Participating Faculty Mentors
|April Blakeslee, Ph.D.
||Matthew Draud, Ph.D.
||Marc Fink, Ph.D.
||Daniel Ginsburg, Ph.D.|
|Kent Hatch, Ph.D.
||Luis R. Martinez, Ph.D.
||Karin Melkonian, Ph.D.
||Grace Rossi, Ph.D.|
|Stephen Tettelbach, Ph.D.
||Scott Santagata, Ph.D.
April Blakeslee, Ph.D.
Dr. April Blakeslee's research centers around global distribution patterns and processes in marine systems, including biodiversity, conservation biology, population genetics, parasite ecology, and biogeography – with an especial focus on the unique and integrative insight that can be gained from studying biological invasions. Recently, biological invasions have become recognized as a major contributor to the global (and often disjunct) distributions of many marine species as a result of their movement and establishment via human transport mechanisms. Over the years, Dr. Blakeslee has examined many integrative aspects of invasion biology and has used intertidal marine invertebrates, especially mollusks and crustaceans, as model organisms because they have contributed numerous marine introductions globally. This summer she plans to explore parasite-induced behavioral and physiological effects in an introduced crab predator, the European green crab, which has been named one of the top 100 worst invaders around the globe. This project includes field work, lab work, and travel, and interested students will learn various aspects of marine ecology, behavioral ecology, parasitology, and invasion biology. In addition, there may be opportunities to explore population genetics related research in Dr. Blakeslee's lab.
Blakeslee, A.M.H., I. Altman, A.W. Miller, J.E. Byers, C.E. Hamer, & G.M. Ruiz (2011) Parasites and invasions: a biogeographic examination of parasites and hosts in native and introduced ranges. Journal of Biogeography. DOI: 10.1111/j.1365-2699.2011.02631.x
Blakeslee, A.M.H., J. Canning-Clode, E.M. Lind & G. Quilez-Badia (2011) Biological invasions in the 21st century: Ecological impacts, predictions, and management across land and sea. Environmental Research 111: 891-892.
Pringle, J., A.M.H. Blakeslee, J.E. Byers & J. Roman (2011) Asymmetric dispersal allows an upstream region to control population structure throughout a species' range. PNAS 108: 15288-15293.
Panova M., A.M.H. Blakeslee, A.W. Miller, T. Mäkinen, G.M. Ruiz, K. Johannesson & C. André (2011) Survival of a North Atlantic marine snail in multiple glacial refugia—implications for phylogeographic patterns. PLOS One 6(3): e17511.
Blakeslee, A.M.H., C.H. McKenzie, J.A. Darling, J.E. Byers, J.M. Pringle & J. Roman (2010) A hitchhiker's guide to the Maritimes: anthropogenic transport facilitates long-distance dispersal of an invasive marine crab to Newfoundland. Diversity and Distributions 16: 879–891.
Matthew Draud, Ph.D.
Diamondback Terrapins on the north shore of Long Island: Diamondback terrapins (Malaclemys terrapin) are native to the Long Island Sound, inhabiting low to moderate salinity estuaries. They are important consumers in estuarine food webs and are an important keystone species in maintaining community stability and biodiversity. By far the two largest concentrations of terrapins along the north shore of Long Island are in Oyster Bay Harbor and Mount Sinai Harbor, which are both economically important estuaries of the Long Island Sound. Diamondbacks were nearly hunted to extinction on Long Island by the early 1900's, because of the high price they brought at market, where they were sold as a meat delicacy. In fact by the mid-1930's, terrapins were so rare in Long Island, that they were considered locally extinct. Terrapin populations noticeably rebounded by the end of the 1960's, but the state of New York and federal agencies remain interested in studies that examine the health of terrapin populations. I initiated a study on Diamondback Terrapins in Oyster Bay Harbor (OBH) in 2000, which has continued for the past 11 summers, and which has expanded all over Long Island. OBH continues to be the main focal population and is an excellent study site since this population has been studied in the past and their results provide a convenient comparison.
Previous Research Findings: Our goals were to estimate the population size, the sex ratio, and size frequencies. Similar to the previous studies, we caught many adults indicating a population numbering in the high hundreds. However, our samples lacked juvenile terrapins and the turtles we caught were on average larger and older than those caught by previous studies. The increased average size was caused by a lack of intermediate sized turtles in our samples. We are concerned that the lack of these smaller/younger year classes is not simply a bias of sampling technique, but rather the result of poor recruitment. Because turtles have long life spans, populations may exist for a long time, despite the complete loss of recruitment due to reproductive failure. In fact, it can take 10-15 years before obvious signs of a turtle population decline become evident, by which time it may be too late to intervene.
