Cytogenetic characterization of a genetic sexing strain in Ceratitis capitata

A genetic sexing strain of Ceratitis capitata, carrying a null mutation for ADH activity linked to the Y chromosome, was analysed cytogenetically. In addition to an insertion of a large part of the Y chromosome into chromosome 2, this strain carries two other chromosomal rearrangements, a deletion in the second chromosome and a reciprocal translocation involving chromosomes 2 and 4. The progeny of the T(2;4) translocation heterozygote with unbalanced chromosome constitution can survive up to the larval and (or) to the adult stage. These cytological characteristics are discussed in relation to the genetic sexing behaviour of this line.Key words: Ceratitis capitata, polytene chromosomes, genetic sexing.

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Sex chromosome aneuploidy in a male-linked translocation in Ceratitis capitata

Canadian Journal of Genetics and Cytology ◽

10.1139/g86-021 ◽

1986 ◽

Vol 28 (1) ◽

pp. 161-167 ◽

Cited By ~ 13

Author(s):

M. Zapater ◽

A. S. Robinson

Keyword(s):

Alcohol Dehydrogenase ◽

Sex Determination ◽

Y Chromosome ◽

Ceratitis Capitata ◽

Sex Chromosome ◽

Translocation Line ◽

Chromosome 2 ◽

Genetic Sexing ◽

Sex Chromosome Aneuploidy ◽

Cytological Data

A translocation line in Ceratitis capitata (2n = 12) linking the male-determining Y chromosome with the autosome carrying the alcohol dehydrogenase (Adh) locus was examined to assign the locus to its chromosome. Adh was assigned to chromosome 2, the largest autosome, representing the first correlation between genetic and cytological data in this species. During the study, male adults with 11 and 12 chromosomes were identified in the population and a model was proposed to account for the appearance of these individuals. Predictions made from the model were in general verified by the subsequent experiments. It was shown that 11-chromosome males were more fertile and produced more males than 12-chromosome males. Eleven-chromosome males produced 11- and 12-chromosome progeny, whereas 12-chromosome males produced only 12-chromosome male progeny. The results are discussed with relation to sex determination in this species and to the use of male-linked translocations for the development of genetic sexing techniques.Key words: Ceratitis, male determination, translocation, aneuploidy.

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Effects of contamination with wild-type males, virgin females or mated females, on the stability of the T:Y(ωp†)30C genetic sexing strain of Ceratitis capitata (Diptera: Tephritidae)

Bulletin of Entomological Research ◽

10.1017/s0007485300040025 ◽

1993 ◽

Vol 83 (4) ◽

pp. 599-606

Author(s):

A.A. Kafu ◽

E. Busch-Petersen ◽

R.J. Wood

Keyword(s):

Y Chromosome ◽

Ceratitis Capitata ◽

White Male ◽

Low Frequency ◽

Mass Rearing ◽

Temporary Increase ◽

Wild Type ◽

Genetic Sexing ◽

Fitness Advantage ◽

Genetic Sexing Strain

AbstractThe T:Y(ωp†)30c genetic sexing strain of Ceratitis capitata (Wiedemann), which is designed to generate males with brown (wild-type) pupae and females with white pupae, was contaminated artificially in a series of population experiments, to investigate the pattern of breakdown of the strain. The frequency of brown female pupae increased whether contamination was with males, unmated females or mated females, but the frequency of white male pupae increased only after male or mated female contamination. Contamination with either sex, mated or unmated, caused a rise in the overall frequency of brown pupae. A fitness advantage of the ωp† gene, when not attached to the Y chromosome, seemed to be indicated. The sex ratio became distorted in favour of females after contamination with females, mated or unmated, but not after male contamination which caused a temporary increase in males. The experiments revealed evidence of a low frequency of natural recombination between ωp† and the translocation breakpoint on the Y chromosome, shown by the appearance of a small number of white males that could not be attributed to the experimental procedure. These findings are shown to be relevant in determining whether wild type contamination has taken place in mass rearing of this strain for sterile male release.

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Pupation Substrate Type and Volume Affect Pupation, Quality Parameters and Production Costs of a Reproductive Colony of Ceratitis capitata (Diptera: Tephritidae) VIENNA 8 Genetic Sexing Strain

Insects ◽

10.3390/insects12040337 ◽

2021 ◽

Vol 12 (4) ◽

pp. 337

Author(s):

Carlos Pascacio-Villafán ◽

Luis Quintero-Fong ◽

Larissa Guillén ◽

José Pedro Rivera-Ciprian ◽

Reynaldo Aguilar ◽

...

Keyword(s):

Wheat Bran ◽

Ceratitis Capitata ◽

Mass Rearing ◽

Physicochemical Characteristics ◽

Production Costs ◽

Cellulose I ◽

Coconut Fiber ◽

Genetic Sexing ◽

Recycled Paper ◽

Genetic Sexing Strain

Adequate pupation substrates and substrate volume are critical factors in the mass-rearing of insects for Sterile Insect Technique (SIT) applications. To identify an ideal pupation substrate for a reproductive colony of Ceratitis capitata (Wiedemann) VIENNA 8 genetic sexing strain, we first examined pupation in cellulose from recycled paper (cellulose I), sawdust, fine wheat bran, vermiculite and coconut fiber using a volume of 2.5–12.5 mL of substrate for each 5 mL volume of fly larvae. We found a positive relationship between substrate volume and pupation, with cellulose I generating the highest proportions of pupation and coconut fiber the lowest. Higher proportions of female flies (white pupae) pupated in sawdust. The proportion of female fliers increased as substrate volume rose in sawdust and coconut fiber, whereas it decreased in vermiculite and cellulose. In a second experiment, we tested three types of cellulose differing in physicochemical characteristics (celluloses I, II and III), sawdust, and fine wheat bran using a substrate:larvae ratio of 1:1. The three types of cellulose produced the highest pupation levels. The highest proportions of female fliers were observed in sawdust, and cellulose types III and II. Cellulose III and sawdust at relatively low volumes were more cost-effective to produce one million pupae than other substrates, including fine wheat bran used in a mass-rearing facility in Mexico.

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