In mammals, the natural resistance-associated macrophage protein 1 gene, Nramp1, plays a major ro... more In mammals, the natural resistance-associated macrophage protein 1 gene, Nramp1, plays a major role in resistance to mycobacterial infections. Chesapeake Bay striped bass (Morone saxatilis) is currently experiencing an epizootic of mycobacteriosis that threatens the health of this ecologically and economically important species. In the present study, we characterized an Nramp gene in this species and obtained evidence that there is induction following Mycobacterium exposure. The striped bass Nramp gene (MsNramp) and a 554-amino-acid sequence contain all the signal features of the Nramp family, including a topology of 12 transmembrane domains (TM), the transport protein-specific binding-protein-dependent transport system inner membrane component signature, three N-linked glycosylation sites between TM 7 and TM 8, sites of casein kinase and protein kinase C phosphorylation in the amino and carboxy termini, and a tyrosine kinase phosphorylation site between TM 6 and TM 7. Phylogenetic ...
Frozen storage can affect the physical characteristics of biological samples, and the effects can... more Frozen storage can affect the physical characteristics of biological samples, and the effects can vary based on the frozen storage method that is used. We compared four frozen storage treatments: (1) flash frozen in liquid nitrogen (LN 2) and stored at −20°C, (2) flash frozen in LN 2 and stored at −65°C, (3) frozen in a saline solution (0.9% NaCl) and stored at −20°C, and (4) glazed with deionized (DI) water and stored at −20°C, to investigate the effects of frozen storage on wet weight, percent dry weight, and length of Mummichogs Fundulus heteroclitus. Mummichog wet weights differed from Prestorage wet weights for all treatments. Postthaw wet weight increased from the Prestorage wet weight for Mummichogs that were frozen in a saline solution (3-5% for 4-12 g fish). Conversely, Postthaw wet weight decreased from Prestorage wet weight (1-4% for 4-12 g fish) for Mummichogs that were frozen with LN 2 and stored at −20°C or −65°C and Mummichogs that were glazed with deionized water and stored at −20°C. Subsequently, percent dry weight was underestimated by 0.77% for the Mummichogs that were frozen in a saline solution and overestimated for those that were frozen with LN 2 and stored at −20°C (0.94%) or −65°C (0.60%) and those that were glazed with deionized water and stored at −20°C (0.71%). Fish total length decreased 2-3% after the samples had been frozen, and they did not differ among the four treatments. When possible, fish that are stored frozen should be measured and weighed alive or immediately after being euthanized, and if this is not possible, we suggest glazing the fish with water and developing correction factors for water loss and shrinkage.
Frozen storage can affect the physical characteristics of biological samples, and the effects can... more Frozen storage can affect the physical characteristics of biological samples, and the effects can vary based on the frozen storage method that is used. We compared four frozen storage treatments: (1) flash frozen in liquid nitrogen (LN 2) and stored at −20°C, (2) flash frozen in LN 2 and stored at −65°C, (3) frozen in a saline solution (0.9% NaCl) and stored at −20°C, and (4) glazed with deionized (DI) water and stored at −20°C, to investigate the effects of frozen storage on wet weight, percent dry weight, and length of Mummichogs Fundulus heteroclitus. Mummichog wet weights differed from Prestorage wet weights for all treatments. Postthaw wet weight increased from the Prestorage wet weight for Mummichogs that were frozen in a saline solution (3-5% for 4-12 g fish). Conversely, Postthaw wet weight decreased from Prestorage wet weight (1-4% for 4-12 g fish) for Mummichogs that were frozen with LN 2 and stored at −20°C or −65°C and Mummichogs that were glazed with deionized water and stored at −20°C. Subsequently, percent dry weight was underestimated by 0.77% for the Mummichogs that were frozen in a saline solution and overestimated for those that were frozen with LN 2 and stored at −20°C (0.94%) or −65°C (0.60%) and those that were glazed with deionized water and stored at −20°C (0.71%). Fish total length decreased 2-3% after the samples had been frozen, and they did not differ among the four treatments. When possible, fish that are stored frozen should be measured and weighed alive or immediately after being euthanized, and if this is not possible, we suggest glazing the fish with water and developing correction factors for water loss and shrinkage.
