scholarly journals Genotype data not consistent with clonal transmission of sea turtle fibropapillomatosis or goldfish schwannoma

2021 ◽  
Vol 6 ◽  
pp. 219
Author(s):  
Máire Ní Leathlobhair ◽  
Kelsey Yetsko ◽  
Jessica A. Farrell ◽  
Carmelo Iaria ◽  
Gabriele Marino ◽  
...  

Recent discoveries of transmissible cancers in multiple bivalve species suggest that direct transmission of cancer cells within species may be more common than previously thought, particularly in aquatic environments. Fibropapillomatosis occurs with high prevalence in green sea turtles (Chelonia mydas) and the geographic range of disease has increased since fibropapillomatosis was first reported in this species. Widespread incidence of schwannomas, benign tumours of Schwann cell origin, reported in aquarium-bred goldfish (Carassius auratus), suggest an infectious aetiology. We investigated the hypothesis that cancers in these species arise by clonal transmission of cancer cells. Through analysis of polymorphic microsatellite alleles, we demonstrate concordance of host and tumour genotypes in diseased animals. These results imply that the tumours examined arose from independent oncogenic transformation of host tissue and were not clonally transmitted. Further, failure to experimentally transmit goldfish schwannoma via water exposure or inoculation suggest that this disease is unlikely to have an infectious aetiology.

1998 ◽  
Vol 4 (S2) ◽  
pp. 1158-1159
Author(s):  
Yuanan Lu ◽  
Vivek R. Nerurkar ◽  
Tina M. Weatherby ◽  
Richard Yanagihara

The near epidemic occurrence of fibropapilloma in green sea turtle (Chelonia my das) (Figure 1) significantly threatens the survival of this species which is protected under the U.S. Endangered Species Act. Although collective evidence suggests a viral etiology, the causative virus of green sea turtle fibropapilloma has not been isolated. To facilitate the isolation and characterization of the causative virus(es), we established 13 cell lines from multiple organs/tissues (tumor, kidney, lung, heart, gall bladder, testis, and skin) of green sea turtles with fibropapilloma. Serial subcultivation of cell lines derived from lungs, testis, eye soft tissues and tumors resulted in the formation of tumor-like aggregates, which attained sizes of 1-2 mm in diameter within two weeks (Figure 2). Media from such cultures, when inoculated onto cells derived from healthy turtle embryos, produced similar tumor-like aggregates, suggesting the presence of a transmissible agent.


2020 ◽  
Vol 32 (6) ◽  
pp. 908-911
Author(s):  
Rebecca Radisic ◽  
Sean D. Owens ◽  
Charles A. Manire ◽  
Nicole Montgomery ◽  
Doug Mader ◽  
...  

Loggerhead ( Caretta caretta; Cc) and green sea ( Chelonia mydas; Cm) turtles admitted to rehabilitation facilities may require blood transfusions for supportive treatment of disorders resulting in life-threatening anemia, but, considering the unique erythrocyte chemistry of sea turtles, standardized donor red blood cell (RBC) storage protocols have not been established. Prolonged cold storage and the effects of various anticoagulant-preservative solutions have been associated with increased RBC osmotic fragility across a broad range of species. Increased RBC fragility in stored RBC products has been associated with acute transfusion reactions. The osmotic fragility test is used to measure erythrocyte resistance to hemolysis while being exposed to a series of dilutions of a saline solution. We obtained baseline measurements for osmotic fragility in healthy Cc and Cm. Osmotic fragility testing was performed on samples from 10 Cc to 10 Cm. Fifty percent (50%) RBC hemolysis was identified at a mean NaCl concentration of 0.38% in both species. Results of our study will help guide future studies evaluating optimal storage solutions for sea turtle blood products.


2019 ◽  
Vol 25 (4) ◽  
pp. 423 ◽  
Author(s):  
Markus Gronwald ◽  
Quentin Genet ◽  
Margaux Touron

We used camera traps to identify invasive Rattus rattus as predators at a green sea turtle, Chelonia mydas, nest in French Polynesia. The footage shows that the hatchlings are a familiar food source for rats and that the control of invasive rats has to be considered for the protection of endangered green sea turtles.


