Mitochondrial variation of the "eyed" turtles (Sacalia) based on known-locality and trade specimens

Bryan L. Stuart is thanked for his hard work to collect wild specimens, as well as providing insightful and useful comments on the data. We thank Abigail Wolf of the Field Museum for providing photographs of specimens. Robert Murphy of the Royal Ontario M

Immunoglobulin joining (J) chain and its expression in the Chinese soft-shelled turtle (Pelodiscus sinensis)

The immunoglobulin (Ig) joining (J) chain plays an important role in the formation of polymeric Igs and their transport into secretions. In the present study, the cDNA sequence of J chain has been cloned from the Chinese soft-shelled turtle (Pelodiscus sinensis) by reverse transcription (RT)-PCR and rapid amplification of cDNA ends (RACE). The cDNA sequence is 2347 bp in length and contains an open reading frame of 480 bp encoding 160 aa including the signal sequence. The deduced amino acid sequence has a high degree of homology with that of an already reported turtle J chain (80.7%), and of chicken (71.3%). By using real-time quantitative RT-PCR analysis, a significant up-regulation of J-chain transcripts was observed in spleen, kidney and blood of turtles injected with inactivated Aeromonas hydrophila, indicating the immune role of J chain in response to bacterial infection. (C) 2009 Elsevier B.V. All rights reserved.

IgM, IgD and IgY and their expression pattern in the Chinese soft-shelled turtle Pelodiscus sinensis

Three Ig isotypes, IgM, IgD, and IgA, were previously known in reptiles. Here, in this report we describe IgM, IgD and a novel immunoglobulin heavy-chain isotype upsilon (IgY) in Chinese soft-shelled turtle (Pelodiscus sinensis). The IgM and IgY constant domains are characteristically similar to their counterparts described in other vertebrates. The expression of IgM and IgD were detected at mRNA level early during embryonic development, and their expression increased during further development. However, the IgY expression was not detected in larval turtles until 90 days after hatching-out. The increase in the transcription of these three Ig molecules was analyzed by using real-time PCR in spleen, kidney and blood following the injection of inactivated Aeromonas hydrophila. The primary increase in the expression of these three Igs was observed I week after the first injection, although not statistically significant, and the second injection 2 weeks after the first injection provoked a significant increase in the expression of these Igs, revealing a pattern of primary and secondary antibody response in the turtle. The present study represents the first report on reptile IgY and the pattern of IgM, IgD and IgY transcription in reptiles. (C) 2009 Elsevier Ltd. All rights reserved.

Molecular characterization and expression profiles in response to bacterial infection of Chinese soft-shelled turtle interleukin-8 (IL-8), the first reptilian chemokine gene

In this study, an IL-8 homologue has been cloned and identified from a reptile, Chinese soft-shelled turtle for the first time. The full-length cDNA of turtle IL-8 was 1188 bp and contained a 312 bp open reading frame (ORF) coding for a protein of 104 amino acids. The chemokine CXC domain, which contained Glu-Leu-Arg (ELR) motif and four cysteine residues, was well conserved in turtle IL-8. The 4924 bp genomic DNA of turtle IL-8 contained four exons and three introns. Phylogenetic analysis showed that the amino acid sequence of turtle IL-8 clustered together with birds. RT-PCR analysis showed that turtle IL-8 mRNA was constitutively expressed liver, spleen, kidney, heart, blood and intestine tissues of control turtles. Real-time quantitative PCR analysis further indicated that the turtle IL-8 mRNA expression was apparent in various tissues at 8 h and up-regulated significantly during 8 h-7 d after Aeromonas hydrophila infection. The present studies will help us to understand the evolution of IL-8 molecule and the inflammatory response mechanism in reptiles. (C) 2009 Elsevier Ltd. All rights reserved.

