Polytene chromosome maps in four species of tsetse flies Glossina austeni, G. pallidipes, G. morsitans morsitans and G. m. submorsitans (Diptera: Glossinidae): a comparative analysis

Abstract

Photographic polytene chromosome maps from pupal trichogen cells of four tsetse species, Glossina austeni, G. pallidipes, G. morsitans morsitans and G. m. submorsitans were constructed and compared. The homology of chromosomal elements between the species was achieved by comparing banding patterns. The telomeric and subtelomeric chromosome regions were found to be identical in all species. The pericentromeric regions were found to be similar in the X chromosome and the left arm of L1 chromosome (L1L) but different in L2 chromosome and the right arm of L1 chromosome (L1R). The L2 chromosome differs by a pericentric inversion that is fixed in the three species, G. pallidipes, G. morsitans morsitans and G. m. submorsitans. Moreover, the two morsitans subspecies appeared to be homosequential and differ only by two paracentric inversions on XL and L2L arm. Although a degree of similarity was observed across the homologous chromosomes in the four species, the relative position of specific chromosome regions was different due to chromosome inversions established during their phylogeny. However, there are regions that show no apparent homology between the species, an observation that may be attributed to the considerable intra--chromosomal rearrangements that have occurred following the species divergence. The results of this comparative analysis support the current phylogenetic relationships of the genus Glossina.

Tsetse flies: Genetics, evolution, and role as vectors

“…Gariou-Papalexiou et al (2007) compared banding patterns among G. pallidipes, G.m. morsitans, G. m. submorsitans , and G. austeni .…”

“…As discussed earlier, G. austeni cytogenetics have been examined (Southern et al, 1972; Gariou-Papalexiou et al, 2007) and chromosome interchanges induced and manipulated experimentally (Curtis et al, 1972). Two subspecies are allopatric and have been described based on differences in body size, color, habitats, and responses to traps (Dias, 1987).…”

Nuclear and Wolbachia-based multimarker approach for the rapid and accurate identification of tsetse species

“…Mitochondrial markers, including cytochrome oxidase 1 (COI), cytochrome oxidase 2 (COII), cytochrome b (CYTB), 16S rRNA, and NADH dehydrogenase 2 (ND2), have also been implemented for the phylogenetic analysis of Glossina species, based on DNA sequencing [ 15 – 17 , 24 – 27 ]. The availability of polytene chromosomes in Glossina and the development of polytene chromosome maps provide additional genetic tools that can shed light on specific chromosomal banding pattern changes and / or rearrangements that could provide diagnostic characters for species identification [ 28 – 31 ].…”