Arendt D, Nübler-Jung K
Institut für Biologie I (Zoologie), Freiburg, Germany.
Mech Dev. 1997 Jan;61(1-2):7-21. doi: 10.1016/s0925-4773(96)00620-x.
The idea that chordates, during their evolution, have inverted their dorsoventral body axis has recently gained substantial support. It has been shown that various dorsoventral patterning genes that are evolutionarily conserved between insects and vertebrates are expressed dorsally in insects, and ventrally in vertebrates, or vice versa. The ventral body side of insects thus seems to correspond to the dorsal body side of vertebrates, and these are nerve cord-bearing, neural body sides in both groups. In order to exclude that the inverted polarity of gene patterning activity is purely accidental, we compare here vertebrate and invertebrate blastula fate maps and their gastrulation patterns in the framework of early gene expression. From this comparison it appears that the neural body sides, 'ventral' in annelids or arthropods, and 'dorsal' in chordates, develop at similar positions with respect to the initial egg asymmetry. In addition, the formation of the neural body sides involves similar movements during gastrulation. We further suggest that the deuterostome gastrulation seen in today's chordates can be derived from a more ancestral gastrulation pattern seen in today's annelids and arthropods, and that the ventral midline cells of insects correspond to the dorsal midline cells of vertebrates.
脊索动物在进化过程中反转了其背腹体轴这一观点最近获得了大量支持。研究表明，昆虫和脊椎动物之间在进化上保守的各种背腹模式基因，在昆虫中表达于背侧，在脊椎动物中表达于腹侧，反之亦然。因此，昆虫的腹侧身体部分似乎对应于脊椎动物的背侧身体部分，并且这两组动物中这些都是带有神经索的神经身体侧。为了排除基因模式活动的反转极性纯粹是偶然的可能性，我们在此比较脊椎动物和无脊椎动物囊胚命运图谱以及它们在早期基因表达框架下的原肠胚形成模式。从这种比较中可以看出，神经身体侧，在环节动物或节肢动物中是“腹侧”，在脊索动物中是“背侧”，相对于初始卵的不对称性，在相似位置发育。此外，神经身体侧的形成在原肠胚形成过程中涉及相似的运动。我们进一步认为，当今脊索动物中所见的后口动物原肠胚形成可以源自当今环节动物和节肢动物中所见的更原始的原肠胚形成模式，并且昆虫的腹侧中线细胞对应于脊椎动物的背侧中线细胞。
