Method, vectors, cells, seeds and kits for stacking genes into a single genomic site

Methods of gene stacking are described herein. The methods can be used to repeatedly add genes into a chosen locus in a precise manner, which ensures co-segregation of all introduced genes and contributes to the stabilization of gene expression. In addition, methods of removing any additional foreign DNA elements such as selectable markers are provided. Seed stocks or cell lines comprising a gene stacking site, vectors containing an insert flanked by target sites for a site-specific DNA recombinase for use in the methods and kits for carrying out the methods are also provided herein

Method, vectors, cells, seeds and kits for stacking genes into a single genomic site

Methods of gene stacking are described herein. The methods can be used to repeatedly add genes into a chosen locus in a precise manner, which ensures co-segregation of all introduced genes and contributes to the stabilization of gene expression. In addition, methods of removing any additional foreign DNA elements such as selectable markers are provided. Seed stocks or cell lines comprising a gene stacking site, vectors containing an insert flanked by target sites for a site-specific DNA recombinase for use in the methods and kits for carrying out the methods are also provided herein

A novel gene silencing vector for plant genomics and biotechnology

Gene silencing is a process of suppressing activity of specific genes by producing “interfering” RNA encoded by foreign genes. This process serves as the principle of genetic modification in plants and animals, which is an important tool in genomics and biotechnology, allowing scientists to manipulate organisms to better meet human demands. New approaches of gene silencing may enable improvements on current practices of genetic modification, and broaden the application and impact of gene silencing in biotechnology. Recently, a novel vector design consisting of the transcription of short gene fragments lacking transcription termination signals was demonstrated to be effective in partial silencing of two separate genes in the model plant, Arabidopsis thaliana. To test the efficacy of this unterminated transgene technique on a broader range of genes in A. thaliana, a DNA vector to clone gene fragments was required. The objective of the present study was to design a silencing vector for rapid cloning of gene fragments and test its utility on new genes. Here, we report the successful construction of a simple transgene vector, pSJN15A, for cloning gene fragments, then plant transformation upon Agrobacterium infection. The pSJN15A vector was designed for direct cloning of gene fragments obtained by polymerase chain reaction. Transcription of gene fragments is directed by read-through activity of a hygromycin resistance gene promoter. The pSJN15A vector was used to develop silencing vectors against four new Arabidopsis genes. Thus, pSJN15A serves as an important DNA resource for testing the efficacy of silencing mediated by the transcription of gene fragments in various dicotyledonous plant species

On pseudo-slant submanifolds of nearly trans-Sasakian manifolds

This paper consist the study of pseudo-slant submanifolds of nearly trans-Sasakian manifolds. Integrability conditions of the distributions on these submanifolds are worked out. Some interesting results regarding such manifolds have also been deduced. An example of a pseudo-slant submanifolds of nearly trans-Sasakian manifold is constracted

On a perfect fluid Kahler spacetime

The object of the present paper is to study a perfect fluid K¨ahlerspacetime. A perfect fluid K¨ahler spacetime satisfying the Einstein field equation with a cosmological term has been studied and the existence of killingand conformal killing vectors have been discussed. Certain results related to sectional curvature for pseudo projectively flat perfect fluid K¨ahler spacetime have been obtained. Dust model for perfect fluid K¨ahler spacetime has also been studied

Synthesis and optical properties of CdTe nanocrystals with improved optical properties

CdTe nanocrystals are prepared by hydrothermal route using the reaction between Cd2+ and KHTe in the presence of thioglycolic acid as the stabilizing agent. Hydrothermal synthesis under optimum conditions resulted in a rapid growth. CdTe nanocrystals with high PL intensity and narrow PL spectra are obtained in less time. The growth mechanism of CdTe nanocrystals is investigated. The growth rate in the initial stage of synthesis is higher in hydrothermal synthesis resulting in an increased growth in diffusion controlled focused region

Efficiency of the nuclease I-SceI in excising selectable marker genes from the plant genome