2018 ◽  
Author(s):  
Stephanie Butera ◽  
Jaime Restrepo

New-born sea turtles face a number of predators between the time the mothers lay eggs on the beach to when the hatchlings grow into larger juveniles. Nest depredation impacts reproductive success of nesting sea turtles, reducing the number of new turtles that make it to the sea. On Tortuguero beach nest predators include; dogs, coati, and raccoons. Nest depredation within Tortuguero National Park (TNP) has decreased dramatically since 1979. This decrease in nest depredation is linked to the increased jaguar population within TNP as the aforementioned species are considered the jaguars natural prey. Although jaguars prey on nesting turtles, they also control the populations of nest predators. Even more, jaguars have been demonstrated to change their behaviour to suit their preference in prey species therefore the nest predator distribution in TNP was examined to investigate whether changes in jaguar prey preference had an effect. Nest predation and the number of adult turtles lost to jaguar depredation were examined to determine the significance of the threat jaguars pose to the sea turtle population. This study investigates the predator prey relationship between jaguars, nest predators, and nesting female sea turtles; aiming to assessing the impact that jaguars have on the turtle's population.


2020 ◽  
Author(s):  
Jana Blechschmidt ◽  
Meike J. Wittmann ◽  
Chantal Blüml

AbstractClimate change poses a threat to species with temperature-dependent sex determination. A recent study on green sea turtles (Chelonia mydas) at the northern Great Barrier Reef (GBR) showed a highly female-skewed sex ratio with almost all juvenile turtles being female. This shortage of males might eventually cause population extinction, unless rapid evolutionary rescue, migration or conservation efforts ensure a sufficient number of males. We built a stochastic individual-based model inspired by C. mydas, but potentially transferrable to other species with TSD. Nest depth, level of shade, and pivotal temperature were evolvable traits. Additionally, we considered the effect of crossbreeding between the northern and southern GBR, nest-site philopatry, and conservation efforts. Among the evolvable traits, nest depth was the most likely to rescue the population in the face of climate change, but even here the more extreme climate-change scenario led to extinction. Surprisingly, nest-site philopatry elevated extinction rates. Conservation efforts to artificially increase nest depth promoted population survival and did not preclude trait evolution. Although extra information is needed to make reliable predictions for the fate of green sea turtles, our results illustrate how evolution can shape the fate of long lived, vulnerable species in the face of climate change.Graphical Abstract


2018 ◽  
Vol 9 (2) ◽  
pp. 617-623 ◽  
Author(s):  
Jennifer N. Niemuth ◽  
Craig A. Harms ◽  
Jeffrey M. Macdonald ◽  
Michael K. Stoskopf

Abstract Metabolomics is the study of metabolites, the small-molecular-weight end products of metabolism. Propylene glycol is a synthetic diol commonly used as antifreeze, as a humectant, and in the production of polyester compounds. In otherwise healthy animals, propylene glycol has generally been considered a contaminant, iatrogenic, or unexplained. We demonstrate the presence of propylene glycol in plasma of free-ranging apparently healthy green sea turtles Chelonia mydas and individuals impacted by cold stun syndrome, without iatrogenic administration or known sample processing contamination, using one- and two-dimensional proton nuclear magnetic resonance spectroscopy techniques. There was not a statistically significant difference in relative propylene glycol concentration between the two cohorts (two-sided random sampling two-sample permutation test, P = 0.842, R = 1,000). The presence of this metabolite raises important questions about sea turtle physiology and potential latent environmental contamination and serves as a starting point for future characterization of lipid metabolism and glycolysis in green sea turtles.


2021 ◽  
Author(s):  
Jindarha Prampramote ◽  
Worakan Boonhoh ◽  
Sutsiree Intongead ◽  
Watchara Sakornwimol ◽  
Pimchanok Prachamkhai ◽  
...  

The impact of macroplastic debris (> 5 mm in size) on marine life is a global concern but is rarely investigated in Thailand. Our objective was to investigate the relationship between stranded sea turtles and macroplastics found in the Central Gulf of Thailand. The turtle (n = 388) stranding record between 2017-2020 was analysed retrospectively to determine their size, species, and interaction with macroplastics. Thereafter, between 2019-2020, macroplastics were collected, from the gastrointestinal (GI) tract of dead turtles and from the beaches where stranded turtles were found. A stereomicroscope was used to visually categorise the macroplastics, and the plastic composition was analysed using a Fourier-transform infrared (FTIR) spectrometer. Green sea turtles (Chelonia mydas) were found to account for the majority of stranded turtles (74%, n = 251), and macroplastics were discovered in 74% of cases of entanglement and ingestion. At the juvenile stage, the stranded turtle was strongly related to macroplastics. Immature turtles were more likely to become entangled than adult turtles. Entangled turtles had a greater survival rate than turtles that had consumed plastic. The plastic fibres were the majority of macroplastics found in the GI tracts (62%, n = 152/244) and on the beach (64%, n = 74/115). Most fibres from GI tracts (83%, n = 126/152) and the beaches (93%, n = 68/74) were identified as the fishing net comprised of polyethylene or polypropylene. We concluded that fishing nets made of polyethylene or polypropylene might be one of the significant causes of sea turtle stranding in the Central Gulf of Thailand, and this issue requires immediate resolution.


