Dr. Ryan Paitz
Associate Professor of Endocrinology
Office
SLB Science Laboratory Building 254
Office Hours
by appointment
Office Phone
Email
- About
- Education
- Selected Research
Biography
I am a comparative physiologist interested in how vertebrate embryos regulate their exposure to maternal steroids and environmental chemicals.
Current Courses
BSC 499.028 Independent Research For The Master's Thesis
BSC 599.028 Research In The Biological Sciences
BSC 299.009 Independent Honor Study
BSC 499.028 Independent Research For The Master's Thesis
BSC 197.001 Molecular And Cellular Basis Of Life
BSC 290.050 Research In Biological Sciences
BSC 599.028 Research In The Biological Sciences
Teaching Interests & Areas
Endocrinology, Comparative Physiology, Developmental Biology, Embryology
Research Interests & Areas
Embryonic development, steroid metabolism, maternal effects, steroids, endocrine disruption
Ph D Biological Sciences
Illinois State University
Normal, IL
BS Genetics
Iowa State University
Ames, IA
Grants and Contracts
2024 Spring BirdFEEDER
Lilly King, Ryan Paitz.
Illinois State University. January 2024 - May 2024
2023 Fall Firebird
Libby Tillman, Ryan Paitz.
Illinois State University. September 2023 - December 2023
2023 Fall Firebird
Alyssa Bernauer, Ryan Paitz.
Illinois State University. September 2023 - December 2023
2023 Fall Firebird
Anna Roseland, Ryan Paitz.
Illinois State University. September 2023 - December 2023
2023 Summer Firebird
Delaney Reynolds, Ryan Paitz.
Illinois State University. June 2023 - August 2023
Book, Chapter
Sex determination and differentiation in reptiles
Amanda Carter, Ryan Paitz, Satomi Kohno.
(2024), 3, 1-33, Hormones and Reproduction of Vertebrates (Second Edition), Elsevier
Journal Article
Socially responsive yolk steroids correlate with gene expression in early extra-embryonic membranes
Jasmeen Kaur, Ryan Paitz, Taylor Verret, Alex Bentz.
Journal of Experimental Biology, (2026)
Early Developmental Decline in HSP Expression Affects Subsequent Response to Transient Heat Exposure
Clinton Warren, Madison Wilken, Jacob Rollins, Ryan Paitz, Rachel Bowden.
Integrative Organismal Biology, (2025)
Elevating Testosterone and Androstenedione Produces Temporary Sex‐Dependent Variation in Japanese Quail (Coturnix japonica) Embryonic Development
Sarah Winnicki, Mark Hauber, Ryan Paitz, Wendy Schelsky.
Journal of Experimental Zoology Part A: Ecological and Integrative Physiology, (2025)
Maternal deposition of hormones and contaminants shape the gonadal transcriptome in American alligators
Christopher Smaga, Samantha Bock, Josiah Johnson, Ryan Paitz, Andrew Letter, Arnold Brunell, Benjamin Parrott.
Proceedings of the Royal Society B, (2025)
Responsiveness to cold snaps by turtle embryos depends on exposure timing 2 and duration
Clinton Warren, Anthony Breitenbach, Rachel Bowden, Ryan Paitz.
Proceedings of the Royal Society B, (2025)
Why not both? A case study in measuring cortisol and corticosterone
Sarah Westrick, Ryan Paitz, Eva Fischer.
Integrative Organismal Biology, (2025)
Yolk steroid concentrations decline in Japanese Quail (Coturnix japonica) eggs throughout incubation
Sarah Winnicki, Mark Hauber, Ryan Paitz, Thomas Benson.
Biorxiv, (2025)
Avian extraembryonic membranes respond to yolk corticosterone early in development
Emily Harders, Mitch Agustin, Ryan Paitz.
Biology Open, (2024)
Extraembryonic metabolism of corticosterone protects against effects of exposure
Emily Harders, Christina Charboneau, Ryan Paitz.
General and Comparative Endocrinology, (2024)
Experiencing short heat waves early in development changes thermal responsiveness of turtle embryos to later heat waves
Anthony Breitenbach, Rosario Marroquin-Flores, Ryan Paitz, Rachel Bowden.