Gene stacking is a method used in biotechnology by which multiple genes can be placed at a single genomic site, thereby simplifying plant breeding. In this approach, DNA nucleases are used for excising selectable marker genes (SMG), which are the unneeded components of transgenic plants. The goal of this project is to evaluate the effectiveness of the nuclease I-SceI in excising DNA in plants. Specifically, this study tests heat-inducible I-SceI through the use of a heat-shock promoter (HS) in order to control SMG excision by heat application. The DNA plasmid containing a visual marker gene flanked by I-SceI target sites and the heat-inducible I-SceI gene has been created and confirmed. Arabidopsis thaliana plants have been transformed with the plasmid, which will be used for testing the efficiency of HS:I-SceI in excising DNA from plant genomes

Efficacy of a Novel Molecular Tool in Silencing Arabidopsis Genes

RNA interference (RNAi), a pathway capable of silencing genes, has until recently only been achievable in the laboratory by the use of one method, expression of inverted repeat sequences of DNA. These constructs generate a double-stranded RNA, which in turn induce post-transcriptional silencing of other genes that bear sequence homology with the transgene. This approach of targeted gene silencing is extremely useful for studying the function of genes and engineering new traits in both plants and animals. It has recently been discovered that a transgene lacking the polyadenylation signal, called a truncated transgene, is also capable of inducing RNAi in plant cells. This technique was used in efficiently silencing two genes of Arabidopsis thaliana, the Phytochrome A (PHYA) and Phytochrome B (PHY B) genes; however, the effectiveness of this method on a broader range of genes is unknown. The purpose of this study is to analyze the effect of truncated-transgene expression on the homologous native genes in the Arabidopsis genome. More specifically, the rate of silencing of three genes, Variegated 2 (VAR2), Brassinosteroid Insensitive 1 (BRI1) and Apetala 1 (AP1) due to the expression of truncated VAR2, BRI1, and AP1 transgenes, respectively, in Arabidopsis thaliana was examined. This experiment provided important data for assessing the efficacy of truncated transgene based gene silencing system for plants

Challenges in setting up a large population-based prospective cohort study in India – learnings from the LoCARPoN cohort

Population-based prospective cohort studies can yield vital new evidence. However, they are difficult to setup especially in non-western contexts such as India. We describe our experience in establishing the Longitudinal Cognition and Aging Research on Population of the National Capital Region (LoCARPoN) cohort, which was the first-of-its-kind public-funded study with target sample size of 15,000, 3 sites, and funds of approx. US$ five million for eight years (2014–2022). LoCARPoN aimed to study incident stroke and dementia in adults aged ≥50 years in urban and rural populations of north India. Among the numerous challenges encountered, important were inadequate funding, lack of adequate space for medical and field sites, difficulty in hiring manpower, lack of IT infrastructure, non-availability of storage facility for biological samples, and absence of dedicated MRI machines. Meticulous planning, adequate funding, trained personnel, institutional and community support are critical for establishing such cohorts in the non-western contexts. Funding: The LoCARPoN cohort study was funded by the Department of Biotechnology (Grant No. BT/IN/Netherlands/03/KP/2012 dated 14/02/2014); and Department of Health Research (Grant No. R.11012/15/2018-HR, dated 09/08/2018), Government of India. The Erasmus component was funded through the Erasmus Medical Centre, Rotterdam, The Netherlands, and the Erasmus University, Rotterdam ( Alzheimer Nederland WE.15-2014-09).</p

Surface passivation of random alloy AlGaAsSb avalanche photodiode

AlGaAsSb attracts significant interest for near‐infrared avalanche photodiodes (APD). The authors report a two‐order reduction in the dark current and a six‐time enhancement of gain in random alloy (RA) AlGaAsSb APD that is surface passivated by conformal coating of Al2O3 via atomic layer deposition (ALD). The dark currents of the APDs with 400‐µm diameter (dry etched) at 90% breakdown voltage (0.9 Vbr) are (5.5 ± 0.5) × 10−5 A, (2.1 ± 0.4) × 10−5 A, and (6.2 ± 0.8) × 10−7 A for non‐passivated, Si3N4 passivated, and Al2O3 passivated devices, respectively. The dark current at a gain of 10 for the Al2O3 passivated device is 1 × 10−8 A which is comparable to the reported value for 100‐µm diameter mesa diodes passivated by SU‐8. Maximum gain values of 6, 12, and 35 were obtained for non‐passivated, Si3N4 passivated, and Al2O3 passivated devices, respectively. Moreover, punch‐through capacitance of 8 pF in a spectral response of 450 to 850 nm was obtained. Thus, Al2O3 passivation can be the best solution for antimonide optoelectronic devices