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''Drosophila simulans'' is a species of fly closely related to ''D. melanogaster'', belonging to the same ''melanogaster'' species subgroup. Its closest relatives are ''D. mauritiana'' and ''D. sechellia''. == Taxonomy== This species was discovered by the fly geneticist Alfred Sturtevant in 1919, when he noticed that the flies used in Thomas Hunt Morgan's laboratory at the Columbia University were actually two distinct species: ''D. melanogaster'' and ''D. simulans''. Males differ in the external genitalia, while trained observers can separate females using colour characteristics. ''D. melanogaster'' females crossed to ''D. simulans'' males produce sterile F1 females and no F1 males. The reciprocal cross produces sterile F1 males and no female progeny. ''D. simulans'' was found later to be closely related to two island endemics, ''D. sechellia'' and ''D. mauritiana''. ''D. simulans'' will mate with these sister species to form fertile females and sterile males, a fact that has made ''D. simulans'' an important model organism for research into speciation. Studies have provided evidences that paternal leakage is an integral part of the inheritance of this species. ''Wolbachia'' infections give insight into how certain species of ''Drosophila'' are related. Through the analysis of cytoplasmic incompatibility and similar mitochondrial DNA, it has been shown that ''D. simulans'' and ''D. mauritiana'' are more closely related to each other than to ''D. sechellia.'' Cytoplasmic incompatibility causes egg and sperm cells to fail in creating viable offspring, a common feature in ''Wolbachia'' infected ''D. simulans'' and ''D. mauritiana'' individuals.〔Rousset, F., Solignac M. 1995. Evolution of single and double Wolbachia symbioses during speciation in the Drosophila simulans complex. Proc. Natl. Acad. Sci. 92: 6389-6393.〕 ''Drosophila sechellia'' has significantly distinct mitochondrial DNA, further emphasizing the evolutionary differences between the three species. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Drosophila simulans」の詳細全文を読む スポンサード リンク
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