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Elasmobranch Molecular Physiology and Endocrinology Research Laboratory (EMPERL)

Current Research in the Elasmobranch Molecular Physiology and Endocrinology Research Laboratory (EMPERL)

The Latest in Elasmobranch Molecular Physiology

Dr. Andrew Evans, principal investigator of EMPERL, drawing blood from a Southern stingray, Dasyatis americana.
Dr. Andrew Evans, principal investigator of EMPERL, drawing blood from a Southern stingray, Dasyatis americana.

The primary goal of the Elasmobranch Molecular Physiology and Endocrinology Research Laboratory (EMPERL) is to elucidate the molecular and physiological processes regulating stress and osmoregulation in the elasmobranch fishes (sharks, skates and stingrays).  In higher vertebrates, including the bony fishes (teleosts), steroid hormones called corticosteroids are the central mediators of stress and osmoregulation. The synthesis and regulation of the unique elasmobranch steroid hormone 1α-hydroxycorticosterone (1α-B) is the current focus of research at EMPERL.  

Dr. Andrew Evans joined GCRL in August of 2012 and is the principal investigator of EMPERL. Dr. Evans is an expert in the synthesis and effects of corticosteroid hormones, as well as vertebrate stress and osmoregulatory physiology.  After receiving his Ph.D. in Marine Science from the University of Texas at Austin, Dr. Evans conducted research examining the effects of early life stress on the adult stress response (including corticosteroid production) as a postdoctoral fellow at the National Institute for Child Health and Human Development at NIH. He served as Biologist on the Reference Sequence Database (RefSeq) Team at the National Center for Biotechnology Information before arriving at GCRL.

Faith Lambert with an Atlantic stingray, Dasyatis sabina, aboard the R/V Tom McIlwain.
Faith Lambert with an Atlantic stingray, Dasyatis sabina, aboard the R/V Tom McIlwain.

 

Faith Lambert is a M.S. student in EMPERL.  She graduated from Michigan Technological University in 2012 with a B.S. in Biochemistry and Molecular Biology and a second B.S. in Biological Sciences with a minor in Spanish.  For her thesis research, Faith is examining the glucocorticoid actions of 1α-B in the Atlantic stingray Dasyatis sabina.  Glucocorticoids are steroid hormones that regulate energy mobilization, such as the release of glucose and other oxidative fuels into the bloodstream.  Faith is investigating the potential for 1α-B to mediate similar processes in the elasmobranch fishes by determining the role that 1α-B plays in the cellular and organismal response of stingrays to stressors such as capture.


 

Beth Jones leading students through a titration reaction to measure dissolved oxygen in the Mississippi Sound.
Beth Jones leading students through a titration reaction to measure dissolved oxygen in the Mississippi Sound.

Beth Jones is the Educational Programs Manager at USM’s Marine Education Center and joined EMPERL as a Ph.D. student in 2013.  She holds a B.S. in Biological Science from East Tennessee State University and a M.S. in Marine Biology from the College of Charleston.  For her dissertation research, Beth is interested in the molecular mechanisms that regulate the hypothalamic-pituitary-interrenal (HPI) axis, or endocrine stress axis.  Because evidence suggests that 1α-B mediates both osmoregulation and the stress response, stress may significantly impact ion homeostasis in elasmobranchs, in addition to the deleterious effects of chronic stress on other critical endocrine systems including those regulating growth and reproduction.  Therefore it is likely that the activity of the HPI axis is tightly regulated in elasmobranchs, as it is in higher vertebrates, and determining the mechanisms for this regulation will be of significance to both elasmobranch conservation and comparative endocrinology.

Lizz Hunt extracting PCR bands from an agarose gel for subsequent cloning and sequencing.
Lizz Hunt extracting PCR bands from an agarose gel for subsequent cloning and sequencing.

 

 

During the summer of 2013, EMPERL hosted two summer interns.  Ethan Semrad, a recent graduate of Belhaven University, joined the laboratory as a Mississippi IDeA Network of Biomedical Research Excellence( MS INBRE) Research Scholar.  Ethan investigated methods for the culture of red blood cells (RBCs) from Atlantic sharpnose sharks. He also examined the expression of multiple genes in RBCs from Atlantic stingrays that are critical for cellular responses to stress and osmoregulatory hormones. 

Lizz Hunt (pictured at right), a graduate of Bowling Green State University, used molecular cloning methods to isolate new mRNA sequences from the Atlantic stingray that will be the focus of future research.  Lizz also examined the relative abundance of interrenal tissue in several species of sharks. With her strong background in animal husbandry and tank design, Lizz was instrumental in designing a new recirculating section of the EMPERL wetlab.


Members of the EMPERL. From left: Ethan Semrad, Lizz Hunt, Beth Jones, Faith Lambert, and Andy Evans.
Members of the EMPERL. From left: Ethan Semrad, Lizz Hunt, Beth Jones, Faith Lambert, and Andy Evans.