Evolution of erythrocyte morphology in amphibians (Amphibia: Anura)

We compared the morphology of the erythrocytes of five anurans, two toad species - Bufo gargarizans (Cantor, 1842) and Duttaphrynus melanostictus (Schneider, 1799) and three frog species - Fejervarya limnocharis (Gravenhorst, 1829), Microhyla ornata (Duméril & Bibron, 1841), and Rana zhenhaiensis (Ye, Fei & Matsui, 1995). We then reconstructed the ancestral state of erythrocyte size (ES) and nuclear size (NS) in amphibians based on a molecular tree. Nine morphological traits of erythrocytes were all significantly different among the five species. The results of principal component analysis showed that the first component (49.1% of variance explained) had a high positive loading for erythrocyte length, nuclear length, NS and ratio of erythrocyte length/erythrocyte width; the second axis (28.5% of variance explained) mainly represented erythrocyte width and ES. Phylogenetic generalized least squares analysis showed that the relationship between NS and ES was not affected by phylogenetic relationships although there was a significant linear relationship between these two variables. These results suggested that (1) the nine morphological traits of erythrocytes in the five anuran species were species-specific; (2) in amphibians, larger erythrocytes generally had larger nuclei.

Flt3 ligand enhanced the immunogenicity of classical swine fever vectored vaccine based on human adenovirus by fusing to the E2 glycoprotein

Background: Classical swine fever (CSF) is a highly contagious disease of domestic pigs and wild boar. CSFV E2 protein is the major target for neutralizing antibodies and the main component of marker vaccine. CSF vaccine based on human adenovirus type 5 (HAdV-5) had achieved an efficient protection in swine. However, the efficacy of rAdV-E2 only expressed the E2 glycoprotein was unstable. As a vaccine adjuvant, FL has been proven to enhance the immune effect, and its extracellular domain retained full biological activity. The adjuvant activity of the porcine Flt3L (the extracellular domain) in CSF vectored vaccine based on HAdV-5 was investigated.Materials, Methods & Results: The FL (the extracellular domain) was linked to the CSFV E2 (N-terminus) by a 10GS (Gly4/Ser) linker. The rAdV-FL-E2 based on HAdV-5 was constructed and the FL-E2 protein expressed in 293 cells infected with rAdV-FL-E2 was confirmed by Western blot with the use of anti-CSFV serum. Twelve CSFV-free cross-bred piglets, which were 6 to 7 weeks old and double confirmed to be free to CSFV specific serum antibodies and antigens using the IDEXX HerdChek* CSFV Antibody Test Kit and real-time RT-PCR, respectively, and were randomly divided into four groups (A, B, C, and D) with three animals in each group. Groups A and B were vaccinated with a dose of 2×106 TCID50 of rAdV-FL-E2, and rAdV-E2 by intramuscular (i.m.) inoculation respectively. All pigs were given a booster immunization at 14 d intervals. Group C was immunized with one-dose CSFV C-strain vaccine and served as the positive control. Group D was injected with DMEM medium. Finally, all animals were challenged with 1×103 TCID50 of CSFV Shimen strain by i.m. injection at 21 d after the second vaccination. CSFV-specific neutralizing antibodies in sera were tested by using the IDEXX HerdChek* CSFV Antibody Test Kit and NPLA.[…](AU)

Evolution of erythrocyte morphology in amphibians (Amphibia: Anura)

We compared the morphology of the erythrocytes of five anurans, two toad species - Bufo gargarizans (Cantor, 1842) and Duttaphrynus melanostictus (Schneider, 1799) and three frog species - Fejervarya limnocharis (Gravenhorst, 1829), Microhyla ornata (Duméril & Bibron, 1841), and Rana zhenhaiensis (Ye, Fei & Matsui, 1995). We then reconstructed the ancestral state of erythrocyte size (ES) and nuclear size (NS) in amphibians based on a molecular tree. Nine morphological traits of erythrocytes were all significantly different among the five species. The results of principal component analysis showed that the first component (49.1% of variance explained) had a high positive loading for erythrocyte length, nuclear length, NS and ratio of erythrocyte length/erythrocyte width; the second axis (28.5% of variance explained) mainly represented erythrocyte width and ES. Phylogenetic generalized least squares analysis showed that the relationship between NS and ES was not affected by phylogenetic relationships although there was a significant linear relationship between these two variables. These results suggested that (1) the nine morphological traits of erythrocytes in the five anuran species were species-specific; (2) in amphibians, larger erythrocytes generally had larger nuclei.(AU)

Flt3 ligand enhanced the immunogenicity of classical swine fever vectored vaccine based on human adenovirus by fusing to the E2 glycoprotein