Journal of Experimental Biology, (2023)
The response to stressors in adulthood depends on the interaction between prenatal exposure to glucocorticoids and environmental context
Ariana Majer, Ryan Paitz, Gianna Tricola, Jack Geuduldig, Hannah Litwa, Jenna Farmer, Brenna Prevelige, Mark Haussmann.
Scientific Reports, (2023)
Why not both? A case study measuring cortisol and corticosterone in poison frogs
Sarah Westrick, Ryan Paitz, Eva Fischer.
BioRxiv, (2023)
Sex-specific effects of hatching order on nestling baseline corticosterone in a wild songbird
Madi Rittinger, Logan Sauers, Ryan Paitz, Christine Poppe, Charles Thompson, Scott Sakaluk.
General and Comparative Endocrinology, (2022)
Temperature fluctuations and estrone sulfate affect gene expression via different mechanisms to promote female development in a species with temperature-dependent sex determination
Rosario Marroquin Flores, Ryan Paitz, Rachel Bowden.
Journal of Experimental Biology, (2022)
Brief exposure to warm temperatures reduces intron retention in Kdm6b in a species with temperature-dependent sex determination
Rosario Marroquin-Flores, Rachel M Bowden, Ryan T Paitz.
Biology Letters, (2021)
Characterizing the timing of yolk testosterone metabolism and the effects of etiocholanolone on development in avian eggs.
Nicole Campbell, Rachel M Bowden, Joseph M Casto, Ryan Paitz.
Journal of Experimental Biology, (2020)
Comment on: Carter AW, Paitz RT, Bowden RM. 2019. The Devil is in the Details: Identifying Aspects of Temperature Variation that Underlie Sex Determination in Species with TSD. Integrative and Comparative Biology 59:1081-8 Reply
Amanda W Carter, Ryan T Paitz, Rachel M Bowden.
Integrative and Comparative Biology60, 60, 1351-1354, (2020)
Effects of predation risk on egg steroid profiles across multiple populations of threespine stickleback
Ryan Paitz, Katie McGhee, John Baker, Susan Foster, Alison Bell.
Scientific Reports, (2020)
In ovo metabolism of estradiol to estrone sulfate in chicken eggs: Implications for how yolk estradiol influences embryonic development
Ryan Paitz, Rachel Angles, Erin Cagney.
General and Comparative Endocrinology, 287, (2020)
Inter-individual variation in anti-parasitic egg rejection behavior: a test of the maternal investment hypothesis.
Hauber Mark, Abolins-Abols, Catrina Kim, Ryan Paitz.
(2020)
Reply to Monsinjon, Girondot, and Guillon
Amanda Carter, Ryan Paitz, Rachel Bowden.
(2020)
In ovo metabolism and yolk glucocorticoid concentration interact to influence embryonic glucocorticoid exposure patterns
Brian Vassallo, Hanna Litwa, Mark Haussmann, Ryan Paitz.
General and Comparative Endocrinology, (2019)
In ovo metabolism of progesterone to 5β-pregnanedione in chicken eggs: Implications for how yolk progesterone influences embryonic development
Ryan Paitz, Erin Cagney.
General and Comparative Endocrinology, (2019)
Is there an oxidative cost of acute stress? Characterization, implication of glucocorticoids and modulation by prior stress experience
Ariana Majer, Vince Fasanello, Kailey Tindle, Brian Frenz, Alexis Zuir, Chelsea Fischer, Kelsey Fletcher, Olivia Seecof, Sarah Gronsky, Brian Vassallo, Wendy Reed, Ryan Paitz, Antoine Stier, Mark Haussmann.
Proceedings of the Royal Society B, (2019)
Quantification of 27 yolk steroid hormones in seven shrubland bird species: interspecific patterns of hormone deposition and links to life history, development, and predation risk
Loren Merrill, Scott Chiavacci, Ryan Paitz.
(2019)
Red-eared slider hatchlings (Trachemys scripta) show a seasonal shift in behavioral types
Haley Nichols, Amanda W Carter, Ryan Paitz, Rachel Michelle Bowden.
Journal of Experimental Zoology, 331, 485-493, (2019)
The devil is in the details: identifying aspects of temperature variation that underlie sex determination in species with TSD
Amanda W Carter, Ryan Paitz, Rachel Michelle Bowden.
