Popis: |
Polytene giant chromosomes of the Phlebotomine sandfly Lutzomyia longipalpis from two localities in Brazil were examined. They are preliminarily described and illustrated from larval salivary gland preparations. Polytenes in other tissues of larvae, pupae and adult flies were found to be unsuitable for detailed study. Salivary chromosome arms were long but thin (‘oligotene’) and given to much ectopic pairing. Despite their fragility and cross-linkage, patterning on these chromosomes was sufficiently well differentiated to be cytotaxonomically useful. The normal mitotic complement comprised 3 pairs of metacentrics and 1 pair of subacrocentrics. None of the chromosome pairs was sexually dimorphic. Meiotic chiasmata were seen in males and females. Characteristics of giant chromosomes in Phlebotominae and Psychodinae are compared and discussed in relation to other Diptera. Cytogenetic evidence supports inclusion of the Psychodidae with the Simuliidae, Ceratopogonidae, Culicidae and Chironomidae in the superfamily Culicoidea. |