Comparative Component Analysis of Exons with Different Splicing Frequencies

Transcriptional isoforms are not just random combinations of exons. What has caused exons to be differentially spliced and whether exons with different splicing frequencies are subjected to divergent regulation by potential elements or splicing signals? Beyond the conventional classification for alternatively spliced exons (ASEs) and constitutively spliced exons (CSEs), we have classified exons from alternatively spliced human genes and their mouse orthologs (12,314 and 5,464, respectively) into four types based on their splicing frequencies. Analysis has indicated that different groups of exons presented divergent compositional and regulatory properties. Interestingly, with the decrease of splicing frequency, exons tend to have greater lengths, higher GC content, and contain more splicing elements and repetitive elements, which seem to imply that the splicing frequency is influenced by such factors. Comparison of non-alternatively spliced (NAS) mouse genes with alternatively spliced human orthologs also suggested that exons with lower splicing frequencies may be newly evolved ones which gained functions with splicing frequencies altered through the evolution. Our findings have revealed for the first time that certain factors may have critical influence on the splicing frequency, suggesting that exons with lower splicing frequencies may originate from old repetitive sequences, with splicing sites altered by mutation, gaining novel functions and become more frequently spliced

AhNRAMP1 Enhances Manganese and Zinc Uptake in Plants

Manganese (Mn) and zinc (Zn) play essential roles in plants. Members of the natural resistance-associated macrophage protein (NRAMP) family transport divalent metal ions. In this research, the function of peanut (Arachis hypogaea L.) AhNRAMP1 in transporting Mn and Zn, as well as its potential for iron(Fe) and Zn biofortification was examined. AhNRAMP1 transcription was strongly induced by Mn- or Zn-deficiency in roots and stems of peanut. Yeast complementation assays suggested that AhNRAMP1 encoded a functional Mn and Zn transporter. Exogenous expression of AhNRAMP1 in tobacco and rice enhanced Mn or Zn concentrations, improving tolerance to Mn or Zn deficiency. With higher Mn concentration, transgenic plants exhibited inhibited growth under Mn excess condition; similar results were obtained under excessive Zn treatment. AhNRAMP1 expression increased biomass in transgenic tobacco and rice, as well as yield in transgenic rice grown on calcareous soil. Compared with non-transformed (NT) plants, Fe and Zn concentrations were elevated whereas concentrations of Mn, copper (Cu), and cadmium (Cd) were not enhanced. These results revealed that AhNRAMP1 contributes to Mn and Zn transport in plants and may be a candidate gene for Fe and Zn biofortification

Real-time tracking and in vivo visualization of β-galactosidase activity in colorectal tumor with a ratiometric near-infrared fluorescent probe

Development of “smart” noninvasive bioimaging probes for trapping specific enzyme activities is highly desirable for cancer therapy in vivo. Given that β-galactosidase (β-gal) is an important biomarker for cell senescence and primary ovarian cancers, we design an enzyme-activatable ratiometric near-infrared (NIR) probe (DCM-βgal) for the real-time fluorescent quantification and trapping of β-gal activity in vivo and in situ. DCM-βgal manifests significantly ratiometric and turn-on NIR fluorescent signals simultaneously in response to β-gal concentration, which makes it favorable for monitoring dynamic β-gal activity in vivo with self-calibration in fluorescent mode. We exemplify DCM-βgal for the ratiometric tracking of endogenously overexpressed β-gal distribution in living 293T cells via the <i>lacZ</i> gene transfection method and OVCAR-3 cells, and further realize real-time in vivo bioimaging of β-gal activity in colorectal tumor-bearing nude mice. Advantages of our system include light-up ratiometric NIR fluorescence with large Stokes shift, high photostability, and pH independency under the physiological range, allowing for the in vivo real-time evaluation of β-gal activity at the tumor site with high-resolution three-dimensional bioimaging for the first time. Our work provides a potential tool for in vivo real-time tracking enzyme activity in preclinical applications

Volume mediano efetivo de cristaloides na prevenção de hipotensão arterial em pacientes submetidas à cesariana com raquianestesia