Lake Waccamaw, NC, is an unusual Carolina bay home to endemic and rare species. Parasites of the ... more Lake Waccamaw, NC, is an unusual Carolina bay home to endemic and rare species. Parasites of the lake-endemic Fundulus waccamensis (Waccamaw Killifish) have not been described previously. In 2011, we collected Waccamaw Killifish (n = 101) by seining and dip netting from 3 sites over 3 seasons (spring, summer, and fall) to investigate the identity, prevalence, and intensity of the parasite-component community. We found 13 taxa of parasites, all of which were new host records, and total prevalence of parasitism = 95%. Infected hosts contained 2.3 ± 1.0 (mean ± SD) parasite species, with the component community composed of 6 ecto-and 7 endoparasites. The most prevalent (70.3%) and highest mean intensity (17.3 metacercariae per host) infections were associated with the generalist trematode Posthodiplostomum minimum.
Videos referred to in the Results, Table 1, Figure 2, and Figure 3 of Coleman and Burge "Ass... more Videos referred to in the Results, Table 1, Figure 2, and Figure 3 of Coleman and Burge "Association behavior between sand tiger sharks and round scad is driven by mesopredators" are included here. Table S2 lists a description of each video (Descriptions), date (Date of occurrence) and time (Clock time of occurrence) of footage, a timing reference to the description within the video (video time), and a link to Youtube (Video reference) of the same footage. Note that file uploads for videos for views of the field site at Frying Pan Tower (in Materials and Methods and Table S2; https://www.youtube.com/playlist?list=PLK1g13VpyT6oYUJL7U3hRPlt2U5L_mcKL) are not included with these uploads as no data or observations are derived from these videos.
A photo and video identification guide to fishes seen on the Cape Fear SharkCam. SharkCam is a so... more A photo and video identification guide to fishes seen on the Cape Fear SharkCam. SharkCam is a solar-powered underwater camera installed 50 feet (15 meters) below the surface of the Atlantic Ocean. It live-streams on Explore.org (https://explore.org/livecams/oceans/shark-cam), a project of the Annenberg Foundation. The camera is mounted on the Frying Pan Tower, a former U.S. Coast Guard Light Station located atop a natural hard bottom reef area approximately 35 miles (56 kilometers) off the coast of Cape Fear, North Carolina. The area supports a huge diversity of marine life including, as the camera and guide's names suggest, sharks.
Current methods of quantification of fecal indicator bacteria (FIB) are based on culturing techni... more Current methods of quantification of fecal indicator bacteria (FIB) are based on culturing techniques. These tests take a minimum of twenty-four hours to complete and offer no information as to the identity of potential host sources. This often results in human health risk advisories in recreational waters being issued after hazards have subsided. Additionally, results from these culturing techniques can be ambiguous when deployed in stormwater source tracking efforts to remediate FIB pollution. A series of new genetic-based methods have been developed to provide more rapid and host specific techniques to measure FIB. Most promising of these are the newly approved USEPA Methods A (for determination of Enterococci) and B (for the determination of Bacteroides) in water. These techniques use TaqMan quantitative real time polymerase chain reaction (qPCR). qPCR is a molecular biology tool that amplifies the DNA of specific genes and allows for quantification of as low as one gene copy. A...
