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Takema Fukatsu - One of the best experts on this subject based on the ideXlab platform.
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cellular mechanism for selective Vertical Transmission of an obligate insect symbiont at the bacteriocyte embryo interface
Proceedings of the National Academy of Sciences of the United States of America, 2012Co-Authors: Ryuichi Koga, Tsutomu Tsuchida, Xianying Meng, Takema FukatsuAbstract:Many insects are associated with obligate symbiotic bacteria, which are localized in specialized cells called bacteriocytes, Vertically transmitted through host generations via ovarial passage, and essential for growth and reproduction of their hosts. Although Vertical Transmission is pivotal for maintenance of such intimate host–symbiont associations, molecular and cellular mechanisms underlying the process are largely unknown. Here we report a cellular mechanism for Vertical Transmission of the obligate symbiont Buchnera in the pea aphid Acyrthosiphon pisum. In the aphid body, Buchnera cells are transmitted from maternal bacteriocytes to adjacent blastulae at the ovariole tips in a highly coordinated manner. By making use of symbiont-manipulated strains of A. pisum, we demonstrated that the facultative symbiont Serratia is, unlike Buchnera, not transmitted from maternal bacteriocytes to blastulae, suggesting a specific mechanism for Buchnera Transmission. EM observations revealed a series of exo-/endocytotic processes operating at the bacteriocyte–blastula interface: Buchnera cells are exocytosed from the maternal bacteriocyte, temporarily released to the extracellular space, and endocytosed by the posterior syncytial cytoplasm of the blastula. These results suggest that the selective Buchnera Transmission is likely attributable to Buchnera-specific exocytosis by the maternal bacteriocyte, whereas both Buchnera and Serratia are nonselectively incorporated by the endocytotic activity of the posterior region of the blastula. The sophisticated cellular mechanism for Vertical Transmission of Buchnera must have evolved to ensure the obligate host–symbiont association, whereas facultative symbionts like Serratia may coopt the endocytotic component of the mechanism for their entry into the host embryos.
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high and low temperatures differently affect infection density and Vertical Transmission of male killing spiroplasma symbionts in drosophila hosts
Applied and Environmental Microbiology, 2008Co-Authors: Hisashi Anbutsu, Shunsuke Goto, Takema FukatsuAbstract:We investigated the Vertical Transmission, reproductive phenotype, and infection density of a male-killing Spiroplasma symbiont in two Drosophila species under physiological high and low temperatures through successive host generations. In both the native host Drosophila nebulosa and the nonnative host Drosophila melanogaster, the symbiont infection and the male-killing phenotype were stably maintained at 25°C, rapidly lost at 18°C, and gradually lost at 28°C. In the nonnative host, both the high and low temperatures significantly suppressed the infection density of the spiroplasma. In the native host, by contrast, the low temperature suppressed the infection density of the spiroplasma whereas the high temperature had little effect on the infection density. These results suggested that the low temperature suppresses both the infection density and the Vertical Transmission of the spiroplasma whereas the high temperature suppresses the Vertical Transmission preferentially. The spiroplasma density was consistently higher in the native host than in the nonnative host, suggesting that the host genotype may affect the infection density of the symbiont. The temperature- and genotype-dependent instability of the symbiont infection highlights a complex genotype-by-genotype-by-environment interaction and may be relevant to the low infection frequencies of the male-killing spiroplasmas in natural Drosophila populations.
Tsutomu Tsuchida - One of the best experts on this subject based on the ideXlab platform.
