About

Dr. Tom E. Porter is a Distinguished University Professor in the College of Agriculture and Natural Resources at the University of Maryland. His research focuses on the neuroendocrine regulation of growth and reproduction, cellular differentiation of the anterior pituitary gland during embryonic development, and the global analysis of gene expression in the neuroendocrine system. Dr. Porter has made significant contributions to the understanding of endocrine mechanisms in avian and animal physiology. He has authored over 113 refereed scientific papers, 23 book chapters or reviews, and 167 abstracts, with his publications cited more than 3,800 times. His work includes the submission of 35,452 nucleotide sequences to GenBank and five cDNA microarray platform submissions to GEO. Dr. Porter has received numerous awards, including the 2023 Distinguished University Professor title, the College of Agriculture and Natural Resources Faculty Research Award, and the Poultry Science Association Fellow designation. He has also served as the President and Vice President of the Poultry Science Association and as Editor-in-Chief for prominent scientific journals. His research has been supported by $29.6 million in federal grants, and he has mentored multiple postdoctoral fellows and graduate students.

Research topics

• Biology
• Genetics
• Zoology
• Computational biology
• Nanotechnology
• Bioinformatics
• Ecology
• Internal medicine
• Chemistry
• Food science
• Medicine
• Endocrinology
• Biochemistry
• Materials science
• Animal science

Selected publications

• Curcumin- and capsaicin-loaded nanoemulsions improve oxidative stress, intestinal morphology, and feed efficiency in slow-growing Korat chickens under high stocking density

  Poultry Science · 2026-01-24 · 2 citations

  articleOpen access

  This study investigated the effects of curcumin (CUR)- and capsaicin (CAP)- loaded nanoemulsion on blood biochemical changes, oxidative status, jejunal morphology, inflammatory parameters, and performance of slow-growing Korat chickens (KRC) raised under high stocking density (HSD). A total of 480 male KRC (21 d of age) were allocated into four groups: (1) HSD without supplementation, (2) normal stocking density (NSD) without supplementation, (3) HSD supplemented with CUR and CAP in powdered form (P-CUR+CAP), and (4) HSD supplemented with CUR- and CAP-loaded nanoemulsions (NE-CUR+CAP). Chickens receiving NE-CUR+CAP showed no adverse changes in liver or kidney function compared with other groups. The heterophil-to-lymphocyte ratio was reduced in NE-CUR+CAP group relative to HSD group and was comparable with NSD and P-CUR+CAP groups (P < 0.05). NE-CUR+CAP also lowered levels of TBA in the liver and jejunum while enhancing hepatic superoxide dismutase activity compared with HSD group (P < 0.05). Villus height, villus height-to-crypt depth ratio, anti-inflammatory response, and cecal Lactobacillus counts were improved, whereas crypt depth and cecal Escherichia coli were reduced in the NE-CUR+CAP group (P < 0.05). Although feed intake, BW, and body weight gain were not affected, the feed conversion ratio was significantly lower in NE-CUR+CAP compared with HSD group (P < 0.05). In conclusion, NE-CUR+CAP mitigated oxidative stress and inflammation, improved intestinal health, and enhanced feed efficiency in slow-growing chickens raised under HSD.

  PublisherDOI

• RNA-seq reveals differentially expressed genes involved in catecholamine synthesis and metabolism in the hypothalamus affecting divergent residual feed intake in slow-growing Korat chickens

  Poultry Science · 2026-05-01

  articleOpen access
  PublisherDOI

• Pituitary-Targeted Knockout of Glucocorticoid Receptors Disrupts Growth Hormone Expression During Embryonic Development

  Endocrinology · 2025-07-08 · 2 citations

  articleOpen accessSenior author

  Numerous studies have implicated glucocorticoids in the regulation of somatotroph differentiation. However, few studies have investigated a requirement for glucocorticoid receptors (GR) in this process. We hypothesized that GR is essential for the normal ontogeny of pituitary growth hormone (GH) during mouse embryonic development. Anterior pituitary cells were isolated from e12.5 to e13.5 mice and e11 chickens and cultured with or without corticosterone (CORT) in the absence or presence of ZK98299, a GR-specific antagonist. CORT induced GH mRNA expression in pituitary cells from both species, and this response was blocked by inclusion of the GR antagonist. Mouse embryos with pituitary-targeted knockout of GR were generated utilizing the cre-LoxP Recombinase system under control of the pituitary-specific alpha-glycoprotein subunit (αGSU) promoter. All cre-positive GR(-/-) embryos died at birth. Therefore, anterior pituitary, brain, heart, liver, and muscle tissues, were collected on embryonic days 17.5/18.5 for RNA isolation and RT-qPCR analysis. Cre mRNA expression was only found in the pituitary, and GR mRNA levels were significantly decreased in the pituitaries of GR(-/-) embryos. GH mRNA was significantly decreased in pituitary-targeted GR(-/-) knockout embryos in comparison to wild-type GR(+/+) embryos. Significant differences in expression of other pituitary hormones in GR(-/-) embryos were not observed, indicating that the effect of pituitary-targeted knockout of GR was restricted to disruption of GH gene expression. To our knowledge, this is the first report that homozygous GR knockout in the anterior pituitary gland in mice suppresses embryonic GH expression, confirming an essential role for GR signaling in the normal ontogeny of somatotrophs.

