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Research Scientists/Postdocs

Research Scientists/Postdoctoral Fellows


Arthur Chlebowski, Ph.D. Research Scientist/Biomedical Engineer

I formally joined the John lab. in 2012 after various visits.  I received my Bachelors, Masters, and Ph.D. from Purdue University with emphasis in Biomedical Engineering. I was introduced to many different fields of study and research opportunities and settled my interest in implantable devices.  During my collegiate tenure, I conducted 7 years of research including design, development, and integration of an implantable intraocular pressure (IOP) monitoring device in collaboration with Dr. Simon John. I also developed a novel packaging technique using Low Temperature Co-fired Ceramic (LTCC) as a casing for implantable devices. 

 Through the collaboration with Dr. John, an important goal of bringing engineers and biologists/geneticist together at a single location was brought to fruition. First, I was invited to join my PhD mentor (Prof. Pedro Irazoqui) while he conducted his sabbatical at the Jackson Lab.  Later I worked with Simon at the Jackson Lab while still a postdoc affiliated with Purdue. I enjoyed this time and valued the exposure and training in world-class biology and genetics while being able to bridge the gap of understanding between scientists and engineers.

Next and due to the great value of this real world experience in biomedical research, physiology and genetics, I was delighted to join Simon’s group full time as a resident biomedical engineer and Research Scientist at the interface between biology and engineering.  In this position, I continue my research to develop and create miniature implantable devices. The opportunity to learn and at the same time bring engineering concepts and ideas to the science that the John lab completes is amazing.  Not only do I continue my research on implantable devices, but I get first hand experience and knowledge of research into glaucoma, physiology, anatomy and genetics and the use of cutting edge microscopy and imaging techniques. I exploit my engineering background to design and implement new tools and experimental setups that advance data collection and the testing of hypotheses. I introduce and teach these engineering concepts to my colleagues, while they in return teach me about genetics and biology.  This furthers my knowledge and understanding of biology. I also mentor and train students and research assistants and help with grant and paper writing. This unique training is allowing me to understand diseases and their progression not only from a global view, but also down to the genetic and molecular variations that causes disease. This is making me a better trained biomedical engineer.

As a research engineer, I am in the great situation of having to run the research engineering space at the lab.  Making sure that all equipment in the engineering space is organized and taken care of, as well as making sure everything is setup for other visiting engineers and scientists, allows me to learn and understand what is necessary to keep a lab and its multifaceted collaborations running.  Lastly, I am learning to communicate effectively.  Explaining my research to other scientists at JAX has given me the ability to explain engineering concepts and ideas to the biology community.  This experience in the John Lab. is allowing me to become more effective at all aspects of research including laboratory management, personnel management and budgeting. It is a huge advantage for my progression to leadership positions in the future.

 

 

 

 


Krish Kizhatil, Ph.D. Research Scientist


I earned my Ph.D. in Microbiology and Immunology at the University of Tennessee, Memphis where I uncovered a role for the cellular cytoskeleton in retrovirus entry. Then, during my postdoctoral studies at Duke University, I developed my skills as a Cell biologist and I identified a novel role for the membrane skeletal protein ankyrin in post-Golgi delivery of membrane proteins to the plasma membrane in epithelial cells and photoreceptors. In the summer of 2009, I came to The Jackson Laboratory because of an opportunity to work with Dr. Simon John, a pioneer in the field of glaucoma research. 

In the John Laboratory, I am learning to use mice to decipher causes of complex diseases. During this training I am mastering clinical and physiological ocular examinations, and the use of mouse genetics and genomics to  identify genes pathways impacting glaucoma. Elevation of intraocular pressure (IOP) is a significant risk factor for developing glaucoma and is caused by disruption in the drainage of aqueous humor. My aim is to identify molecular pathways regulating IOP elevation. Currently, my major focus is on understanding the molecular mechanisms of aqueous humor drainage into Schlemm’s canal. As a part of this study, I am taking a holistic approach in characterizing the cells of the Schlemm’s canal at a cellular as well as transcriptome level.  I am also involved in the development of implantable pressure sensors that can be monitored by radio-telemetry and in understanding the role of endothelial and  immune components in the progression of glaucoma and the death of retinal ganglion cell neurons. These studies are predicted to reveal a new understanding that can be used to design new therapeutic interventions. 





Peter Williams, Ph.D. Postdoctoral Fellow

I received my undergraduate training at Cardiff University completing a BSc (Hons) in Neuroscience focusing primarily on molecular and sensory neuroscience. During this time I joined the laboratories of Profs. James Morgan and Marcela Votruba in the School of Optometry and Vision Sciences, Cardiff University doing a research dissertation on retinal ganglion cell dendritic and synaptic plasticity in OPA1 mutant mice (a model of autosomal dominant optic atrophy).  I continued this project into full graduate training completing my PhD in Visual Neuroscience and Molecular Biology in 2012. As well as studying the effects of OPA1 mutations on retinal ganglion cell plasticity in mice, I spent time developing novel transfection methods (in vivo magnetofection), revealed an early marker of neuronal degeneration in the APPswe Alzheimer’s mouse model, and generated a library of tree shrew (Tupaia belangeri) retinal ganglion cells.

In the autumn of 2011, I was lucky enough to be invited to the Jackson Laboratory as part of a collaboration project between Profs. James Morgan (Cardiff University) and Simon John, studying dendritic degeneration on retinal ganglion cells during DBA/2J glaucoma. Having thoroughly enjoyed this project and seeking the mentor ship of Simon to progress intellectually as an independent scientist, I joined the John lab as a Post Doctoral Fellow in Spring, 2012.