Simultaneous determination of microcystin contaminations in various vertebrates (fish, turtle, duck and water bird) from a large eutrophic Chinese lake, Lake Taihu, with toxic Microcystis blooms

This is the first to conduct Simultaneous determination of microcystin (MC) contaminations in multi-groups of vertebrates (fish, turtle, duck and water bird) from Lake Taihu with Microcystis blooms. MCs (-RR, -YR, -LR) in Microcystis scum was 328 mu g g(-1) DW. MCs reached 235 mu g g(-1) DW in intestinal contents of phytoplanktivorous silver carp, but never exceeded 0.1 mu g g(-1) DW in intestinal contents of other animals. The highest MC content in liver of fish was in Carassius auratus (150 ng g(-1) DW), followed by silver carp and Culter ilishaeformis, whereas the lowest was in common carp (3 ng g(-1) DW). In livers of turtle, duck and water bird, MC content ranged from 18 to 30 ng g(-1) DW. High MC level was found in the gonad, egg yolk and egg white of Nycticorax nycticorax and Anas platyrhynchos, suggesting the potential effect of MCs on water bird and duck embryos. High MC contents were identified for the first time in the spleens of N. nycticorax and A. platyrhynchos (6.850 and 9.462 ng g(-1) DW, respectively), indicating a different organotropism of MCs in birds. Lakes with deaths of turtles or water birds in the literatures had a considerably higher MC content in both cyanobacteria and wildlife than Lake Taihu, indicating that toxicity of cyanobacteria may determine accumulation level of MCs and consequently fates of aquatic wildlife. (C) 2009 Elsevier B.V. All rights reserved.

Identification of differentially expressed immune-relevant genes in Chinese soft-shelled turtle (Trionyx sinensis) infected with Aeromonas hydrophila

Expressed sequence tag (EST) analysis is an efficient tool for gene discovery and profiling gene expression. Aeromonas hydrophila, a ubiquitous waterborne bacterium, is one of the most frequent pathogens isolated from diseased aquatic organisms. In order to understand the molecular mechanism of anti-bacteria immune response in reptile, we have investigated the differentially expressed genes in Chinese soft-shelled turtle (Trionyx sinensis) experimentally infected with A. hydrophila by suppression subtractive hybridization (SSH). Forty-two genes were identified from more than 200 clones, of which 25 genes are found for the first time in reptiles, and classified into 6 categories: 18 in defense/immunity. 4 in catalysis, 2 in retrotransposon; 2 in cell signal transduction, 5 in cell metabolism, 10 in protein expression, and 1 in cell structure. Of the 42 differentially expressed genes, 6 genes, IL-8, serum amyloid A (SAA), CD9, CD59, activating transcription factor 4 (ATF4) and cathepsin L genes, were further observed to be up-regulated in the infected turtles by virtual Northern hybridization and RT-PCR assays. (C) 2008 Elsevier B.V. All rights reserved.

Effects of animal-plant protein ratio in extruded and expanded diets on nitrogen and energy budgets of juvenile Chinese soft-shelled turtle (Pelodiscus sinensis Wiegmann)

In this study, we investigated the effects of animal-plant protein ratio in extruded and expanded diets on nutrient digestibility, nitrogen and energy budgets of juvenile soft-shelled turtle (Pelodiscus sinensis). Four extruded and expanded feeds (diets 1-4) were formulated with different animal-plant protein ratios (diet 1, 1.50:1; diet 2, 2.95:1; diet 3, 4.92:1; diet 4, 7.29:1). The apparent digestibility coefficients (ADCs) of dry matter and crude lipid for diet 1 were significantly lower than those for diets 2-4. There was no significant difference in crude protein digestibility among diets 1-4. The ADC of carbohydrate was significantly increased with the increase in animal-plant protein. Although nitrogen intake rate, faecal nitrogen loss rate and excretory nitrogen loss rate of turtles fed diet 1 were significantly higher than those fed diets 2-4, nitrogen retention rate, net protein utilization and biological value of protein in these turtles were significantly lower than those fed diets 2-4. In addition, energy intake rate, excretory energy loss rate and heat production rate of turtles fed diet 1 were also significantly higher than those fed diets 2-4. Faecal energy loss was significantly reduced with the increase in the animal-plant protein ratio. The ADC of energy and assimilation efficiency of energy significantly increased with a higher animal-plant protein ratio. The growth efficiency of energy in the group fed diet 1 was significantly lower than those in the groups fed diets 2-4. Together, our results suggest that the optimum animal-plant protein ratio in extruded and expanded diets is around 3:1.

中国非海产龟鳖类的研究

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