We tagged 12 Carcharhinus limbatus with acoustic transmitters and monitored their presence at fiv... more We tagged 12 Carcharhinus limbatus with acoustic transmitters and monitored their presence at five piers along the north-east coast of South Carolina, USA in 2016 and four piers in 2017 using acoustic receivers. Data were analysed with pier association indices (PAI), mixed models and fast Fourier transformation analyses to identify potential factors related to residence time and presence at piers and any cyclical patterns in visits to piers. While the majority of monitored C. limbatus were infrequently detected at piers, three (25.0%) were highly associated with piers (PAI ≥ 0.50). Of the C. limbatus that were detected after initial capture, three (25.0%) recorded detection events only at the pier where they were tagged and two individuals (16.7%) recorded at least one detection event at all monitored piers. The best-fit model explaining C. limbatus residence time at piers included terms for pier location and diel cycle (wi = 0.88), whereas the best fit model explaining presence-absence of C. limbatus at piers included terms for tidal height, diel cycle, barometric pressure and angler count (wi = 0.98). Carcharhinus limbatus did not appear to display cyclical patterns in their visits to piers. Along the north-east coast of South Carolina, association of C. limbatus with piers is a phenomenon for a proportion of mature individuals, but continued research is necessary to understand if this behaviour is driven by attraction to and feeding on angler discards or increased foraging opportunities resulting from the attraction of potential prey to the physical structure provided by piers.
Abstract Lake Waccamaw, NC, is an unusual Carolina bay home to endemic and rare species. Parasite... more Abstract Lake Waccamaw, NC, is an unusual Carolina bay home to endemic and rare species. Parasites of the lake-endemic Fundulus waccamensis (Waccamaw Killifish) have not been described previously. In 2011, we collected Waccamaw Killifish (n = 101) by seining and dip netting from 3 sites over 3 seasons (spring, summer, and fall) to investigate the identity, prevalence, and intensity of the parasite-component community. We found 13 taxa of parasites, all of which were new host records, and total prevalence of parasitism = 95%. Infected hosts contained 2.3 ± 1.0 (mean ± SD) parasite species, with the component community composed of 6 ecto- and 7 endoparasites. The most prevalent (70.3%) and highest mean intensity (17.3 metacercariae per host) infections were associated with the generalist trematode Posthodiplostomum minimum.
The rhizocephalan barnacle Loxothylacus panopaei is a parasitic castrator of xanthid crabs that h... more The rhizocephalan barnacle Loxothylacus panopaei is a parasitic castrator of xanthid crabs that has invaded the U.S. Atlantic coast. It was transported to the Chesapeake Bay in the mid-1960s with mud crabs associated with Gulf coast oysters and has since spread north to Long Island Sound, New York, and south to Cape Canaveral, Florida. Here we report parasite prevalence at 3 South Carolina sites--2 from which the parasite had not been previously reported--and examine the genetic relationships of North and South Carolina L. panopaei populations relative to Gulf of Mexico and other Atlantic coast parasite populations. Total L. panopaei prevalence was 24.2% among all 3 sites, with monthly prevalence as high as 51.6% at Waties Island, South Carolina. Sequence analyses of North and South Carolina specimens revealed the presence of 4 cytochrome c oxidase subunit I haplotypes--3 commonly found in other invasive populations and 1 new haplotype found in a single specimen from the Rachel Carson Reserve in Carteret County, North Carolina--and indicate that the Carolina populations are a result of range expansion from the original Atlantic coast invasion.
Peroxinectin (Pox), which promotes cell adhesion and encapsulation of bacteria in crustaceans, is... more Peroxinectin (Pox), which promotes cell adhesion and encapsulation of bacteria in crustaceans, is synthesized in granular and semigranular hemocytes. In this study, real-time PCR was used to quantify Pox transcripts in individual tissues of the Pacific white shrimp, Litopenaeus vannamei, over 48 h following injection of a sublethal dose of the shrimp pathogen Vibrio campbellii. The resulting data were used to infer the movements of hemocytes among the tissues in response to bacterial challenge. Over all times and treatments, Pox transcripts (ng total RNA)(-1) varied by orders of magnitude among individual tissues, such that circulating hemocytes > gills > heart lymphoid organ hepatopancreas approximately muscle. Relatively low constitutive expression of Pox in the lymphoid organ compared to circulating hemocytes, gills, and heart supports a primary role for this organ in bacteriostasis and degradation, rather than encapsulation of invasive bacteria. Numbers of Pox transcripts increased significantly at the injection site within 4 h and remained significantly elevated for 48 h, consistent with a rapid and sustained recruitment of hemocytes to the site of injection. Transcripts increased significantly in the gill but not in other tissues over the time-course of this experiment. These expression data reinforce the role of the gill in trapping and encapsulating invasive bacteria as a primary strategic focus during the early phase of the crustacean immune response and, by comparison with earlier studies of lysozyme expression in the same tissues, suggest differential roles for various tissues in a successful immune response.