2020 ◽  
Author(s):  
Nicholas B. Blackburn ◽  
Ana Cristina Leandro ◽  
Nina Nahvi ◽  
Mariana A. Devlin ◽  
Marcelo Leandro ◽  
...  

ABSTRACTSea turtle fibropapillomatosis (FP) is a tumor promoting disease that is one of several threats globally to endangered sea turtle populations. The prevalence of FP is highest in green sea turtle (Chelonia mydas) populations, and historically has shown considerable temporal growth. FP tumors can significantly affect the ability of turtles to forage for food and avoid predation and can grow to debilitating sizes. In the current study, based in South Texas, we have applied transcriptome sequencing to FP tumors and healthy control tissue to study the gene expression profiles of FP. By identifying differentially expressed turtle genes in FP, and matching these genes to their closest human ortholog we draw on the wealth of human based knowledge, specifically human cancer, to identify new insights into the biology of sea turtle FP. We show that several genes aberrantly expressed in FP tumors have known tumor promoting biology in humans, including CTHRC1 and NLRC5, and provide support that disruption of the Wnt signaling pathway is a feature of FP. Further, we profiled the expression of current targets of immune checkpoint inhibitors from human oncology in FP tumors and identified potential candidates for future studies.


2021 ◽  
Vol 12 ◽  
Author(s):  
Nicholas B. Blackburn ◽  
Ana Cristina Leandro ◽  
Nina Nahvi ◽  
Mariana A. Devlin ◽  
Marcelo Leandro ◽  
...  

Sea turtle fibropapillomatosis (FP) is a tumor promoting disease that is one of several threats globally to endangered sea turtle populations. The prevalence of FP is highest in green sea turtle (Chelonia mydas) populations, and historically has shown considerable temporal growth. FP tumors can significantly affect the ability of turtles to forage for food and avoid predation and can grow to debilitating sizes. In the current study, based in South Texas, we have applied transcriptome sequencing to FP tumors and healthy control tissue to study the gene expression profiles of FP. By identifying differentially expressed turtle genes in FP, and matching these genes to their closest human ortholog we draw on the wealth of human based knowledge, specifically human cancer, to identify new insights into the biology of sea turtle FP. We show that several genes aberrantly expressed in FP tumors have known tumor promoting biology in humans, including CTHRC1 and NLRC5, and provide support that disruption of the Wnt signaling pathway is a feature of FP. Further, we profiled the expression of current targets of immune checkpoint inhibitors from human oncology in FP tumors and identified potential candidates for future studies.


2019 ◽  
Vol 99 (8) ◽  
pp. 1879-1887 ◽  
Author(s):  
Silmara Rossi ◽  
Angélica María Sánchez-Sarmiento ◽  
Robson Guimarães dos Santos ◽  
Roberta Ramblas Zamana ◽  
Fabiola Eloisa Setim Prioste ◽  
...  

AbstractFibropapillomatosis (FP) can be an important conservation threat to green sea turtles (Chelonia mydas) due to its widespread distribution and complex aetiology. Thus, understanding the impacts of FP in sea turtle populations is a research priority towards conservation efforts. The body condition index (BCI), based on straight carapace length (SCL) and body mass (BM), is an accurate indicator of body-nutritional condition that can be used in routine green turtle health evaluations. This study aimed to compare BCI in FP-free (N = 369) and FP-affected (N = 518) green turtles from Brazilian feeding areas. Body condition indices were evaluated in terms of the South-west Atlantic Fibropapillomatosis Score – FPSSWA (mild, moderate and severe), study sites (five Brazilian states), origin (intentional capture, fishery, stranding and afloat) and sex (when known). Curved and straight carapace lengths, and body mass were recorded in order to calculate BCI. Statistical analysis revealed significant differences in BCI among green turtles from different study areas (P = 0.02), and lower BCI values in FP-free than in FP-positive individuals (P < 0.0001). With regards to origin, the highest BCI was found in the intentional capture group (N = 245; 1.47 ± 0.16), followed by fishery (N = 180; 1.46 ± 0.20). Analysis according to sex revealed a higher mean BCI among females than males (P < 0.017). This study provides relevant data on the health and nutritional status of green turtles along the Brazilian coast, in important feeding areas for this species.


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