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Papers by Matthew Elrod-Erickson
Trends in Cell Biology, 1998
Reproductive Toxicology, 2012
Zebrafish (Danio rerio) are model organisms for testing developmental toxicity at the morphologic... more Zebrafish (Danio rerio) are model organisms for testing developmental toxicity at the morphological level. In this study, influence of temperature (24.5-28.5 • C) and silver nanoparticles on developmental staging, ear-eye distance, and ratio of ear-eye distance to inner ear diameter was investigated. As temperature decreased, all endpoints showed developmental delay, with differences between endpoints in amount and type of delay measured. Differences in developmental delay patterns were observed, with rate delays increasing over time when staging endpoints were utilized and rates remaining constant when using ear-eye measurements. Integrated predictive equations were created to normalize each endpoint for temperature. Influence of image rotation on ear-eye distance accuracy showed that more than 75% eye overlap during analysis is necessary to minimize error. Exposure to silver nanoparticles demonstrated a lack of consistency between developmental endpoints and highlighted the usefulness of a multi-endpoint approach when measuring changes to developmental timing.
Journal of Phycology, 2005
The Chlorarachniophyceae are unicellular eukaryotic algae characterized by an amoeboid morphology... more The Chlorarachniophyceae are unicellular eukaryotic algae characterized by an amoeboid morphology that may be the result of secondary endosymbiosis of a green alga by a nonphotosynthetic amoeba or amoeboflagellate. Whereas much is known about the phylogeny of chlorarachniophytes, little is known about their physiology, particularly that of their lipids. In an initial effort to characterize the lipids of this algal class, four organisms from three genera were examined for their fatty acid and sterol composition. Fatty acids from lipid fractions containing chloroplast-associated glycolipids, storage triglycerides, and cytoplasmic membrane-associated polar lipids were characterized. Glycolipidassociated fatty acids were of limited composition, principally eicosapentaenoic acid [20:5(n-3)] and hexadecanoic acid (16:0). Triglyceride-associated fatty acids, although minor, were found to be similar in composition. The polar lipid fraction was dominated by lipids that did not contain phosphorus and had a more variable fatty acid composition with 16:0 and docosapentaenoic acid [22:5(n-3)] dominant along with a number of minor C 18 and C 20 fatty acids. Crinosterol and one of the epimeric pair poriferasterol/stigmasterol were the sole sterols. Several genes required for synthesis of these sterols were computationally identified in Bigelowiella natans Moestrup. One sterol biosynthesis gene showed the greatest similarity to SMT1 of the green alga, Chlamydomonas reinhardtii. However, homologues to other species, mostly green plant species, were also found. Further, the method used for identification suggested that the sequences were transferred to a genetic compartment other than the likely original location, the nucleomorph nucleus.
Monitoring expression of the developmentally regulated genes shh, sox2, and tnnt1 by reverse tran... more Monitoring expression of the developmentally regulated genes shh, sox2, and tnnt1 by reverse transcriptase polymerase chain reaction (RT-PCR) allows determination of the rate of embryogenesis in zebrafish (Danio rerio) embryos without direct visual observation. The utility of combining this approach and morphological methods during toxicity studies was demonstrated with embryos developing at either 28.5 8C or 24.5 8C and with embryos exposed to sublethal doses of silver nanoparticles. Environ Toxicol Chem 2014;33:xx-xx. # 2013 SETAC
Environmental Toxicology and Chemistry, 2012
Silver nanoparticles (Ag NPs) have been classified as the most abundant NP found in commercial pr... more Silver nanoparticles (Ag NPs) have been classified as the most abundant NP found in commercial products. In the present study, zebrafish (Danio rerio) and bacteria (Escherichia coli; ATCC 25922) were used to test the size-dependent toxicological effects of Ag NPs, the effects of ionic silver versus Ag NPs, and Ag NP effects on mortality using mass concentration (mg/L) compared with total surface area (nm 2 /L). Several diameters of Ag NPs (20, 50, 110 nm) as well as AgNO 3 were chosen as experimental treatments. Treated zebrafish embryos exhibited anomalies of the heart, namely, slower heart rates and pericardial edema. A size-dependent response was not observed in zebrafish when viewing mortality across all Ag NP treatments, although 20 nm elicited the highest incidence of abnormal motility and induced slower development. An Ag NP dose-and size-dependent response was observed in treated bacteria using mass concentration, with 20-nm Ag NP producing the highest mortality rate. In both zebrafish and bacteria, AgNO 3 was shown to be more toxic than Ag NPs at equivalent concentrations. When total surface area of Ag NPs was used to gauge bacterial mortality, a total surface area-dependent, but not size-dependent, response was observed for all three Ag NPs used in the present study, with nearly 100% mortality observed once a total surface area of approximately 1E þ 18 nm 2 /L was reached. This trend was not apparent, however, when measuring total surface area for zebrafish mortality.
