Opa-like repeats in the genome of the Medfly Ceratitis capitata

Abstract

The sequence determination of several genomic clones isolated from the Mediterranean fruitfly Ceratitis capitata identified the existence of opa-like repeats, often more than one being clustered in small chromosomal segments. These repeats have previously been shown to consist of stretches of tandemly reiterated glutamine-encoding residues, and they are found in multiple genes of several organisms. Most of the repeats described here are flanked or interrupted by stop codons in all reading frames and, thus, could not possibly be part of protein-coding sequences. Furthermore, these repeats, of which there are several hundred in the genome of the Medfly, can be used effectively for the determination of sequence polymorphisms, providing a convenient approach to obtain additional landmarks for the construction of genomic maps of this economically important insect.

The Ceratitis capitata homologue of the Drosophila sex-determining gene Sex-lethal is structurally conserved, but not sex-specifically regulated

“…Using a Sxl cDNA fragment from D. melanogaster containing the two well-conserved RNA-binding domains (Bell et al, 1988), several overlapping cDNA clones were isolated from an embryonic library and from an adult female library prepared from C. capitata (Fig. 1A; Furia et al, 1993;Siden-Kiamos et al, 1993). The protein-coding region of adult cDNA A1 (Genbank accession number AF026145) of C. capitata corresponds to that of the female-specific cDNA cF1 of Drosophila (Bell et al, 1988).…”

Γενετική και κυτταρογενετική ανάλυση - σύνθεση του πρώτου ισορροπημένου χρομοσώματος στη μεσογειακή μύγα ceratitis capitata

“…Ιδιαίτερη συμβολή στον εμπλουτισμό της γενετικής πληροφορίας της μεσογειακής μύγας έχει η εφαρμογή γενετικής ανάλυσης πολυμορφισμών στο επίπεδο του DNA. Οι πολυμορφισμοί αυτοί μπορεί να οφείλονται σε πολυμορφικές περιοριστικές θέσεις (RFLPs-restriction fragment length polymorphisms, RAPDs-random amplified polymorphic DNAs) ή σε τυχαίο αριθμό επαναλήψεων μικροδορυφορικού DNA (VNTR's) (Haymer 1994, Siden-Kiamos et al 1993, Sheppard et al 1992. Πρόσφατα δημιουργήθηκαν τρία διαφορετικά συστήματα μετασχηματισμού της γεννητικής σειράς (germ line transformation) στην C. capitata.…”