My current research focuses on retinal and optic nerve degeneration in the DBA/2J mouse, a widely used model of glaucoma, and the protective nature of γ- and X-ray radiation in this model. I am using modern genomic tools, including RNA-sequencing, to characterize the transcriptomes of different cell types to better understand glaucomatous disease pathogenesis. I am also involved with collaborative projects with biomedical and electrical engineering faculty members from Purdue University working on novel optogenetic tools, vagus nerve stimulation as well as strategies for blocking monocyte adhesion in disease.

Under the mentorship of Simon I have been given the chance to develop my critical thinking and decision-making skills as I work through increasingly more complex problems in neurobiology.  Through my RNA-sequencing dataset I have identified novel genes and pathways that may be involved in the earliest time points during glaucomatous progression. I am currently working on strategies to test these genes through targeted knockouts, by using the John Lab’s vast database of ENU G1 mutant mice and by novel drug therapies. Through this I am learning to use a range of genetic and genomic tools to dissect the mechanisms of complex neurodegenerative disease.

I work closely with another Post Doctoral Fellow, Jeffrey Harder, with whom I manage two research assistants. Simon’s lab is providing me with the skills to help me become an independent scientist, involving me with all aspects of lab planning.  





Jeffrey Harder, Ph.D. Postdoctoral Fellow

I graduated with a B.S. in Computer Science at Pennsylvania State University and developed a strong interest in human disease research.  This led me to enroll in a graduate program at the University of Rochester called Pathways of Human Disease.  As part of my Ph.D. research I defined genes responsible for retinal ganglion cell death during development, after mechanical optic nerve injury, and in DBA/2J glaucoma.  

I joined the John Lab in the spring of 2013 excited by the opportunity of working with Dr. Simon John. The John Lab’s record in mentoring and the success of Simon’s former postdocs in obtaining faculty positions and funding was very attractive.  The  support of other John Lab members and the intellectual and technical expertise at The Jackson Laboratory, including excellent scientific services that would allow me to get more science accomplished, was also important in my decision. The John lab has excellent resources, expertise and organizational structure. Although glaucoma is a complex age-related disease, this environment allows me to run multiple projects.  It also allows me to use a multidisciplinary approach. 

Using DBA/2J mice as a model of glaucoma, my current research focuses on axon degeneration, the role of innate immunity in the central nervous system, and the role of diet in neurodegeneration.  This includes studying the role of JNKs in glaucomatous injury and working to identify early signaling events that may initiate injury. For another project, I am collaborating with faculty from Dalhousie University working on defining human genes responsible for exfoliation syndrome glaucoma.  I also work closely with Pete Williams and help direct two research assistants in the lab.  This opportunity to collaborate and manage while working through complex projects with the mentorship of Simon is extremely valuable. It is broadening my conceptual thinking abilities both scientifically and managerially.  Importantly, I am improving the array of skill sets necessary for running a lab



Mimi deVries, Ph.D. Lab Manager/Research Scientist

I received my undergraduate and graduate training at the North-West University in South Africa.  After receiving my B.Sc. degree with majors in Biochemistry, Physiology and Psychology, I went on to complete my B.Sc. Honors, M.Sc., and Ph.D. degrees in Biochemistry.  My M.Sc. thesis work focused on the screening of families with Osteogenesis Imperfecta (OI: Brittle Bone Disease) for possible mutations in type I collagen.  This study eventually led to the identification of the mutation in a1(I) type I collagen in one family, as well as the establishment of a prenatal diagnostic test for this family.  For my Ph.D. thesis I focused on delineating the cis- and trans-factors responsible for regulating the transcription of the a1(I) type I collagen gene.

After completing my Ph.D., I wanted to gain experience in genetics and developmental biology, as a knowledge base in these two areas is critical for understanding disease processes.  I joined the laboratory of Dr. Barbara Knowles at The Jackson Laboratory as a Postdoctoral Fellow, and continued in her laboratory as a Research Scientist.  During this time I was able to elucidate the role of specific maternal genes in the oocyte-to-embryo transition. I was fortunate to then join the John Laboratory. This move not only gave me an opportunity to work in a vibrant lab utilizing my managerial, mentoring and experimental skills, but also brought me back to my “roots”. I’m once again working on a disease model using the experience I gained along my scientific journey while learning new things in a supportive and exciting environment.  My major research is on the biomedical and deployment side of a project that is developing an innovative, ultra-miniature pressure-measuring device with an automated reading system. The tiny devices will permanently reside in the mouse eye providing valuable long-term data. These devices will allow experiments that are not currently possible. The technology is being designed to allow modification for human deployment to improve patient care. These devices will also improve my other projects that develop inducible models of glaucoma and that identify new mouse strains with glaucoma.

When my mother heard I was moving from South Africa to an island on the coast of Maine, she promptly started knitting sweaters!  Despite the drastic change in temperature, life on MDI has suited me very well.  Apart from finding a scientific home filled with excellent scientists with a wealth of knowledge, incredible resources, and an opportunity to transfer knowledge to younger generations, I also found a home in the community.  I now live on the “Quiet Side” of MDI with my husband - whom I met on said island on the coast of Maine - and one slightly nutty Beagle.  We love to sail and hike on and around MDI, and get away from the “crowds” by going to Moosehead Lake.