12 June 2014

PhD defense Alonzo Alfaro-Núñez

'Tracing the co-evolutionary history of the Chelonid fibropapilloma-associated herpesvirus and its host sea turtles'

Time

23. June 2014, 13:15 - 16:00

Place

Geocenter Denmark, IGN, Øster Voldgade 10, K 1350 Copenhagen

Thesis

This thesis describes various aspects of marine turtle (Testudines) evolution and  tackles a well-described and controversial disease of these animals, fibropapillomatosis (FP), which is believed to be caused by the Chelonid fibropapilloma-associated herpesvirus (CFPHV).

PhD-fellow Alonzo Alfaro-Núñez

A large dataset of samples from five globally distributed marine turtle species was analysed in order to detect the presence of CFPHV DNA. These samples represent both clinical (FP tumour) and subclinical (non-tumour) CFPHV infections. Validated methods were developed and applied in order to determine the global prevalence of the CFPHV among these species.

Singleplex and nested PCR, Sanger sequencing and qPCR techniques were used to achieve these goal. Moreover, by using next generation sequencing we obtained a large number of full turtle mitochondrial genomes and a few entire CFPHV genomes were obtained from various samples.

Finally, large quantities of nuclear DNA data was generated by shotgun sequencing across two species of marine turtles. The most remarkable findings indicate that 100% of the FP exhibiting green turtles yielded CFPHV DNA sequences, unexpectedly, so did 15% of the clinically healthy turtles, presumably through persistent latent infections, often at surprisingly high levels.

Supervisors

Professor Tom Gilbert, Natural History Museum of Denmark

Associate Professor Mads Frost Bertelsen, Center for Zoo and Wild Animal Health

Professor Anders Miki Bojesen, Faculty of Health and Medical Sciences

Assessment committee

Assoc. Professor Peter Rask Møller, Chairman, Natural History Museum of Denmark

Professor Kyle Van Houtan, Duke University

Senior Lecturer Ellen Ariel, James Cook University