Natural size variation among embryos leads to the corresponding scaling in gene expression.
Natural size variation among embryos leads to the corresponding scaling in gene expression.
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DOI：
10.1016/j.ydbio.2020.03.014
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发表时间：
2020-06-15
影响因子：
2.7
通讯作者：
Fainsod A
中科院分区：
文献类型：
--
作者：
Leibovich A;Edri T;Klein SL;Moody SA;Fainsod A
来自实验室种群的非洲爪蟾蛙通常产卵，卵的大小有很大的差异。我们发现，这些最初的大小差异，随后影响的大小的胚胎开始生长之前，在生长期间的蝌蚪的大小。尽管这些蝌蚪的大小不同，但它们的组织、器官和结构似乎总是比例适当的，即它们表现出静态异速生长。非洲爪蟾最初的轴向图案事件发生在一个球形胚胎中，这使得它们的大小依赖特征很容易记录下来。我们研究了早期非洲爪蟾胚胎的大小分布，并测量了约38%的直径不同，中位数约为1.43毫米。这个范围的胚胎大小对应于约1.9倍的表面积差异和2.6倍的体积差异。我们研究了胚胎大小和基因表达之间的关系，并观察到在原肠胚阶段直径和RNA含量之间的显着相关性。此外，我们研究了中胚层模式的基因的表达水平，诱导神经系统和介导的大，小胚胎外胚层细胞神经前体细胞的进展。我们发现，这些因子中的大多数表达水平与不同的胚胎大小和总胚胎RNA含量成比例。与转录水平的变化一致，较大胚胎中的表达结构域随着表面积的增加而成比例地增加，保持其相对于胚胎总大小的相对表达结构域大小。因此，我们的研究确定了一种机制，通过调整调节中胚层诱导和模式化的基因的转录水平，使基因表达结构域适应胚胎大小。在神经板中，除了表达结构域的缩放外，我们在小胚胎和大胚胎中观察到相似的细胞大小和细胞密度，这表明在大胚胎中发生了额外的细胞分裂以补偿增加的大小。我们的研究结果详细显示非洲爪蟾胚胎之间的大小变异和转录适应尺度基因表达的大小。这些观察结果进一步支持BMP/Akt信号传导参与缩放过程。
Xenopus laevis frogs from laboratory stocks normally lay eggs with extensive size variability. We find that these initial size differences subsequently affect the size of the embryos prior to the onset of growth, and the size of tadpoles during the growth period. Even though these tadpoles differ in size, their tissues, organs, and structures always seem to be properly proportioned, i.e. they display static allometry. Initial axial patterning events in Xenopus occur in a spherical embryo, allowing easy documentation of their size-dependent features. We examined the size distribution of early Xenopus laevis embryos and measured diameters that differed by about 38% with a median of about 1.43 mm. This range of embryo sizes corresponds to about a 1.9-fold difference in surface area and a 2.6-fold difference in volume. We examined the relationship between embryo size and gene expression and observed a significant correlation between diameter and RNA content during gastrula stages. In addition, we investigated the expression levels of genes that pattern the mesoderm, induce the nervous system and mediate the progression of ectodermal cells to neural precursors in large and small embryos. We found that most of these factors were expressed at levels that scaled with the different embryo sizes and total embryo RNA content. In agreement with the changes in transcript levels, the expression domains in larger embryos increased proportionally with the increase in surface area, maintaining their relative expression domain size in relation to the total size of the embryo. Thus, our study identified a mechanism for adapting gene expression domains to embryo size by adjusting the transcript levels of the genes regulating mesoderm induction and patterning. In the neural plate, besides the scaling of the expression domains, we observed similar cell sizes and cell densities in small and large embryos suggesting that additional cell divisions took place in large embryos to compensate for the increased size. Our results show in detail the size variability among Xenopus laevis embryos and the transcriptional adaptation to scale gene expression with size. The observations further support the involvement of BMP/ADMP signaling in the scaling process.
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影响因子：
64.5
作者：
Inomata, Hidehiko;Shibata, Tatsuo;Sasai, Yoshiki
通讯作者：
Sasai, Yoshiki
DOI：
10.1073/pnas.1203000109
发表时间：
2012-09-18
影响因子：
11.1
作者：
Inui, Masafumi;Montagner, Marco;Piccolo, Stefano
通讯作者：
Piccolo, Stefano
DOI：
10.1073/pnas.0509483102
发表时间：
2005-12-20
影响因子：
11.1
作者：
Gregor, T;Bialek, W;Wieschaus, EF
通讯作者：
Wieschaus, EF
影响因子：
2.5
作者：
De Robertis, Edward M.;Moriyama, Yuki;Colozza, Gabriele
通讯作者：
Colozza, Gabriele
影响因子：
10.5
作者：
CHRISTIAN, JL;MOON, RT
通讯作者：
MOON, RT