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cellular mechanism for selective Vertical Transmission of an obligate insect symbiont at the bacteriocyte embryo interface
Proceedings of the National Academy of Sciences of the United States of America, 2012Co-Authors: Ryuichi Koga, Tsutomu Tsuchida, Xianying Meng, Takema FukatsuAbstract:Many insects are associated with obligate symbiotic bacteria, which are localized in specialized cells called bacteriocytes, Vertically transmitted through host generations via ovarial passage, and essential for growth and reproduction of their hosts. Although Vertical Transmission is pivotal for maintenance of such intimate host–symbiont associations, molecular and cellular mechanisms underlying the process are largely unknown. Here we report a cellular mechanism for Vertical Transmission of the obligate symbiont Buchnera in the pea aphid Acyrthosiphon pisum. In the aphid body, Buchnera cells are transmitted from maternal bacteriocytes to adjacent blastulae at the ovariole tips in a highly coordinated manner. By making use of symbiont-manipulated strains of A. pisum, we demonstrated that the facultative symbiont Serratia is, unlike Buchnera, not transmitted from maternal bacteriocytes to blastulae, suggesting a specific mechanism for Buchnera Transmission. EM observations revealed a series of exo-/endocytotic processes operating at the bacteriocyte–blastula interface: Buchnera cells are exocytosed from the maternal bacteriocyte, temporarily released to the extracellular space, and endocytosed by the posterior syncytial cytoplasm of the blastula. These results suggest that the selective Buchnera Transmission is likely attributable to Buchnera-specific exocytosis by the maternal bacteriocyte, whereas both Buchnera and Serratia are nonselectively incorporated by the endocytotic activity of the posterior region of the blastula. The sophisticated cellular mechanism for Vertical Transmission of Buchnera must have evolved to ensure the obligate host–symbiont association, whereas facultative symbionts like Serratia may coopt the endocytotic component of the mechanism for their entry into the host embryos.
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Cellular mechanism for selective Vertical Transmission of an obligate insect symbiont at the bacteriocyte-embryo interface.
Proceedings of the National Academy of Sciences of the United States of America, 2012Co-Authors: Tsutomu TsuchidaAbstract:Many insects are associated with obligate symbiotic bacteria, which are localized in specialized cells called bacteriocytes, Vertically transmitted through host generations via ovarial passage, and essential for growth and reproduction of their hosts. Although Vertical Transmission is pivotal for maintenance of such intimate host-symbiont associations, molecular and cellular mechanisms underlying the process are largely unknown. Here we report a cellular mechanism for Vertical Transmission of the obligate symbiont Buchnera in the pea aphid Acyrthosiphon pisum. In the aphid body, Buchnera cells are transmitted from maternal bacteriocytes to adjacent blastulae at the ovariole tips in a highly coordinated manner. By making use of symbiont-manipulated strains of A. pisum, we demonstrated that the facultative symbiont Serratia is, unlike Buchnera, not transmitted from maternal bacteriocytes to blastulae, suggesting a specific mechanism for Buchnera Transmission. EM observations revealed a series of exo-/endocytotic processes operating at the bacteriocyte-blastula interface: Buchnera cells are exocytosed from the maternal bacteriocyte, temporarily released to the extracellular space, and endocytosed by the posterior syncytial cytoplasm of the blastula. These results suggest that the selective Buchnera Transmission is likely attributable to Buchnera-specific exocytosis by the maternal bacteriocyte, whereas both Buchnera and Serratia are nonselectively incorporated by the endocytotic activity of the posterior region of the blastula. The sophisticated cellular mechanism for Vertical Transmission of Buchnera must have evolved to ensure the obligate host-symbiont association, whereas facultative symbionts like Serratia may coopt the endocytotic component of the mechanism for their entry into the host embryos.
Anna Bajer - One of the best experts on this subject based on the ideXlab platform.
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bartonella infections in three species of microtus prevalence and genetic diversity Vertical Transmission and the effect of concurrent babesia microti infection on its success
Parasites & Vectors, 2018Co-Authors: Katarzyna Tolkacz, Mohammed Alsarraf, Dorota Dwuznik, Maciej Grzybek, Jerzy M Behnke, Maciej Kowalec, Anna BajerAbstract:Background Bartonella spp. cause persistent bacterial infections in mammals. Although these bacteria are transmitted by blood-feeding arthropods, there is also evidence for Vertical Transmission in their mammalian hosts. We aimed to determine: (i) the prevalence and diversity of Bartonella spp. in a Microtus spp. community; (ii) whether Vertical Transmission occurs from infected female voles to their offspring; (iii) the effect of concurrent Babesia microti infection on the success of Vertical Transmission of Bartonella; and (iv) the impact of congenital infection on pup survival.
