@article {8318, title = {High-quality single amplicon sequencing method for illumina MiSeq platform using pool of {\textquoteright}N{\textquoteright} (0-10) spacer-linked target specific primers without PhiX spike-in [Next Gen Genomics Facility (INT)]}, journal = {BMC Genomics}, volume = {24}, year = {2023}, month = {2023 Mar 23}, pages = {141}, abstract = {

BACKGROUND: Illumina sequencing platform requires base diversity in the initial 11 cycles for efficient cluster identification and colour matrix estimation. This limitation yields low-quality data for amplicon libraries having homogeneous base composition. Spike-in of PhiX library ensures base diversity but reduces the overall number of sequencing reads for data analysis. To overcome such low diversity issues during amplicon sequencing on illumina platforms, we developed a high throughput single amplicon sequencing method by introducing {\textquoteright}N{\textquoteright} (0-10) spacers in target gene amplification primers that are pooled for simple handling.

RESULT: We evaluated the efficiency of {\textquoteright}N{\textquoteright} (0-10) spacer-linked primers by targeting bacterial 16S V3-V4 region, demonstrating heterogeneous base library construction. The addition of {\textquoteright}N{\textquoteright} (0-10) spacers causes sequencing frameshift at every base that leads to base diversity and produces heterogeneous high quality reads within a single amplicon library. We have written a python based command-line software,"MetReTrim", to trim the {\textquoteright}N{\textquoteright} (0-10) spacers from the raw reads ( https://github.com/Mohak91/MetReTrim ). We further demonstrated the accuracy of this method by comparative mock community analysis with standard illumina V3-V4 primer method. The ZymoBIOMICS{\texttrademark} microbial community DNA standard was used as a control for this study. We performed data analysisusing the DADA2 pipeline where taxonomy was assigned using SILVA database as reference. We observed no difference between the communities represented by our method and standard illumina V3-V4 primer method.

CONCLUSION: This method eliminates the need for PhiX spike-in for single amplicon sequencing on illumina MiSeq platform. This allows for sequencing of more number of samples in a run and a reduction in the overall cost. Given that Illumina sequencing works on SBS chemistry irrespective of the platform (such as HiSeq, MiSeq, NextSeq, NovaSeq, etc.) we propose that this strategy of using {\textquoteright}N{\textquoteright} (0-10) spacer-linked primer design can be adopted for generating high-quality single locus amplicon sequencing in a high throughput manner across the illumina platform subject to further validation.

}, keywords = {Bacteria, Gene Library, High-Throughput Nucleotide Sequencing, Microbiota, RNA, Ribosomal, 16S, Sequence Analysis, DNA}, issn = {1471-2164}, doi = {10.1186/s12864-023-09233-4}, author = {Naik, Tejali and Sharda, Mohak and C P, Lakshminarayanan and Virbhadra, Kumar and Pandit, Awadhesh} } @article {1464, title = {Human induced pluripotent stem cell-derived lung epithelial system for SARS-CoV-2 infection modeling and its potential in drug repurposing [Eyestem Research Pvt. Ltd., a C-CAMP Startup]}, journal = {Stem Cells Dev}, year = {2020}, month = {2020 Aug 31}, abstract = {

The lung is the most vulnerable target for the SARS-CoV-2 infection and respiratory failure causing Acute Respiratory Distress Syndrome (ARDS) is its foremost outcome. However, the current primary in vitro models in use for SARS-CoV-2 display apparent limitations for modeling such complex human respiratory disease. While patient cells can directly model the effects of a drug, their availability and capacity for expansion are limited compared to the transformed/immortalized cells or the tumor-derived cell lines. What{\textquoteright}s more, the latter may harbor genetic and metabolic abnormalities in the course of their derivation, making them unsuitable for drug screening. Therefore, it is important to create physiologically relevant human-cell models that can replicate the pathophysiology of SARS-CoV-2, thus, facilitating drug testing. Here, we show preliminary data on how human induced pluripotent stem cells (hiPSC)-based lung epithelial cell system could emerge as a relevant and sensitive platform for modelling SARS-CoV-2 infection and drug screening.

}, issn = {1557-8534}, doi = {10.1089/scd.2020.0152}, author = {Surendran, Harshini and Nandakumar, Swapna and Pal, Rajarshi} } @article {1115, title = {Hematite Nanoparticles: synthesis, characterization and aquatic ecotoxicity effects [Central Imaging and Flow Cytometry Facility]}, journal = {Research Journal of Biotechnology}, volume = {14}, year = {2019}, chapter = {21}, abstract = {

Iron oxide nanoparticles have been investigated recently for their useful applications in numerous biomedical areas, in environmental remediation and in different industrial applications. In any case, additional risks have been identified with the release of nanoparticles into the environment. In the present study the toxicity of hematite nanoparticles to marine algae, Chlorella vulgaris was studied with focus on oxidative stress and cytotoxicity analysis. The synthesized hematite nanoparticles are in the range of 26-50 nm. Result showed that Chlorella vulgaris growth reduced with increasing concentrations. The nanoparticles induced oxidative stress was the main toxic mechanism. The nanoparticles and Chlorella vulgaris cell physical interaction also contributed to the nanotoxicity. Field Emission Scanning Electron Microscope shows the morphological changes and cell damage. In 24h, treatment mortality was 20 {\textendash} 70 \% and LC50 value for 24h was 393.60 mg/L. Toxicity study on copepod showed mortality increased from 20- 100\% for 48hr and LC50 value for 44h was 221.34 mg/L.