Mycobacteriosis in Chesapeake Bay (USA) striped bass Morone saxatilis is an ongoing disease probl... more Mycobacteriosis in Chesapeake Bay (USA) striped bass Morone saxatilis is an ongoing disease problem with important economic implications for a large commercial and recreational fishery. Additionally, striped bass serve as a reservoir of potential mycobacterial zoonoses. Recently, we described a striped bass gene homolog of the natural resistance-associated macrophage protein family (MsNramp), which is responsible for resistance to mycobacterial infections in mice. Striped bass MsNramp is strongly induced in peritoneal exudate cells (PE) in vivo after intraperitoneal injection with Mycobacterium spp. The purpose of the present study was to investigate short-term in vitro MsNramp expression and reactive oxygen intermediate (ROI) production in primary cultures of adherent PE after exposure to bacterial lipopolysaccharide (LPS), or live- or heat-killed (HK) Mycobacterium marinum. PE expressed significantly higher levels of MsNramp at 4 and 24 h post-treatment with live and HK M. marinum. MsNramp response to LPS was dose-dependent in these cells, with maximum expression at 4 h and 20 microg/ml LPS. Treatment of PE with LPS resulted in increased intracellular superoxide anion levels, whereas treatment with live M. marinum caused a significant depression. This study is the first report of induction of a teleost Nramp in vitro by mycobacteria, and supports findings of teleost Nramp induction by LPS.
In mammals, the natural resistance-associated macrophage protein 1 gene, Nramp1, plays a major ro... more In mammals, the natural resistance-associated macrophage protein 1 gene, Nramp1, plays a major role in resistance to mycobacterial infections. Chesapeake Bay striped bass (Morone saxatilis) is currently experiencing an epizootic of mycobacteriosis that threatens the health of this ecologically and economically important species. In the present study, we characterized an Nramp gene in this species and obtained evidence that there is induction following Mycobacterium exposure. The striped bass Nramp gene (MsNramp) and a 554-amino-acid sequence contain all the signal features of the Nramp family, including a topology of 12 transmembrane domains (TM), the transport protein-specific binding-protein-dependent transport system inner membrane component signature, three N-linked glycosylation sites between TM 7 and TM 8, sites of casein kinase and protein kinase C phosphorylation in the amino and carboxy termini, and a tyrosine kinase phosphorylation site between TM 6 and TM 7. Phylogenetic ...
Frozen storage can affect the physical characteristics of biological samples, and the effects can... more Frozen storage can affect the physical characteristics of biological samples, and the effects can vary based on the frozen storage method that is used. We compared four frozen storage treatments: (1) flash frozen in liquid nitrogen (LN 2) and stored at −20°C, (2) flash frozen in LN 2 and stored at −65°C, (3) frozen in a saline solution (0.9% NaCl) and stored at −20°C, and (4) glazed with deionized (DI) water and stored at −20°C, to investigate the effects of frozen storage on wet weight, percent dry weight, and length of Mummichogs Fundulus heteroclitus. Mummichog wet weights differed from Prestorage wet weights for all treatments. Postthaw wet weight increased from the Prestorage wet weight for Mummichogs that were frozen in a saline solution (3-5% for 4-12 g fish). Conversely, Postthaw wet weight decreased from Prestorage wet weight (1-4% for 4-12 g fish) for Mummichogs that were frozen with LN 2 and stored at −20°C or −65°C and Mummichogs that were glazed with deionized water and stored at −20°C. Subsequently, percent dry weight was underestimated by 0.77% for the Mummichogs that were frozen in a saline solution and overestimated for those that were frozen with LN 2 and stored at −20°C (0.94%) or −65°C (0.60%) and those that were glazed with deionized water and stored at −20°C (0.71%). Fish total length decreased 2-3% after the samples had been frozen, and they did not differ among the four treatments. When possible, fish that are stored frozen should be measured and weighed alive or immediately after being euthanized, and if this is not possible, we suggest glazing the fish with water and developing correction factors for water loss and shrinkage.