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Bartonella infections in three species of Microtus: prevalence and genetic diversity, Vertical Transmission and the effect of concurrent Babesia microti infection on its success
Parasites & Vectors, 2018Co-Authors: Katarzyna Tołkacz, Mohammed Alsarraf, Maciej Grzybek, Jerzy M Behnke, Maciej Kowalec, Dorota Dwużnik, Anna BajerAbstract:Background Bartonella spp. cause persistent bacterial infections in mammals. Although these bacteria are transmitted by blood-feeding arthropods, there is also evidence for Vertical Transmission in their mammalian hosts. We aimed to determine: (i) the prevalence and diversity of Bartonella spp. in a Microtus spp. community; (ii) whether Vertical Transmission occurs from infected female voles to their offspring; (iii) the effect of concurrent Babesia microti infection on the success of Vertical Transmission of Bartonella ; and (iv) the impact of congenital infection on pup survival. Results We sampled 124 Microtus arvalis , 76 Microtus oeconomus and 17 Microtus agrestis . In total, 115 embryos were isolated from 21 pregnant females. In the following year 11 pregnant females were kept until they had given birth and weaned their pups ( n = 62). Blood smears and PCR targeting the Bartonella- specific rpoB gene fragment (333bp) were used for the detection of Bartonella . Bartonella DNA was detected in 66.8% (145/217) of the wild-caught voles. Bartonella infection was detected in 81.8% (36/44) of pregnant female voles. Bartonella -positive individuals were identified among the embryos (47.1%; 40/85) and in 54.8% (34/62) of pups. Congenitally acquired Bartonella infections and co-infection with B. microti had no impact on the survival of pups over a 3-week period post partum . Among 113 Bartonella sequences, four species were detected: Bartonella taylorii , Bartonella grahamii , Bartonella doshiae and a Bartonella rochalimae -like genotype. Bartonella taylorii clade B was the dominant species in wild-caught voles (49%), pregnant females (47%), their embryos (85%), dams (75%) and pups (95%). Conclusions High prevalence of Bartonella spp. infection maintained in Microtus spp. community is followed by a high rate of Vertical Transmission of several rodent species of Bartonella in three species of naturally infected voles, M. arvalis , M. oeconomus and M. agrestis . Congenitally acquired Bartonella infection does not affect the survival of pups. Co-infection with B. microti does not affect the effectiveness of the Vertical Transmission of Bartonella in voles. Bartonella taylorii clade B was found to be the dominant species in wild-caught voles, including pregnant females and dams, and in their offspring, and was also found to be the most successful in Vertical Transmission.
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bartonella infections in three species of microtus prevalence and genetic diversity Vertical Transmission and the effect of concurrent babesia microti infection on its success
Parasites & Vectors, 2018Co-Authors: Katarzyna Tolkacz, Mohammed Alsarraf, Dorota Dwuznik, Maciej Grzybek, Jerzy M Behnke, Maciej Kowalec, Anna BajerAbstract:Bartonella spp. cause persistent bacterial infections in mammals. Although these bacteria are transmitted by blood-feeding arthropods, there is also evidence for Vertical Transmission in their mammalian hosts. We aimed to determine: (i) the prevalence and diversity of Bartonella spp. in a Microtus spp. community; (ii) whether Vertical Transmission occurs from infected female voles to their offspring; (iii) the effect of concurrent Babesia microti infection on the success of Vertical Transmission of Bartonella; and (iv) the impact of congenital infection on pup survival. We sampled 124 Microtus arvalis, 76 Microtus oeconomus and 17 Microtus agrestis. In total, 115 embryos were isolated from 21 pregnant females. In the following year 11 pregnant females were kept until they had given birth and weaned their pups (n = 62). Blood smears and PCR targeting the Bartonella-specific rpoB gene fragment (333bp) were used for the detection of Bartonella. Bartonella DNA was detected in 66.8% (145/217) of the wild-caught voles. Bartonella infection was detected in 81.8% (36/44) of pregnant female voles. Bartonella-positive individuals were identified among the embryos (47.1%; 40/85) and in 54.8% (34/62) of pups. Congenitally acquired Bartonella infections and co-infection with B. microti had no impact on the survival of pups over a 3-week period post partum. Among 113 Bartonella sequences, four species were detected: Bartonella taylorii, Bartonella grahamii, Bartonella doshiae and a Bartonella rochalimae-like genotype. Bartonella taylorii clade B was the dominant species in wild-caught voles (49%), pregnant females (47%), their embryos (85%), dams (75%) and pups (95%). High prevalence of Bartonella spp. infection maintained in Microtus spp. community is followed by a high rate of Vertical Transmission of several rodent species of Bartonella in three species of naturally infected voles, M. arvalis, M. oeconomus and M. agrestis. Congenitally acquired Bartonella infection does not affect the survival of pups. Co-infection with B. microti does not affect the effectiveness of the Vertical Transmission of Bartonella in voles. Bartonella taylorii clade B was found to be the dominant species in wild-caught voles, including pregnant females and dams, and in their offspring, and was also found to be the most successful in Vertical Transmission.
