果蠅與蟋蟀腿發(fā)育的差異
cricket leg buds: spots in T1/T2 and rings in T3. Asterisks
indicate non-specific staining.
對(duì)果蠅的研究為我們了解發(fā)育開辟了廣闊的天地。而將果蠅與其他昆蟲相比較,又提供了許多形態(tài)進(jìn)化的寶貴思路。最近的一個(gè)報(bào)道顯示果蠅與蟋蟀腿發(fā)育的差異僅由一個(gè)單基因的表達(dá)模式變化引起。
蟋蟀和果蠅(Drosophila
melanogaster)分屬于昆蟲綱的兩個(gè)不同的總目(suborder)。蟋蟀(Gryllus
bimaculatus)是一種半變態(tài)式昆蟲,卵孵化后就是小型成體模樣,然后長(zhǎng)大后成熟,不象果蠅還要?dú)v經(jīng)蛹這個(gè)中間態(tài),進(jìn)行全變態(tài)過程。
果蠅中有關(guān)腿發(fā)育的基因有三個(gè),Dmhh,Dmwg,Dmdpp, Niwa et al.報(bào)道,這三個(gè)基因的同源物在Gryllus bimaculatus中也存在,而且在胚胎中的表達(dá)模式也很相似。果蠅中腿成蟲盤和Gryllus
bimaculatus的腿芽(bud)中,wg都是沿著前后邊緣的腹面表達(dá),hh充斥后部,而dpp基因在兩種昆蟲中則發(fā)生了不同,除了背部表達(dá)強(qiáng),腹部表達(dá)弱外。Gbdpp首先沿著腿芽背側(cè)呈點(diǎn)狀表達(dá),然后轉(zhuǎn)為5個(gè)圓形環(huán),這5個(gè)環(huán)被認(rèn)為與G沿著proximo–distal
axis的5個(gè)腿節(jié)對(duì)應(yīng),奇怪的是,腿部T1,T2區(qū)的dpp表達(dá)消失了,T3區(qū)維持,這可能說明了將來此處會(huì)有強(qiáng)勁的跳躍肌出現(xiàn)。
這三種因子的類似模式說明進(jìn)化過程中,控制腿發(fā)育過程的保守性,而dpp表達(dá)的模式不同則說明了具體物種在腿形態(tài)學(xué)上的差異。
相關(guān)文章:
ORIGINAL RESEARCH PAPER
Niwa , N. et al. Correlation
of diversity of leg morphology in Gryllus bimaculatus (cricket) with
divergence in dpp expression pattern during leg development.
Development 127, 4373–4381 ( 2000) PubMed
FURTHER READING
Jockusch, E. L. et al. Leg
development in flies versus grasshoppers: differences in dpp
expression do not lead to differences in the expression of downstream
components of the leg patterning pathway. Development 127, 1617–1626 ( 2000) PubMed
Friedrich, M. Divergent
decapentaplegic expression patterns in compound eye development and the evolution of insect metamorphosis. J. Exp. Zool. 288, 39–55 (
2000) PubMed, 百拇醫(yī)藥
indicate non-specific staining.
對(duì)果蠅的研究為我們了解發(fā)育開辟了廣闊的天地。而將果蠅與其他昆蟲相比較,又提供了許多形態(tài)進(jìn)化的寶貴思路。最近的一個(gè)報(bào)道顯示果蠅與蟋蟀腿發(fā)育的差異僅由一個(gè)單基因的表達(dá)模式變化引起。
蟋蟀和果蠅(Drosophila
melanogaster)分屬于昆蟲綱的兩個(gè)不同的總目(suborder)。蟋蟀(Gryllus
bimaculatus)是一種半變態(tài)式昆蟲,卵孵化后就是小型成體模樣,然后長(zhǎng)大后成熟,不象果蠅還要?dú)v經(jīng)蛹這個(gè)中間態(tài),進(jìn)行全變態(tài)過程。
果蠅中有關(guān)腿發(fā)育的基因有三個(gè),Dmhh,Dmwg,Dmdpp, Niwa et al.報(bào)道,這三個(gè)基因的同源物在Gryllus bimaculatus中也存在,而且在胚胎中的表達(dá)模式也很相似。果蠅中腿成蟲盤和Gryllus
bimaculatus的腿芽(bud)中,wg都是沿著前后邊緣的腹面表達(dá),hh充斥后部,而dpp基因在兩種昆蟲中則發(fā)生了不同,除了背部表達(dá)強(qiáng),腹部表達(dá)弱外。Gbdpp首先沿著腿芽背側(cè)呈點(diǎn)狀表達(dá),然后轉(zhuǎn)為5個(gè)圓形環(huán),這5個(gè)環(huán)被認(rèn)為與G沿著proximo–distal
axis的5個(gè)腿節(jié)對(duì)應(yīng),奇怪的是,腿部T1,T2區(qū)的dpp表達(dá)消失了,T3區(qū)維持,這可能說明了將來此處會(huì)有強(qiáng)勁的跳躍肌出現(xiàn)。
這三種因子的類似模式說明進(jìn)化過程中,控制腿發(fā)育過程的保守性,而dpp表達(dá)的模式不同則說明了具體物種在腿形態(tài)學(xué)上的差異。
相關(guān)文章:
ORIGINAL RESEARCH PAPER
Niwa , N. et al. Correlation
of diversity of leg morphology in Gryllus bimaculatus (cricket) with
divergence in dpp expression pattern during leg development.
Development 127, 4373–4381 ( 2000) PubMed
FURTHER READING
Jockusch, E. L. et al. Leg
development in flies versus grasshoppers: differences in dpp
expression do not lead to differences in the expression of downstream
components of the leg patterning pathway. Development 127, 1617–1626 ( 2000) PubMed
Friedrich, M. Divergent
decapentaplegic expression patterns in compound eye development and the evolution of insect metamorphosis. J. Exp. Zool. 288, 39–55 (
2000) PubMed, 百拇醫(yī)藥
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