eggs through the reduction of arthropod prédation.     

Capsicum annuum tobacco mosaic virus-induced clone 1 expression perturbation alters the plant's response to ethylene and interferes with the redox homeostasis

Capsicum annuum tobacco mosaic virus (TMV)-induced clone 1 (CaTin1) gene was expressed early during incompatible interaction of hot pepper (Caspsicum annuum) plants with TMV and Xanthomonas campestris. RNA-blot analysis showed that CaTin1 gene was expressed only in roots in untreated plants and induced mainly in leaf in response to ethylene, NaCl, and methyl viologen but not by salicylic acid and methyl jasmonate. The ethylene dependence of CaTin1 induction upon TMV inoculation was demonstrated by the decrease of CaTin1 expression in response to several inhibitors of ethylene biosynthesis or its action. Transgenic tobacco (Nicotiana tabacum) plants expressing CaTin1 gene in sense- or antisense-orientation showed interesting characteristics such as the accelerated growth and the enhanced resistance to biotic as well as abiotic stresses. Such characteristics appear to be caused by the elevated level of ethylene and H2O2. Moreover, in transgenic plants expressing antisense CaTin1 gene, the expression of some pathogenesis-related genes was enhanced constitutively, which may be mainly due to the increased ethylene level. The promoter of CaTin1 has four GCC-boxes, two AT-rich regions, and an elicitor-inducible W-box. The induction of the promoter activity by ethylene depends on GCC-boxes and by TMV on W-box. Taken together, we propose that the CaTin1 up-regulation or down-regulation interferes with the redox balance of plants leading to the altered response to ethylene and biotic as well as abiotic stresses.     

Selective precipitation and recovery of xylanase using surfactant and organic solvent

The selective precipitation of xylanase from an aqueous phase containing mixtures of xylanase and cellulase was studied using an ionic surfactant as precipitating ligand and a polar organic solvent as recovery solvent. Of four ionic surfactants tested, sodium di-(2-ethylhexyl) sulfosuccinate (AOT) showed a complete removal of xylanase at pH 4.5. The recovery of xylanase from the xylanase-AOT complex was a strong function of the type and the volume of the polar solvent and of the concentration of sodium acetate buffer in the final aqueous solution used to solubilize the recovered xylanase. With ethanol as a recovery solvent, a recovery of xylanase activity of 78 +/- 10% was obtained. The cellulase activity in the recovered xylanase was below the detection limit. The results demonstrate that an ionic surfactant can recover enzymes from aqueous solutions without loss in their activity.