The development of genetic markers to sex subadult loggerhead sea turtles (Caretta caretta) using AFLP technology


Meeting Abstract

91-7  Wednesday, Jan. 6 11:45  The development of genetic markers to sex subadult loggerhead sea turtles (Caretta caretta) using AFLP technology STEGMAN, C.E.*; SHEDLOCK, A.M.; College of Charleston; College of Charleston stegmance@g.cofc.edu

The emerging field of genomics is transforming our ability to investigate the integrative biology of marine organisms. One technique for rapidly and economically sampling the genome-wide level of polymorphisms in a species without a priori genome data is amplified fragment length polymorphism (AFLP). AFLP can generate large datasets of potentially polymorphic loci using relatively few primer combinations and restriction endonucleases. The objective of this study is to develop sex-linked markers using AFLP to sex subadult loggerhead individuals non-invasively and efficiently. Loggerhead turtles possess temperature-dependent sex determination (TSD), in which incubation temperatures during a thermosensitive period of development determine sex. The mechanism behind TSD is not fully understood, and it is unclear to what extent genetics is involved. Currently, the sex of an individual is determined through hormonal assay, laparoscopic gonadal examination, or necropsy. These techniques are time consuming and difficult to perform in the field, however, and the question of how to genotype the sex of turtles accurately and efficiently remains an important research focus. For this study, DNA isolated from blood samples collected in Florida Bay was processed with an AFLP starter kit. AFLP products were visualized using the Beckman Coulter CEQ 8000 genotyping system. Sixty four primer pair combinations were run on 32 samples with known sex (16 male; 16 female). An analysis of sex-specific amplification patterns based on normalized fluorescent signal strengths, amplification frequencies, and fixed polymorphisms screened among thousands of amplified loci will be discussed in relation to identifying primer pairs warranting expanded genomic investigation.

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