Please use this identifier to cite or link to this item:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/15485
Title: | 以 c002 和 Apsage 的表現探究豌豆蚜的唾腺發育 Formation of salivary glands in the pea aphid Acyrthosiphon pisum: c002 and Apsage expressions |
Authors: | Chun-Wei Lai 賴峻偉 |
Advisor: | 張俊哲(Chun-che Chang) |
Keyword: | 豌豆蚜,唾腺,c002,Apsage,孤雌無性胎生, pea aphid,salivary gland,c002,Apsage,asexual viviparous reproduction, |
Publication Year : | 2021 |
Degree: | 碩士 |
Abstract: | 蚜蟲屬於半翅目中的蚜總科,藉由刺吸式口器取食植物汁液。若取食植物遭受病毒感染,病毒便會感染蚜蟲作為傳播媒介,待下一次的吸食感染新的植物。目前已知蚜蟲會透過具唾液分泌功能的唾腺傳播病毒,然而唾腺在胚胎時期的特化及發育仍是未解之謎。本研究中,我首先針對蚜蟲專屬的唾腺基因 c002 合成反義股探針,探究 c002 mRNA 在豌豆蚜胚胎時期的表現情形。全胚胎整體原位雜合實驗的結果顯示,c002 mRNA 最早被偵測於出現表皮的胚胎時期,表現在外型可辨認的唾腺上。為了調查唾腺是否在更早的發育時期即開始特化,我們在豌豆蚜中選定了黑腹果蠅的唾腺基因 sage 之同源基因 Apsage,並檢視該基因在胚胎時期的表現。全胚胎整體原位雜合實驗的結果顯示 Apsage mRNA 會自肢芽萌發期至表皮發育期間連續表現,並且與 c002 共同表現於胚胎唾腺上。上述結果強烈意味著,第一,於肢芽萌發期,Apsage mRNA 在下唇節中表現的特定位置應為初始唾腺。第二,Apsage 保留著黑腹果蠅 sage 在胚胎唾腺的表現特性。比較黑腹果蠅與豌豆蚜的唾腺發育,兩者的唾腺均在胚帶延長末期開始特化。雖兩昆蟲之初始唾腺均出現於胚胎腹側處,但是豌豆蚜的唾腺卻會在胚胎翻轉後期,進入背部區域。從本研究中可以得出幾個總結:sage 在完全變態或是漸進變態昆蟲中是一個高度保守的唾腺標記分子;蚜蟲專屬的唾腺基因 c002 在晚期胚胎的唾腺即開始表現,顯示了該基因對於若蟲的取食十分重要。最後,唾腺在昆蟲中不同的分佈位置,可能具備特殊的生物意義,例如滿足取食上的需求。 Aphids belong to the superfamily Aphidoidea of Hemiptera, feeding on plants with the sucking mouthparts. Meanwhile, aphids can uptake viruses from the plant sap, vectoring them from one plant to another. It has been clear that aphids adopt salivary glands (SGs) to transmit viruses in addition to secreting saliva for digestion. However, when SGs are specified during embryogenesis in aphids remains unknown. In my study, I first synthesized antisense riboprobes of c002, an aphid-specific gene of SGs, investigating how c002 mRNA was expressed during embryogenesis in the pea aphid Acyrthosiphon pisum. Results of the whole mount in situ hybridization (WISH) show that transcripts of c002 were first detected on morphologically identifiable SGs of the embryos with cuticle. To investigate whether SGs were specified in earlier embryos, I monitored the expression of Apsage, a homologue of the SG gene sage in the fly Drosophila melanogaster. WISH results showed that Apsage signals could be continuously monitored from limb-bud formation to cuticle formation, during which signals of c002 and Apsage were colocalized in the embryonic SGs. This strongly suggests that: (1) Apsage transcripts restricted to the labial segments in the embryos with visible limb buds are primordia of SGs; and (2) The feature of sage expression in embryonic SGs of Drosophila is remained in Apsage in the pea aphid. Like D. melanogaster, specification of SGs in A. pisum also started in late germ band extension. However, primordia of SGs in D. melanogaster are located in the ventral side whereas those of SGs in A. pisum were identified in late embryos after katatrepsis. Taken together, we conclude that: (1) sage is a highly conserved SG marker for both holometabolous and hemimetabolous insects; (2) aphid-specific SG gene like c002 is indispensable for feeding of nymphs as c002 is expressed in SGs of late-stage embryos; and (3) locations of SGs may serve special functions to satisfy a particular engulfment need. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/15485 |
DOI: | 10.6342/NTU202100450 |
Fulltext Rights: | 未授權 |
Appears in Collections: | 基因體與系統生物學學位學程 |
Files in This Item:
File | Size | Format | |
---|---|---|---|
U0001-0302202113384400.pdf Restricted Access | 78.9 MB | Adobe PDF |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.