  PublisherOA PDFDOI

• ScRNAseq Analysis of Chicken Embryonic Pituitary Reveals Cell Heterogeneity and a Cell Type Coexpressing <i>Gh</i> and <i>Pomc</i>

  Endocrinology · 2025-12-05

  articleOpen accessSenior author

  Gene expression profiles and the heterogeneity among hormone-producing pituitary cells remain poorly characterized in most vertebrates, especially in chicken embryos. Using single-cell RNA sequencing, the transcriptomes of 4346 basal and 10 835 corticosterone (CORT)-treated embryonic day 11 chicken pituitary cells were sequenced. Classical endocrine cell clusters were identified, and some were shown to express previously unreported marker genes. A cluster of uncommitted cells was identified that expressed markers for multiple endocrine cell types, with ∼30% coexpressing Gh and Pomc mRNA. We named this population of cells the cortico-somatotrophs. The existence of cortico-somatotrophs were confirmed at both the mRNA and protein level. We further characterized the corticosomatotrophs by utilizing the known effect of CORT to increase somatotroph abundance. Identification of cortico-somatotrophs challenges the prevailing view that corticotrophs and somatotrophs develop from distinct cell lineages.

  PublisherOA PDFDOI

• Effects of commercial genetic selection on gene expression in the developing neuroendocrine system of broilers

  Poultry Science · 2025-12-23 · 1 citations

  articleOpen accessSenior author

  Selective breeding of broilers has significantly improved growth rates, muscle mass, and feed efficiency and may have influenced the neuroendocrine systems that regulate growth and metabolism. Embryonic development represents one-third of the life of a modern broiler. To assess the impact of genetic selection on the neuroendocrine regulation of growth and metabolism during embryonic development, we examined mRNA expression of growth-related genes in the hypothalamus and anterior pituitary of two chicken breeds: the modern Ross 708 broiler and the Athens Canadian Random Bred (ACRB) line, the oldest established strain for meat-type chickens. Hypothalami and pituitary glands were dissected from embryos at days 10, 12, 14, 16, and 18 of incubation (n = 4 for each combination of breed, age, and gender). Levels of mRNA for each target gene were quantified using reverse transcription-quantitative PCR. In the adrenocorticotropic axis, pituitary corticotropin-releasing hormone receptor 1 mRNA levels were influenced by the interaction of breed, age, and gender (P < 0.05). In the thyrotropic axis, pituitary thyroid-stimulating hormone β-subunit mRNA levels were affected by the interaction of breed, age, and gender (P < 0.05). In the somatotropic axis, mRNA levels of hypothalamic somatostatin were higher in ACRB than Ross, whereas overall pituitary growth hormone mRNA levels were greater in Ross than ACRB (P < 0.05). Pituitary growth hormone-releasing hormone receptor 2 and pituitary adenylate cyclase-activating polypeptide receptor 1 were influenced by the interaction between breed and age (P < 0.05). In the gonadotropic axis, hypothalamic gonadotropin-releasing hormone 1 and gonadotropin-inhibiting hormone were influenced by breed, age, and gender, while mRNA levels of pituitary follicle-stimulating hormone β-subunit were affected by the interaction between breed and age (P < 0.05). Hypothalamic agouti-related peptide, neuropeptide Y, and proopiomelanocortin mRNA levels were higher in ACRB than Ross in females (P < 0.05). These findings indicate that genetic selection of broilers has altered the adrenocorticotropic, somatotropic, thyrotropic, and gonadotropic axes, as well as hypothalamic control of appetite and metabolism during embryonic development.

