Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Boulevard, St Augustine, FL 32080-8610, USA.
Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Boulevard, St Augustine, FL 32080-8610, USA
Development. 2020 Sep 23;147(18):dev189373. doi: 10.1242/dev.189373.
The TGF-β superfamily comprises two distinct branches: the Activin/Nodal and BMP pathways. During development, signaling by this superfamily regulates a variety of embryological processes, and it has a conserved role in patterning the dorsal-ventral body axis. Recent studies show that BMP signaling establishes the dorsal-ventral axis in some mollusks. However, previous pharmacological inhibition studies in the annelid , a sister clade to the mollusks, suggests that the dorsal-ventral axis is patterned via Activin/Nodal signaling. Here, we determine the role of both the Activin/Nodal and BMP pathways as they function in axis patterning. Antisense morpholino oligonucleotides were targeted to and , transcription factors specific to the Activin/Nodal and BMP pathways, respectively. Following microinjection of zygotes, resulting morphant larvae were scored for axial anomalies. We demonstrate that the Activin/Nodal pathway of the TGF-β superfamily, but not the BMP pathway, is the primary dorsal-ventral patterning signal in These results demonstrate variation in the molecular control of axis patterning across spiralians, despite sharing a conserved cleavage program. We suggest that these findings represent an example of developmental system drift.
TGF-β 超家族包括两个不同的分支：Activin/Nodal 和 BMP 途径。在发育过程中，该超家族的信号转导调节多种胚胎发生过程，并且在背腹体轴的模式形成中具有保守作用。最近的研究表明，BMP 信号在一些软体动物中建立了背腹轴。然而，先前在环节动物（软体动物的姐妹类群）中的药理学抑制研究表明，背腹轴是通过 Activin/Nodal 信号转导形成的。在这里，我们确定了 Activin/Nodal 和 BMP 途径在 轴模式形成中的作用。反义 morpholino 寡核苷酸分别针对 Activin/Nodal 和 BMP 途径的特异性转录因子 和 进行靶向。在对受精卵进行微注射后，对出现轴向异常的突变体幼虫进行评分。我们证明，TGF-β 超家族的 Activin/Nodal 途径，而不是 BMP 途径，是 中背腹向模式形成的主要信号。这些结果表明，尽管共享保守的分裂程序，但螺旋动物中轴模式形成的分子控制存在差异。我们认为这些发现代表了发育系统漂移的一个例子。
