Size of nesting female Broad-snouted Caimans (Caiman latirostris Daudin 1802)

The southern distribution of the Broad-snouted Caiman (Caiman latirostris Daudin 1802) in Argentina occurs in Santa Fe Province, where its population has been under management by "Proyecto Yacaré" since 1990. From 1997 to 2016, we captured 77 nesting female Broad-snouted Caimans in Santa Fe Province. Our results suggest that previously defined size classes for Broad-snouted Caiman do not adequately describe the reproductively mature female segment of the population. Here we propose to change size ranges for general size classes for Broad-snouted Caiman. In addition, we have observed that reintroduced reproductive females by Proyecto Yacaré represent about 32% of captured females. These results indicate that reintroduced females by the management program are surviving and reproducing in the wild at least up to 20 years.

Micronuclei and other nuclear abnormalities on Caiman latirostris (Broad-snouted caiman) hatchlings after embryonic exposure to different pesticide formulations

This study aimed to evaluate the embryotoxicity and genotoxicity of pesticide commercial formulations widely used in soybean crops through the Micronucleus (MN) test and other Nuclear Abnormalities (NAs) in erythrocytes of broad-snouted caiman (Caiman latirostris), exposed by topical application through the eggshell. Embryos were exposed (during all incubation: 70 days approximately) to sub-lethal concentrations of two glyphosate formulations PanzerGold® (PANZ) and Roundup® Full II (RU) (500, 750, 1000µg/egg); to the endosulfan (END) formulation Galgofan® and the cypermethrin (CYP) formulation Atanor® (1, 10, 100, and 1000µg/ egg). Blood samples were taken at the moment of hatching from the spinal vein for the application of the MN test and analysis of other NAs in erythrocytes, as markers of genotoxicity. Results indicated a significant increase in the frequency of MN for PANZ1000, END 10, CYP 1 and CYP 100 (p<0.05), and in the frequency of other NAs including Buds: END 100, 1000 and CYP 10 (p<0.05), eccentric nuclei: END 1, 10, 1000, CYP 10, 100, 1000 (p<0.01) and END 100 (p<0.05), notched nuclei: END 1, 10 (p<0.01) and END 1000, CYP 10, 100,1000 (p<0.05), and total nuclear abnormalities: END 1, 10, 100, 1000, CYP 10, 100 and 1000 (p<0.01), and the positive control (PC) (p<0.05), compared with the negative control. It was demonstrated a concentration dependent-effect in MN frequency only for PANZ (R2=0.98; p<0.01). Our study demonstrated that commercial formulations of pesticides induced genotoxic effects on C. latirostris, and NAs are a good indicator of genotoxicity in this specie.

Abstract P3-05-05: HER2 Expression and Gene copy analysis by Immunofluorescence and Fluorescence in situ Hybridization, on a Single formalin-fixed paraffin-embedded tissue section

Introduction: Breast cancer is the most common cancer for women worldwide. HER2 expression and gene copy number are important when determining eligibility for adjuvant therapy and/or chemotherapy medications. One challenging issue for breast cancer testing is intratumoral heterogeneity of HER2 gene amplification. Intratumoral heterogeneity can make it difficult to localize target cells of interest. Serial tissue sections used for independent H&E, IHC and FISH stains also increase the difficulty to localize targets due to cellular truncation. We have developed a system to assess both HER2 expression and gene copy number on the same cell.

Method: Immunofluorescence (IF) and Fluorescence in situ Hybridization (FISH) were performed on tissue sections from 19 patients with invasive ductal breast carcinoma. Cases were selected based on prior HER2 FISH results (HER2:Chromosome 17 = ratio) representing unamplified (&lt;2.0), amplified (≥2.0) and equivocal (1.8–2.2). Samples were collected from June 2011 – February 2012. Tissue sections were cut at 4uM from formalin-fixed paraffin-embedded tissue blocks. Slides were stained with antibodies for HER2 (Clone #D8F12, Cell Signaling, Danvers, MA), cytokeratin (Clone #AE1, eBioscience, San Diego, CA) and Pan cytokeratin (Clone #PCK-26, Sigma-Aldrich, St. Louis, MO). The whole tissue imaging was performed on the In-Cell (GE Healthcare, Chalfont St. Giles, UK) at 10X. Proprietary software developed by GRC (GE Global Research, Niskayuna, NY) controlled the hardware and performed numerous algorithmic functions. Regions of Interest (ROI) were selected by a pathologist on a whole tissue image and coordinates were recorded by the software. The slides were then imaged at 40x using the previously recorded ROI's. The same slides were stained with the PathVysion HER2/CEP17 FISH kit (Abbott Molecular, Des Plaines, IL). Slides were registered to the previous IF scan using recorded coordinates and tissue morphology recognition algorithms. The sections were imaged for FISH at 40X using the previous ROI selections. Cases were assessed for successful protein and genetic expression using proprietary visualization tools for combined analysis.

