Cryopreservation of embryos of the Mediterranean fruit fly Ceratitis capitata Vienna 8 Genetic Sexing Strain

Authors: AUGUSTINOS, ANTONIOS - International Atomic Energy Agency (IAEA); Rajamohan, Arun; KYRITSIS, GEORGE - International Atomic Energy Agency (IAEA); ZACHAROPOULOU, ANTIGONE - International Atomic Energy Agency (IAEA); HAQ, IHSAN UL - International Atomic Energy Agency (IAEA); TARGOVSKA, ASYA - International Atomic Energy Agency (IAEA); CACERES, CARLOS - International Atomic Energy Agency (IAEA); BOURTZIS, KOSTAS - International Atomic Energy Agency (IAEA); ABD-ALLA, ADLY - International Atomic Energy Agency (IAEA)

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2016
Publication Date: 8/18/2016
Publication URL: http://handle.nal.usda.gov/10113/5661744
Citation: Augustinos, A., Rajamohan, A., Kyritsis, G., Zacharopoulou, A., Haq, I., Targovska, A., Caceres, C., Bourtzis, K., Abd-Alla, A.M. 2016. Cryopreservation of embryos of the Mediterranean fruit fly Ceratitis capitata Vienna 8 Genetic Sexing Strain. PLoS One. 11(8):e0160232. Available: http://dx.doi.org/10.1371/journal.pone.0160232.

Interpretive Summary: The Mediterranean fruit fly, Ceratitis capitata, one of the most serious pests of fruit crops world-wide is efficiently controlled using sterile insect technique (SIT). Vienna 8 is an important genetic strain that is added to the efficiency cost effectiveness of the medfly SIT program. Mass rearing can result in extensive inbreeding and pose major risks such as deterioration and loss of important genetic characteristics in any insect strain. In the present study, we present a modified procedure to cryopreserve the embryos of the medfly Vienna 8 GSS based on vitrification. Two strains of Vienna 8 fly namely V8-118 and V8228 were subjected to cryopreservation procedure. Forty-eight hours old embryos incubated at 24°C, were found to be the most suitable for cryopreservation treatments. Post-cryopreservation assessment data showed no negative impact of the cryopreservation process on egg hatch rate, pupation rates, adult emergence rates and stability of the tsl character in both V8-118 and V8-228. In summary, our study provides an optimized cryopreservation procedure to cryopreserve the medfly Vienna 8 GSS and documents the absence of any negative impact on the genetic structure and quality of the strain.

Technical Abstract: The Mediterranean fruit fly, Ceratitis capitata, is one of the most serious pests of fruit crops world-wide. During the last decades, area-wide pest management (AW-IPM) approaches with a sterile insect technique (SIT) component have been used to control populations of this pest in an effective and environment-friendly manner. The development of genetic sexing strains (GSS), such as the Vienna 8 strain, has played a major role in increasing the efficacy and reducing the cost of SIT programs. In this respect, the Genetic Sexing Strain Vienna 8 was developed and is widely used. Mass rearing, extensive inbreeding, possible bottleneck phenomena and hitch-hiking effects pose major risks for deterioration and loss of important genetic characteristics of this strain. In the present study, we present a modified procedure to cryopreserve the embryos of the medfly Vienna 8 GSS based on vitrification. Forty-eight hours old embryos, incubated at 24°C, were found to be the most suitable for treatment and high production rates. Our data suggest the absence of any negative impact of the cryopreservation process on egg hatch rate, pupation rates, adult emergence rates and stability of the tsl character on two established cryopreserved lines, named V8-118 and V8-228. Taken together, our study provides an optimized cryopreservation procedure to cryopreserve the medfly Vienna 8 GSS and documents the absence of any negative impact on the genetic structure and quality of the strain.