  PublisherDOI

• Transcriptome profiling of the pituitary gland reveals candidate genes for divergent feed efficiency in slow-growing chickens

  Italian Journal of Animal Science · 2025-12-08 · 1 citations

  articleOpen access

  Feed efficiency (FE) is a critical trait in poultry production, including slow-growing chicken breeds such as the Korat (KR) chicken. In this study, transcriptome profiling of the pituitary gland was performed to investigate the molecular mechanisms underlying FE differences between low residual feed intake (LRFI) and high residual feed intake (HRFI) groups. A total of 22 differentially expressed genes (DEGs) were identified, with three upregulated and 19 downregulated in the LRFI group. Among them, thyrotropin-releasing hormone receptor 3 (<i>TRHR3</i>), a gene associated with metabolic regulation in the pituitary, was significantly downregulated in the LRFI group, while elevated plasma levels of tetraiodothyronine (T₄). Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis on gene sets revealed that better FE in KR chickens is related to linoleic and alpha-linolenic acid metabolism, as well as steroid hormone biosynthesis, highlighting their roles in thyroid hormone secretion, muscle development, and lipid metabolism. Unravelling pathways and key genes which are involved in variation of RFI in KR chickens will be useful to search for candidate DNA markers in the parental lines in order to improve FE of the KR chicken. 22 differentially expressed genes in the pituitary gland were linked to feed efficiency in chickens.KEGG pathway analysis in chickens with better feed efficiency showed changes in pathways related to thyroid hormone secretion, muscle growth, and fat metabolism.Pituitary transcriptome profiling reveals key molecular mechanisms behind feed efficiency in chickens. 22 differentially expressed genes in the pituitary gland were linked to feed efficiency in chickens. KEGG pathway analysis in chickens with better feed efficiency showed changes in pathways related to thyroid hormone secretion, muscle growth, and fat metabolism. Pituitary transcriptome profiling reveals key molecular mechanisms behind feed efficiency in chickens.

  PublisherDOI

• Effect of early-life thermal conditioning on mRNA expression in tissues under heat stress and non-heat stress conditions in broiler chickens

  Poultry Science · 2025-12-11

  articleOpen accessSenior author

  Heat stress (HS) adversely impacts broiler health, productivity, and welfare, especially in market-age chickens. This study investigated the effects of early-life thermal conditioning (TC) on the expression of genes related to stress responses, thermoregulation, and metabolism in various tissues, including the hypothalamus, anterior pituitary gland, thyroid gland, adrenal gland, adipose tissue, liver, heart, breast, and thigh with and without HS in broilers. Male Ross 708 chicks were subjected to TC at 37.8°C or non-thermal conditioning (NTC) at 33°C for 24 h on d 3 after hatch. On d 31, birds from both groups were exposed to either HS (35°C) or non-heat stress (NHS; 22°C) conditions for 8 h, with collection of tissue samples for reverse transcription-quantitative PCR (RT-qPCR) analysis beginning after 4 h of HS. TC had no effect on production parameters, including BW, FI, BWG, and F/G. Key findings indicated that early-life TC significantly altered hypothalamic and pituitary expression of genes associated with stress adaptation under HS. Early-life TC increased hypothalamic neuropeptide Y expression under heat stress, which may contribute to improved stress adaptation. Additionally, TC resulted in higher heat shock protein 90 expression in thigh muscle and reduced heat shock protein 70 expression in breast muscle, highlighting tissue-specific adaptive responses. Interestingly, heart tissue from TC birds exhibited increased melanocortin 2 receptor mRNA levels under HS, suggesting improved cardiovascular resilience. Other tissues, including the adrenal gland, thyroid, liver, and adipose tissue, showed minimal gene expression changes in response to TC, implying selective tissue conditioning. These results suggest that early-life TC primes specific tissues to enhance HS resilience by modulating stress-response pathways, which may benefit poultry production in high-temperature environments. This research underscores the potential of TC as a management strategy for improving broiler response to HS challenges and circumventing the negative repercussions of HS on broiler health and performance.

  PublisherDOI

• Global gene expression analysis of the turkey hen hypothalamo-pituitary-gonadal axis during the preovulatory hormonal surge

