Improved stability of genetic sex-separation strains for the Mediterranean fruit fly, Ceratitis capitata

Genome ◽  
1994 ◽  
Vol 37 (1) ◽  
pp. 72-82 ◽  
Author(s):  
G. Franz ◽  
E. Gencheva ◽  
Ph. Kerremans
Keyword(s):  
Ceratitis Capitata ◽  
Recombination Frequency ◽  
Fruit Fly ◽  
Mass Rearing ◽  
Temperature Sensitive ◽  
Genetic Sexing ◽  
Male Recombination ◽  
Comparable Level ◽  
Improved Stability ◽  
Genetic Sexing Strains

In the existing genetic sexing strains for the medfly, Ceratitis capitata, male recombination leads to breakdown of the sexing mechanism under mass rearing conditions. The rate of breakdown depends on the recombination frequency and on the fitness of the recombinants. We have tested two different sexing genes, white pupa and a temperature sensitive lethal, in combination with the translocation T(Y;5)30C. Both sexing strains broke down, although at very different rates. In the case of the white pupa strain, 3.5% recombinants were observed after rearing the strain for 15 generations. The second strain, utilizing white pupa and the temperature sensitive lethal as selectable markers, already reached a comparable level after six generations and was broken down completely in the ninth generation. In these strains the frequency of recombination is high because the breakpoint of T(Y;5)30C and the sexing gene(s) are far apart. To remedy the situation, we have isolated four new translocations with breakpoints located closer to the sexing genes. Mass rearing was simulated for several generations with strains based on these translocations and no breakdown was observed under the conditions used.Key words: medfly, sterile insect technique, genetic sexing, recombination.

scholarly journals Genetic analysis of medfly populations in an area of sterile insect technique applications

2021 ◽  
Author(s):  
Rubén Sancho ◽  
Ana Guillem-Amat ◽  
Elena López-Errasquín ◽  
Lucas Sánchez ◽  
Félix Ortego ◽  
...  
Keyword(s):  
Genetic Markers ◽  
Sterile Insect Technique ◽  
Ceratitis Capitata ◽  
Natural Populations ◽  
Low Frequency ◽  
Fruit Fly ◽  
Wild Populations ◽  
Genetic Sexing ◽  
Environmental Implications ◽  
Genetic Sexing Strains

AbstractThe sterile insect technique (SIT) is widely used in integrated pest management programs for the control of the Mediterranean fruit fly (medfly), Ceratitis capitata. The genetic interactions between the released individuals from the genetic sexing strains (GSS), used for SIT applications worldwide, and wild individuals have not been studied. Under the hypothesis that a number of Vienna GSS individuals released to the field might not be completely sterile and may produce viable offspring, we have analyzed medfly Spanish field populations to evaluate the presence of Vienna strain genetic markers. To this goal, we have used contrasted nuclear and mitochondrial genetic markers, and two novel sets of nuclear polymorphisms with the potential to be markers to discriminate between Vienna and wild individuals. Nuclear Vienna markers located on the 5th chromosome of Vienna males have been found in 2.2% (19 from 875) of the Spanish wild medfly females captured at the area where SIT is applied. In addition, a female-inherited mitochondrial Vienna marker has been found in two from the 19 females showing nuclear Vienna markers. The detection of several of these markers in single individuals represents evidence of the introgression of Vienna strain into natural populations. However, alternative explanations as their presence at low frequency in wild populations in the studied areas cannot be fully discarded. The undesired release of non-fully sterile irradiated GSS individuals into the field and their interactions with wild flies, and the potential environmental implications should be taken into account in the application of the SIT.

Simulation of instability in genetic sexing strains: effects of male recombination in association with other biological parameters

1991 ◽  
Vol 81 (1) ◽  
pp. 11-20 ◽  
Author(s):  
E. Busch-Petersen ◽  
H. Baumgartner
Keyword(s):  
Genetic Recombination ◽  
Mass Rearing ◽  
Biological Parameters ◽  
Genetic Sexing ◽  
Male Recombination ◽  
Rate Of Progression ◽  
Control Programmes ◽  
Males And Females ◽  
Low Levels ◽  
Genetic Sexing Strains

AbstractGenetic systems have been developed in several insect species for separating males and females prior to releasing sterilized males in pest control programmes using the sterile insect technique. The systems generally depend on translocating a readily selectable gene onto the Y chromosome. A potential source of instability in such a system is genetic recombination in the male. Although such recombination was originally thought to be absent in most cyclorrhaphous Diptera, low levels have recently been found. We have developed a computer model which simulates the progression of instability in the presence of male recombination, which can be used to assess the influence of rate of recombination in combination with a range of associated genetic and biological parameters. Male recombination alone or fitness of the Y-linked translocation were found to contribute relatively little to the rate of progression of instability. By contrast reduced fitness or mating competitiveness associated with the selectable gene had a strong effect. The sex ratio and the ratio of carriers to non-carriers of the selectable gene showed patterns characteristic of the parameters modelled. The relevance of such data to the development of suitable strains for genetic sex-separation and the replacement of strains under mass rearing conditions are discussed.

