Polytene chromosome mapping in Ceratitis capitata (Diptera: Tephritidae)

Abstract

Polytene chromosome reference maps of the five autosomes of Ceratitis capitata from male pupal orbital bristle trichogen cells are presented and a correlation is established between two of them and the two largest of the five autosomes in the haploid mitotic complement. Characteristic features of each chromosome are described identifying areas that are difficult to analyze and noting the existence of common alternative band expression. A quantitative analysis of the mitotic karyotype of C. capitata indicates that the two smallest autosome pairs cannot be reliably distinguished. This may present problems with future attempts to establish homologies between the remaining mitotic and polytene chromosomes. A comparison of polytene chromosome banding patterns from salivary gland and trichogen cells failed to find any homologous regions, or even to identify homologous chromosomes. The banding differences are not explained by variation in puffing patterns, heterochromatin expression, or polyteny levels, but appear to reflect fundamental differences in banding patterns of the chromosomes in each tissue. Key words: Ceratitis capitata, polytene chromosome map, mitotic chromosome measurements.

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.…”

“…2f-g) may represent the underreplicated XX and XY sex chromosomes. Even though this correspondence is proposed for other Diptera as well (Childress 1969;Bedo 1982Bedo , 1987Bedo and Zacharopoulou 1988;Mavragani-Tsipidou et al 1992;Shahjahan and Yesmin 2002;Kounatidis et al 2008;Drosopoulou et al 2010;Zacharopoulou et al 2011), further analysis is needed to establish the exact correlation between the two sets of chromosomal elements (mitotic and polytene) and to elucidate the fate of the sex chromosomes of the mitotic complement.…”

Genetic and cytogenetic analysis of the American cherry fruit fly, Rhagoletis cingulata (Diptera: Tephritidae)

“…The absence of banded sex chromosomes is 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. curcubitae (Shahjahan and Yesmin 2002), R. pomonella (Procunier and Smith 1993) R. cerasi (Kounatidis et al 2008), R. completa (Drosopoulou et al 2010), Dacus ciliatus ) and on the califorids Lucilia cuprina (Childress 1969;Foster et al 1980;Bedo 1982) and Chrysomya bezziana (Bedo 1992).…”

“…This observation is comparable with the situation in R. completa, where the sex chromosomes are also of equal size (Drosopoulou et al 2010). The correspondence of the heterochromatic network of the polytene nuclei to the sex chromosomes of the mitotic complement has also been proposed for other Diptera (Childress 1969;Bedo 1982Bedo , 1987Bedo and Zacharopoulou 1988;Mavragani-Tsipidou et al 1992;Shahjahan and Yesmin 2002;Kounatidis et al 2008;Drosopoulou et al 2010Drosopoulou et al , 2011. Further analysis of X-linked sequences and the localization by in situ hybridization of genes in both mitotic and polytene chromosomes will be needed in order to establish correlations between the two sets of chromosomal elements (mitotic and polytene) and to provide information on the fate of the sex chromosomes of the mitotic complements.…”

Mitotic and salivary gland chromosome analyses in the Musca domestica L. (house fly) (Diptera: Muscidae)

“…The presence of several break points and constrictions make it difficult, for the moment, to determine the exact position of centromeres. However, in this paper, subject to further studies for confirmation, we determined the probable positions of centromeres according to the characters used by Foster et al (1980) and Bedo (1987) for determining the same structure in Lucilia cuprina and Ceratitis cap itata, respectively.…”