Results: We evaluated a total of 22 breast cancer cases with 19 cases detecting both protein and gene expression. Of the three cases that could not be evaluated the rationale is as follows: tissue damage incurred during imaging, insufficient focus during the FISH imaging portion, and poor signal to noise of the FISH dots.

Conclusion: The reported incidence of intratumoral HER2 amplification heterogeneity is as high as 30%. The challenges associated with tumor heterogeneity may benefit from a standardize analysis method. Using integrated images generated by this system, pathologist is able to select the appropriate cells for HER2 copy number enumeration based on the expression level of HER2 protein, in the same cell, allowing rapid identification of intratumoral heterogeneity.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-05-05.

Genotoxicity of the herbicide formulation Roundup (glyphosate) in broad-snouted caiman (Caiman latirostris) evidenced by the Comet assay and the Micronucleus test

The genotoxicity of pesticides is an issue of worldwide concern. The present study was undertaken to evaluate the genotoxic potential of a widely used herbicide formulation, Roundup (glyphosate), in erythrocytes of broad-snouted caiman (Caiman latirostris) after in ovo exposure. Caiman embryos were exposed at early embryonic stage to different sub-lethal concentrations of Roundup (50, 100, 200, 300, 400, 500, 750, 1000, 1250 and 1750microg/egg). At time of hatching, blood samples were obtained from each animal and two short-term tests, the Comet assay and the Micronucleus (MN) test, were performed on erythrocytes to assess DNA damage. A significant increase in DNA damage was observed at a concentration of 500microg/egg or higher, compared to untreated control animals (p<0.05). Results from both the Comet assay and the MN test revealed a concentration-dependent effect. This study demonstrated adverse effects of Roundup on DNA of C. latirostris and confirmed that the Comet assay and the MN test applied on caiman erythrocytes are useful tools in determining potential genotoxicity of pesticides. The identification of sentinel species as well as sensitive biomarkers among the natural biota is imperative to thoroughly evaluate genetic damage, which has significant consequences for short- and long-term survival of the natural species.

Sex reversal effects on Caiman latirostris exposed to environmentally relevant doses of the xenoestrogen bisphenol A

Exposure to environmental contaminants known as endocrine disruptors (EDs) alters the development and function of reproductive organs in several species. Bisphenol A (BPA) is an estrogenic chemical that leaches from dental materials and plastic food and beverage containers. BPA has been found in sewage, surface and drinking water, and therefore poses a potentially significant risk for human and wildlife. Prenatal exposure of rodents to environmentally relevant doses of BPA alters the development of the reproductive organs of male and female offspring. Species with temperature dependent sex determination (TSD) could act as sentinels of ecosystem health by providing sensitive biomarkers of endocrine disruptor's effects. We selected Caiman latirostris as an animal model to study endocrine disruption caused by BPA. The aim of this study was to determine whether exposure in ovum to BPA could cause estrogen-like effects on the reproductive system of C. latirostris. Sex determination and gonadal histoarchitecture were the endpoints evaluated after in ovum exposure to different doses of BPA and 17beta-estradiol (E(2)). We confirmed that C. latirostris is a species with TSD and additionally demonstrated that BPA causes estrogen-like developmental effects by reversing gonadal sex and altering gonadal histoarchitecture. Differences in responses to BPA and E(2) in our in vivo system were on the order of 100-fold. In contrast published in vitro studies have reported differences on the order of 10,000x or more. These results support the utility of C. latirostris, a species in which sex determination is temperature dependent, as a tool in assessing estrogenic activity in vivo and as a sentinel to monitor EDs in aquatic environment.