Recovery of a marked translocation strain that will facilitate the isolation of balancer chromosomes in the Mediterranean fruit fly,Ceratitis capitata

Abstract

The results of two screens for mutations and chromosomal aberrations in Ceratitis capitata are presented. Three dominant mutations were recovered, including Sb, which is associated with a homozygous lethal translocation between the third and fifth chromosomes, T(3;5)Sb, with the fifth chromosome breakpoint adjacent to y. The T(3;5)Sb chromosome is maintained by selecting for Sb in a T(3;5)Sb, w2 Sb y2 wp/w2 y2 wp stock and can be used to distinguish between other chromosomes carrying differential combinations of the recessive markers w2 y2 wp. The ability to isolate particular marked chromosomes is essential in order to recover an inversion-based balancer chromosome. In addition to the recovery of dominant mutations, gamma-ray induced somatic mosaics of w2 and y2 and zygotic w mosaics were found. The generation of zygotic mosaics following mutagenesis can give mutants with a mosaic germ line that fail to breed true in the first generation. A screen of 22,830 irradiated chromosomes failed to recover variegating alleles of w, although such alleles might be recovered in a larger screen. The high frequency of dominant mutations and the instability at the w locus in our stocks implies a background level of dysgenic activity. These results have implications for the construction and long-term maintenance of genetically modified strains.

An integrated genetic and cytogenetic map for the Mediterranean fruit fly, Ceratitis capitata, based on microsatellite and morphological markers

“…Strain ew dp, which carries the recessive morphological markers ew (eroded wings) and dp (dark pupae) on the third autosome (Roessler and Rosenthal 1990). Strain CyBar, which is homozygous for the dominant Cy (Curly wings) mutation (Gubb et al 1998) and heterozygous for the dominant Bar (Bar eye) mutation, which is homozygous lethal (Roessler and Rosenthal 1990), both mapped on the fourth chromosome. Strains w 2 y 2 wp Sr 2 and w 2 y 2 wp (Gubb et al 1998;Gourzi et al 2000) which carry the recessive mutations w 2 (white eye), y 2 (yellow body), wp (white pupae) and the dominant Sr 2 (Sergeant) mutation, which is homozygous lethal (Gourzi et al 2000;Niyazi et al 2005) all mapped on the fifth chromosome.…”

A review of more than 30 years of cytogenetic studies of Tephritidae in support of sterile insect technique and global trade

“…These results showed that a translocation-based balancer might be a more feasible target in C. capitata. In fact, during the first attempts, a marked translocation strain was recovered T(3;5)Sb, y (Gubb et al, 1998). However, translocation strains are not ideal, as adjacent-1 segregation and recombination events may give aneuploidy progeny, thus reducing the fertility of the strain.…”

Απομόνωση μικροδορυφόρων στη μεσογειακή μύγα Ceratitis Capitata και η χρησιμοποίηση τους στη φυσική και γενετική χαρτογράφηση του γονιδιώματος του εντόμου

“…Η υπερέχουσα µετάλλαξη Sv (Shaven) είναι βιώσιµη σε οµοζυγωτία. Στα ετεροζυγωτικά άτοµα απουσιάζει µέρος των σµηρίγγων από την περιοχή του θώρακα, ενώ σε οµοζυγωτία ο αριθµός των σµηρίγγων µειώνεται µέχρι σχεδόν την πλήρη εξαφάνισή τους (Gubb et al 1998).…”