Frozen storage can affect the physical characteristics of biological samples, and the effects can... more Frozen storage can affect the physical characteristics of biological samples, and the effects can vary based on the frozen storage method that is used. We compared four frozen storage treatments: (1) flash frozen in liquid nitrogen (LN 2) and stored at −20°C, (2) flash frozen in LN 2 and stored at −65°C, (3) frozen in a saline solution (0.9% NaCl) and stored at −20°C, and (4) glazed with deionized (DI) water and stored at −20°C, to investigate the effects of frozen storage on wet weight, percent dry weight, and length of Mummichogs Fundulus heteroclitus. Mummichog wet weights differed from Prestorage wet weights for all treatments. Postthaw wet weight increased from the Prestorage wet weight for Mummichogs that were frozen in a saline solution (3-5% for 4-12 g fish). Conversely, Postthaw wet weight decreased from Prestorage wet weight (1-4% for 4-12 g fish) for Mummichogs that were frozen with LN 2 and stored at −20°C or −65°C and Mummichogs that were glazed with deionized water and stored at −20°C. Subsequently, percent dry weight was underestimated by 0.77% for the Mummichogs that were frozen in a saline solution and overestimated for those that were frozen with LN 2 and stored at −20°C (0.94%) or −65°C (0.60%) and those that were glazed with deionized water and stored at −20°C (0.71%). Fish total length decreased 2-3% after the samples had been frozen, and they did not differ among the four treatments. When possible, fish that are stored frozen should be measured and weighed alive or immediately after being euthanized, and if this is not possible, we suggest glazing the fish with water and developing correction factors for water loss and shrinkage.
Lake Waccamaw, NC, is an unusual Carolina bay home to endemic and rare species. Parasites of the ... more Lake Waccamaw, NC, is an unusual Carolina bay home to endemic and rare species. Parasites of the lake-endemic Fundulus waccamensis (Waccamaw Killifish) have not been described previously. In 2011, we collected Waccamaw Killifish (n = 101) by seining and dip netting from 3 sites over 3 seasons (spring, summer, and fall) to investigate the identity, prevalence, and intensity of the parasite-component community. We found 13 taxa of parasites, all of which were new host records, and total prevalence of parasitism = 95%. Infected hosts contained 2.3 ± 1.0 (mean ± SD) parasite species, with the component community composed of 6 ecto-and 7 endoparasites. The most prevalent (70.3%) and highest mean intensity (17.3 metacercariae per host) infections were associated with the generalist trematode Posthodiplostomum minimum.
Videos referred to in the Results, Table 1, Figure 2, and Figure 3 of Coleman and Burge "Ass... more Videos referred to in the Results, Table 1, Figure 2, and Figure 3 of Coleman and Burge "Association behavior between sand tiger sharks and round scad is driven by mesopredators" are included here. Table S2 lists a description of each video (Descriptions), date (Date of occurrence) and time (Clock time of occurrence) of footage, a timing reference to the description within the video (video time), and a link to Youtube (Video reference) of the same footage. Note that file uploads for videos for views of the field site at Frying Pan Tower (in Materials and Methods and Table S2; https://www.youtube.com/playlist?list=PLK1g13VpyT6oYUJL7U3hRPlt2U5L_mcKL) are not included with these uploads as no data or observations are derived from these videos.
