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Kazuaki Takehara - One of the best experts on this subject based on the ideXlab platform.
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doi:10.1155/2012/847505 Research Article Genetic Analysis of Avian Influenza Viruses: Cocirculation of
2016Co-Authors: Nonstructural B Gene, Dany Shoham, Kazuaki TakeharaAbstract:Copyright © 2012 Alam Jahangir et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The pandemic influenza virus strains of 1918 (H1N1), 1957 (H2N2), 1968 (H3N2), and 2009 (H1N1) have genes related to avian influenza viruses (AIVs). The nonstructural (NS) gene of AIVs plays a significant role in host-viral interaction. However, little is known about the degree of diversity of this gene in Northern Pintail (Anas acuta) ducks wintering in Japan. This study describes characteristics of Pintail-originated H1N1, H1N2, H1N3, H5N2, H5N3, H5N9, and H7N7 viruses. Most of the viruses were revealed to be avian strains and not related to pandemic and seasonal flu strains. Nevertheless, the NP genes of 62.5 % (5/8) viruses were found closely related to a A/swine/Korea/C12/08, indicating exchange of genetic material and ongoing mammalian-linked evolution of AIVs. Besides, all the viruses, except Aomori/422/07 H1N1, contain PSIQSR∗GLFmotif usually found in avian, porcine, and human H1 strains. The Aomori/422/07 H1N1 has a PSVQSR∗GLF motif identical to a North American strain. This findings linked to an important intercontinental, Asian-American biogeographical interface. Phylogenetically all the viruses were clustered in Eurasian lineage. Cocirculation of allele A and B (NS gene) viruses was evident in the study implying the existence o
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genetic analysis of avian influenza viruses cocirculation of avian influenza viruses with allele a and b nonstructural gene in Northern Pintail anas acuta ducks wintering in japan
Influenza Research and Treatment, 2012Co-Authors: Alam Jahangir, Sakchai Ruenphet, Dany Shoham, Kazuaki Takehara, Nadia SultanaAbstract:The pandemic influenza virus strains of 1918 (H1N1), 1957 (H2N2), 1968 (H3N2), and 2009 (H1N1) have genes related to avian influenza viruses (AIVs). The nonstructural (NS) gene of AIVs plays a significant role in host-viral interaction. However, little is known about the degree of diversity of this gene in Northern Pintail (Anas acuta) ducks wintering in Japan. This study describes characteristics of Pintail-originated H1N1, H1N2, H1N3, H5N2, H5N3, H5N9, and H7N7 viruses. Most of the viruses were revealed to be avian strains and not related to pandemic and seasonal flu strains. Nevertheless, the NP genes of 62.5% (5/8) viruses were found closely related to a A/swine/Korea/C12/08, indicating exchange of genetic material and ongoing mammalian-linked evolution of AIVs. Besides, all the viruses, except Aomori/422/07 H1N1, contain PSIQSR∗GLF motif usually found in avian, porcine, and human H1 strains. The Aomori/422/07 H1N1 has a PSVQSR∗GLF motif identical to a North American strain. This findings linked to an important intercontinental, Asian-American biogeographical interface. Phylogenetically all the viruses were clustered in Eurasian lineage. Cocirculation of allele A and B (NS gene) viruses was evident in the study implying the existence of a wide reservoir of influenza A viruses in Pintail wintering in Japan.
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phenotypic genetic and phylogeographical characterization of avian influenza virus subtype h5n2 isolated from Northern Pintail anas acuta in japan
Virus Research, 2009Co-Authors: Alam Jahangir, Sakchai Ruenphet, Dany Shoham, Masashi Okamura, Masayuki Nakamaura, Kazuaki TakeharaAbstract:Intercontinental movements of Northern Pintail (Anas acuta) ducks wintering in Japan create a high-risk of both incursion and dispersion of avian influenza viruses (AIVs) that circulate in the ducks’ breeding grounds in Siberia and Alaska. This predisposition is likely amplified by bi-directional conveyance of AIVs between Japan and China. In this study, H5N2 viruses were characterized by means of HA cleavage site sequencing and found to be low pathogenic. Through entire genome analysis, as well as in ovo and in vitro pathogenicity tests, one isolate – A/Northern Pintail/Akita/714/06 H5N2 (Akita/714/06 H5N2) – was characterized. Comparative molecular analysis revealed that genes of this virus have 97.5–99.6% and 96.7–100% likeness at nucleotide and at amino acid level, respectively, with genes of different subtypes of viruses isolated from China, Korea, Russia, and Italy. Phylogenetically, Akita/714/06 (H5N2) clustered with viruses isolated from Eurasian countries. Partial affinity to a recent Korean porcine strain is noticeable. Related evolutionary, ecological, and phenotypic aspects were discussed, thereby signifying the importance of the described pathogen–host–ecosystem interfaces.
