Molecular mechanisms for the evolution of insect prolegs

2016 Fiscal Year Final Research Report

• Project/Area Number: 25440220
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Biodiversity/Systematics
• Research Institution: National Agriculture and Food Research Organization (2016); National Institute of Agrobiological Sciences (2013-2015)
• Principal Investigator: Tomita Shuichiro 国立研究開発法人農業・食品産業技術総合研究機構, 生物機能利用研究部門 新産業開拓研究領域, ユニット長 (30360457)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 連続相同 / カイコ / カブラハバチ

Outline of Final Research Achievements

Proleg is abdominal appendage that develops in the larval abdomen of Lepidoptera, Mecoptera and Symphyta of Hymenoptera. The limited distribution of proleg-baring species raises the question whether prolegs are homologous structures or convergent traits. To address this issue we analyzed the molecular mechanisms underlying the proleg development. Dll expression is detected at their tips during embryonic development in Bombyx mori.
The development of appendages in abdominal segments are suppressed by the expression of Ubx, abd-A and Abd-B. Strange enough, the abd-A null mutant strain of Bombyx fail to develop prolegs . Moreover, knocking-down Dll made no effects on proleg development while gnathal appendages and thoracic legs are greatly reduced. Prolegs of Athalia rosae (Hymenoptera) are also segmented but lack crochets or any distal-most structures and no Dll expression was detected. These results suggest prolegs of Lepidoptera and Hymenoptera are of different origin.

Free Research Field

発生生物学