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Announcement of the ASTS Satellite Conference/Mixer at 2014 SOT Annual Meeting

Workshops/ConferencesDear Colleagues,
I'm writing to officially invite you to the 53rd Annual Meeting of the Society of Toxicology (SOT) in Phoenix, Arizona, USA, March 23-27, 2014. This year's activity will also include an evening reception for all current and potential ASTS members and friends as well as sympathizers. Highlights of the evening will include a presentation by Dr. Aina Adeogun of the University of Ibadan, Nigeria. Please spread the word and mark your calendars!

Date: Tuesday, March 25, 2014 6:30 PM – 8:30 PM

Sheraton Phoenix Downtown
340 N 3rd St
Phoenix, AZ 85004

Room: Paradise Valley

Presentation: Prof. Aina Adeogun, University of Ibadan, Ibadan, Nigeria: “Endocrine disrupting chemicals in the African Environment: Status and Challenges”

Abstract: There is growing concern worldwide on the effects of endocrine disrupting chemicals (EDC's) on aquatic organisms and wildlife. Aquatic organisms are particularly vulnerable to exposure because their ecosystems act as sinks for a wide variety of pollutants and this has prompted the development of molecular assays to monitor environmental impacts. In Africa however, the mechanistic approach to elucidate such effects on the reproductive success of aquatic organisms is poorly understood in most states.
Vitellogenin (Vtg) expression, gonad histological alterations are amongst specific biomarkers for monitoring the effects of EDC's in fish. Therefore, characterizing Vtg expression and gonad alterations is of particular interest in a region where effluents from anthropogenic sources are discharged largely untreated into aquatic the environment. Vtg expression in male, female and juvenile fish with gonad alterations were evaluated in wild type Cichlids (Oreochromis niloticus, Tilapia zillii, Tilapia guineensis, Sarotherodon galilaeus, Sarotherodon melanotheron, Hemichromis fasciatus and Chromidotilapia guentheri) collected from two manmade lakes (Eleyele and Dandaru) and Ogun river (the largest and longest river in Southwest Nigeria) to assess endocrine disruption in fish. Vitellogenin-B2a (Vtg-B2a) gene expression in the liver of fish was detected using RT-qPCR. Histological examination of fish gonads revealed the development of primary oocytes alongside maturing spermatocytes in juvenile fish, primary oocytes within testicular tissue and empty seminiferous tubules in adult male fish. A significant expression of Vtg-B2a gene was recorded in all adult male fish (14.62±0.50), juvenile male (12.73±1.03) compared to adult female (5.42±0.74) fish indicating a disruption in steroidal hormone signaling pathway. Vtg expression correlated with morphological and pathological presentation of intersex in adult/juvenile male fish. The results of this study indicate that a potential hazard exist regarding reproductive impairment for Cichlids in the Nigerian aquatic environment and represent the first indication of the risk of endocrine disrupting chemicals for a commercially important food fish in Nigeria. As such Cichlids could be used as sentinel species for evaluating the presence of EDC's in the African aquatic environment because of their importance to the population structure of rivers and lakes.

Dr Aina O. Adeogun is a Senior Lecturer in Aquatic Toxicology, Hydrobiology and Fisheries Research Unit, Department of Zoology, University of Ibadan, Nigeria. Dr Adeogun received her B.Sc degree in Zoology from the University of Ibadan in 1992, M.Sc degree in Hydrobiology and Fisheries in 1994 and Ph.D in 2004. Her research interest is focused on elucidating the molecular mechanism by which endocrine disrupting chemicals interfere with the endocrine system in fish, with specific interest on Vitellogenin expression, steroidal hormone synthesis and intersex. In 2013, she received a grant from The World Academy of Science (TWAS) to investigate “Vitellogenin expression and Intersex in fish from Lagos Lagoon, Southwest Nigeria”. Her laboratory is currently addressing the biologically important unanswered question on altered endocrine function in wild-caught fish in Nigeria. She has approached the topic with creativity, vision and tenacity and her passion has resulted in the establishment of collaboration with senior colleagues at the Norwegian University of Science and Technology (NTNU), Trondheim, Norway.

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