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RESEARCH ARTICLE Vertical Transmission of Babesia microti in BALB/c Mice: Preliminary Report
2016Co-Authors: Malgorzata Bednarska, Katarzyna Tolkacz, Anna Bajer, Anna Drozdowska, Ewa J. Mierzejewska, Renata Welc-falęciakAbstract:Babesia spp. (Apicomplexa, Piroplasmida) are obligate parasites of many species of mam-mals, causing a malaria-like infection- babesiosis. Three routes of Babesia infection have been recognized to date. The main route is by a tick bite, the second is via blood transfu-sion. The third, Vertical route of infection is poorly recognized and understood. Our study focused on Vertical Transmission of B.microti in a well-established mouse model. We assessed the success of this route of infection in BALB/c mice with acute and chronic infec-tions of B.microti. In experimental groups, females were mated on the 1st day of Babesia infection (Group G0); on the 28th day post infection (dpi) in the post- acute phase of the par-asite infection (G28); and on the 90th and 150th dpi (G90 and G150 group, respectively), in the chronic phase of the parasite infection. Pups were obtained from 58 % of females mated in the post-acute phase (G28) and from 33 % of females in groups G90 and G150. Mice mated in the pre-acute phase of infection (G0) did not deliver pups. Congenital B.microti infections were detected by PCR amplification of Babesia 18S rDNA in almost all pups (96%) from the experimental groups G28, G90 and G150. Parasitaemia in the F1 genera-tion was low and varied between 0.01–0.001%. Vertical Transmission of B.microti was dem-onstrated for the first time in BALB/c mice
Richard Cordaux - One of the best experts on this subject based on the ideXlab platform.
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sex chromosomes control Vertical Transmission of feminizing wolbachia symbionts in an isopod
PLOS Biology, 2019Co-Authors: Thomas Becking, Mohamed Amine Chebbi, Isabelle Giraud, Bouziane Moumen, Tiffany Laverre, Yves Caubet, Jean Peccoud, Clement Gilbert, Richard CordauxAbstract:Microbial endosymbiosis is widespread in animals, with major ecological and evolutionary implications. Successful symbiosis relies on efficient Vertical Transmission through host generations. However, when symbionts negatively affect host fitness, hosts are expected to evolve suppression of symbiont effects or Transmission. Here, we show that sex chromosomes control Vertical Transmission of feminizing Wolbachia endosymbionts in the isopod Armadillidium nasatum. Theory predicts that the invasion of an XY/XX species by cytoplasmic sex ratio distorters is unlikely because it leads to fixation of the unusual (and often lethal or infertile) YY genotype. We demonstrate that A. nasatum X and Y sex chromosomes are genetically highly similar and that YY individuals are viable and fertile, thereby enabling Wolbachia spread in this XY-XX species. Nevertheless, we show that Wolbachia cannot drive fixation of YY individuals, because infected YY females do not transmit Wolbachia to their offspring, unlike XX and XY females. The genetic basis fits the model of a Y-linked recessive allele (associated with an X-linked dominant allele), in which the homozygous state suppresses Wolbachia Transmission. Moreover, production of all-male progenies by infected YY females restores a balanced sex ratio at the host population level. This suggests that blocking of Wolbachia Transmission by YY females may have evolved to suppress feminization, thereby offering a whole new perspective on the evolutionary interplay between microbial symbionts and host sex chromosomes.
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Sex chromosomes control Vertical Transmission of feminizing Wolbachia symbionts in an isopod.
