Mitotic and polytene chromosomes analysis of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

Abstract

The Oriental fruit fly, Batrocera dorsalis s.s. (Hendel) is one of the most destructive agricultural pests, belonging to a large group of difficult to distinguish morphologically species, referred as the B. dorsalis complex. We report here a cytogenetic analysis of two laboratory strains of the species and provide a photographic polytene chromosome map from larval salivary glands. The mitotic complement consists of six chromosome pairs including a heteromorphic sex (XX/XY) chromosome pair. Analysis of the polytene complement has shown a total of five polytene chromosomes (10 polytene arms) that correspond to the five autosomes. The most important landmarks of each polytene chromosome and characteristic asynapsis at a specific chromosomal region are presented and discussed. Chromosomal homology between B. dorsalis and Ceratitis capitata has been determined by comparing chromosome banding patterns. The detection of chromosome inversions in both B. dorsalis strains is shown and discussed. Our results show that the polytene maps presented here are suitable for cytogenetic analysis of this species and can be used for comparative studies among species of the Tephritidae family. They also provide a diagnostic tool that could accelerate species identification within the B. dorsalis complex and could shed light on the ongoing speciation in this complex. Polytene chromosome maps can facilitate the development of biological control methods and support the genome mapping project of the species that is currently in progress.

Cytogenetic analysis of the Ethiopian fruit fly Dacus ciliatus (Diptera: Tephritidae)

“…The arms of each individual chromosome are unequal in length, corresponding to the submetracentric mitotic arms. No banded sex chromosomes were identified in the polytene complement of D. ciliatus, consistent with previous reports on C. capitata (Bedo 1986(Bedo , 1987Zacharopoulou 1987Zacharopoulou , 1990, B. oleae (Mavragani-Tsipidou et al 1992;Zambetaki et al 1995), B. tryoni (Zhao et al 1998), B. cucurbitae (Shahjahan and Yesmin 2002), B. dorsalis (Zacharopoulou et al 2011), R. cerasi (Kounatidis et al 2008) and R. completa (Drosopoulou et al 2010) and on the califorids, Lucilia cuprina (Childress 1969;Foster et al 1980;Bedo 1982) and Chrysomya bezziana (Bedo 1992). The heterochromatic network found in all polytene nuclei of D. ciliatus individuals (Fig.…”

“…1). Consistent with most tephritid species analyzed so far (Bush 1962;Bhatnagar et al 1980;Singh and Gupta 1984;Bedo 1986;Solferini and Morgante 1987;Zacharopoulou 1987Zacharopoulou , 1990Mavragani-Tsipidou et al 1992;Baimai et al 1995Baimai et al , 1999Baimai et al , 2000Selivon and Perondini 1997;Zhao et al 1998;Shahjahan and Yesmin 2002;Cevallos and Nation 2004;Selivon et al 2005;Kounatidis et al 2008;Cáceres et al 2009;Garcia-Martinez et al 2009;Drosopoulou et al 2010;Zacharopoulou et al 2011), the heterogametic karyotype (XY) of D. ciliatus was ascribed to the male. However, this is a subject of further investigation and confirmation since female heterogamety was detected in some tephritids (Frias 1992;Davies and Roderick 2005).…”

“…As in several other studies on tephritids (Foster et al 1980;Bedo 1986;Zacharopoulou 1987Zacharopoulou , 1990MavraganiTsipidou et al 1992;Zhao et al 1998;Shahjahan and Yesmin 2002;Kounatidis et al 2008;Drosopoulou et al 2010;Zacharopoulou et al 2011), no typical chromocenter like that of Drosophila melanogaster exists in the D. ciliatus polytene complement. Each individual polytene chromosome is easily identified by the different size and appearance of its heterochromatic centromeric mass (Fig.…”

“…2a-e). Characteristic centromeric masses, which are identifying landmarks of each polytene chromosome, have been found in other Diptera as well (Mavragani-Tsipidou et al 1992;Zhao et al 1998;Kounatidis et al 2008;Drosopoulou et al 2010;Zacharopoulou et al 2011). The observed differences in size, density and appearance of these structures might reflect differences in the amount of pericentromeric heterochromatin.…”

Characterization and evaluation of microsatellite markers in a strain of the oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae), with a genetic sexing character used in sterile insect population control

“…Further cytogenetic study should be done to characterize the chromosomal translocation nature of this strain, as per the work of Zacharopoulou et al (2011). Although the Y-pseudo-linked loci were applied for male-specific genotyping for practical strain identification, it is also conceivable that they could be developed and used in future sperm marking applications involving SIT.…”