backResearcher Profile

John H. Youson

Job Title: Chair, Division of Life Sciences, and Professor of Zoology
Employer: University of Toronto
Place of Birth: Victoria, BC, Canada
Public School attended: Margaret Jenkins
High School attended: Oak Bay High School
Further Education: University of Victoria (B.Sc.), McGill University (M.Sc.), University of Western Ontario (Ph.D.).
Geographic focus of research: Great Lakes watershed, Western Canada, formerly Eastern Canada, U.S. streams within the Great Lakes watershed

Brief synopsis of current research:
Two major areas of reseach.
1. The hormonal and environmental cues of lamprey metamorphosis. This topic involves physiological, morphological and molecular comparisons of metamorphosis in the sea lamprey and nonparasitic species of lamprey. Objective: discover the factors which are driving the parasitic and nonparasitic adult life histories.
2. The phylogenetic development of endocrine glands in fishes of ancient lineage. Morphological and molecular studies of jawless and ancient ray-finned fishes. Objective: to discover the time of divergence in the structure and function of some endocrine glands and their hormones.

Mailing address:
Chair, Division of Life Sciences, University of Toronto at Scarborough, Scarborough, Ontario M1C 1A4 Canada
Phone: (416)287-7397; Fax: (416)287-7676


Recent Publications:

Youson, J. H. 1997. Is lamprey metamorphosis regulated by thyroid hormones? From the Symposium on “Developmental Endocrinology of Nonmammalian Vertebrates”, Annual Meeting of the SICB, Dec. 26-31., 1996, Albuquerque, NM. Amer. Zoologist 37: 439-460.

Youson, J. H. and A. A. Al-Mahrouki. 1999. Ontogenetic and phylogenetic development of the endocrine pancreas (islet organ) in fishes. Gen. Comp. Endocrinol. 116: 409-421

Youson, J. H. 1999. Lampreys and biomedical research. (Spotlight article). Biological Sciences Review 11: 25-28.

Holmes, J.A., H. Chu, S. Khanam, R. G. Manzon and, J. H. Youson. 1999. Spontaneous and induced metamorphosis in the American brook lamprey, Lampetra appendix. Can. J. Zool.77: 959-971.

Manzon, R.G., and J. H. Youson. 1999. Temperature and KClO4-induced metamorphosis in the sea lamprey (Petromyzon marinus). Comp. Biochem. Physiol.124C: 253-257. Featured article.

Fish are good model systems for studying basic biological questions but at the same time I feel that the work has a direct application to preserving an important natural resource, for example, the work that I do with sea lampreys of the Great Lakes. There is also excellent potential for some of the results in the basic science to lead to discoveries which are directly applicable to humans. For instance, there are now several hormones being applied to humans which were first discovered in fish.