A photo and video identification guide to fishes seen on the Cape Fear SharkCam. SharkCam is a so... more A photo and video identification guide to fishes seen on the Cape Fear SharkCam. SharkCam is a solar-powered underwater camera installed 50 feet (15 meters) below the surface of the Atlantic Ocean. It live-streams on Explore.org (https://explore.org/livecams/oceans/shark-cam), a project of the Annenberg Foundation. The camera is mounted on the Frying Pan Tower, a former U.S. Coast Guard Light Station located atop a natural hard bottom reef area approximately 35 miles (56 kilometers) off the coast of Cape Fear, North Carolina. The area supports a huge diversity of marine life including, as the camera and guide's names suggest, sharks.
Current methods of quantification of fecal indicator bacteria (FIB) are based on culturing techni... more Current methods of quantification of fecal indicator bacteria (FIB) are based on culturing techniques. These tests take a minimum of twenty-four hours to complete and offer no information as to the identity of potential host sources. This often results in human health risk advisories in recreational waters being issued after hazards have subsided. Additionally, results from these culturing techniques can be ambiguous when deployed in stormwater source tracking efforts to remediate FIB pollution. A series of new genetic-based methods have been developed to provide more rapid and host specific techniques to measure FIB. Most promising of these are the newly approved USEPA Methods A (for determination of Enterococci) and B (for the determination of Bacteroides) in water. These techniques use TaqMan quantitative real time polymerase chain reaction (qPCR). qPCR is a molecular biology tool that amplifies the DNA of specific genes and allows for quantification of as low as one gene copy. A...
We tagged 12 Carcharhinus limbatus with acoustic transmitters and monitored their presence at fiv... more We tagged 12 Carcharhinus limbatus with acoustic transmitters and monitored their presence at five piers along the north-east coast of South Carolina, USA in 2016 and four piers in 2017 using acoustic receivers. Data were analysed with pier association indices (PAI), mixed models and fast Fourier transformation analyses to identify potential factors related to residence time and presence at piers and any cyclical patterns in visits to piers. While the majority of monitored C. limbatus were infrequently detected at piers, three (25.0%) were highly associated with piers (PAI ≥ 0.50). Of the C. limbatus that were detected after initial capture, three (25.0%) recorded detection events only at the pier where they were tagged and two individuals (16.7%) recorded at least one detection event at all monitored piers. The best-fit model explaining C. limbatus residence time at piers included terms for pier location and diel cycle (wi = 0.88), whereas the best fit model explaining presence-absence of C. limbatus at piers included terms for tidal height, diel cycle, barometric pressure and angler count (wi = 0.98). Carcharhinus limbatus did not appear to display cyclical patterns in their visits to piers. Along the north-east coast of South Carolina, association of C. limbatus with piers is a phenomenon for a proportion of mature individuals, but continued research is necessary to understand if this behaviour is driven by attraction to and feeding on angler discards or increased foraging opportunities resulting from the attraction of potential prey to the physical structure provided by piers.
Abstract Lake Waccamaw, NC, is an unusual Carolina bay home to endemic and rare species. Parasite... more Abstract Lake Waccamaw, NC, is an unusual Carolina bay home to endemic and rare species. Parasites of the lake-endemic Fundulus waccamensis (Waccamaw Killifish) have not been described previously. In 2011, we collected Waccamaw Killifish (n = 101) by seining and dip netting from 3 sites over 3 seasons (spring, summer, and fall) to investigate the identity, prevalence, and intensity of the parasite-component community. We found 13 taxa of parasites, all of which were new host records, and total prevalence of parasitism = 95%. Infected hosts contained 2.3 ± 1.0 (mean ± SD) parasite species, with the component community composed of 6 ecto- and 7 endoparasites. The most prevalent (70.3%) and highest mean intensity (17.3 metacercariae per host) infections were associated with the generalist trematode Posthodiplostomum minimum.
