Genome size estimation with quantitative real-time PCR in two Tephritidae species: Ceratitis capitata and Bactrocera oleae

The medfly Ceratitis capitata and the olive fruit fly Bactrocera oleae belong to the Tephritidae family of Diptera, a family whose members cause severe damages in agriculture worldwide. For such insect pests, the utmost concern is their population control. The sterile insect technique (SIT) has been used in the Tephritidae family with varying degrees of success. Its efficient use usually depends on the development of genetic sexing strains and the release of only male flies. However, such advances are based on modern genetic, molecular and genomic tools. The medfly is clearly the prototype of the family, since such tools have advanced considerably, which has resulted in effective SIT efforts around the world. A whole-genome sequencing project of this insect is already underway. In contrast, similar tools in the olive fly lag behind, even though the insect is considered a promising candidate for a next SIT target. An accurate estimate of genome size provides a preliminary view of genome complexity and indicates possible difficulties in genome assembly in whole-genome projects. Taking advantage of a quantitative real-time PCR approach, we determined the genome size of these two species C.capitata and B.oleae as 591 Mb (CI range: 577605 Mb) and 322 Mb (CI range: 310334 Mb) respectively.