Karyotypic and Molecular Identification of Laboratory Stocks of the South American Fruit Fly Anastrepha fraterculus (Wied) (Diptera: Tephritidae)

Abstract

The taxonomic status of the tephritid pest Anastrepha fraterculus (Wied.) is a controversial subject, mainly because of misinterpretation of the observed genetic variation. In this work, the different karyotypes and DNA polymorphism of a geographically defined population from Northeastern Argentina were studied, using derived stocks maintained in the laboratory during 25 generations. The karyotypes were analyzed using C-banding and N-banding techniques, while DNA analysis was performed through the DNA polymerase chain reaction (PCR). The variants isolated from both the wild Montecarlo population and the derived laboratory stocks were fully compatible and are present in other wild populations from South Brazil (lat 31 degrees 30' S) to Mid-Argentina (lat 34 degrees 30' S). Single-pair crosses among stocks carrying different chromosomal variants demonstrated the absence of isolation barriers. The polymorphic fragments isolated by RAPDs/PCR showed polymorphisms among stocks whereas the analysis of rDNA ITS1 exhibit a unique ITS1 length. Our results seem to indicate that all the examined variants belong to a single species with extended polymorphism and therefore do not support the hypothesis that the extended chromosomal polymorphism in A. fraterculus implies the existence of a complex of cryptic species.

Karyotype characterization of Anastrepha fruit flies (Diptera: Tephritidae)

“…However, in karyological studies of Anastrepha (Basso et al 2003) and other genera of fruit flies [e.g. Dacus cucurbitae Coquillet (Gopalan 1972), Ceratitis capitata (Wiedemann) (Zacharopoulou 1986), Rhagoletis pomonella (Walsh) (Procunier & Smith 1993), Bactrocera oleae Gmelin (Canovai et al 1996 )], the autosomes are numbered in a descending order, the largest being number 2 (or II).…”

“…However, it was shown later on that one of these karyotypes belong indeed to A. sororcula (Morgante et al 1993). Polymorphism specially of the sex chromosomes was found by Basso & Manso (1998) and Basso et al (2003) (Selivon 1996;Selivon et al 2004Selivon et al , 2005.…”

Sex chromosomes in mitotic and polytene tissues of Anastrepha fraterculus (Diptera, Tephritidae) from Argentina: a review

“…Lifschitz et al (1999) described an acrocentric X chromosome and a small submetacentric Y chromosome (see also Basso and Manso 1998, Basso et al 2003). Lifschitz et al (1999) and Manso and Basso (1999) also reported four morphological variants of the X chromosome (named X 1 , X 2 , X 3 and X 4 ) and six variants of the Y chromosome (named Y 1 , Y 2 …Y 6 ) at low frequency (Figure 1).…”

Cytological characterization of sex chromosomes and ribosomal DNA location in <i>Anastrepha</i> species (Diptera, Tephritidae)

“…Later on the distribution of heterochromatic chromosome regions was described, based on C-and N-banding techniques Morgante, 1987, 1990;Morgante et al, 1993Morgante et al, , 1996Basso and Manso, 1998;Basso et al, 2003;Selivon et al, 2004Selivon et al, , 2005aSelivon et al, , 2005b.…”