Recruitment can be reduced due to a paucity of sexually mature adults, the lack of suitable nesting habitat, and/or heavy predation of eggs, hatchlings, or juveniles. We believe that in this case, the primary culprit is the lack of suitable nesting habitat. We have profiled the entire shoreline of our study area and found only sporadic suitable nesting habitat. Shoreline development, including the building of small sea walls, fences, and soft-sand beaches has eliminated much of the original nesting habitat. Interestingly, since terrapins will nest in lawns or in flowerbeds, we could probably restore a portion of the nesting area by simply providing access across the sea walls or under fences.
2012 Research Objectives: To fully understand the status of the terrapin population in Oyster Bay Harbor, we must have a reliable estimate of population size, population sex ratio, and population size structure. I plan to continue my mark-recapture study next summer and expand the study area both east and west of the epicenter of our previous work. We use passive, long-term, identification tags (PIT tags). PIT tags are encapsulated microchips, the size of a rice grain. Hand-held, battery operated, scanners send low energy radio signals that energize the microchip to transmit its unique number, which is subsequently displayed for the observer to record. Each chip sends a unique number, which can never be altered and which is permanent. The tags are injected under the skin in the hind leg.
The second major goal is to observe as many nesting females as possible in areas where we have observed nesting in past seasons. Using binoculars, observers can watch nesting females, without disturbing them, from behind blinds that are erected several hundred meters from the nesting habitat. Once a female completes the nest, she is captured for measurement data and identification/PIT tagging, and the exact location of the nest will be identified by GPS and a map of the nesting area will be constructed. Eggs are excavated, counted, weighed, measured and returned. Nests are protected by hardware cloth cages constructed on site.
Marc Fink, Ph.D.
The lab is focused on elucidating the mechanisms underlying oncogenesis in breast cancer. HER2 is an oncogene that is amplified in ~25% of breast cancers and is currently targeted by several drugs including Trastuzumab (HerceptinTM) and Lapatinib (TykerbTM). HER2 belongs to the EGFR (Epidermal Growth Factor Receptor) family of receptor tyrosine kinases and forms heterodimers, with EGFR and HER3, upon ligand stimulation. These events trigger a cascade of events that increase proliferation, survival, and migration of mammary epithelial cells. Breast cancer cells develop resistance to the current drugs and newer drugs are needed to treat these patients.
The laboratory is focusing on the following projects:
1. Heregulin stimulation of several HER2+ breast cancer cell lines leads to increased proliferation and activation of the MAP Kinase pathway. We have identified p90RSK activation upon Heregulin exposure in breast cancer cell lines. Current projects are focused on identifying how RSK regulates proliferation in HER2+ breast cancers.
2. Several approaches are being used to identify novel signaling molecules in HER2+ breast cancer.
3. Systems biology approaches are being developed to map the global response of breast cancer cells to growth factor stimulation. Of particular interest is the cellular response to multiple inputs.
Undergraduate and Graduate students participate in the research by performing experiments on their own projects. Techniques used in the laboratory include cell culture, cell signaling analysis, molecular pharmacology, microscopy, molecular biology, and protein biochemistry. Several students choose to participate in projects that utilize bioinformatics techniques and gene expression analysis.
Daniel Ginsburg, Ph.D.
Humans have 25,000 different genes, but not all of them are being expressed in all cells. In fact, the regulation of gene expression is crucial in many aspects of cell regulation and metabolism. The ability to turn on and off genes allows cells to respond to external stimuli, differentiate, survive, and grow. The first step in gene expression is transcription, synthesizing an RNA molecule from a DNA template. Our lab studies the molecular mechanism of transcription. One of the primary regulators of transcription is chromatin, the protein-DNA complex that makes up the chromosomes in eukaryotic cells. Chromatin limits what proteins have access to the DNA, so it must be altered for transcription to take place. We investigate how changes in chromatin and transcription are linked. We focus on a couple specific chromatin changes and look at how they affect the binding of different protein complexes to chromatin. We use yeast as our model organism, because they are fast-growing, easy to manipulate, and at the level of transcription, identical to higher eukaryotes. Our lab carries out experiments involving molecular biology, genetics, and biochemistry, and we are looking for motivated students to contribute to our ground-breaking research.
Kent Hatch, Ph.D.