JUSTIFICATIVA E OBJETIVOS: A hipotensão materna associada à raquianestesia no parto cesáreo é a complicação mais frequente e problemática, com sérios riscos para a mãe e comprometimento do bem-estar neonatal. Nesse contexto, o volume efetivo de cristaloides por via intravenosa como uma estratégia de prevensão ainda não foi estimado. MÉTODOS: Oitenta e cinco parturientes com estado físico ASA I/II submetidas à cesariana seletiva foram selecionadas e 67 mulheres elegíveis foram designadas para receber uma pré-carga de cristaloides com 2 mL de bupivacaína hiperbárica a 0,5% (10 mg) mais 50 µg de morfina. O volume de cristaloides foi determinado por um método sequencial up-and-down. Os cristaloides foram infundidos a uma taxa de 100 a 150 mL.min-1 antes da anestesia espinal. O volume inicial de cristaloides foi de 5 mL.kg-1. Os dados do efeito do volume foram ajustados para o modelo sigmoidal de máxima eficácia e a mediana do volume efetivo (VE50) e seu intervalo de confiança (IC) de 95% foram calculados usando a estimativa de máxima verossimilhança e a regressão logística de Firth corrigida. RESULTADOS: Sessenta e sete parturientes completaram o estudo e foram analisadas. Vinte e oito pacientes (41,8%) desenvolveram hipotensão, com queda da pressão arterial sistólica (PAS) superior a 20% do valor basal. O VE50 de cristaloides foi de 12,6 mL.kg-1 (IC 95%, 11,6 a 14,8 mL.kg-1). Com a correção de Firth, a probabilidade conjunta do volume efetivo de cristaloides a 13 mL.kg-1 foi de 50,2% (IC 95%, 30,0% a 83,1%). CONCLUSÕES: O VE50 estimado da pré-carga de cristaloides necessário para prevenir a hipotensão induzida por anestesia espinhal em parto cesáreo é de 13 mL.kg-1 (valor aproximado). Porém, a profilaxia ou terapia com vasoconstritores também deve ser preparada e administrada no momento oportuno

A Multiaddressable Photochromic Bisthienylethene with Sequence-Dependent Responses: Construction of an INHIBIT Logic Gate and a Keypad Lock

A photochromic bisthienylethene derivative (<b>BIT</b>) containing two imidazole units has been synthesized and fully characterized. When triggered by chemical ions (Ag⁺), protons, and light, <b>BIT</b> can behave as an absorbance switch, leading to a multiaddressable system. <b>BIT</b> exhibits sequence-dependent responses via efficient interaction of the specific imidazole unit with protons and Ag⁺. Furthermore, an INHIBIT logic gate and a keypad lock with three inputs are constructed with the unimolecular platform by employing an absorption mode at different wavelengths as outputs on the basis of an appropriate combination of chemical and photonic stimuli

Near-Infrared Colorimetric and Fluorescent Cu²⁺ Sensors Based on Indoline–Benzothiadiazole Derivatives via Formation of Radical Cations

The donor–acceptor system of indoline–benzothiadiazole is established as the novel and reactive platform for generating amine radical cations with the interaction of Cu²⁺, which has been successfully exploited as the building block to be highly sensitive and selective near infrared (NIR) colorimetric and fluorescent Cu²⁺ sensors. Upon the addition of Cu²⁺, an instantaneous red shift of absorption spectra as well as the quenched NIR fluorescence of the substrates is observed. The feasibility and validity of the radical cation generation are confirmed by cyclic voltammetry and electron paramagnetic resonance spectra. Moreover, the introduction of an aldehyde group extends the electron spin density and changes the charge distribution. Our system demonstrates the large scope and diversity in terms of activation mechanism, response time, and property control in the design of Cu²⁺ sensors

Self-Assembly Solid-State Enhanced Red Emission of Quinolinemalononitrile: Optical Waveguides and Stimuli Response

The fluorescence of luminescent emitters is often quenched in the solid state, because of the typical aggregation-caused quenching (ACQ) effect, which is a thorny obstacle to high-performance organic optoelectronic materials. The exploration of solid-state enhanced long wavelength, red-emitting chromophores, especially possessing one-dimensional (1D) assembly features, is of great importance. Interestingly, an excellent solid-state enhanced red emission system (denoted as ED) based on quinolinemalononitrile has been developed via the delicate modification of the conventional ACQ dicyanomethylene-4<i>H</i>-pyran (DCM) derivative (denoted as BD) through crystal engineering. ED exhibits extraordinary self-assembly property in a variety of solvents, even realizing the “waving ribbons” with a length of 6 mm and a diameter of 10 μm. Crystal analysis shows that the CH···π and CH···N supramolecular interactions of ED contribute to the twisted self-assembly solid-state enhanced emission phenomenon. However, for BD, strong face-to-face stacking leads to fluorescence quenching in the solid state. Because of such easy assembly and strong solid-state emission properties, application for optical waveguides of ED is realized with a low optical loss. Stimuli-responsive behavior is also elaborated with color change between orange and red by grinding/fuming or pressing/heating