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avian influenza and newcastle disease viruses from Northern Pintail in japan isolation characterization and inter annual comparisons during 2006 2008
Virus Research, 2009Co-Authors: Alam Jahangir, Sakchai Ruenphet, Dany Shoham, Masashi Okamura, Masayuki Nakamura, Shuhei Ueda, Yuichi Ueno, Junji Shindo, Kazuaki TakeharaAbstract:Since wild ducks constitute a vital element in the epizootiology of avian influenza viruses (AIVs) as well as avian paramyxoviruses (APMVs) and play a key role in the ecology and inter-species transmission of these viruses, it is crucial to elucidate the diversity and prevalence of these viruses within these bird populations. This report shows the presence, antigenic diversity, and inter-annual prevalence variations of AIVs in apparently healthy Northern Pintail (Anas acta) wintering in Japan. We also provide evidence that this host carries APMV-1: Newcastle disease virus (NDV) and other haemagglutinating viruses. Composite samples (n = 2381) of fresh fecal materials were collected from Northern Pintail during November 2007–March 2008 at different locations of Tohoku district, main Island, Japan. We isolated 47 haemagglutinating viruses, out of which 25 were identified as AIVs, representing 9 combinations of 5 different haemagglutinin (HA) and 6 neuraminidase (NA) subtypes. Both H5 and H7 subtypes were identified and found to be low pathogenic. A further 11 viruses were grouped into APMV-1 (NDV). The rest of the viruses (n = 11) remained to be identified. Some of the HA subtypes and NA subtypes detected during the first season reoccurred in the second season, as well as some of their combinations; yet, several new subtypes and combinations appeared during the second season. These findings indicate that different subtypes of AIVs, NDV and other haemagglutinating viruses circulate subclinically in the Pintail populations sampled. Pintails should be regarded, potentially, as important spreaders of AIVs and NDVs, particularly due to their extensively ramified flyways, which include various inter-continental routes.
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surveillance of avian influenza viruses in Northern Pintails anas acuta in tohoku district japan
Avian Diseases, 2008Co-Authors: Alam Jahangir, Masashi Okamura, Kouji Sakai, Yuko Watanabe, Masayuki Nakamura, Omoto Chinen, Shoki Yamazaki, Kazuaki TakeharaAbstract:Among winter migratory waterfowl, Northern Pintails (Anas acuta), in one of the largest flocks in Tohoku district, northeast Japan, were surveyed for influenza A viruses at five wintering sites in three prefectures, viz., Aomori, Akita, and Miyagi. A total of 38 influenza A viruses were isolated from 2066 fecal samples collected during November 2006 through March 2007. The overall isolation rate was 1.84%. Eleven different subtypes were isolated, including nine H5N2, seven H6N8, seven H10N1, four H4N6, three H6N1, three H11N9, and one each of H1N1, H6N2, H6N5, H10N9, H11N1. Only the H4N6 subtype was detected during two successive months, November and December, from Lake Ogawara of Aomori prefecture. One wintering site, Lake Izunuma of Miyagi prefecture, was negative for virus isolation throughout the study period. During the sampling period, the highest virus isolation rate was in December (4.90%) followed by November (2.18%), January (0.91%), and February (0.30%). Virus isolation was negative for samples collected in March 2007. These results suggest that influenza viruses are introduced by Northern Pintail when they migrate into Japan, but the viruses are not maintained in the flocks, most likely because the birds are not breeding during the winter. We believe that this relatively large data set creates a strong foundation for future studies of avian influenza virus (AIV) prevalence, evolution, and ecology in wintering sites, along with the role of Northern Pintails in the spread of AIV during their migration from Northern Russia and Asia to Japan.
Alam Jahangir - One of the best experts on this subject based on the ideXlab platform.
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genetic analysis of avian influenza viruses cocirculation of avian influenza viruses with allele a and b nonstructural gene in Northern Pintail anas acuta ducks wintering in japan
Influenza Research and Treatment, 2012Co-Authors: Alam Jahangir, Sakchai Ruenphet, Dany Shoham, Kazuaki Takehara, Nadia SultanaAbstract:The pandemic influenza virus strains of 1918 (H1N1), 1957 (H2N2), 1968 (H3N2), and 2009 (H1N1) have genes related to avian influenza viruses (AIVs). The nonstructural (NS) gene of AIVs plays a significant role in host-viral interaction. However, little is known about the degree of diversity of this gene in Northern Pintail (Anas acuta) ducks wintering in Japan. This study describes characteristics of Pintail-originated H1N1, H1N2, H1N3, H5N2, H5N3, H5N9, and H7N7 viruses. Most of the viruses were revealed to be avian strains and not related to pandemic and seasonal flu strains. Nevertheless, the NP genes of 62.5% (5/8) viruses were found closely related to a A/swine/Korea/C12/08, indicating exchange of genetic material and ongoing mammalian-linked evolution of AIVs. Besides, all the viruses, except Aomori/422/07 H1N1, contain PSIQSR∗GLF motif usually found in avian, porcine, and human H1 strains. The Aomori/422/07 H1N1 has a PSVQSR∗GLF motif identical to a North American strain. This findings linked to an important intercontinental, Asian-American biogeographical interface. Phylogenetically all the viruses were clustered in Eurasian lineage. Cocirculation of allele A and B (NS gene) viruses was evident in the study implying the existence of a wide reservoir of influenza A viruses in Pintail wintering in Japan.