Trends in Cell Biology, 1998
Reproductive Toxicology, 2012
Zebrafish (Danio rerio) are model organisms for testing developmental toxicity at the morphologic... more Zebrafish (Danio rerio) are model organisms for testing developmental toxicity at the morphological level. In this study, influence of temperature (24.5-28.5 • C) and silver nanoparticles on developmental staging, ear-eye distance, and ratio of ear-eye distance to inner ear diameter was investigated. As temperature decreased, all endpoints showed developmental delay, with differences between endpoints in amount and type of delay measured. Differences in developmental delay patterns were observed, with rate delays increasing over time when staging endpoints were utilized and rates remaining constant when using ear-eye measurements. Integrated predictive equations were created to normalize each endpoint for temperature. Influence of image rotation on ear-eye distance accuracy showed that more than 75% eye overlap during analysis is necessary to minimize error. Exposure to silver nanoparticles demonstrated a lack of consistency between developmental endpoints and highlighted the usefulness of a multi-endpoint approach when measuring changes to developmental timing.
Journal of Phycology, 2005
The Chlorarachniophyceae are unicellular eukaryotic algae characterized by an amoeboid morphology... more The Chlorarachniophyceae are unicellular eukaryotic algae characterized by an amoeboid morphology that may be the result of secondary endosymbiosis of a green alga by a nonphotosynthetic amoeba or amoeboflagellate. Whereas much is known about the phylogeny of chlorarachniophytes, little is known about their physiology, particularly that of their lipids. In an initial effort to characterize the lipids of this algal class, four organisms from three genera were examined for their fatty acid and sterol composition. Fatty acids from lipid fractions containing chloroplast-associated glycolipids, storage triglycerides, and cytoplasmic membrane-associated polar lipids were characterized. Glycolipidassociated fatty acids were of limited composition, principally eicosapentaenoic acid [20:5(n-3)] and hexadecanoic acid (16:0). Triglyceride-associated fatty acids, although minor, were found to be similar in composition. The polar lipid fraction was dominated by lipids that did not contain phosphorus and had a more variable fatty acid composition with 16:0 and docosapentaenoic acid [22:5(n-3)] dominant along with a number of minor C 18 and C 20 fatty acids. Crinosterol and one of the epimeric pair poriferasterol/stigmasterol were the sole sterols. Several genes required for synthesis of these sterols were computationally identified in Bigelowiella natans Moestrup. One sterol biosynthesis gene showed the greatest similarity to SMT1 of the green alga, Chlamydomonas reinhardtii. However, homologues to other species, mostly green plant species, were also found. Further, the method used for identification suggested that the sequences were transferred to a genetic compartment other than the likely original location, the nucleomorph nucleus.
Monitoring expression of the developmentally regulated genes shh, sox2, and tnnt1 by reverse tran... more Monitoring expression of the developmentally regulated genes shh, sox2, and tnnt1 by reverse transcriptase polymerase chain reaction (RT-PCR) allows determination of the rate of embryogenesis in zebrafish (Danio rerio) embryos without direct visual observation. The utility of combining this approach and morphological methods during toxicity studies was demonstrated with embryos developing at either 28.5 8C or 24.5 8C and with embryos exposed to sublethal doses of silver nanoparticles. Environ Toxicol Chem 2014;33:xx-xx. # 2013 SETAC
Environmental Toxicology and Chemistry, 2012
Silver nanoparticles (Ag NPs) have been classified as the most abundant NP found in commercial pr... more Silver nanoparticles (Ag NPs) have been classified as the most abundant NP found in commercial products. In the present study, zebrafish (Danio rerio) and bacteria (Escherichia coli; ATCC 25922) were used to test the size-dependent toxicological effects of Ag NPs, the effects of ionic silver versus Ag NPs, and Ag NP effects on mortality using mass concentration (mg/L) compared with total surface area (nm 2 /L). Several diameters of Ag NPs (20, 50, 110 nm) as well as AgNO 3 were chosen as experimental treatments. Treated zebrafish embryos exhibited anomalies of the heart, namely, slower heart rates and pericardial edema. A size-dependent response was not observed in zebrafish when viewing mortality across all Ag NP treatments, although 20 nm elicited the highest incidence of abnormal motility and induced slower development. An Ag NP dose-and size-dependent response was observed in treated bacteria using mass concentration, with 20-nm Ag NP producing the highest mortality rate. In both zebrafish and bacteria, AgNO 3 was shown to be more toxic than Ag NPs at equivalent concentrations. When total surface area of Ag NPs was used to gauge bacterial mortality, a total surface area-dependent, but not size-dependent, response was observed for all three Ag NPs used in the present study, with nearly 100% mortality observed once a total surface area of approximately 1E þ 18 nm 2 /L was reached. This trend was not apparent, however, when measuring total surface area for zebrafish mortality.