}, author = {Suman Thodhal Yoganandham and Radhika Rajasree Santha Ravindranath* and Gayathri Sathyamoorthy and Remya Rajan Renuka and Aranganathan Lakshminarayanan} } @article {1458, title = {The Hox gene uses Doublesex as a cofactor to promote neuroblast apoptosis in the central nervous system [Transgenic Fly Facility]}, journal = {Development}, volume = {146}, year = {2019}, month = {2019 08 22}, abstract = {

Highly conserved DM domain-containing transcription factors (Doublesex/MAB-3/DMRT1) are responsible for generating sexually dimorphic features. In the central nervous system, a set of Doublesex (Dsx)-expressing neuroblasts undergo apoptosis in females whereas their male counterparts proliferate and give rise to serotonergic neurons crucial for adult mating behaviour. Our study demonstrates that the female-specific isoform of Dsx collaborates with Hox gene () to bring about this apoptosis. Biochemical results suggest that proteins AbdB and Dsx interact through their highly conserved homeodomain and DM domain, respectively. This interaction is translated into a cooperative binding of the two proteins on the apoptotic enhancer in the case of females but not in the case of males, resulting in female-specific activation of apoptotic genes. The capacity of AbdB to use the sex-specific isoform of Dsx as a cofactor underlines the possibility that these two classes of protein are capable of cooperating in selection and regulation of target genes in a tissue- and sex-specific manner. We propose that this interaction could be a common theme in generating sexual dimorphism in different tissues across different species.

}, keywords = {Animals, Apoptosis, DNA-Binding Proteins, Drosophila, Drosophila Proteins, Female, Gene Expression Regulation, Developmental, Genes, Homeobox, Homeodomain Proteins, Male, Neural Stem Cells, Protein Isoforms, Sex Characteristics}, issn = {1477-9129}, doi = {10.1242/dev.175158}, author = {Ghosh, Neha and Bakshi, Asif and Khandelwal, Risha and Rajan, Sriivatsan Govinda and Joshi, Rohit} } @article {1196, title = {Hypoxic Non-replicating Persistent Develops Thickened Outer Layer That Helps in Restricting Rifampicin Entry [Electron Microscopy Facility]}, journal = {Front Microbiol}, volume = {10}, year = {2019}, month = {2019}, pages = {2339}, abstract = {

Bacteria undergo adaptive morphological changes to survive under stress conditions. The present work documents the morphological changes in () cells cultured under hypoxic condition using Wayne{\textquoteright}s hypoxia model involving non-replicating persistence stages 1 and 2 (NRP stage 1 and NRP stage 2) and reveals their physiological significance. Transmission electron microscopy of the NRP stage 2 cells showed uneven but thick outer layer (TOL), unlike the evenly thin outer layer of the actively growing mid-log phase (MLP) cells. On the contrary, the saprophytic NRP stage 2 cells lacked TOL. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) of the NRP stage 2 cells confirmed the rough uneven surface unlike the smooth surface of the MLP cells. Zeta potential measurements showed high negative charge on the surface of NRP stage 2 cells and polysaccharide specific calcofluor white (CFW) staining of the cells revealed high content of polysaccharide in the TOL. This observation was supported by the real-time PCR data showing high levels of expression of the genes involved in the synthesis of sugars, such as trehalose, mannose and others, which are implicated in polysaccharide synthesis. Experiments to understand the physiological significance of the TOL revealed restricted entry of the biologically low-active 5-carboxyfluorescein-rifampicin (5-FAM-RIF), at concentrations equivalent to microbicidal concentrations of the unconjugated biologically active rifampicin, into the NRP stage 2 cells, unlike in the MLP cells. Further, as expected, mechanical removal of the TOL by mild bead beating or release of the NRP stage 2 cells from hypoxia into normoxia in fresh growth medium also significantly increased 5-FAM-RIF permeability into the NRP stage 2 cells to an extent comparable to that into the MLP cells. Taken together, these observations revealed that cells under hypoxia develop TOL that helps in restricting rifampicin entry, thereby conferring rifampicin tolerance.

}, issn = {1664-302X}, doi = {10.3389/fmicb.2019.02339}, author = {Jakkala, Kishor and Ajitkumar, Parthasarathi} } @article {1013, title = {Highly Sensitive LC-MS/MS-ESI method Development for the Determination of 5,7-dihydroxyflavone in Mouse Plasma and Pharmacokinetic Study in Lean and Diet Induced Obese Mice [High Throughput Screening Facility].}, journal = {Der Pharmacia Lettre}, volume = {10}, year = {2018}, type = {Research Article}, chapter = {1-12}, abstract = {

Diet-induced obese (DIO) mice have been commonly used extensively as an animal model of obesity and diabetes in the efficacy assessment for new drug candidates. Physiological and biochemical alterations are reported in DIO mice due to modulations of drug-metabolizing enzymes and high calorie intake. Limited studies have been reported regarding the effect of obesity/diabetes on pharmacokinetics (PK) in animals. A simple, specific and sensitive rapid LC-ESI-MS/MS method has been developed and validated for the quantification of chrysin (5,7-dihydroxyflavone) using tolbutamide as an internal standard (IS) as per regulatory guidelines. Sample preparation was accomplished through a simple protein precipitation. Chromatographic separation of 5,7-dihydroxyflavone and IS was performed on Atlantis C-18 column using an isocratic mobile phase comprising 0.2\% formic acid in water and acetonitrile (20:80, v/v) at a flow rate of 0.9 mL/min. Elution of 5,7-dihydroxyflavone and IS occurred at ~2.49 and 2.34 min, respectively. The total chromatographic run time was 3.2 min. A linear response function was established in the concentration range of 4.50-4500 ng/mL. This novel method has been applied to a pharmacokinetic study in lean and DIO mice.

}, author = {Amir Siddiqui and . Badruddeen and Juber Akhtar and Shahab Uddin MS and Chandrashekaran S and Mohammad Irfan Khan and Mohammad Khalid} }