Molecular ecology of marine turtles: new approaches and future directions

The study of turtle population genetics has come a long way in the past few decades. In the early 1990s, technologies such as polymerase chain reaction (PCR) and automated DNA sequencing spearheaded a boom in molecular ecology. Microsatellite and mitochondrial DNA haplotype markers became the methods of choice for many turtle studies. Today, the rate of research continues unabated. The emergence of new methods, approaches and ideas means exciting prospects for the molecular ecology of marine turtles. A review of genetic markers that have been used for turtle research provides a starting point for those breaking into this area for the first time. Here current molecular techniques are discussed, but upcoming new ideas and methods are also highlighted. A recently proposed hypothesis to explain the polyandrous behaviour of female turtles means a fresh direction for multiple paternity studies. A new statistical approach (individual-based analysis) offers future studies analytical methods other than F-statistics, and an alternative means to test male-biased gene flow. Paternity analysis now enables robust reconstruction of male genotypes from their offspring, elucidating the genetics of adult male turtles without collecting them in the field. With whole genome amplification (WGA) limited DNA samples can be amplified for long-term storage, large-scale analyses and easy exchange between laboratories. New genetic markers are essential for future progress, and breakthrough DNA sequencing technologies will facilitate marker discovery. The next-generation sequencing methods also means that the new ‘-omics’ techniques of genomics and transcriptomics may in the future be applicable to marine turtle research.