'Public Library of Science (PLoS)', 2019Co-Authors: Thomas Becking, Mohamed Amine Chebbi, Isabelle Giraud, Bouziane Moumen, Tiffany Laverre, Yves Caubet, Jean Peccoud, Clement Gilbert, Richard CordauxAbstract:Microbial endosymbiosis is widespread in animals, with major ecological and evolutionary implications. Successful symbiosis relies on efficient Vertical Transmission through host generations. However, when symbionts negatively affect host fitness, hosts are expected to evolve suppression of symbiont effects or Transmission. Here, we show that sex chromosomes control Vertical Transmission of feminizing Wolbachia endosymbionts in the isopod Armadillidium nasatum. Theory predicts that the invasion of an XY/XX species by cytoplasmic sex ratio distorters is unlikely because it leads to fixation of the unusual (and often lethal or infertile) YY genotype. We demonstrate that A. nasatum X and Y sex chromosomes are genetically highly similar and that YY individuals are viable and fertile, thereby enabling Wolbachia spread in this XY-XX species. Nevertheless, we show that Wolbachia cannot drive fixation of YY individuals, because infected YY females do not transmit Wolbachia to their offspring, unlike XX and XY females. The genetic basis fits the model of a Y-linked recessive allele (associated with an X-linked dominant allele), in which the homozygous state suppresses Wolbachia Transmission. Moreover, production of all-male progenies by infected YY females restores a balanced sex ratio at the host population level. This suggests that blocking of Wolbachia Transmission by YY females may have evolved to suppress feminization, thereby offering a whole new perspective on the evolutionary interplay between microbial symbionts and host sex chromosomes
Gary Toedter - One of the best experts on this subject based on the ideXlab platform.
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beta 2 microglobulin hiv 1 p24 antibody and acid dissociated hiv 1 p24 antigen levels predictive markers for Vertical Transmission of hiv 1 in pregnant ugandan women
AIDS, 1993Co-Authors: Brooks J Jackson, Peter Kataaha, David L Hom, Francis Mmiro, Laura A Guay, Christopher M Ndugwa, Lawrence Marum, Estelle Piwowar, Karen Brewer, Gary ToedterAbstract:This study sought to evaluate the clinical utility of plasma beta2-microglobulin (beta2M) levels acid-dissociated HIV-1 p24 antigen and HIV-1 p24-antibody titers in predicting HIV-1 Vertical Transmission in 227 HIV-1-infected Ugandan pregnant women. Plasma beta2M levels acid-dissociated HIV-1 p24-antigen positivity and HIV-1 p24-antibody titers were determined using commercial enzyme immunoassays (EIA) in a Ugandan cohort of 52 HIV-1-seropositive transmitting mothers 175 HIV-1-seropositive non-transmitting mothers and 52 seronegative mothers within 6 weeks prior to delivery. Transmitter mothers had significantly higher plasma concentrations of beta2M (1.80 + or - 1.13 mg/1) than non-transmitter seropositive mothers (1.32 + or - 0.81 mg/1; P = 0.0013). Similarly a significantly higher proportion of transmitter mothers had detectable p24 antigen than non-transmitter mothers [6 out of 51 (11.8%) vs. 6 out of 173 (3.5%); P = 0.03]. Compared with the Vertical Transmission rate of 23% in the seropositive group the positive predictive values of a beta2M level > 1.5 mg/1 or detectable HIV-1 p24 antigen for Vertical Transmission were 34 and 50% respectively. 5 of 6 (83.3%) seropositive mothers with both a beta2M level > 1.5 mg/1 and detectable p24 antigenemia transmitted HIV-1 infection to their infants compared with 25 of 124 (20.2%) seropositive mothers with values below the cut-off values for both tests (P = 0.00249). However beta2M was not found to be a significant independent predictor of Vertical Transmission when analyzed in a multivariate model with p24 antigenemia. There was no significant difference in HIV-1 p24-antibody titers in transmitter mothers vs. non-transmitter mothers (P = 0.299). Beta2M levels and acid-dissociated HIV-1 p24-antigen assays may be used to predict which HIV-1 infected pregnant women are at greatest risk for Vertical Transmission. However only the p24-antigen test was independently predictive of Vertical Transmission and its clinical utility is limited. (authors)