Integrative and Comparative Biology, 59, 1081-1088, (2019)
Evidence of embryonic regulation of maternally derived yolk corticosterone
Amanda W Carter, Rachel Michelle Bowden, Ryan Paitz.
Journal of Experimental Biology, 221, jeb 182600, (2018)
Short heatwaves during fluctuating incubation regimes produce females under temperaturedependent sex determination with implications for sex ratios in nature
Amanda Carter, Ben Sadd, Tracy Tuberville, Ryan Paitz, Rachel Bowden.
Scientific Reports, (2018)
Temperature fluctuations and maternal estrogens as critical factors for understanding temperature-dependent sex determination in nature
Rachel Michelle Bowden, Ryan Paitz.
Journal of Experimental Zoology, 329, 177-184, (2018)
Characterizing the distribution of steroid sulfatase during embryonic development: when and where might metabolites of maternal steroids be reactivated?
Ryan Paitz, Kristin Duffield, Rachel Michelle Bowden.
Journal of Experimental Biology, 220 (24), 4567-4570, (2017)
Rates of parasitism, but not allocation of egg resources, vary among and within hosts of a generalist avian brood parasite
Loren Merrill, Scott Chiavacci, Ryan Paitz, TJ Benson.
Oecologia, 184 (2), 399-410, (2017)
Seasonal shifts in sex ratios are mediated by maternal effects and fluctuating incubation temperatures
Amanda Carter, Rachel Bowden, Ryan Paitz.
Functional Ecology, 31, 876-884, (2017)
Testing the predictions of coping styles theory in threespined sticklebacks
Miles K. Bensky, Laura Pereira, Ryan Paitz, Alison M. Bell.
Behavioural processes, 136, 1-10, (2017), 10.1016/j.beproc.2016.12.011
Turtle hatchlngs show behavioral types that are robust to environmental manipulations during development
Amanda W Carter, Ryan Paitz, Katie E McGhee, Rachel Michelle Bowden.
Physiology and Behavior, 155, 46-55, (2016)
Changes in the concentrations of four maternal steroids during embryonic development in the threespined stickleback (Gasterosteus aculeatus).
Ryan Paitz, B C Mommer, E Suhr, A M Bell.
Journal of experimental zoology. Part A, Ecological genetics and physiology, 323 (7), 422-9, (2015), 10.1002/jez.1937
The in ovo conversion of oestrone to oestrone sulfate is rapid and subject to inhibition by Bisphenol A.
Ryan Paitz, Rachel Michelle Bowden.
Biology letters, 11 (4), 20140946, (2015), 10.1098/rsbl.2014.0946
Constancy in an inconstant world: moving beyond constant temperatures in the study of reptilian incubation.
Rachel Michelle Bowden, A W Carter, Ryan Paitz.
Integrative and comparative biology, 54 (5), 830-40, (2014), 10.1093/icb/icu016
Glucocorticoid metabolism in the in ovo environment modulates exposure to maternal corticosterone in Japanese quail embryos (Coturnix japonica).
B G Vassallo, Ryan Paitz, V J Fasanello, M F Haussmann.
Biology letters, 10 (11), 20140502, (2014), 10.1098/rsbl.2014.0502
Humoral immune responses are maintained with age in a long-lived ectotherm, the red-eared slider turtle.
L M Zimmerman, S G Clairardin, Ryan Paitz, J W Hicke, K A LaMagdeleine, Laura Anne Vogel, Rachel Michelle Bowden.
The Journal of experimental biology, 216 (Pt 4), 633-40, (2013), 10.1242/jeb.078832
Sulfonation of maternal steroids is a conserved metabolic pathway in vertebrates.
Ryan Paitz, Rachel Michelle Bowden.
Integrative and comparative biology, 53 (6), 895-901, (2013), 10.1093/icb/ict027
The western painted turtle genome, a model for the evolution of extreme physiological adaptations in a slowly evolving lineage.