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surveillance and characterization of newcastle disease viruses isolated from Northern Pintail anas acuta in japan during 2006 09
Avian Diseases, 2011Co-Authors: Alam Jahangir, Sakchai Ruenphet, Dany Shoham, Masashi Okamura, Kae Morikawa, Yuki Miyoshi, Eiko Hanawa, Masayuki NakamuraAbstract:Abstract A total of 38 Newcastle disease virus (NDV) isolates were obtained from 6060 fecal samples from Northern Pintail (Anas acuta) ducks collected in the Tohoku district in Japan during 2006–09. One isolate from each sampling location and date was selected for a total of 38 isolates, then 15 of these were characterized for their pathogenicity by mean death time of minimum lethal dose (MDT/MLD) using chicken embryos and by plaque formation on chicken embryo fibroblasts. Furthermore, nine isolates were randomly selected from these 15 isolates, and the fusion protein genes were sequenced to characterize amino acid sequences around the cleavage site. All 15 were confirmed to be nonvirulent by MDT/MLD test, and nine isolates were also confirmed as nonvirulent by the cleavage site of the fusion protein 112G/E-K/R-Q-G/E-R*L117 that was specific for nonvirulent NDVs. The characteristics of nine isolates identified by phylogenic analysis of the fusion protein gene indicated that the isolates belong to genotype...
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phenotypic genetic and phylogeographical characterization of avian influenza virus subtype h5n2 isolated from Northern Pintail anas acuta in japan
Virus Research, 2009Co-Authors: Alam Jahangir, Sakchai Ruenphet, Dany Shoham, Masashi Okamura, Masayuki Nakamaura, Kazuaki TakeharaAbstract:Intercontinental movements of Northern Pintail (Anas acuta) ducks wintering in Japan create a high-risk of both incursion and dispersion of avian influenza viruses (AIVs) that circulate in the ducks’ breeding grounds in Siberia and Alaska. This predisposition is likely amplified by bi-directional conveyance of AIVs between Japan and China. In this study, H5N2 viruses were characterized by means of HA cleavage site sequencing and found to be low pathogenic. Through entire genome analysis, as well as in ovo and in vitro pathogenicity tests, one isolate – A/Northern Pintail/Akita/714/06 H5N2 (Akita/714/06 H5N2) – was characterized. Comparative molecular analysis revealed that genes of this virus have 97.5–99.6% and 96.7–100% likeness at nucleotide and at amino acid level, respectively, with genes of different subtypes of viruses isolated from China, Korea, Russia, and Italy. Phylogenetically, Akita/714/06 (H5N2) clustered with viruses isolated from Eurasian countries. Partial affinity to a recent Korean porcine strain is noticeable. Related evolutionary, ecological, and phenotypic aspects were discussed, thereby signifying the importance of the described pathogen–host–ecosystem interfaces.
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avian influenza and newcastle disease viruses from Northern Pintail in japan isolation characterization and inter annual comparisons during 2006 2008
Virus Research, 2009Co-Authors: Alam Jahangir, Sakchai Ruenphet, Dany Shoham, Masashi Okamura, Masayuki Nakamura, Shuhei Ueda, Yuichi Ueno, Junji Shindo, Kazuaki TakeharaAbstract:Since wild ducks constitute a vital element in the epizootiology of avian influenza viruses (AIVs) as well as avian paramyxoviruses (APMVs) and play a key role in the ecology and inter-species transmission of these viruses, it is crucial to elucidate the diversity and prevalence of these viruses within these bird populations. This report shows the presence, antigenic diversity, and inter-annual prevalence variations of AIVs in apparently healthy Northern Pintail (Anas acta) wintering in Japan. We also provide evidence that this host carries APMV-1: Newcastle disease virus (NDV) and other haemagglutinating viruses. Composite samples (n = 2381) of fresh fecal materials were collected from Northern Pintail during November 2007–March 2008 at different locations of Tohoku district, main Island, Japan. We isolated 47 haemagglutinating viruses, out of which 25 were identified as AIVs, representing 9 combinations of 5 different haemagglutinin (HA) and 6 neuraminidase (NA) subtypes. Both H5 and H7 subtypes were identified and found to be low pathogenic. A further 11 viruses were grouped into APMV-1 (NDV). The rest of the viruses (n = 11) remained to be identified. Some of the HA subtypes and NA subtypes detected during the first season reoccurred in the second season, as well as some of their combinations; yet, several new subtypes and combinations appeared during the second season. These findings indicate that different subtypes of AIVs, NDV and other haemagglutinating viruses circulate subclinically in the Pintail populations sampled. Pintails should be regarded, potentially, as important spreaders of AIVs and NDVs, particularly due to their extensively ramified flyways, which include various inter-continental routes.
