蛋白質去磷酸酶PP2A Bβ調節次單元為果蠅附屬肢體、神經發育及卵新生所需

Bβ Regulatory Subunit of PP2A is Essential for Appendage Development, Neurogenesis and Oogenesis in Drosophila

葉柏安(Po-An Yeh) ； 蘇銘燦(Ming-Tsan Su)

《Bio Formosa》 44卷1期 (2009/06) Pp. 53-60

https://doi.org/10.6248/BF.2009.44(1).06

摘要

果蠅twins（tws）基因產物可在卵生成時護士細胞中偵測到，其在胚胎表現主要在腹部神經管束（ventral nerves cord），在幼蟲期除了在中樞神經系統外，更表現在唾腺、翅碟、腳碟及眼碟組織中，先前研究著重其在決定細胞命運的角色，本研究則探討其在上述各組織器官的功能。如前人研究發現，突變果蠅有出現重複翅囊（wing pouch）的現象，我們進一步發現成蟲翅膀上突變細胞群組（somatic clone）剛毛缺失，類似的性狀也可在複眼、前肢及背甲上發現，螢光免疫染色更發現tws突變造成感光細胞無法發育。突變幼蟲的唾腺較鬆散，抗體染色顯示分隔接合組織（septate junction）減少及分佈改變，且纖維肌動蛋白（F-Actin）及細胞外形不正常，幼蟲中樞神經的細胞數也較野生果蠅少，突變濾泡細胞群組中則發現Dlg蛋白不正常地累積在頂側的（apical）細胞膜邊，突變果蠅大部分死於幼蟲期，死亡的幼蟲體腔中則常有黑色腫瘤組織，此外tws功能缺失也導致微管及多種胞器包括細胞核、粒腺體，內質網及高爾基氏體的不正常。

關鍵字

果蠅 ； 胞器 ； 蛋白質去磷酸酶 ； 調節次單元 ； 卵生成 ； 神經發育

並列摘要

Drosophila twins (tws), a Bβ regulatory subunit of PP2A, has been shown to be expressed in various tissues during development. Previous study has demonstrated that tws is required for cell fate determination as well as mitosis. In this study we investigated its developmental function in which it is expressed. As the previous report, we found that hypomorphic tws mutation leads to the formation of duplicated wing pouch. We further demonstrated that reduction of tws expression causes various developmental defects, including loss of wing hair, notum bristle and photoreceptor. Septate junction and organization of filamentous actin (F-Actin) were altered in mutant salivary gland. Disc large (Dlg) protein was accumulated at apical membrane of mutant follicle cell. Melanoma tissues were observed in body cavity of mutant larva. tws is also likely to play a role in various organelles, including nuclei, mitochondrion, Golgi body and endoplasmic reticulum, because alterations in morphology and subcellular localization of theses organelles were observed in tws mutant salivary gland.

並列關鍵字

Drosophila ； organelle ； protein phosphatase ； regulatory subunit ； oogenesis ； neurogenesis