H B Shaffer, P Minx, D E Warren, A M Shedlock, R C Thomson, N Valenzuela, J Abramyan, C T Amemiya, D Badenhorst, K K Biggar, Glen Borchert, C W Botka, Rachel Michelle Bowden, E L Braun, A M Bronikowski, B G Bruneau, L T Buck, B Capel, T A Castoe, M Czerwinski, K D Delehaunty, S V Edwards, C C Fronick, M K Fujita, L Fulton, T A Graves, R E Green, W Haerty, R Hariharan, O Hernandez, L W Hillier, A K Holloway, D Janes, F J Janzen, C Kandoth, L Kong, A P de Koning, Y Li, R Literman, S E McGaugh, L Mork, M O'Laughlin, Ryan Paitz, D D Pollock, C P Ponting, S Radhakrishnan, B J Raney, J M Richman, J St John, T Schwartz, A Sethuraman, P Q Spinks, K B Storey, N Thane, T Vinar, L M Zimmerman, W C Warren, E R Mardis, R K Wilson.
Genome biology, 14 (3), R28, (2013), 10.1186/gb-2013-14-3-r28
Characterizing the metabolism and movement of yolk estradiol during embryonic development in the red-eared slider (Trachemys scripta).
Ryan Paitz, A R Sawa, Rachel Michelle Bowden.
General and comparative endocrinology, 176 (3), 507-12, (2012), 10.1016/j.ygcen.2011.10.009
No evidence that estrogens affect the development of the immune system in the red-eared slider turtle, Trachemys scripta.
L M Zimmerman, Ryan Paitz, S G Clairardin, Laura Anne Vogel, Rachel Michelle Bowden.
Hormones and behavior, 62 (3), 331-6, (2012), 10.1016/j.yhbeh.2012.04.009
The decline in yolk progesterone concentrations during incubation is dependent on embryonic development in the European starling.
Ryan Paitz, Joseph M Casto.
General and comparative endocrinology, 176 (3), 415-9, (2012), 10.1016/j.ygcen.2011.12.014
Biological activity of oestradiol sulphate in an oviparous amniote: implications for maternal steroid effects.
Ryan Paitz, Rachel Michelle Bowden.
Proceedings. Biological sciences / The Royal Society, 278 (1714), 2005-10, (2011), 10.1098/rspb.2010.2128
Embryonic modulation of maternal steroids in European starlings (Sturnus vulgaris).
Ryan Paitz, Rachel Michelle Bowden, Joseph M Casto.
Proceedings. Biological sciences / The Royal Society, 278 (1702), 99-106, (2011), 10.1098/rspb.2010.0813
The ontogeny of postmaturation resource allocation in turtles.
Rachel Michelle Bowden, Ryan Paitz, F J Janzen.
Physiological and biochemical zoology : PBZ, 84 (2), 204-11, (2011), 10.1086/658292
Progesterone metabolites, "xenobiotic-sensing" nuclear receptors, and the metabolism of maternal steroids.
Ryan Paitz, Rachel Michelle Bowden.
General and comparative endocrinology, 166 (2), 217-21, (2010), 10.1016/j.ygcen.2009.11.011
Temperature, phenotype, and the evolution of temperature-dependent sex determination: how do natural incubations compare to laboratory incubations?
Ryan Paitz, A C Gould, M C Holgersson, Rachel Michelle Bowden.
Journal of experimental zoology. Part B, Molecular and developmental evolution, 314 (1), 86-93, (2010), 10.1002/jez.b.21312
Variation in the seasonal patterns of innate and adaptive immunity in the red-eared slider (Trachemys scripta).
L M Zimmerman, Ryan Paitz, Laura Anne Vogel, Rachel Michelle Bowden.
The Journal of experimental biology, 213 (Pt 9), 1477-83, (2010), 10.1242/jeb.037770
A modified yolk biopsy technique improves survivorship of turtle eggs.
Rachel Michelle Bowden, L Smithee, Ryan Paitz.
Physiological and biochemical zoology : PBZ, 82 (5), 611-15, (2009), 10.1086/596579
Living at extremes: development at the edges of viable temperature under constant and fluctuating conditions.
H L Les, Ryan Paitz, Rachel Michelle Bowden.
Physiological and biochemical zoology : PBZ, 82 (2), 105-12, (2009), 10.1086/590263
Rapid decline in the concentrations of three yolk steroids during development: is it embryonic regulation?
Ryan Paitz, Rachel Michelle Bowden.
General and comparative endocrinology, 161 (2), 246-51, (2009), 10.1016/j.ygcen.2009.01.018
A proposed role of the sulfotransferase/sulfatase pathway in modulating yolk steroid effects.