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surveillance of avian influenza viruses in Northern Pintails anas acuta in tohoku district japan
Avian Diseases, 2008Co-Authors: Alam Jahangir, Masashi Okamura, Kouji Sakai, Yuko Watanabe, Masayuki Nakamura, Omoto Chinen, Shoki Yamazaki, Kazuaki TakeharaAbstract:Among winter migratory waterfowl, Northern Pintails (Anas acuta), in one of the largest flocks in Tohoku district, northeast Japan, were surveyed for influenza A viruses at five wintering sites in three prefectures, viz., Aomori, Akita, and Miyagi. A total of 38 influenza A viruses were isolated from 2066 fecal samples collected during November 2006 through March 2007. The overall isolation rate was 1.84%. Eleven different subtypes were isolated, including nine H5N2, seven H6N8, seven H10N1, four H4N6, three H6N1, three H11N9, and one each of H1N1, H6N2, H6N5, H10N9, H11N1. Only the H4N6 subtype was detected during two successive months, November and December, from Lake Ogawara of Aomori prefecture. One wintering site, Lake Izunuma of Miyagi prefecture, was negative for virus isolation throughout the study period. During the sampling period, the highest virus isolation rate was in December (4.90%) followed by November (2.18%), January (0.91%), and February (0.30%). Virus isolation was negative for samples collected in March 2007. These results suggest that influenza viruses are introduced by Northern Pintail when they migrate into Japan, but the viruses are not maintained in the flocks, most likely because the birds are not breeding during the winter. We believe that this relatively large data set creates a strong foundation for future studies of avian influenza virus (AIV) prevalence, evolution, and ecology in wintering sites, along with the role of Northern Pintails in the spread of AIV during their migration from Northern Russia and Asia to Japan.
Paul L. Flint - One of the best experts on this subject based on the ideXlab platform.
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Logistic regression models of variation in avian influenza virus (AIV) seroprevalence in adult waterfowl sampled in Alaska, USA, 1998–2010 (n = 3,588).
2013Co-Authors: Heather M. Wilson, Paul L. Flint, Jeffery S. Hall, Christian J. Franson, Craig R. Ely, Joel A. Schmutz, Michael D. SamuelAbstract:ak = number of parameters in model.bThe best approximating model has the lowest Akaike's Information Criterion (AIC) value and the highest model weight (ωi), relative to others in the model set.In this model suite, only the effects of species and sex were examined. Species include tundra swan (TUSW; Cygnus columbianus), cackling goose (CACG; Branta hutchinsii), Pacific black brant (BLBR; B. bernicla nigricans), greater white-fronted goose (GWFG; Anser albifrons), emperor goose (EMGO; A. canagica), Northern Pintail (NOPI; Anas acuta), Pacific common eider (COEI; Somateria mollissima v-nigrum), spectacled eider (SPEI; S. fischeri), Steller's eider (STEI; Polysticta stelleri), long-tailed duck (LTDU; Clangula hyemalis), and black scoter (BLSC; Melanitta nigra).
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Logistic regression models of variation in avian influenza virus (AIV) seroprevalence in waterfowl sampled in Alaska, USA, 1998–2010 (n = 3405), examining the effects of age while controlling for sex and species.
2013Co-Authors: Heather M. Wilson, Paul L. Flint, Jeffery S. Hall, Christian J. Franson, Craig R. Ely, Joel A. Schmutz, Michael D. SamuelAbstract:ak = number of parameters in model.bThe best approximating model has the lowest Akaike's Information Criterion (AIC) value and the highest model weight (ωi), relative to others in the model set.Ages classes included “sub-adult”, representing hatch year (HY) birds for Northern Pintails and second year (SY) birds for all other species, and “adults”, representing after hatch year (AHY) birds for Northern Pintails and/or after second year (ASY) birds for other species. Species include tundra swan (TUSW; Cygnus columbianus), cackling goose (CACG; Branta hutchinsii), greater white-fronted goose (GWFG; Anser albifrons), Pacific black brant (BLBR; B. bernicla nigricans), and Northern Pintail (NOPI; Anas acuta).
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satellite tracking of Northern Pintail anas acuta during outbreaks of the h5n1 virus in japan implications for virus spread
Ibis, 2010Co-Authors: Noriyuki Yamaguchi, Paul L. Flint, Jerry W Hupp, Hiroyoshi Higuchi, John M PearceAbstract:We fitted Northern Pintail Anas acuta in Japan with satellite transmitters and monitored their spring migration movements relative to locations where the highly pathogenic H5N1 avian influenza virus was detected in Whooper Swans Cygnus cygnus in 2008. Pintails were assumed not to be infected with the H5N1 virus at the time they were marked because capture occurred between 2 and 5 months before reported outbreaks of the virus in Japan. We assessed spatial and temporal overlap between marked birds and occurrence of the virus and tracked Pintails after they departed outbreak locations. Eight of 66 (12.1%) Northern Pintails marked with satellite transmitters used wetlands in Japan where the H5N1 virus was detected in Whooper Swans. Apparent survival did not differ between Pintails that used H5N1 sites and those that did not. However, the proportion of Pintails that migrated from Japan was significantly lower among birds that used H5N1 sites compared with those that did not (0.50 vs. 0.79). Northern Pintails were present at the H5N1 sites from 1 to 88 days, with five birds present at the sites from 0 to 7 days prior to detection of the virus in Swans. The six Pintails observed to depart H5N1 sites did so within 2-77 days of the reported outbreaks and moved between 6 and 1200 km within 4 days of departure. Four Pintails migrated to eastern Russia. After their departure from outbreak sites, Northern Pintails made long-distance migrations within the period when newly infected ducks would shed the H5N1 virus. This supports a hypothesized mechanism by which a highly pathogenic avian influenza virus could be spread by migratory birds.