Background for Project 1
Stable isotopes have been used extensively to study migration, diet, and trophic levels (steps up the food chain) among wild animals. However, these studies are based on many assumptions that have gone untested in either the lab or the field. This is particularly true concerning the study of trophic levels based on 15N/14N ratios of tissues. As one moves up the food chain the 15N/14N ratio of the animals increases. It is commonly assumed that the 15N/14N ratio increases by 3.4 parts per thousand (relative to a standard) with each complete step up the food chain. However, it has become increasingly apparent that this does not hold true across species. Interestingly, very few controlled laboratory studies have actually been done to assess how 15N/14N ratios increase as trophic level increases.
We propose to study the effect of trophic level on 15N/15N ratios in the most clear manner possible by studying the effects of cannibalism in insects on trophic levels. This eliminates any confounding factors that may be caused by feeding different prey species to different predators. Prey species may not all be at the same trophic level, and therefore neither might the predator species. By examining the effect of cannibalism on 15N/14N ratios we know we will be measuring the pure effect of trophic level on the stable isotope ratios. To do this, we will use crickets and mealworms. Each species will be set in an isolated system where they will be fed a previous generation of the same species in an effort to generate the pure effect of trophic level on the stable isotope ratios of 15N. We predict a constant increase within a species of the 15N/14N ratio of the tissues with increased trophic level. However, we predict that this value will differ between the species.
Background for Project 2
Toe clipping is widely used as a method of marking amphibians typically for mark and recapture studies. It has more recently been utilized to gather information on genetic studies, histological examinations and age determination of the amphibian. However, there is little data on the survival rates or overall fate of toe clipped individuals. There has been previous research suggesting that with the increase of toes clipped, the overall recapture rates significantly decrease. (McCarthy and Parris 2004.) These decreased recapture rates may have different causes, not related to survival.
This study aims to look at the overall survival rates of toe clipped frogs by measuring activity rate, growth rate, recapture avoidance and death. Currently it is unknown if toe clipping has a detrimental affect of these animals. This is important to look at because toe clipping is often used for population estimations. By gaining a better understanding of what happens to the animals after toe clipping we can determine if these estimates are indeed correct or if there is something else occurring.
Luis R. Martinez, Ph.D.
The Martinez laboratory at LIU-Post studies host-pathogen interactions.
We are interested in understanding two basic questions:
Which mechanisms are used by microbes to invade, survive, and cause disease to the host?
How does the host defend itself against microbial assault?
We approach our research in an interdisciplinary manner; undergraduate students that join the lab will be trained on basic microbiology, microscopy, immunological and tissue culture techniques, molecular biology, antimicrobial research, and animal models of infection.
Impact of Methamphetamine Abuse on Innate Immunity and Blood Brain Barrier Integrity
Methamphetamine (METH) is a major public health and safety problem in the United States. METH is a strong addictive central nervous system (CNS) stimulant that mimics the pharmacological effects of cocaine. However, the pharmacological effects of METH are longer lasting than cocaine. The blood brain barrier (BBB) is a unique interface that in part functions to prevent microbial invasion of the CNS. Due to the modification of the expression of adhesion molecules at the level of the endothelial cells of the BBB, cocaine modulates the transmigration of leukocytes resulting in BBB dysfunction and increased cell emigration from the blood vessels to the brain. These effects increase the probability of invasion of pathogens into the brain. Although there is substantial evidence of the effects of cocaine on BBB function, the effects of METH on brain vasculature have not been studied extensively.
We were the first to demonstrate the detrimental impact of METH on host immune function in response to a systemic microbial challenge. We now have preliminary results suggesting that, like cocaine, METH modifies the expression of adhesion molecules at the level of the endothelial cells of the BBB. Hence, METH likely modulates the transmigration of leukocytes. Thus, METH could impair the function of the BBB leading to cell emigration from the blood vessels to the brain, which would increase the probability of dissemination of pathogens to the brain.
The encapsulated AIDS-associated pathogenic fungus Cryptococcus neoformans frequently infects the CNS; globally there are ~1 million cases of CNS cryptococcosis every year. In addition, C. neoformans is an excellent model organism for the study of CNS susceptibility due to the availability of tools such as specific antibodies and well-established animal models.
We hypothesized that METH alters the innate immunity function and BBB integrity increasing susceptibility to infectious diseases, including CNS infection. We anticipate that our findings will result in a deeper understanding of the mechanisms for the increased severity of microbial disease in METH abusers and lead to the development of more effective public health strategies to deal with this scourge of our society.
Martinez, L. R., M. R. Mihu, A. Gacser, L. Santambrogio, and J. D. Nosanchuk. 2009. Methamphetamine enhances histoplasmosis by immunosuppression of the host. J Infect Dis. 200:131-41.
