The Role of Zygotic Gene Activation Controlling the Onset and Coordination of Mid-blastula Transition

Im frühen Embryo vermehren sich die Kerne zunächst durch 13 synchrone Kernteilungen. Nach den Kernteilungen stoppt der Zellzyklus, die zygotische Transkription wird aktiviert, maternale RNAs werden abgebaut und die Zellularisation beginnt. Dieser Übergang wird allgemein als mid-blastula transition (MBT) bezeichnet. Es konnte gezeigt werden, dass (1) die Verlängerung der Interphasen und Regulatoren des Zellzyklus wie z.B. grapes, (2) der Abbau maternaler RNAs wie z.B. string mRNA und (3) die Expression zygotischer Mitoseinhibitoren wie z.B. frühstart an der zeitlichen Koordination des Übergangs beteiligt sind. Trotzdem ist der molekulare Mechanismus zur Kontrolle der Kernteilungszahl immer noch unbekannt. Um die Rolle der zygotischen Genexpression bei der Regulation des MBT-Starts zu erforschen, wurden zwei Ansätze gewählt: (1) Die Analyse genomischer Regulationselemente von frühstart. (2) Die phänotypische Analyse eines neuen RNA Polymerase II Alleles, RPII215X161. Mittels Reporterassay wurden zwei Motive in der Promoterregion von frühstart identifiziert die eine verfrühte Expression von frühstart verhindern. Mittels EMSA wurde ein weiteres Motiv identifiziert, an das Proteine binden und das für eine starke frühstart Expression notwendig ist. Die Analyse des neuen RNA Polymerase II Allels RPII215X161 ergab einen Einzelbasenaustausch innerhalb der 3„-untranslatierten Region der RNA Polymerase II, der zu erhöhten Protein- und Transkriptmengen im Embryo führt. Die Hälfte der mutierten Embryonen (unabhängig vom zygotischen Genotyp) durchlaufen nur 12 Kernteilungszyklen und beginnen dann verfrüht mit der Zellularisation. Zusätzlich werden in allen Embryonen die zygotischen Gene slam und frühstart verfrüht exprimiert sowie die maternalen Transkripte der string und twine früher abgebaut als im Wildtyp. Die Daten zeigen, dass die Aktivierung zygotischer Gene eine essentielle Rolle bei der zeitlichen Regulation und Koordination der MBT spielt

The Study of Clustering of Taiwanese Tourists\u27 Motivations to Hong Kong

Abstract Driven by the political and economic forces of cross-strait, Taiwan has become one of the major source markets for Hong Kong tourism industry since 1987. The major purposes of this study were to investigate the following factors (1) The influential factors of travel motivation, (2) The clusters of travel motivations, (3) The marketing segmentation of clusters of Taiwanese tourists to visit Hong Kong. Through ten travel agents, self-report surveys were distributed to collect data from 366 Taiwanese travelers. Hence, four push factors and six pull factors were identified as travel motivations through the factor analysis. Combined with the cluster analysis; five new groups were founded. Finally, five clusters which process unique profiles (location difference, visiting frequency, travel satisfaction, and destination loyalty) were addressed. The suggestions of developing effective market strategies to attract Taiwanese tourists to Hong Kong were also provided

Crystal structure of archaeal RNase HII: a homologue of human major RNase H

AbstractBackground: RNases H are present in all organisms and cleave RNAs in RNA/DNA hybrids. There are two major types of RNases H that have little similarity in sequence, size and specificity. The structure of RNase HI, the smaller enzyme and most abundant in bacteria, has been extensively studied. However, no structural information is available for the larger RNase H, which is most abundant in eukaryotes and archaea. Mammalian RNase H participates in DNA replication, removal of the Okazaki fragments and possibly DNA repair.Results: The crystal structure of RNase HII from the hypothermophile Methanococcus jannaschii, which is homologous to mammalian RNase H, was solved using a multiwavelength anomalous dispersion (MAD) phasing method at 2 Å resolution. The structure contains two compact domains. Despite the absence of sequence similarity, the large N-terminal domain shares a similar fold with the RNase HI of bacteria. The active site of RNase HII contains three aspartates: Asp7, Asp112 and Asp149. The nucleotide-binding site is located in the cleft between the N-terminal and C-terminal domains.Conclusions: Despite a lack of any detectable similarity in primary structure, RNase HII shares a similar structural domain with RNase HI, suggesting that the two classes of RNases H have a common catalytic mechanism and possibly a common evolutionary origin. The involvement of the unique C-terminal domain in substrate recognition explains the different reaction specificity observed between the two classes of RNase H