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breeding season sympatry facilitates genetic exchange among allopatric wintering populations of Northern Pintails in japan and california
The Condor, 2009Co-Authors: Paul L. Flint, Joseph P. Fleskes, John M Pearce, Hiroyoshi Higuchi, Kiyoaki Ozaki, Brian M Guzzetti, Tetsuo Shimada, Dirk V DerksenAbstract:Abstract. The global redistribution of pathogens, such as highly pathogenic avian influenza, has renewed interest in the connectivity of continental populations of birds. Populations of the Northern Pintail (Anas acuta) wintering in Japan and California are considered separate from a management perspective. We used data from band recoveries and population genetics to assess the degree of biological independence of these wintering populations. Distributions of recoveries in Russia of Northern Pintails originally banded during winter in North America overlapped with distributions of Northern Pintails banded during winter in Japan. Thus these allopatric wintering populations are partially sympatric during the breeding season. The primary areas of overlap were along the Chukotka and Kamchatka peninsulas in Russia. Furthermore, band recoveries demonstrated dispersal of individuals between wintering populations both from North America to Japan and vice versa. Genetic analyses of samples from both wintering popu...
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genetic evidence of intercontinental movement of avian influenza in a migratory bird the Northern Pintail anas acuta
Molecular Ecology, 2008Co-Authors: Anson V Koehler, Paul L. Flint, John M Pearce, Christian J. FransonAbstract:The role of migratory birds in the movement of the highly pathogenic (HP) avian influenza H5N1 remains a subject of debate. Testing hypotheses regarding intercontinental movement of low pathogenic avian influenza (LPAI) viruses will help evaluate the potential that wild birds could carry Asian-origin strains of HP avian influenza to North America during migration. Previous North American assessments of LPAI genetic variation have found few Asian reassortment events. Here, we present results from whole-genome analyses of LPAI isolates collected in Alaska from the Northern Pintail (Anas acuta), a species that migrates between North America and Asia. Phylogenetic analyses confirmed the genetic divergence between Asian and North American strains of LPAI, but also suggested inter-continental virus exchange and at a higher frequency than previously documented. In 38 isolates from Alaska, nearly half (44.7%) had at least one gene segment more closely related to Asian than to North American strains of LPAI. Additionally, sequences of several Asian LPAI isolates from GenBank clustered more closely with North American Northern Pintail isolates than with other Asian origin viruses. Our data support the role of wild birds in the intercontinental transfer of influenza viruses, and reveal a higher degree of transfer in Alaska than elsewhere in North America.
Dany Shoham - One of the best experts on this subject based on the ideXlab platform.
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doi:10.1155/2012/847505 Research Article Genetic Analysis of Avian Influenza Viruses: Cocirculation of
2016Co-Authors: Nonstructural B Gene, Dany Shoham, Kazuaki TakeharaAbstract:Copyright © 2012 Alam Jahangir et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The pandemic influenza virus strains of 1918 (H1N1), 1957 (H2N2), 1968 (H3N2), and 2009 (H1N1) have genes related to avian influenza viruses (AIVs). The nonstructural (NS) gene of AIVs plays a significant role in host-viral interaction. However, little is known about the degree of diversity of this gene in Northern Pintail (Anas acuta) ducks wintering in Japan. This study describes characteristics of Pintail-originated H1N1, H1N2, H1N3, H5N2, H5N3, H5N9, and H7N7 viruses. Most of the viruses were revealed to be avian strains and not related to pandemic and seasonal flu strains. Nevertheless, the NP genes of 62.5 % (5/8) viruses were found closely related to a A/swine/Korea/C12/08, indicating exchange of genetic material and ongoing mammalian-linked evolution of AIVs. Besides, all the viruses, except Aomori/422/07 H1N1, contain PSIQSR∗GLFmotif usually found in avian, porcine, and human H1 strains. The Aomori/422/07 H1N1 has a PSVQSR∗GLF motif identical to a North American strain. This findings linked to an important intercontinental, Asian-American biogeographical interface. Phylogenetically all the viruses were clustered in Eurasian lineage. Cocirculation of allele A and B (NS gene) viruses was evident in the study implying the existence o
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genetic analysis of avian influenza viruses cocirculation of avian influenza viruses with allele a and b nonstructural gene in Northern Pintail anas acuta ducks wintering in japan
Influenza Research and Treatment, 2012Co-Authors: Alam Jahangir, Sakchai Ruenphet, Dany Shoham, Kazuaki Takehara, Nadia SultanaAbstract:The pandemic influenza virus strains of 1918 (H1N1), 1957 (H2N2), 1968 (H3N2), and 2009 (H1N1) have genes related to avian influenza viruses (AIVs). The nonstructural (NS) gene of AIVs plays a significant role in host-viral interaction. However, little is known about the degree of diversity of this gene in Northern Pintail (Anas acuta) ducks wintering in Japan. This study describes characteristics of Pintail-originated H1N1, H1N2, H1N3, H5N2, H5N3, H5N9, and H7N7 viruses. Most of the viruses were revealed to be avian strains and not related to pandemic and seasonal flu strains. Nevertheless, the NP genes of 62.5% (5/8) viruses were found closely related to a A/swine/Korea/C12/08, indicating exchange of genetic material and ongoing mammalian-linked evolution of AIVs. Besides, all the viruses, except Aomori/422/07 H1N1, contain PSIQSR∗GLF motif usually found in avian, porcine, and human H1 strains. The Aomori/422/07 H1N1 has a PSVQSR∗GLF motif identical to a North American strain. This findings linked to an important intercontinental, Asian-American biogeographical interface. Phylogenetically all the viruses were clustered in Eurasian lineage. Cocirculation of allele A and B (NS gene) viruses was evident in the study implying the existence of a wide reservoir of influenza A viruses in Pintail wintering in Japan.