Genetic and cytogenetic analysis of Y-autosome translocations in the Mediterranean fruit fly, Ceratitis capitata

Genome ◽  
1992 ◽  
Vol 35 (2) ◽  
pp. 264-272 ◽  
Author(s):  
Ph. Kerremans ◽  
E. Gencheva ◽  
G. Franz
Keyword(s):  
Ceratitis Capitata ◽  
Fruit Fly ◽  
Mass Rearing ◽  
Mediterranean Fruit Fly ◽  
Structural Basis ◽  
Mitotic Chromosomes ◽  
Genetic Sexing ◽  
Radiation Induced ◽  
Low Levels ◽  
The Mediterranean

Radiation-induced translocations in the Mediterranean fruit fly, Ceratitis capitata, linking the Y chromosome to either autosome 3 or 4 produced pseudolinkage between sex and the mutations dark pupa (dp) and apricot eye (ap), respectively. The genetic behaviour of six new strains is described and the structural basis of five of them is determined through analysis of polytene and mitotic chromosomes. Five strains exhibited low levels of recombination; however, one strain produced a larger number than expected of aberrant, wild-type females. We provide evidence that this is the consequence of the survival of adjacent-1 segregation products until adulthood.Key words: medfly, mass rearing, genetic sexing, recombination, segregation.

scholarly journals Host Suitability and Fitness-Related Parameters in Coptera haywardi (Hymenoptera: Diapriidae) Reared on Irradiated Ceratitis capitata (Diptera: Tephritidae) Pupae Stemming From the tsl Vienna-8 Genetic Sexing Strain

2020 ◽  
Vol 113 (4) ◽  
pp. 1666-1674 ◽  
Author(s):  
Segundo R Núñez-Campero ◽  
Lorena Suárez ◽  
María Josefina Buonocore Biancheri ◽  
Jorge Cancino ◽  
Fernando Murúa ◽  
...  
Keyword(s):  
Ceratitis Capitata ◽  
Biological Control Agent ◽  
Adult Life ◽  
Mass Rearing ◽  
Control Agent ◽  
Temperature Sensitive ◽  
Full Potential ◽  
Genetic Sexing ◽  
Fitness Parameters ◽  
Genetic Sexing Strain

Abstract Coptera haywardi (Ogloblin) is a pupal endoparasitoid of tephritid flies with great potential as a biological control agent worldwide as it does not attack other Diptera. To reach its full potential, its mass rearing needs to be enhanced lowering costs. Here, we focused on the use of irradiated pupae of Ceratitis capitata (Wiedemann) stemming from the temperature-sensitive lethal (tsl) Vienna-8 genetic sexing strain (= CcVienna-8), which is mass-produced in the San Juan Medfly and Parasitoid Mass Rearing Facility in Argentina. Exposure of 1- to 2-d-old CcVienna-8 pupae irradiated at 90 Gy to 6- to 8-d-old C. haywardi females at a 10:1 host/parasitoid ratio for 24 h turned out to be highly successful for the rearing of this parasitoid. High radiation doses (90–100 Gy) did not adversely influence fitness parameters of C. haywardi offspring F1, namely lifetime reproductive rates, adult life expectancy, and survival time. Demographic parameters in C. haywardi F1 from irradiated CcVienna-8 young pupae were improved compared to those values recorded from parasitoid originated from nonirradiated CcVienna-8 pupae. These findings will help to enhance parasitoid mass rearing for augmentative releases against medfly in Argentinean fruit-producing regions.