Paper-Based ELISA: A Novel Diagnostic Approach for Monitoring Aqueous Humour VEGF Level in Ocular Diseases

We commonly diagnose ocular diseases via both morphological changes and symptoms. It is necessary to develop biochemically based assays for early or follow-up diagnosis of these diseases with a focus on robustness and ease of handling. To lay out a prospective path toward this goal, we describe and propose the use of ultrahigh sensitive paper-based ELISA (p-ELISA), which uses a treated piece of filter paper to monitor the activity of ocular diseases (i.e., detecting the vascular endothelial growth factor (VEGF) concentration in aqueous humour for proliferative diabetic retinopathy or age-related macular degeneration diagnosis). The advantages of p-ELISA include the following: (1) the capacity to directly measure biomarker concentrations in aqueous humour using only a tiny sample volume (as little as 2 μL); (2) significantly increased sensitivity compared to conventional ELISA (fg/mL levels); and (3) inexpensive materials and a short operation duration. P-ELISA is a novel point-of-care diagnostic tool with the significant potential to advance ophthalmological treatment guidelines by facilitating early detection and routinely monitoring therapeutic response

Quantitative assessment of female pattern hair loss

AbstractBackground/ObjectiveThe conventional approach to evaluate female pattern hair loss (FPHL) is to visually inspect and score images of balding area (BA). However, visual estimates vary widely among different physicians, and may hinder objective assessment of hair loss and subsequent treatment response. For this reason, we propose a quantitative method using a computer-aided imaging system to help physicians evaluate the severity of FPHL clinically.MethodsWe use a series of digital image processing techniques to measure the width of central balding area of FPHL. A total of 184 photos were collected form 33 Chinese women with FPHL (stages I-2 to II-2 on the Savin scale). Each photograph underwent standardized exposure correction. The balding areas were detected through this computer system and then transformed into an equivalent ellipse by principal component analysis. The width of ellipse [balding width (BW)] was measured. Spearman's rank correlation was used to detect the correlation between our measurements and clinical staging.ResultsExposure correction resulted in a 16.97% (|BWcorrected − BWoriginal|/BWcorrected) difference in BW.‏ The average BW was 54.98 mm in all patients, 25.79 mm in type I-2 patients, 37.41 mm in I-3, 54.08 mm in I-4, 72.10 mm in II-1, and 85.53 mm in II-2. The values of BW were correlated with Savin scale stages clinically (rBW = 0.967), which was significant statistically (p < 0.05).ConclusionA computer-aided imaging system could be a useful tool to assist physicians to evaluate the balding area more precisely for clinical staging in FPHL. The BW instead of the balding area is simple to use clinically to represent the severity of FPHL

Interplay between the magnetic and electric degrees-of-freedom in multiferroic Co3TeO6

Neutron diffraction, magnetic susceptibility, specific heat, and dielectric constant measurements of single crystal Co3TeO6 have been measured to study the interplay between the ferroelectricity and magnetic order. Long range incommensurate magnetic order develops below TM1=26 K, which is followed by three additional zero-field phase transitions at TM2=19.5 K, TM3=18 K, and TM4=16 K where the incommensurate order changes and commensurate order develops. In magnetic fields up to 14 T we find that the magnetic intensities and incommensurate wave vector are dramatically altered as ferroelectricity develops, with a fifth abrupt transition around 10 T. The overall behavior characterizes Co3TeO6 as a type-II multiferroic.Comment: Phys. Rev. B (in press