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surveillance and characterization of newcastle disease viruses isolated from Northern Pintail anas acuta in japan during 2006 09
Avian Diseases, 2011Co-Authors: Alam Jahangir, Sakchai Ruenphet, Dany Shoham, Masashi Okamura, Kae Morikawa, Yuki Miyoshi, Eiko Hanawa, Masayuki NakamuraAbstract:Abstract A total of 38 Newcastle disease virus (NDV) isolates were obtained from 6060 fecal samples from Northern Pintail (Anas acuta) ducks collected in the Tohoku district in Japan during 2006–09. One isolate from each sampling location and date was selected for a total of 38 isolates, then 15 of these were characterized for their pathogenicity by mean death time of minimum lethal dose (MDT/MLD) using chicken embryos and by plaque formation on chicken embryo fibroblasts. Furthermore, nine isolates were randomly selected from these 15 isolates, and the fusion protein genes were sequenced to characterize amino acid sequences around the cleavage site. All 15 were confirmed to be nonvirulent by MDT/MLD test, and nine isolates were also confirmed as nonvirulent by the cleavage site of the fusion protein 112G/E-K/R-Q-G/E-R*L117 that was specific for nonvirulent NDVs. The characteristics of nine isolates identified by phylogenic analysis of the fusion protein gene indicated that the isolates belong to genotype...
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phenotypic genetic and phylogeographical characterization of avian influenza virus subtype h5n2 isolated from Northern Pintail anas acuta in japan
Virus Research, 2009Co-Authors: Alam Jahangir, Sakchai Ruenphet, Dany Shoham, Masashi Okamura, Masayuki Nakamaura, Kazuaki TakeharaAbstract:Intercontinental movements of Northern Pintail (Anas acuta) ducks wintering in Japan create a high-risk of both incursion and dispersion of avian influenza viruses (AIVs) that circulate in the ducks’ breeding grounds in Siberia and Alaska. This predisposition is likely amplified by bi-directional conveyance of AIVs between Japan and China. In this study, H5N2 viruses were characterized by means of HA cleavage site sequencing and found to be low pathogenic. Through entire genome analysis, as well as in ovo and in vitro pathogenicity tests, one isolate – A/Northern Pintail/Akita/714/06 H5N2 (Akita/714/06 H5N2) – was characterized. Comparative molecular analysis revealed that genes of this virus have 97.5–99.6% and 96.7–100% likeness at nucleotide and at amino acid level, respectively, with genes of different subtypes of viruses isolated from China, Korea, Russia, and Italy. Phylogenetically, Akita/714/06 (H5N2) clustered with viruses isolated from Eurasian countries. Partial affinity to a recent Korean porcine strain is noticeable. Related evolutionary, ecological, and phenotypic aspects were discussed, thereby signifying the importance of the described pathogen–host–ecosystem interfaces.
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avian influenza and newcastle disease viruses from Northern Pintail in japan isolation characterization and inter annual comparisons during 2006 2008
Virus Research, 2009Co-Authors: Alam Jahangir, Sakchai Ruenphet, Dany Shoham, Masashi Okamura, Masayuki Nakamura, Shuhei Ueda, Yuichi Ueno, Junji Shindo, Kazuaki TakeharaAbstract:Since wild ducks constitute a vital element in the epizootiology of avian influenza viruses (AIVs) as well as avian paramyxoviruses (APMVs) and play a key role in the ecology and inter-species transmission of these viruses, it is crucial to elucidate the diversity and prevalence of these viruses within these bird populations. This report shows the presence, antigenic diversity, and inter-annual prevalence variations of AIVs in apparently healthy Northern Pintail (Anas acta) wintering in Japan. We also provide evidence that this host carries APMV-1: Newcastle disease virus (NDV) and other haemagglutinating viruses. Composite samples (n = 2381) of fresh fecal materials were collected from Northern Pintail during November 2007–March 2008 at different locations of Tohoku district, main Island, Japan. We isolated 47 haemagglutinating viruses, out of which 25 were identified as AIVs, representing 9 combinations of 5 different haemagglutinin (HA) and 6 neuraminidase (NA) subtypes. Both H5 and H7 subtypes were identified and found to be low pathogenic. A further 11 viruses were grouped into APMV-1 (NDV). The rest of the viruses (n = 11) remained to be identified. Some of the HA subtypes and NA subtypes detected during the first season reoccurred in the second season, as well as some of their combinations; yet, several new subtypes and combinations appeared during the second season. These findings indicate that different subtypes of AIVs, NDV and other haemagglutinating viruses circulate subclinically in the Pintail populations sampled. Pintails should be regarded, potentially, as important spreaders of AIVs and NDVs, particularly due to their extensively ramified flyways, which include various inter-continental routes.
