Developmental effects of embryonic exposure to toxaphene in the American alligator (Alligator mississippiensis)

Milnes, Matthew R.; Allen, Davina; Bryan, Teresa A.; Sedacca, Cassidy D; Guillette, Louis J.

doi:10.1016/j.cca.2004.05.006

Cited by 24 publications

(15 citation statements)

References 29 publications

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“…All work involving alligators was performed under the guidelines specified by the Institutional Animal Care and Use Committee at the University of Florida. Egg collection, handling, and incubation methods have been published previously in detail [2,12]. In brief, soon after oviposition, six complete clutches of eggs were collected from Lake Apopka and Lake Woodruff National Wildlife Refuge during June 2001.…”

Section: Experimental Design and Animal Carementioning

confidence: 99%

Influences of Sex, Incubation Temperature, and Environmental Quality on Gonadal Estrogen and Androgen Receptor Messenger RNA Expression in Juvenile American Alligators (Alligator mississippiensis)1

Moore

Milnes

Kohno

et al. 2010

Biology of Reproduction

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Gonadal steroid hormone receptors play a vital role in transforming ligand signals into gene expression. We have shown previously that gonads from wild-caught juvenile alligators express greater levels of estrogen receptor 1 (ESR1) than estrogen receptor 2 (ESR2). Furthermore, sexually dimorphic ESR2 mRNA expression (female > male) observed in animals from the reference site (Lake Woodruff, FL, USA) was lost in alligators from the contaminated Lake Apopka (FL, USA). We postulated that environmental contaminant exposure could influence gonadal steroid hormone receptor expression. Here, we address questions regarding gonadal estrogen and androgen receptor (AR) mRNA expression in 1-yr-old, laboratory-raised alligators. What are relative expression levels within gonads? Do these levels vary between sexes or incubation temperatures? Can contaminant exposure change these levels? We observed a similar pattern of expression (ESR1 > AR > ESR2) in ovary and testis. However, both incubation temperature and environment modulated expression. Males incubated at 33.5 degrees C expressed greater AR levels than females incubated at 30 degrees C; dimorphic expression was not observed in animals incubated at 32 degrees C. Compared to Lake Woodruff alligators, Lake Apopka animals of both sexes showed lesser ESR2 mRNA expression levels. Employing cluster analyses, we integrated these receptor expression patterns with those of steroidogenic factors. Elevated ESR2 and CYP19A1 expressions were diagnostic of alligator ovary, whereas elevated HSD3B1, CYP11A1, and CYP17A1 expressions were indicative of testis. In contrast, AR, ESR1, and NR5A1 showed variable expressions that were not entirely associated with sex. These findings demonstrate that the mRNA expression of receptors required for steroid hormone signaling are modified by exposure to environmental factors, including temperature and contaminants.

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Section: Experimental Design and Animal Carementioning

confidence: 99%

Influences of Sex, Incubation Temperature, and Environmental Quality on Gonadal Estrogen and Androgen Receptor Messenger RNA Expression in Juvenile American Alligators (Alligator mississippiensis)1

Moore

Milnes

Kohno

et al. 2010

Biology of Reproduction

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“…In recent years, several studies evaluated the impact of CYP and END formulations on the ISs of non-target organisms; these studies demonstrated that concentrations of these agents commonly applied in agriculture generated adverse effects in different wild species (Pushpanjali et al 2005;Velisek et al 2006;Beldomenico et al 2007;Bachetta et al 2011). Many studies have been made in order to assess exposure to pesticides in different crocodilian species at different life stages, including viable and non-viable eggs (Crain et al 1999;Milnes et al 2004), juveniles Lind et al 2004) and adults (Crain et al 1998). However, there have been few studies that evaluated the effects of pesticides on their ISs.…”

Section: Discussionmentioning

confidence: 99%

Total and differential white blood cell counts inCaiman latirostrisafterin ovoandin vivoexposure to insecticides

Latorre

Romito

Larriera

et al. 2016

Journal of Immunotoxicology

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Agricultural activities associated mainly with soybean crops affect the natural environment and wildlife by habitat destruction and the extensive use of agrochemicals. The aim of this study was to evaluate immunotoxic effects of the insecticides cypermethrin (CYP) and endosulfan (END) in Caiman latirostris analyzing total blood cell count (TWBC) and differential white blood cell count (DWBC) after in ovo and in vivo exposure. Eggs (in ovo) and hatchlings (in vivo) from nests harvested in natural habitats were artificially incubated and reared under controlled conditions in the Proyecto Yacare (Gob.Santa Fe/MUPCN) facilities. Exposure of embryos was performed by topication on the eggshell during the first stage of development. The treatments were distilled water (negative control; NC), ethanol (vehicle control; VC), four groups treated with different concentrations of CYP and four groups with END. In vivo exposure was performed by immersion; treatments were NC, VC, two groups exposed to CYP and two to END. After embryonic exposure to the insecticides, no differences were found in TWBC or DWBC among the neonates exposed to pesticides versus controls. In the in vivo scenario, similar results were obtained for TWBC, but DWBC data showed differences between NC hatchlings and CYP-1 hosts for heterophil, lymphocyte and monocyte levels, and between NC and END-1 hosts for lymphocyte and monocyte levels. Research on the effects of pesticide exposure on this species is of special interest not only to assess the impact on caiman populations, but also to further characterize the species as a potential sentinel of ecosystem health. ARTICLE HISTORY

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“…Laboratory work involving alligators was performed under Institutional Animal Care and Use Committee guidelines at the University of Florida. Egg collection, handling, and incubation methods have been previously published in detail [2,29]. Complete clutches of eggs were collected soon after oviposition from Lake Apopka and Lake Woodruff National Wildlife Refuge, FL, USA.…”

Section: Experimental Design and Animal Carementioning

confidence: 99%

Altered gonadal expression of TGF-β superfamily signaling factors in environmental contaminant-exposed juvenile alligators

Moore

Milnes

Kohno

et al. 2011

The Journal of Steroid Biochemistry and Molecular Biology

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Developmental effects of embryonic exposure to toxaphene in the American alligator (Alligator mississippiensis)

Cited by 24 publications

References 29 publications

Influences of Sex, Incubation Temperature, and Environmental Quality on Gonadal Estrogen and Androgen Receptor Messenger RNA Expression in Juvenile American Alligators (Alligator mississippiensis)1

Influences of Sex, Incubation Temperature, and Environmental Quality on Gonadal Estrogen and Androgen Receptor Messenger RNA Expression in Juvenile American Alligators (Alligator mississippiensis)1

Total and differential white blood cell counts inCaiman latirostrisafterin ovoandin vivoexposure to insecticides

Altered gonadal expression of TGF-β superfamily signaling factors in environmental contaminant-exposed juvenile alligators

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