Developmental Origins of Mosaic Brain Evolution: Morphometric Analysis of the Developing Zebra Finch Brain
Developmental Origins of Mosaic Brain Evolution: Morphometric Analysis of the Developing Zebra Finch Brain
复制标题
DOI：
10.1002/cne.22005
复制
发表时间：
2009-05-10
影响因子：
2.5
通讯作者：
Striedter, Georg F.
中科院分区：
文献类型：
--
作者：
Charvet, Christine J.;Striedter, Georg F.
在成年斑胸草雀 (Taeniopygia guttata) 中，端脑占据整个大脑的 64%。这个部分与鹦鹉中看到的相似，但许多其他鸟类的端脑要小得多。本研究的目的是确定斑胸草雀端脑增大的发育时间过程和细胞基础，然后将这些发现与其他鸟类端脑增大的已知情况进行比较。为此，我们从胚胎和孵化后斑胸草雀的连续切片中估计了所有主要大脑区域的体积。我们还用抗增殖细胞核抗原和磷酸化组蛋白 H3 的抗体标记增殖细胞。这项工作的一个重要发现是，斑胸草雀在孵化时的端脑包含一个厚的增殖性脑室下区（SVZ），从大脑皮层下延伸到背侧大脑皮层。数据还表明，相对于鹌鹑（鸡形目），斑胸草雀的端脑神经发生的开始和结束都延迟。这种神经发生的延迟，加上 SVZ 的扩大，可能是斑胸草雀等雀形目动物端脑增大的主要原因。此外，雀形目动物通过减小中脑顶盖的比例尺寸来扩大其端脑。由于在神经发生开始之前，斑胸草雀的推定顶盖比鹌鹑小，因此顶盖大小的差异不可能是由于神经发生时间的进化改变所致。总的来说，这些发现表明，几种不同的发育机制是雀形目动物大型端脑进化的基础。 J.Comp。内罗尔。 514:203-213, 2009。(C) 2009 Wiley-Liss, Inc.
In adult zebra finches (Taeniopygia guttata), the telencephalon occupies 64% of the entire brain. This fraction is similar to what is seen in parrots, but many other birds possess a significantly smaller telencephalon. The aim of the present study was to determine the developmental time course and cellular basis of telencephalic enlargement in zebra finches, and then to compare these findings with what is known about telencephalic enlargement in other birds. To this end we estimated the volumes of all major brain regions from serial sections in embryonic and post-hatching zebra finches. We also labeled proliferating cells with antibodies against proliferating cell nuclear antigen and phosphorylated histone H3. An important finding to emerge from this work is that the telencephalon of zebra finches at hatching contains a thick proliferative subventricular zone (SVZ) that extends from the subpallium into the dorsal pallium. The data also show that the onset and offset of telencephalic neurogenesis are both delayed in zebra finches relative to quail (Galliformes). This delay in neurogenesis, in conjunction with the expanded SVZ, probably accounts for most of the telencephalic enlargement in passerines such as the zebra finch. In addition, passerines enlarged their telencephalon by decreasing the proportional size of their midbrain tectum. Because the presumptive tectum is proportionally smaller in zebra finches than quail before neurogenesis begins, this difference in tectum size cannot be due to evolutionary alterations in neurogenesis timing. Collectively these findings indicate that several different developmental mechanisms underlie the evolution of a large telencephalon in passerines. J. Comp. Neurol. 514:203-213, 2009. (C) 2009 Wiley-Liss, Inc.