Background: Classical swine fever (CSF) is a highly contagious disease of domestic pigs and wild boar. CSFV E2 protein is the major target for neutralizing antibodies and the main component of marker vaccine. CSF vaccine based on human adenovirus type 5 (HAdV-5) had achieved an efficient protection in swine. However, the efficacy of rAdV-E2 only expressed the E2 glycoprotein was unstable. As a vaccine adjuvant, FL has been proven to enhance the immune effect, and its extracellular domain retained full biological activity. The adjuvant activity of the porcine Flt3L (the extracellular domain) in CSF vectored vaccine based on HAdV-5 was investigated.Materials, Methods & Results: The FL (the extracellular domain) was linked to the CSFV E2 (N-terminus) by a 10GS (Gly4/Ser) linker. The rAdV-FL-E2 based on HAdV-5 was constructed and the FL-E2 protein expressed in 293 cells infected with rAdV-FL-E2 was confirmed by Western blot with the use of anti-CSFV serum. Twelve CSFV-free cross-bred piglets, which were 6 to 7 weeks old and double confirmed to be free to CSFV specific serum antibodies and antigens using the IDEXX HerdChek* CSFV Antibody Test Kit and real-time RT-PCR, respectively, and were randomly divided into four groups (A, B, C, and D) with three animals in each group. Groups A and B were vaccinated with a dose of 2×106 TCID50 of rAdV-FL-E2, and rAdV-E2 by intramuscular (i.m.) inoculation respectively. All pigs were given a booster immunization at 14 d intervals. Group C was immunized with one-dose CSFV C-strain vaccine and served as the positive control. Group D was injected with DMEM medium. Finally, all animals were challenged with 1×103 TCID50 of CSFV Shimen strain by i.m. injection at 21 d after the second vaccination. CSFV-specific neutralizing antibodies in sera were tested by using the IDEXX HerdChek* CSFV Antibody Test Kit and NPLA.[…]

Locomotion and survival of two sympatric larval anurans, Bufo gargarizans (Anura: Bufonidae) and Rana zhenhaiensis (Anura: Ranidae), after partial tail loss

Tadpoles of two sympatric anurans, Bufo gargarizans Cantor, 1842 and Rana zhenhaiensis Ye, Fei & Matsui, 1995, were used as model organisms to examine the effects of different levels of tail loss on swimming performance and survival. On average, B. gargarizans tadpoles were shorter and had smaller tails and body mass than R. zhenhaiensis. After 75% tail loss, the survival rate of experimental and control B. gargarizans tadpoles, and of experimental tadpoles of the two species, differed significantly; the number of tadpoles surviving a complete impairment of their swimming ability did not differ between B. gargarizans and R. zhenhaiensis. After 50% tail loss, the swimming performance (swimming speed, maximum distance and number of stops) of the two species was significantly affected. However, the adverse influence of tail loss on the swimming speed of B. gargarizans tadpoles was greater compared to R. zhenhaiensis tadpoles. Our data indicates that a 50% tail loss results in swimming costs for B. gargarizans and R. zhenhaiensis tadpoles, and that 75% tail loss decreases the survival rate of B. gargarizans tadpoles. Therefore, we conclude that tadpoles of different species and with the same degree of tail loss use distinctive strategies to improve individual fitness in the face of predator pressure.(AU)

Locomotion and survival of two sympatric larval anurans, Bufo gargarizans (Anura: Bufonidae) and Rana zhenhaiensis (Anura: Ranidae), after partial tail loss

Tadpoles of two sympatric anurans, Bufo gargarizans Cantor, 1842 and Rana zhenhaiensis Ye, Fei & Matsui, 1995, were used as model organisms to examine the effects of different levels of tail loss on swimming performance and survival. On average, B. gargarizans tadpoles were shorter and had smaller tails and body mass than R. zhenhaiensis. After 75% tail loss, the survival rate of experimental and control B. gargarizans tadpoles, and of experimental tadpoles of the two species, differed significantly; the number of tadpoles surviving a complete impairment of their swimming ability did not differ between B. gargarizans and R. zhenhaiensis. After 50% tail loss, the swimming performance (swimming speed, maximum distance and number of stops) of the two species was significantly affected. However, the adverse influence of tail loss on the swimming speed of B. gargarizans tadpoles was greater compared to R. zhenhaiensis tadpoles. Our data indicates that a 50% tail loss results in swimming costs for B. gargarizans and R. zhenhaiensis tadpoles, and that 75% tail loss decreases the survival rate of B. gargarizans tadpoles. Therefore, we conclude that tadpoles of different species and with the same degree of tail loss use distinctive strategies to improve individual fitness in the face of predator pressure.