title: Triacylglyceride physiology in the short-finned eel, Anguilla australis--the effects of androgen.
abstract: The importance of androgens (especially 11-ketotestosterone) during previtellogenesis in eels is well established. In wild pubertal migrants, circulating 11-ketotestosterone levels correlate with a number of morphological and molecular changes. Here, we test the prediction that this correlation represents a causal relationship by artificially raising the levels of circulating 11-ketotestosterone in prepubertal nonmigratory female and pubertal, migratory male short-finned eels (Anguilla australis) using sustained-release hormone implants. In females, increases in hepatosomatic index and transcript copy numbers of hepatic apolipoprotein B and microsomal triacylglyceride transfer protein indicated increased repackaging of endogenously sourced triacylglycerides. These changes in liver measures were reflected in increased concentrations of serum triacylglycerides. However, despite a small increase in gonadosomatic index, ovarian lipoprotein receptor transcript abundances were not affected by 11-ketotestosterone. Interestingly, no such changes in hepatic gene expression were detected in a dose-response experiment using males. We propose that the androgens are inducing the observed changes in previtellogenic females, although it remains unclear to what extent these effects are direct or indirect.
authors.affiliation: Department of Zoology, University of Otago, Dunedin, New Zealand; and erin.damsteegt@otago.ac.nz.
authors.forename: Erin L
authors.identifier: http://orcid.org/0000-0001-8972-9313
authors.initials: EL
authors.lastname: Damsteegt
authors.affiliation: Department of Zoology, University of Otago, Dunedin, New Zealand; and.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ozaki
authors.affiliation: Department of Biochemistry, School of Medical Sciences, University of Otago, Dunedin, New Zealand.
authors.forename: Sally P A
authors.initials: SP
authors.lastname: McCormick
authors.affiliation: Department of Zoology, University of Otago, Dunedin, New Zealand; and.
authors.forename: P Mark
authors.initials: PM
authors.lastname: Lokman
mesh_terms: D000728:Androgens / Q000008:administration & dosage* / Q000097:blood; D000811:Anguilla / Q000097:blood*; D000818:Animals; D001055:Apolipoproteins B / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D004343:Drug Implants; D005260:Female; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D012737:Sex Factors; D012741:Sexual Maturation; D013739:Testosterone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D013997:Time Factors; D014280:Triglycerides / Q000097:blood*; D015854:Up-Regulation
chemical_list: D000728:Androgens; D001055:Apolipoproteins B; D002352:Carrier Proteins; D004343:Drug Implants; D029941:Fish Proteins; D012333:RNA, Messenger; D014280:Triglycerides; C106092:microsomal triglyceride transfer protein; D013739:Testosterone; D002784:Cholesterol; C003600:11-ketotestosterone
keywords: 11-ketotestosterone; androgen receptor; apolipoprotein b; apolipoprotein e; fatty acid transport protein; lipoprotein lipase; low-density lipoprotein receptor; microsomal triacylglyceride transfer protein; time-course experiment; triacylglyceride; very-low density lipoprotein; vitellogenin receptor