Posterior localization of ApVas1 positions the preformed germ plasm in the sexual oviparous pea aphid Acyrthosiphon pisum.
Posterior localization of ApVas1 positions the preformed germ plasm in the sexual oviparous pea aphid Acyrthosiphon pisum.
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DOI：
10.1186/2041-9139-5-18
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发表时间：
2014
期刊：
影响因子：
4.1
通讯作者：
Chang CC
中科院分区：
文献类型：
--
作者：
Lin GW;Cook CE;Miura T;Chang CC
一些动物的种系规范是由早期胚胎发生期间母系遗传的种质驱动的（遗传模式），而在其他动物中，种系规范是由发育中期或晚期的邻近细胞的信号诱导的（诱导模式）。在后生动物中，诱导模式似乎是一种更普遍、更古老的条件。继承模式由此衍生。然而，关于无性繁殖和有性繁殖生物体的种系规范，尚不清楚是否使用两种策略，每个繁殖阶段使用一种策略，或者两个阶段仅使用一种策略。之前我们已经证明，无性胎生豌豆蚜的生殖细胞的规格取决于预先形成的种质。在这项研究中，我们扩展了这项工作来研究生殖细胞在有性卵生胚胎中是如何被指定的，旨在了解豌豆蚜中是否存在种系指定的发育可塑性。我们采用 Apvas1（豌豆蚜中的果蝇 vasa 直系同源物）作为种系标记来检查种质是否在卵生发育过程中预先形成，正如在胎生胚胎中已经看到的那样。在卵子发生过程中，Apvas1 mRNA和ApVas1蛋白均均匀分布。受精后，Apvas1 的均匀表达仍保留在卵子中，但从第五个核周期开始，ApVas1 发生后定位。 Apvas1/ApVas1 的后共定位首先在正在进行细胞化的合胞胚层中被发现，后来我们可以在成熟胚胎形态可识别的生殖细胞中检测到 Apvas1/ApVas1 的特异性表达。这表明 Apvas1/ApVas1 阳性细胞是原始生殖细胞，并且在细胞化之前 ApVas1 的后部定位定位了预先形成的种质。我们得出的结论是，无性和有性豌豆蚜虫都依赖于预先形成的种质来指定生殖细胞，并且与轴模式不同，种系规范的发育可塑性不会发生在两个蚜虫繁殖阶段。因此，卵生豌豆蚜中预先形成的种质所暗示的母本遗传模式在半变态动物中成为非典型案例，迄今为止，合子诱导模式在大多数其他研究的昆虫中盛行。
Germline specification in some animals is driven by the maternally inherited germ plasm during early embryogenesis (inheritance mode), whereas in others it is induced by signals from neighboring cells in mid or late development (induction mode). In the Metazoa, the induction mode appears as a more prevalent and ancestral condition; the inheritance mode is therefore derived. However, regarding germline specification in organisms with asexual and sexual reproduction it has not been clear whether both strategies are used, one for each reproductive phase, or if just one strategy is used for both phases. Previously we have demonstrated that specification of germ cells in the asexual viviparous pea aphid depends on a preformed germ plasm. In this study, we extended this work to investigate how germ cells were specified in the sexual oviparous embryos, aiming to understand whether or not developmental plasticity of germline specification exists in the pea aphid. We employed Apvas1, a Drosophila vasa ortholog in the pea aphid, as a germline marker to examine whether germ plasm is preformed during oviparous development, as has already been seen in the viviparous embryos. During oogenesis, Apvas1 mRNA and ApVas1 protein were both evenly distributed. After fertilization, uniform expression of Apvas1 remained in the egg but posterior localization of ApVas1 occurred from the fifth nuclear cycle onward. Posterior co-localization of Apvas1/ApVas1 was first identified in the syncytial blastoderm undergoing cellularization, and later we could detect specific expression of Apvas1/ApVas1 in the morphologically identifiable germ cells of mature embryos. This suggests that Apvas1/ApVas1-positive cells are primordial germ cells and posterior localization of ApVas1 prior to cellularization positions the preformed germ plasm. We conclude that both asexual and sexual pea aphids rely on the preformed germ plasm to specify germ cells and that developmental plasticity of germline specification, unlike axis patterning, occurs in neither of the two aphid reproductive phases. Consequently, the maternal inheritance mode implicated by a preformed germ plasm in the oviparous pea aphid becomes a non-canonical case in the Hemimetabola, where so far the zygotic induction mode prevails in most other studied insects.
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影响因子：
64.5
作者：
HAY, B;JAN, LY;JAN, YN
通讯作者：
JAN, YN
影响因子：
2.6
作者：
Chang, C-c.;Hsiao, Y-m.;Chang, T-H.
通讯作者：
Chang, T-H.
影响因子：
1.5
作者：
HEMING, BS
通讯作者：
HEMING, BS
影响因子：
2.7
作者：
Duncan, Elizabeth J.;Benton, Matthew A.;Dearden, Peter K.
通讯作者：
Dearden, Peter K.
影响因子：
9.2
作者：
Ewen-Campen, Ben;Donoughe, Seth;Extavour, Cassandra G.
通讯作者：
Extavour, Cassandra G.