Jamie Corro

Dissertation Research: Elucidating the physiology of mycobacteria with ribosome hibernation induced by zinc starvation

Advisor: Dr. Anil Ojha

Rational: Ribosomes are essential biomolecular machines utilized for protein synthesis in every kingdom of life. Zinc is an important micronutrient controlling the expression and incorporation of different ribosomal proteins. In zinc-replete conditions, zinc-binding ribosomal paralogues (called C+) are incorporated into the ribosome. In zinc depleted, but still growth permissive conditions, non-zinc binding paralogues (called C-) replace their zinc binding counterparts in the ribosome. In zinc-starved and growth-restrictive conditions, the ribosomes stabilize as hibernating 70S monosomes through the coordinated binding of Mrf and Mpy, in which Mrf recruits Mpy to bind the ribosomal decoding center.

-Used genetic, biochemical, microscopic, single-cell analysis, in vitro, and in vivo studies to visually distinguish ribosome remodeling and ribosome hibernation and relate this to bacterial physiology and antibiotic tolerance.

-Constructed and visualized fluorescent reporters and proteins in Mycobacterium smegmatis and Mycobacterium tuberculosis using epifluorescent microscopy, confocal microscopy, and flow cytometry.

-Purified ribosomal proteins and ribosomal subunits and studied them using biocheimal assays and immunoblotting.

-Researched changes in bacterial physiology using biochemical assays and confocal microscopy.

-Used microfluidics and epifluorescent microscopy to visualize single-cell growth dynamics.

-Analyzed mouse lung tissue using confocal microscopy.

-Performed RNA Seq for Mycobacterium smegmatis and Mycobacterium tuberculosis samples to gain insight into changes in the transcription profile during ribosome hibernation.

-Used ICP-MS to determine the exact zinc concentration within bacterium.

-Prepared Mycobacterium tuberculosis samples for metabolite extraction and profiling

-Performed immunofluorescent staining and visualization of mouse lung sections infected with Mycobacterium tuberculosis and visualized changes in neutrophil recruitment and abundance using confocal microscopy

Performed general clerical, administrative, and lab duties under the direction of Dr. Feigelis, including: ICD-9, Medical Coding, prescription processing, management of patient records and appointments, centrifuging of blood samples, faxing, copying, and payment processing.

-Determined and assessed the potency and composition of vitamins, food additives, and supplements using HPLC.

-Determined particle size of analytes, formulations, beads, crystals, powders, and granular compounds.

-Determined moisture content of analytes, formulations, beads, crystals, powders, and granular compounds.

-Determined composition using FTIR spectra of products, analytes, formulations, beads, crystals, powders, and granular compounds.

-Researched conservation genetics of: the black colobus (Colobus satanas satanas), red colobus (Procolobus pennantii pennantii), and drill (Mandrillus leucophaeus poensis), 3 endemic primate species to Bioko Island primates that are currently endangered due to their hunting for bushmeat.

-Employed bioinformatically mined loci and primers from the rhesus macaque (Macaca mulatta) on chromosomes 1 and 2 to study primates and assess their genetic health.

Extracted DNA, amplified using a 3-primer method of PCR involving a forward primer with a tail, a reverse primer, and a labeled primer with a tail, verified using gel electrophoresis, and genotyped using a CEQ 8000.

-Analyzed statistics using Genepop to determine heterozygosity deficiency, deviations from Hardy-Weinberg Equilibrium, and inbreeding.

employed by the department in future rape cases to detect female epithelial cells and male sperm cells.

-Prepared serial dilutions of human semen and then stained samples using either the SPERM HY-LITER or the already employed Kernechtrot-Picroindigocarmine Stain (KPIC).

-Assessed the sensitivity of the assay and compared it to the KPIC.

-Viewed and analyzed specimens using fluorescent microscopy.

-Received fluorescent microscopy training and certification from Dina Mattes and SPERM HY-LITER training from Dr. Jennifer Old.

-Used Gas Chromatography (GC-FID) to determine the presence of residual monomers remaining after polymerization reactions.

-Used Fourier Transform Infrared Spectroscopy (FTIR) for composition identification of both liquid samples and packaging substrates.

-Used Gel Permeation Chromatography (GPC) to determine molecular weight distribution of samples.

-Used Diferential Scanning Calorimetry to determine the glass transition of samples.

-Used Gas Chromatography Mass Spectrometry (GC-MS) to determine the identity of volatile components and monomers.

-Used High Pressure Liquid Chromatography (HPLC) to determine sample purity and residual monomers of glycol based polymers.

-Used headspace GC-MS to identify volatile organic solvents and headspace GC-FID to quantify them.

-Performed flashpoint determination using ERDCO SETAFLASH Model 01SF flashpoint and Miniflash FLA by Grabner flashpoint.

-Determined surface energy of substrates using Dynamic Absorption Tester (DAT).

-Determined acid and amine value numbers using standard acid base titrations.

-Investigated and conducted independent research project that sought to develop a method to determine the hydroxyl value number of materials soluble in dimethyl sulfoxide (DMSO), but not the standard acetonitrile, using a potentiometric titration.

-Determined total percent non-volatiles (TNV).

-Created low density polyethylene, polypropylene, and polyethylene terephthalate laminates using experimental paraffinic polymers from Japan and tested their efficacy and tensile strength using an INSTRON.

-Created the media plates that the Caenorhabditis elegans (C. elegans) lived.

Responsible for stocking the lab with plates that contained: NGM medium and specialty plates used for RNAi and Ampicillin-Tetracycline Resistance assays.

-Created stock cholesterol, buffer, and amino acid solutions, created an inventory log of all chemicals, amino acids, and supplies, and helped with the initial design of a yeast two-hybrid assay.

-Helped develop laboratory curriculum for Dr. Brenner’s genetics class.

-Created stocks and records of C. elegans mutants, testing mating capabilities and phenotypic effects of mutant C. elegans for recessive lethality or deleterious, epistatic and lethal interactions of various mutations

-Inoculated C. elegan NGM plates, bacteria plated, and created their living medium.