The rhizocephalan barnacle Loxothylacus panopaei is a parasitic castrator of xanthid crabs that h... more The rhizocephalan barnacle Loxothylacus panopaei is a parasitic castrator of xanthid crabs that has invaded the U.S. Atlantic coast. It was transported to the Chesapeake Bay in the mid-1960s with mud crabs associated with Gulf coast oysters and has since spread north to Long Island Sound, New York, and south to Cape Canaveral, Florida. Here we report parasite prevalence at 3 South Carolina sites--2 from which the parasite had not been previously reported--and examine the genetic relationships of North and South Carolina L. panopaei populations relative to Gulf of Mexico and other Atlantic coast parasite populations. Total L. panopaei prevalence was 24.2% among all 3 sites, with monthly prevalence as high as 51.6% at Waties Island, South Carolina. Sequence analyses of North and South Carolina specimens revealed the presence of 4 cytochrome c oxidase subunit I haplotypes--3 commonly found in other invasive populations and 1 new haplotype found in a single specimen from the Rachel Carson Reserve in Carteret County, North Carolina--and indicate that the Carolina populations are a result of range expansion from the original Atlantic coast invasion.
Peroxinectin (Pox), which promotes cell adhesion and encapsulation of bacteria in crustaceans, is... more Peroxinectin (Pox), which promotes cell adhesion and encapsulation of bacteria in crustaceans, is synthesized in granular and semigranular hemocytes. In this study, real-time PCR was used to quantify Pox transcripts in individual tissues of the Pacific white shrimp, Litopenaeus vannamei, over 48 h following injection of a sublethal dose of the shrimp pathogen Vibrio campbellii. The resulting data were used to infer the movements of hemocytes among the tissues in response to bacterial challenge. Over all times and treatments, Pox transcripts (ng total RNA)(-1) varied by orders of magnitude among individual tissues, such that circulating hemocytes > gills > heart lymphoid organ hepatopancreas approximately muscle. Relatively low constitutive expression of Pox in the lymphoid organ compared to circulating hemocytes, gills, and heart supports a primary role for this organ in bacteriostasis and degradation, rather than encapsulation of invasive bacteria. Numbers of Pox transcripts increased significantly at the injection site within 4 h and remained significantly elevated for 48 h, consistent with a rapid and sustained recruitment of hemocytes to the site of injection. Transcripts increased significantly in the gill but not in other tissues over the time-course of this experiment. These expression data reinforce the role of the gill in trapping and encapsulating invasive bacteria as a primary strategic focus during the early phase of the crustacean immune response and, by comparison with earlier studies of lysozyme expression in the same tissues, suggest differential roles for various tissues in a successful immune response.
Mycobacteriosis in Chesapeake Bay (USA) striped bass Morone saxatilis is an ongoing disease probl... more Mycobacteriosis in Chesapeake Bay (USA) striped bass Morone saxatilis is an ongoing disease problem with important economic implications for a large commercial and recreational fishery. Additionally, striped bass serve as a reservoir of potential mycobacterial zoonoses. Recently, we described a striped bass gene homolog of the natural resistance-associated macrophage protein family (MsNramp), which is responsible for resistance to mycobacterial infections in mice. Striped bass MsNramp is strongly induced in peritoneal exudate cells (PE) in vivo after intraperitoneal injection with Mycobacterium spp. The purpose of the present study was to investigate short-term in vitro MsNramp expression and reactive oxygen intermediate (ROI) production in primary cultures of adherent PE after exposure to bacterial lipopolysaccharide (LPS), or live- or heat-killed (HK) Mycobacterium marinum. PE expressed significantly higher levels of MsNramp at 4 and 24 h post-treatment with live and HK M. marinum. MsNramp response to LPS was dose-dependent in these cells, with maximum expression at 4 h and 20 microg/ml LPS. Treatment of PE with LPS resulted in increased intracellular superoxide anion levels, whereas treatment with live M. marinum caused a significant depression. This study is the first report of induction of a teleost Nramp in vitro by mycobacteria, and supports findings of teleost Nramp induction by LPS.
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