Epizootiology, ultrastructure, and molecular characterization of the myxosporean associated with parasitic encephalitis of farmed Atlantic salmon (Salmo salar) in Ireland
In 1995 at a sea-farm in Ireland, Atlantic salmon (Salmo salar) smolts from a freshwater hatchery were introduced in spring and autumn into two marine rearing sites, one with and one without a history of epizootic mortality believed due to parasitic encephalitis. No neurologic signs were observed, b...
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ftunivconn:oai:opencommons.uconn.edu:dissertations-1700 2023-05-15T15:32:02+02:00 Epizootiology, ultrastructure, and molecular characterization of the myxosporean associated with parasitic encephalitis of farmed Atlantic salmon (Salmo salar) in Ireland Frasca, Salvatore 1998-01-01T08:00:00Z https://opencommons.uconn.edu/dissertations/AAI9906694 http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:9906694 EN eng OpenCommons@UConn https://opencommons.uconn.edu/dissertations/AAI9906694 http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:9906694 Doctoral Dissertations Biology Molecular|Biology Neuroscience|Biology Genetics|Biology Zoology|Agriculture Animal Pathology|Biology Veterinary Science|Agriculture Fisheries and Aquaculture text 1998 ftunivconn 2022-07-11T18:38:56Z In 1995 at a sea-farm in Ireland, Atlantic salmon (Salmo salar) smolts from a freshwater hatchery were introduced in spring and autumn into two marine rearing sites, one with and one without a history of epizootic mortality believed due to parasitic encephalitis. No neurologic signs were observed, but parasites and encephalitis were detected in brains of smolts from both sites, with prevalences of each that were significantly greater in smolts from the site with a previous history of epizootic mortality. Parasites and encephalitis were first detected in smolts sampled at 26 and 4 days post-introduction, respectively. Histopathologic examinations of brains showed that parasites were detected with significantly greater frequency in the optic tectum of the mesencephalon than in the diencephalon, metencephalon, or myelencephalon, and were not detected in the telencephalon. Foci of encephalitis were non-suppurative, multifocal, and were detected in each neuroanatomical subdivision, with significantly greater frequency in the myelencephalon. The ultrastructure of the parasite was that of an intercellular, presporogonic, multicellular, developmental stage of a histozoic myxosporean. Parasite stages were branching tubular structures containing generative cells arranged individually or in cell-in-cell doublets, and were located between bundles of axons with compression of axons along segments of their plasmalemma. No mature spores were detected. Polymerase chain reaction, Southern hybridization, dideoxynucleotide chain-termination DNA sequencing, and in situ hybridization were used in concert to characterize segments of the small subunit ribosomal RNA gene. Assessments of homology were made between sequences from the SSU rRNA gene of the parasite and those of seven myxosporeans from three separate genera, e.g., Myxobolus, Henneguya, and Ceratomyxa. The partial SSU rRNA gene sequence from the parasite was most homologous to SSU rRNA gene sequences from species of Myxobolus, and was 99% homologous to sequences from the SSU ... Text Atlantic salmon Salmo salar University of Connecticut (UConn): DigitalCommons@UConn Doublets ENVELOPE(98.667,98.667,-66.417,-66.417) |
institution |
Open Polar |
collection |
University of Connecticut (UConn): DigitalCommons@UConn |
op_collection_id |
ftunivconn |
language |
English |
topic |
Biology Molecular|Biology Neuroscience|Biology Genetics|Biology Zoology|Agriculture Animal Pathology|Biology Veterinary Science|Agriculture Fisheries and Aquaculture |
spellingShingle |
Biology Molecular|Biology Neuroscience|Biology Genetics|Biology Zoology|Agriculture Animal Pathology|Biology Veterinary Science|Agriculture Fisheries and Aquaculture Frasca, Salvatore Epizootiology, ultrastructure, and molecular characterization of the myxosporean associated with parasitic encephalitis of farmed Atlantic salmon (Salmo salar) in Ireland |
topic_facet |
Biology Molecular|Biology Neuroscience|Biology Genetics|Biology Zoology|Agriculture Animal Pathology|Biology Veterinary Science|Agriculture Fisheries and Aquaculture |
description |
In 1995 at a sea-farm in Ireland, Atlantic salmon (Salmo salar) smolts from a freshwater hatchery were introduced in spring and autumn into two marine rearing sites, one with and one without a history of epizootic mortality believed due to parasitic encephalitis. No neurologic signs were observed, but parasites and encephalitis were detected in brains of smolts from both sites, with prevalences of each that were significantly greater in smolts from the site with a previous history of epizootic mortality. Parasites and encephalitis were first detected in smolts sampled at 26 and 4 days post-introduction, respectively. Histopathologic examinations of brains showed that parasites were detected with significantly greater frequency in the optic tectum of the mesencephalon than in the diencephalon, metencephalon, or myelencephalon, and were not detected in the telencephalon. Foci of encephalitis were non-suppurative, multifocal, and were detected in each neuroanatomical subdivision, with significantly greater frequency in the myelencephalon. The ultrastructure of the parasite was that of an intercellular, presporogonic, multicellular, developmental stage of a histozoic myxosporean. Parasite stages were branching tubular structures containing generative cells arranged individually or in cell-in-cell doublets, and were located between bundles of axons with compression of axons along segments of their plasmalemma. No mature spores were detected. Polymerase chain reaction, Southern hybridization, dideoxynucleotide chain-termination DNA sequencing, and in situ hybridization were used in concert to characterize segments of the small subunit ribosomal RNA gene. Assessments of homology were made between sequences from the SSU rRNA gene of the parasite and those of seven myxosporeans from three separate genera, e.g., Myxobolus, Henneguya, and Ceratomyxa. The partial SSU rRNA gene sequence from the parasite was most homologous to SSU rRNA gene sequences from species of Myxobolus, and was 99% homologous to sequences from the SSU ... |
format |
Text |
author |
Frasca, Salvatore |
author_facet |
Frasca, Salvatore |
author_sort |
Frasca, Salvatore |
title |
Epizootiology, ultrastructure, and molecular characterization of the myxosporean associated with parasitic encephalitis of farmed Atlantic salmon (Salmo salar) in Ireland |
title_short |
Epizootiology, ultrastructure, and molecular characterization of the myxosporean associated with parasitic encephalitis of farmed Atlantic salmon (Salmo salar) in Ireland |
title_full |
Epizootiology, ultrastructure, and molecular characterization of the myxosporean associated with parasitic encephalitis of farmed Atlantic salmon (Salmo salar) in Ireland |
title_fullStr |
Epizootiology, ultrastructure, and molecular characterization of the myxosporean associated with parasitic encephalitis of farmed Atlantic salmon (Salmo salar) in Ireland |
title_full_unstemmed |
Epizootiology, ultrastructure, and molecular characterization of the myxosporean associated with parasitic encephalitis of farmed Atlantic salmon (Salmo salar) in Ireland |
title_sort |
epizootiology, ultrastructure, and molecular characterization of the myxosporean associated with parasitic encephalitis of farmed atlantic salmon (salmo salar) in ireland |
publisher |
OpenCommons@UConn |
publishDate |
1998 |
url |
https://opencommons.uconn.edu/dissertations/AAI9906694 http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:9906694 |
long_lat |
ENVELOPE(98.667,98.667,-66.417,-66.417) |
geographic |
Doublets |
geographic_facet |
Doublets |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_source |
Doctoral Dissertations |
op_relation |
https://opencommons.uconn.edu/dissertations/AAI9906694 http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:9906694 |
_version_ |
1766362541237207040 |