Scott R Derrickson - One of the best experts on this subject based on the ideXlab platform.
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Seasonal patterns of LH, testosterone and semen quality in the Northern Pintail duck (Anas acuta)
2015Co-Authors: L. M. Penfold, Scott R Derrickson, W. Lynch, T L Herzog, D. E. Wildt, L. Ware, S. L. MonfortAbstract:Abstract. This study characterized seasonal changes in circulating LH and testosterone and in semen production and quality in the Northern Pintail duck. Plasma LH and testosterone were measured in blood samples collected weekly throughout the year from eight males exposed to natural fluctuations in day length and temperature. Semen quality was evaluated weekly in these same males from April-June, the months when spermatozoa were produced. Semen quality {based on sperm concentration and normal morphology) peaked 0-2 weeks after sperm production onset and decreased sharply before sperm production cessation in late June. Nadir LH concentrations were measured in July and August with peak LH observed in May and November. There were clear seasonal patterns in circulating testosterone with July-September values being less (P<0.05) than October-December which, in turn, were less {P<0.05) than January-March. Maximal circulating testosterone (P<0.05) occurred during April-June, coincident with semen production. Weekly circulating LH during the breeding season was directly related to testosterone concentrations (P<0.01), but was not correlated to any specific semen or sperm trait (P>{).{)5). Testosterone concentrations throughout the breeding season were correlated (P<0.05) to total numbers of spermatozoa produced (volume X cell concentration) and percent normal sperm morphology. In summary, the Northern Pintail experiences seasonal hormone fluctuations, with maximum circulating testosterone coinciding with peak ejaculate quality reflected by the production of high numbers of morphologically normal spermatozoa
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characterization of Northern Pintail anas acuta ejaculate and the effect of sperm preservation on fertility
Reproduction, 2001Co-Authors: Linda M. Penfold, Scott R Derrickson, W. Lynch, V.k. Harnal, D.m. Bird, David E. WildtAbstract:Despite an abundance of waterfowl worldwide (154species are currently recognized; Ellis-Joseph et al.,1992),the survival of many individual species is threatened.According to a Conservation and Assessment ManagementPlan Workshop for waterfowl (Ellis-Joseph et al.,1992),species under threat of extinction include the Hawaiiangoose or Nene (Branta sandvicensis), Hawaiian duck (Anaswyvlliana), Laysan teal (Anas laysanensis), Tule goose(Anser albifrons gambelli) and Trumpeter swan (Olor buc-cinator). Other species, like the Northern Pintail (Anasacuta) are subject to non-cyclical population decreases orlocal–regional range contractions, indicative of species orpopulations that are not yet endangered, but may becomeso in the near future (US Fish and Wildlife Service, 1999). As populations decrease in size (in nature or captivity),inbreeding can occur which, in turn, can reduce reproduc-tive fitness (Nei et al., 1975), including fecundity and sur-vivability (Ralls and Ballou, 1986). When genetic variationis maintained or increased, population vigour and the ability to adapt to environmental change are enhanced.Challenges in waterfowl management include cross-species hybridization (Ankney et al., 1986) that can resultin a loss of species uniqueness and specialized adaptiveand fitness traits, and failure to reproduce in captivityowing to behavioural problems associated with confine-ment (Hediger, 1965). One solution to these managementchallenges is the use of assisted breeding techniques in-cluding sperm preservation combined with artificial in-semination (AI). Such strategies can complement captivebreeding programs by: (1) preserving valuable genes fromindividuals for infusing into future generations; (2) reduc-ing disease transfer risk by transporting genetic material instead of birds between flocks; and (3) providing a reposi-tory of genetic material for species not yet endangered thatmay be threatened eventually by unexpected hybridization(with common species) or by natural catastrophe.Although information is available on basic sperm physiol-ogy from agriculturally valuable birds, especially chickensand turkeys (Bakst, 1990), there is a dearth of informationon non-domestic birds. If AI is to be an effective tool forthe management and conservation of rare waterfowlspecies, a high priority should be basic reproductive stud-ies that focus on consistent sperm collection and spermsensitivity to cooling and freeze–thawing.Short-term (6 h) preservation of semen has been usedextensively in the turkey industry (Sexton, 1981; Bakst,1990), but has been shown to result in reduced fertilityover time (Wishart, 1984; Sexton, 1988a; Thurston, 1995).Several studies have addressed the issue of developing cryopreservation techniques for domestic birds, includingdomestic fowls (Polge, 1951) and domestic drakes (Tai etal., 1983; Tselutin et al., 1995; Watanabe et al., 1981).
