Novel patterns of gonadogenesis and steroidogenesis in sea lamprey (Petromyzon marinus)

dc.contributor.advisorBeamish, F.W.H.
dc.contributor.authorLowartz, Maria Serena
dc.date.accessioned2021-01-26T15:14:23Z
dc.date.available2021-01-26T15:14:23Z
dc.date.copyright1999
dc.degree.departmentDepartment of Zoologyen_US
dc.degree.grantorUniversity of Guelphen_US
dc.degree.nameMaster of Scienceen_US
dc.description.abstractI investigated gonadal differentiation and steroidogenesis of sea lamprey, ' Petromyzon marinus'. Gonadal biopsy of large larvae was used to compare initial and subsequent assessments of morphology. Sex reversals, oocyte atresia and testis development from atypical gonads suggest that gonadal sex remains labile throughout most of the larval phase. The resultant increase in male abundance supports the argument that high lamprey density produces male larvae. I observed production of a potentially feminizing hormone (15[alpha]-hydroxyprogesterone) by gonads of larvae and juveniles. No synthesis of potentially masculinizng androgens was apparent, nor did larval gonads appear to metabolize androgen substrate. However, environmental stimuli are associated with larval masculinization. Larval gonads, therefore, may differentiate into ovaries by default and into testes via an environmental influence which induces masculinizing steroid synthesis/metabolism. Larvae about to metamorphose and metamorphosing and transformed lampreys metabolized androgen precursor which produced steroids possibly used in gonad development and/or metamorphosis.en_US
dc.identifier.urihttps://hdl.handle.net/10214/24043
dc.language.isoen
dc.publisherUniversity of Guelphen_US
dc.rights.licenseAll items in the Atrium are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectgonadal differentiationen_US
dc.subjectsteroidogenesisen_US
dc.subjectsea lampreyen_US
dc.subjectPetromyzon marinusen_US
dc.subjectmorphologyen_US
dc.titleNovel patterns of gonadogenesis and steroidogenesis in sea lamprey (Petromyzon marinus)en_US
dc.typeThesisen_US

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