  Poultry Science · 2023-02-02 · 7 citations

  articleOpen accessSenior author

  The preovulatory hormonal surge (PS) consists of elevated circulating luteinizing hormone (LH) and progesterone levels and serves as the primary trigger for ovarian follicle ovulation. Increased LH and progesterone, produced by the pituitary and the granulosa layer of the largest ovarian follicle (F1), respectively, result from hypothalamic stimulation and steroid hormone feedback on the hypothalamo-pituitary-gonadal (HPG) axis. The hypothalamus, pituitary, F1 granulosa, and granulosa layer of the fifth largest follicle (F5) were isolated from converter turkey hens outside and during the PS and subjected to RNA sequencing (n = 6 per tissue). Differentially expressed genes were subjected to functional annotation using DAVID and IPA. A total of 12, 250, 1235, and 1938 DEGs were identified in the hypothalamus, pituitary, F1 granulosa, and F5 granulosa respectively (q<0.05, |fold change|>1.5, FPKM>1). Gene Ontology (GO) analysis revealed key roles for metabolic processes, steroid hormone feedback, and hypoxia induced gene expression changes. Upstream analysis identified a total of 4, 42, 126, and 393 potential regulators of downstream gene expression in the hypothalamus, pituitary, F1G, and F5G respectively, with a total of 63 potential regulators exhibiting differential expression between samples collected outside and during the PS (|z-score|>2). The results from this study serve to increase the current knowledge base surrounding the regulation of the PS in turkey hens. Through GO analysis, downstream processes and functions associated with the PS were linked to identified DEGs, and through upstream analysis, potential regulators of DEGs were identified for further analysis. Linking upstream regulators to the downstream PS and ovulation events could allow for genetic selection or manipulation of ovulation frequencies in turkey hens.

  PublisherDOI

• Editorial: The legacy of mentorship

  World s Poultry Science Journal · 2022-10-02

  editorialOpen access1st authorCorresponding
  PublisherOA PDFDOI

• The Effect of Commercial Genetic Selection on Somatotropic Gene Expression in Broilers: A Potential Role for Insulin-Like Growth Factor Binding Proteins in Regulating Broiler Growth and Body Composition

  Frontiers in Physiology · 2022-06-27 · 25 citations

  articleOpen access

  The somatotropic axis influences growth and metabolism, and many of its effects are a result of insulin-like growth factor (IGF) signaling modulated by IGF-binding proteins (IGFBPs). Modern commercial meat-type (broiler) chickens exhibit rapid and efficient growth and muscle accretion resulting from decades of commercial genetic selection, and it is not known how alterations in the IGF system has contributed to these improvements. To determine the effect of commercial genetic selection on somatotropic axis activity, two experiments were conducted comparing legacy Athens Canadian Random Bred and modern Ross 308 male broiler lines, one between embryonic days 10 and 18 and the second between post-hatch days 10 and 40. Gene expression was evaluated in liver and breast muscle ( pectoralis major ) and circulating hormone concentrations were measured post-hatch. During embryogenesis, no differences in IGF expression were found that corresponded with difference in body weight between the lines beginning on embryonic day 14. While hepatic IGF expression and circulating IGF did not differ between the lines post-hatch, expression of both IGF1 and IGF2 mRNA was greater in breast muscle of modern broilers. Differential expression of select IGFBPs suggests their action is dependent on developmental stage and site of production. Hepatic IGFBP1 appears to promote embryonic growth but inhibit post-hatch growth at select ages. Results suggest that local IGFBP4 may prevent breast muscle growth during embryogenesis but promote it after hatch. Post-hatch, IGFBP2 produced in liver appears to inhibit body growth, but IGFBP2 produced locally in breast muscle facilitates development of this tissue. The opposite appears true for IGFBP3, which seems to promote overall body growth when produced in liver and restrict breast muscle growth when produced locally. Results presented here suggest that paracrine IGF signaling in breast muscle may contribute to overall growth and muscle accretion in chickens, and that this activity is regulated in developmentally distinct and tissue-specific contexts through combinatorial action of IGFBPs.

  PublisherOA PDFDOI

Recent grants

• NIH Grant F32DK008332

  NIH · $79k

Frequent coauthors

• Larry A. Cogburn

  71 shared

• Jean Simon

  Indian Council of Forestry Research and Education

  60 shared

• Michel Jacques M.J. Duclos

  52 shared

• Laura E. Ellestad

  University of Georgia

  36 shared

• Samuel E. Aggrey

  University of Georgia

  32 shared

• Élisabeth Le Bihan-Duval

  Biologie des Oiseaux et Aviculture

  30 shared

• Kristen Brady

  27 shared

• Hsiao‐Ching Liu

  North Carolina State University

  26 shared

Education

• Ph.D, Animal Science

  University of Minnesota

  1988

Awards & honors

• 2023 Named Distinguished University Professor
• 2023 College of Agriculture and Natural Resources Faculty Re…
• 2022 Elected President of the Poultry Science Association
• 2021 Elected Vice President of the Poultry Science Associati…
• 2021 Named Editor-in-Chief for World’s Poultry Science Journ…