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characterization of Northern Pintail anas acuta ejaculate and the effect of sperm preservation on fertility
Reproduction, 2001Co-Authors: Linda M. Penfold, Scott R Derrickson, W. Lynch, V.k. Harnal, D.m. Bird, David E. WildtAbstract:Northern Pintail duck semen and sperm traits were characterized, and the fertility of cold-stored spermatozoa was investigated using artificial insemination. Excellent quality ejaculates containing high proportions of motile spermatozoa were collected from drakes within 20 s by a massage technique. Semen was collected in Beltsville poultry semen extender, pooled and cold-stored (4 degrees C) for 0, 24, 48 or 72 h. Hens were inseminated with 100 microl twice a week, and eggs were assessed for fertilization and hatch success. Fertilization success was similar (P > 0.05) for semen cold-stored for 0 (51.6%), 24 (51.5%), 48 (41.1%) and 72 h (22.3%; P > 0.05). Similar (P > 0.05) percentages of fertilized eggs hatched to live offspring (73.1, 71.4, 87.0 and 80.0%, respectively). Fresh semen was also equilibrated with 1 or 4% dimethylsulphoxide or glycerol, and cryopreserved at the following rates: (1) approximately 60 degrees C min(-1) (in liquid nitrogen [LN(2)] vapour) for 10 min; (2) 1 degrees C min(-1) to -20 degrees C, LN(2) vapour for 10 min; and (3) 1 degrees C min(-1) to -35 degrees C, all followed by immersion in LN(2). After thawing for 30 s at 37 degrees C or 20 min at 4 degrees C, sperm motility and viability were assessed. The highest numbers of motile spermatozoa were recovered after slow-fast freezing (2) and thawing at 0 degrees C (P < 0.05), but survival was inadequate to allow artificial insemination. Nonetheless, cold storage provides an effective means of short-term storage with no loss of fertility in this waterfowl species.
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seasonal patterns of lh testosterone and semen quality in the Northern Pintail duck anas acuta
Reproduction Fertility and Development, 2000Co-Authors: Linda M. Penfold, Scott R Derrickson, W. Lynch, David E. Wildt, T L Herzog, Lisa H Ware, Steven L. MonfortAbstract:This study characterized seasonal changes in circulating LH and testosterone and in semen production and quality in the Northern Pintail duck. Plasma LH and testosterone were measured in blood samples collected weekly throughout the year from eight males exposed to natural fluctuations in day length and temperature. Semen quality was evaluated weekly in these same males from April–June, the months when spermatozoa were produced. Semen quality (based on sperm concentration and normal morphology) peaked 0–2 weeks after sperm production onset and decreased sharply before sperm production cessation in late June. Nadir LH concentrations were measured in July and August with peak LH observed in May and November. There were clear seasonal patterns in circulating testosterone with July–September values being less (P 0.05). Testosterone concentrations throughout the breeding season were correlated (P<0.05) to total numbers of spermatozoa produced (volume cell concentration) and percent normal sperm morphology. In summary, the Northern Pintail experiences seasonal hormone fluctuations, with maximum circulating testosterone coinciding with peak ejaculate quality reflected by the production of high numbers of morphologically normal spermatozoa.
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hormonal dynamics during mate choice in the Northern Pintail a test of the challenge hypothesis
Animal Behaviour, 1997Co-Authors: Lisa G Sorenson, Andrea M Brown, Paul M Nolan, Scott R Derrickson, Steven L. MonfortAbstract:Abstract In previous mate choice experiments, we found no relationship between dominance rank and pairing success in male Northern Pintails, Anas acuta Once chosen by a female, however, males became aggressive, initiated fights with higher-ranked males and quickly established dominance. In the present study, we tested a variation of the ‘challenge’ hypothesis, that the behavioural stimuli associated with acquiring and defending a mate induce an increase in testosterone level, which in turn facilitates aggressive behaviours required for males to establish dominance. We measured plasma hormone levels (testosterone, dihydrotestosterone, luteinizing hormone and corticosterone) before and after mate choice in two experiments in which males competed for a single female (experiments 1 and 2) and in a control experiment in which no female was introduced (experiment 3). We used groups of either three adult males (experiment 1) or one adult and two yearling males (experiments 2 and 3). Contrary to expectation, in experiment 1, plasma levels of corticosterone increased significantly and testosterone levels decreased in chosen males following mate choice. The magnitude of change in corticosterone was positively correlated with the rate of aggression by males. Chosen adult males in experiment 2 showed similar patterns of hormone change (corticosterone increase and testosterone decrease), although not all changes were significant. Hormone levels of unchosen yearlings in experiment 2 and control adults and yearlings in experiment 3 showed no changes. The results are consistent with the hypothesis that behavioural stimuli associated with successful pair formation induce a transitory increase in circulating levels of corticosterone, which in turn mediates the behavioural response of increased aggression leading to the establishment of dominance following mate choice. A short-term increase in corticosterone may be adaptive in this situation because it would mobilize energy stores needed by the male to defend the new pair bond and establish dominance.