Effect of Alcohol Abuse on Microbial Pathogenesis
We utilize the pathogenic and medically relevant pathogen Acinetobacter baumannii to investigate alcohol-related abuse and host-pathogen interaction questions. This Gram-negative bacterium has gained particular notoriety as one of the leading causes of opportunistic nosocomial infections worldwide. As a consequence of its notorious ability to acquire or upregulate antibiotic drug resistance determinants, it has justifiably been propelled to the forefront of medical attention. The organism commonly targets the most vulnerable hospitalized patients, those who are critically ill with breaches in skin integrity and airway protection. A particular at risk group for A. baumannii-associated pneumonia are individuals with a history of alcohol abuse who characteristically have a fulminant clinical course with secondary bloodstream infection and mortality rate of 40 to 60%. The source of infection may be carriage in the nasopharynx, which occurs in up to 10% of community residents with excessive alcohol consumption.
The ability of A. baumannii to cause disease in alcoholics makes the study of its virulence mechanisms and host interactions crucial in order to develop better public health strategies to decrease the susceptibility to disease of individuals at risk as well as generate novel approaches to patient care. Key questions include: Does alcohol enhances the susceptibility of the host's immune system to A. baumannii? Are there host-specific factors that contribute to A. baumannii pathogenesis in alcoholic individuals? Relative to other Gram-negative organisms, such as P. aeruginosa, very little is known about the host-pathogen interactions involving A. baumannii. Identification of such factors could expose new virulence factors and important characteristics of A. baumannii pathogenesis.
Mihu, M. R. and L. R. Martinez. 2011. Novel therapies for treatment of multi-drug resistant Acinetobacter baumannii skin infections. Virulence. 2:97-102.
Mihu, M. R., U. Sandkovsky, G. Han, J. M. Friedman, J. D. Nosanchuk, and L. R. Martinez. 2010. Nitric oxide releasing nanoparticles are therapeutic for Acinetobacter baumannii wound infections. Virulence. 1:62-67.
Karin Melkonian, Ph.D.
My laboratory has focused for many years on the antimicrobial testing of modified carbohydrate- and protein-based surfaces (wood, paper, cotton, silk, wool, etc.). The novel modification destroys microorganisms through first a pirecing then and electrocution mechanism. These surfaces have been found to be antibacterial and antifungal against a number of pathogenic organisms (including P. aeruginosa, S. aureus, E.coli and B. anthrasis, the bacteria that causes anthrax and C.albicans). The lab is currently examining the antiviral effect of these surfaces. We are infecting eukaryotic dog kidney cells with influenza virus and testing whether they provide any antiviral protection to the cells.
Additionally, we have shown these surfaces to be anticoagulating. Having both antimicrobial and anticoagulating properties provide many potential important medical uses for these surfaces, such as production of blood bags, wound dressings, etc. We are interested in further characterizing the anticoagulating effect and understand the biochemical reactions involved for future therapeutic use.
Grace Rossi, Ph.D.
Project Description: Dr. Rossi's laboratory focuses on the pharmacological characteristics of the opioid system through the use of molecular and behavioral techniques. Over the past year Dr. Rossi and her collaborators at Memorial Sloan Kettering Cancer Center have identified and characterized spliced variants of the mu-opioid receptor that are involved in chronic pain and analgesia. These studies involve detailed micro-injections while analyzing blood pressure, analgesia, inflammation, motor skills, and place-preference conditioning. Studies are performed on mice that have been genetically modified and lacking a selective opioid gene.
Background Info (if needed): Since the cloning of the first opiate receptor, opiate pharmacology has become increasingly complex while the population of chronic pain sufferers increases. The overall goal in this laboratory is to further characterize the opioid receptor system in order to better treat chronic pain conditions without producing side effects such as tolerance, dependence and addiction. To do this, one must examine the actions of several known opiates as well as newly synthesized compounds at the level of the spinal and supraspinal nervous systems. Experiments include testing animals that have been treated with antisense oligos (reverse strands of the DNA) to the mu-opioid receptor. Using reverse strands of DNA allows one to map the annealed receptor protein with the desired target. This type of antisense-mapping is a useful tool for matching drugs to their specific receptors.
Requirements: Person must be at least 15 years of age, willing to handle mice, and adeptly skilled in basic handling techniques. Teaching of behavioral laboratory techniques will occur on premises.
Xu, J., Xu, M., Rossi, GC., Pasternak, G.W., and Pan, Y-X. Identification and characterization of seven new exon 11-associated splice variants of the rat mu opioid receptor gene, OPRM1. Molecular Pain; (2011), Jan 21;7(1):9.
Rossi, G., Barbut, D., Richelson, E., Matulonis, J., and Pasternak, GW. Systemically and topically active antinociceptive neurotensin compounds, Journal of Pharmacology and Experimental Therapeutics, (2010) Sep 1;334(3):1075-9.
