Office: SLB 244; Phone: (309) 438-3834; e-mail: rmbowde@ilstu.edu
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Office/Lab: SLB 245; Phone: 309-438-3196
Ryan Paitz (PhD student) 
e-mail: rpaitz@ilstu.edu
Deciphering the physiological mechanisms that underlie yolk steroid effects
It is well established that perinatal steroids play a critical role in directing differentiation during embryonic development in vertebrates. Because of this, it has been proposed that females may be able to influence offspring development by modifying the embryonic endocrine environment. Numerous studies have demonstrated that manipulating the maternal endocrine environment can have long term effects on the developing offspring but the mechanisms by which maternal endocrine signals influence offspring are not very well understood. My research focuses on the mechanisms that underlie how maternally derived yolk steroids influence the developing offspring in oviparous vertebrates. Specifically, I will be addressing two mechanistic questions: 1. How do lipophilic steroids make it from the lipid rich yolk to the aqueous embryonic environment? 2. How do steroids, present at the time of oviposition, influence some offspring traits while not influencing other traits known to be regulated by steroids? Current experiments are examining the role of sulfotransferase activity in deactivating yolk steroids and the role sulfatase activity in potentially reactivating these steroids later in development. This sulfotranferase-sulfatase pathway may potentially provide a mechanism to answer both of the research questions.
Laura Zimmerman (MS student)
Reptiles hold an important place in evolutionary history, providing the key link between the ectothermic fishes and amphibians, and the endothermic birds and mammals, and thus a greater understanding of the reptile immune system could provide important insights into the evolutionary history of immune responses. Previous research has shown that aspects of these responses exhibit seasonal variation that is species specific. One goal of my study is to examine the effects of season on immune responses in adult red-eared sliders. A second goal of my research is to examine how estrogens affect the immune response of female turtles. Estrogens are generally considered to be immunostimultory, and are known to vary seasonally. As part of my thesis work, I will experimentally manipulate estrogen levels and I hypothesize that increasing estrogen levels will result in an increased immune response. I am using a variety of immune measures to look at innate, cell-mediated, and humoral immunity.
Mikael Holgersson (MS student) 
Since the early 1970's, turtles have been recognized as natural carriers of Salmonella and consequently as excellent vectors of human salmonellosis. The FDA federally banned the sale of turtles with shell lengths less than 4 inches in 1975 after many turtle owners, particularly children, contracted Salmonella from their pets as a result of poor hygiene practices and general ignorance. The human health hazard posed by turtles has driven a large body of research since that time, but few studies have examined the natural interaction of Salmonella and their turtle hosts. I am directing my efforts to help fill this gap and am currently working on a multipart project to 1) assess Salmonella prevalence in a turtle community near the Illinois River, 2) determine how developing red-eared slider turtles contract Salmonella, and 3) determine if Salmonella infections result in measurable costs to developing red-eared slider turtles. I am using selective plating techniques and thereafter ELISA and/or PCR to detect and identify the Salmonella organism.
Amelia Gould, Sandrine Clairardin, Adam Griffin (ISU Undergraduates)
Amelia is currently investigating how temperature fluctuations during incubation effecthatchling shell pigmentation. Sandrine and Adam are examining how temperature variability during embryonic development affects hatchling phenotypes.
Kemi Onajin (Illinois Wesleyan University)
Kemi is studying how the conditions experienced during incubation influence digit lengths in hatchling turtles.
Lab Alumni
Heidi Harms (M.S. 2007)
"Characterization of immune parameters during development and adulthood in the red-eared slider turtle (Trachemys scripta elegans)"
Heidi graduated in May and is currently an AssistantToxicologist at Covance Laboratories, Inc. - Madison, WI.
Heather Les (B.S. 2007)
Heather worked in the lab for 2.5 years and has co-authored numerous publications and presentations relating to the effects of the incubation environment on hatchling phenotype. Heather is currently at the University of Illinois.
Lauren Kozlowski/Smithee (B.S. 2005)
Lauren worked in the lab for 2 years and has co-authored presentations and a manuscript (in review). Lauren is currently a vet tech for Abbott Labs (Chicago, IL) working on in vivo Cancer biology in immunocompromised mice.