現(xiàn)代昆蟲唯一已知的背側(cè)附器是翅膀及其衍生物,，它們僅僅出現(xiàn)在其第二及第三胸節(jié)上。然而,，在化石記錄中翅狀墊卻存在于昆蟲其它的無翅節(jié)段上。
現(xiàn)在，Takahiro Ohde及其同事證明,，2個分別出現(xiàn)在黃粉蟲甲蟲 Tenebrio molitor 第一胸節(jié)和腹節(jié)上的特別翅狀墊可通過減少該昆蟲中 Hox 基因的表達而被誘導成為翅狀附器。相關(guān)論文發(fā)表在3月14日的Science上,。
據(jù)這些研究人員披露,，這些身體區(qū)域仍然保持著某種可被開啟而萌發(fā)出新附器的翅膀發(fā)育機制。他們的發(fā)現(xiàn)意味著這些區(qū)域——也被稱為序列翼翅同系物——并沒有在進化中喪失,，而是進行了修改以允許出現(xiàn)極為多樣的昆蟲身體構(gòu)造,。Ohde及其他的研究人員提出,，其它昆蟲物種身體上的無翅節(jié)段可能也有長出翅膀的潛力。(生物谷Bioon.com)
DOI: 10.1126/science.1234219
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PMID:
Insect Morphological Diversification Through the Modification of Wing Serial Homologs
Takahiro Ohde, Toshinobu Yaginuma, Teruyuki Niimi.
Fossil insects living some 350 million years ago show winglike pads on all thoracic and abdominal segments, which suggests their serial homology. It remains unclear whether winglike structures in nonwinged segments have been lost or modified through evolution. Here, we identified a ventral/lateral part of the body wall on the first thoracic segment, the hypomeron, and pupal dorsolateral denticular outgrowths as wing serial homologs in the mealworm beetle Tenebrio molitor. Both domains transform into winglike structures under Hox RNA interference conditions. Gene expression and functional analyses revealed central roles for the key wing selector genes, vestigial and scalloped, in the hypomeron and the denticular outgrowth formation. We propose that modification, rather than loss, of dorsal appendages has provided an additional diversifying mechanism of insect body plan.