Stephen Tettelbach, Ph.D.
Description of Research Program: Stephen Tettelbach
The research that my students and I do seeks to better understand how and why marine populations vary in a changing environment; in turn, we have applied our findings toward the development and improvement of management and culture strategies for commercially important shellfish species. In particular, as part of our bay scallop restoration efforts in eastern Long Island waters, we have worked to develop and improve techniques for planting bay scallops and enhancing their survival, growth and reproductive success. This work has contributed significantly to increases in larval recruitment and has helped rebuild population sizes/densities and the commercial scallop fishery of New York. We do a great deal of Scuba diving and other fieldwork to monitor populations and conduct manipulative experiments; in addition, we have documented new discoveries about the basic biology and ecology of several marine species. Current research projects include: restoration of Peconic bay scallop populations and fisheries; habitat utilization by juvenile bay scallops; age, growth and initial reproductive maturity of the channeled whelk; predation of planted bay scallops by channeled whelk; locomotory behavior of adult hard clams.
Carroll, J.M., B.T. Furman, S.T. Tettelbach, B.J. Peterson. 2012. Balancing the edge effects budget: bay scallop settlement and loss along a seagrass edge. Ecology. in press
Tettelbach, S.T., D. Barnes, J. Aldred, G. Rivara, D. Bonal, A. Weinstock, C. Fitzsimons-Diaz, J. Thiel, M.C. Cammarota, A. Stark, K. Wejnert, R. Ames, J. Carroll. 2011. Utility of high density plantings in bay scallop, Argopecten irradians irradians, restoration. Aquaculture International. 19(4):715-739.
Carroll, J. M., B. J. Peterson, D. Bonal, A. Weinstock, C. F. Smith and S. T. Tettelbach. 2010. Comparative survival of bay scallops in eelgrass and the introduced alga, Codium fragile, in a New York estuary. Marine Biology 157:249–259.
Scott Santagata, Ph.D.
Proposal Title: DNA barcoding of phoronid larval biodiversity and their correspondence to known adult types.
1) Gather mitochondrial and nuclear sequences from various unidentified types of phoronid larvae
2) Match these larval types with known adult forms based on published phylogenetic sequences
3) Estimate the true worldwide diversity of phoronids
4) Investigate the genetic diversity among Pacific populations of Phoronis pallida
The phoronids include two genera and at least 10 universally recognized species that are largely supported by molecular phylogenetic data (Santagata and Cohen, 2009). Although the evolutionary relationships within phoronids and brachiopods are still under debate, phoronids and brachiopods clearly reside within the assemblage of protostome animals known as the Lophotrochozoa or Spiralia. Individual species of adult phoronids often occur in conspecific aggregations that may facilitate cross-fertilization, and, in general, most species exhibit cosmopolitan geographic distributions. All but one phoronid species produce a distinctive larval form known as the actinotroch, and at the time of metamorphic competence actinotroch larval forms develop distinctive larval and presumptive juvenile traits that allow for accurate discrimination among species types (Santagata and Zimmer, 2002). Based on these data there are more discrete larval types than described adult types. The worldwide diversity of phoronid species is likely underestimated due to in part to the greater ease of collecting larval types from the plankton rather than finding adults that typically occur in cryptic subtidal habitats.
Currently one undergraduate student in my laboratory is working on a DNA barcoding project of phoronid larvae from my samples. We have successfully isolated mitochondrial sequences from individual phoronid larvae and plan to isolate other taxonomically informative nuclear sequences in the future. These sequences will be compared to those available on Genbank isolated as part of a previous phylogenetic project (Santagata and Cohen, 2009). These procedures would be easily carried out at Friday Harbor Laboratories, and the geographic location would allow several other unidentified actinotrochs types to be collected and included in the study. A Blinks scholar participating in this study would learn various molecular techniques such as DNA isolation, primer design, PCR, and molecular phylogenetic analyses. We would also conduct field sampling on San Juan Island, and collect plankton samples from various locations in Washington and Oregon. As a secondary project (time allowing) we would also investigate the genetic diversity among Pacific populations of Phoronis pallida.
Santagata S, Cohen B: Phoronid phylogenetics (Brachiopoda; Phoronata): evidence from morphological cladistics, small and large subunit rDNA sequences, and mitochondrial cox1. Zoological Journal of the Linnean Society 2009, 157:34-50.
Santagata S, Zimmer R: Comparison of the neuromuscular systems among actinotroch larvae: systematic and evolutionary implications. Evol Dev 2002, 4:43-54.