Radiation on Medfly Larvae of tsl Vienna-8 Genetic Sexing Strain Displays Reduced Parasitoid Encapsulation in Mass-Reared Diachasmimorpha longicaudata (Hymenoptera: Braconidae)

2020 ◽  
Vol 113 (3) ◽  
pp. 1134-1144 ◽  
Author(s):  
Lorena Suárez ◽  
María Josefina Buonocore Biancheri ◽  
Guillermo Sánchez ◽  
Jorge Cancino ◽  
Fernando Murúa ◽  
...  
Keyword(s):  
Fruit Fly ◽  
Mass Rearing ◽  
Mediterranean Fruit Fly ◽  
Dose Effect ◽  
Temperature Sensitive ◽  
Genetic Sexing ◽  
Diachasmimorpha Longicaudata ◽  
Key Factor ◽  
Genetic Sexing Strain ◽  
Parasitoid Encapsulation

Abstract Improvements in the mass rearing of Diachasmimorpha longicaudata (Ashmead) on larvae of the Vienna-8 temperature-sensitive lethal genetic sexing strain of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) (= GSS Vienna-8) at the San Juan biofactory, Argentina, are currently under way. Lowering cost production is a key factor regarding parasitoid rearing. Thus, the variation in mass-reared parasitoid encapsulation levels and the incidence of superparasitism were determined; also, the gamma radiation dose-effect relation on host larvae and the influence of Mediterranean fruit fly strain were considered. Naked Mediterranean fruit fly larvae of both GSS Vienna-8 and a wild bisexual strain (= WBS) aged 6-d-old were irradiated at 0, 20, 40, 60, 80, 100, and 120 Gy, and exposed to parasitoid females. Melanization level was tested for encapsulated parasitoid larval first-instars (= L1). Non-irradiated and irradiated WBS larvae at 20–40 Gy displayed a significantly higher incidence of encapsulation when compared with GSS Vienna-8 larvae. The low melanized level in encapsulated parasitoid L1 was the most common melanization process at 72 h puparium dissection. A high melanized level was only found in non-irradiated WBS larvae. Irradiated GSS Vienna-8 larvae can neutralize the host immunological reactions over irradiated WBS larvae much more quickly. Superparasitism intensity in both Mediterranean fruit fly strains was not affected by radiation doses. High levels of superparasitism seemingly helped to overcome the host’s immune reaction by the surviving parasitoid larva. Parasitoid emergence increased from 60 Gy onwards in both Mediterranean fruit fly strains. Radiation in GSS Vienna-8 larvae may favor host’s antagonistic reactions decrease in relation with D. longicaudata development.

scholarly journals Lessons from Drosophila: Engineering Genetic Sexing Strains with Temperature-Sensitive Lethality for Sterile Insect Technique Applications

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 243
Author(s):  
Thu N. M. Nguyen ◽  
Amanda Choo ◽  
Simon W. Baxter
Keyword(s):  
Rna Polymerase Ii ◽  
Sterile Insect Technique ◽  
Genetic Research ◽  
Point Mutations ◽  
Random Mutagenesis ◽  
Fruit Fly ◽  
Temperature Sensitive ◽  
Agricultural Pests ◽  
Genetic Sexing ◽  
Genetic Sexing Strains

A major obstacle of sterile insect technique (SIT) programs is the availability of robust sex-separation systems for conditional removal of females. Sterilized male-only releases improve SIT efficiency and cost-effectiveness for agricultural pests, whereas it is critical to remove female disease-vector pests prior to release as they maintain the capacity to transmit disease. Some of the most successful Genetic Sexing Strains (GSS) reared and released for SIT control were developed for Mediterranean fruit fly (Medfly), Ceratitis capitata, and carry a temperature sensitive lethal (tsl) mutation that eliminates female but not male embryos when heat treated. The Medfly tsl mutation was generated by random mutagenesis and the genetic mechanism causing this valuable heat sensitive phenotype remains unknown. Conditional temperature sensitive lethal mutations have also been developed using random mutagenesis in the insect model, Drosophila melanogaster, and were used for some of the founding genetic research published in the fields of neuro- and developmental biology. Here we review mutations in select D. melanogaster genes shibire, Notch, RNA polymerase II 215kDa, pale, transformer-2, Dsor1 and CK2α that cause temperature sensitive phenotypes. Precise introduction of orthologous point mutations in pest insect species with CRISPR/Cas9 genome editing technology holds potential to establish GSSs with embryonic lethality to improve and advance SIT pest control.

scholarly journals Ceratitis capitata genetic sexing strains: laboratory evaluation of strains from mass-rearing facilities worldwide

2017 ◽  
Vol 164 (3) ◽  
pp. 305-317 ◽  
Author(s):  
A.A. Augustinos ◽  
A. Targovska ◽  
E. Cancio-Martinez ◽  
E. Schorn ◽  
G. Franz ◽  
...  
Keyword(s):  
Ceratitis Capitata ◽  
Mass Rearing ◽  
Laboratory Evaluation ◽  
Genetic Sexing ◽  
Genetic Sexing Strains
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