Permalink : http://hdl.handle.net/2115/45186

アナナスショウジョウバエ亜群における種分化を染色体変異と塩基配列に基づき検討した. Drosophila bipectinata complex内の4種の関係は, 染色体変異に基づく分岐図と分子レベルの分岐図が一致した. しかし, D. ananassae complex では染色体変異に基づく分岐図が分子レベルのものと一致しなかった. これは種分化後に種間交雑があり, 遺伝子流動が生じたことを示唆する. 古典的な染色体多型の分岐図をもとに塩基配列情報の解析を行うことにより, より詳細な系統関係が推定でき, 遺伝子の種間移入の歴史が推測できる.
We compared chromosomal and molecular cladograms of three different taxonomic levels of the Drosophila ananassae species subgroup: 1) between complexes (the ananassae, bipectinata and ercepeae complexes, and D. varians), 2) between species within the bipectinata complex (D. bipectinata, D. parabipectinata, D.malerkotliana, and D. pseudoananassae), and 3) between species within the ananassae cluster of the ananassae complex (D. ananassae, D. parapallidosa, D. pallidosa, D. pallidosa-like-WAU, and D. papuensis-like). Polytene chromosome data were consistent with molecular data within the bipectinata complex. On the other hand, we found that cladograms based on DNA sequence data were inconsistent with those from chromosomal arrangement data in the ananassae cluster. The inconsistency might be explained by gene flow caused by recent hybridization between species. Chromosomal arrangement (especially inversion) data would give us more information than nucleotide data alone.