Ryan Paitz, Rachel Michelle Bowden.
Integrative and comparative biology, 48 (3), 419-27, (2008), 10.1093/icb/icn034
Experience pays: offspring survival increases with female age.
Ryan Paitz, H K Harms, Rachel Michelle Bowden, F J Janzen.
Biology letters, 3 (1), 44-6, (2007)
Experimental test of the effects of fluctuating incubation temperatures on hatchling phenotype.
H L Les, Ryan Paitz, Rachel Michelle Bowden.
Journal of experimental zoology. Part A, Ecological genetics and physiology, 307 (5), 274-80, (2007), 10.1002/jez.374
Age and season impact resource allocation to eggs and nesting behavior in the painted turtle.
H K Harms, Ryan Paitz, Rachel Michelle Bowden, F J Janzen.
Physiological and biochemical zoology : PBZ, 78 (6), 996-1004, (2005), 10.1086/432920
Female red-winged blackbirds (Agelaius phoeniceus) do not alter nest site selection, maternal programming, or hormone-mediated maternal effects in response to perceived nest predation or brood parasitism risk
Janice Enos, Rebecca Ducay, Ryan Paitz, Michael Ward, Mark Hauber.
General and Comparative Endocrinology
Presentations
Developmental endocrinology before gonads: Do extraembryonic membranes initiate sex differences?
Ryan Paitz, Mark Haussmann, Ken Fields.
Society of Integrative and Comparative Biology, Atlanta, GA, January, 2025
Effects of early heat exposure on heat-shock protein responsiveness in turtle embryos
Clinton Warren, Madison Wilken, Ryan Paitz, Rachel Bowden.
Society of Integrative and Comparative Biology, Atlanta, GA, January, 2025
The role individual social experiences play in shaping maternal hormone allocation
Jasmeen Kaur, Ryan Paitz, Golnaz Habibi, Eli Bridge, Alexandra Bentz.
Society of Integrative and Comparative Biology, Atlanta, GA, January, 2025
Yolk estrogens and primordial germ cells in a species with temperature-dependent sex determination
Madison Wilken, Clinton Warren, Rachel Bowden, Ryan Paitz.
Society of Integrative and Comparative Biology, Atlanta, GA, January, 2025
Yolk steroids but not antibodies vary with prior maternal disease exposure and diet.
Sarah DuRant, Erin Sauer, Ashley Love, Ryan Paitz.
Society of Integrative and Comparative Biology, Atlanta, GA, January, 2025
Avian embryos concurrently metabolize and respond to yolk corticosterone
Emily Harders, Ryan Paitz.
Society of Integrative and Comparative Biology Meeting, Austin, TX, January 4, 2023
How to pick a lane: Exploring TSD mechanisms when embryos are exposed to male- and female-producing temperatures during development
Tony Breitenbach, Ryan Paitz, Rachel Bowden.
Society of Integrative and Comparative Biology, Online, January, 2022
Rapid response of intron retention in Kdm6b may mediate the temperature response of testis-determining genes in the red-eared slider turtle
Rosario Marroquin Flores, Rachel Bowden, Ryan Paitz.
Society of Integrative and Comparative Biology, Phoenix, AZ, January, 2022
Do thermal fluctuations affect gene expression differently than constant conditions?
Tony Breitenbach, , Ryan Paitz.
Society of Integrative and Comparative Biology, Online, January, 2021
Heat Wave Timing, Continuity, and Length Affect Temperature-dependent Sex Determination in a Freshwater Turtle
Tony Breitenbach, Amanda Carter, Ryan Paitz, Rachel Michelle Bowden.
Society of Integrative and Comparative Biology, Tampa, FL, January, 2019
Do vertebrate eggs contain maternally derived steroidogenic enzymes that are susceptible to inhibition by endocrine disruptors?
Ryan Paitz, Rachel Michelle Bowden.
Society for Integrative and Comparative Biology, West Palm Beach, FL, January 3, 2015
Does sex vary with season via maternal estrogens when temperatures fluctuate?
Amanda W Carter, Rachel Michelle Bowden, Ryan Paitz.
Society for Integrative and Comparative Biology, West Palm Beach, FL, January 3, 2015