Developmental genetics of allometric variation between species

随着生物体的生长，它们也会改变形状。例如，人类的头部比身体的其他部分生长得慢，因此在成人的总尺寸中所占的比例小于婴儿。形状和大小的类似变化在新物种的进化中很重要，在作物和牲畜的育种中也很重要（例如果实更大的植物）。尽管在80多年前人们就认识到了大小和形状变化的重要性，当时这种现象被命名为异速生长（来自希腊语allo ` different <$和metron `measure <$），但其原因仍然是未知的。我们已经用植物的叶子和花瓣作为生长形状的例子来理解异速生长是如何控制的。我们杂交了两种金鱼草（金鱼草）不同大小的叶片和花瓣。通过比较每个后代的这些器官的大小与它继承的基因，我们能够找到导致器官大小差异的基因。这些基因也影响形状（即控制异速生长）。我们将利用这一发现，沿着发展的新技术和植物品种，对异速生长中自然变异的原因进行首次综合研究。我们将试图发现叶子和花瓣在生长过程中是如何改变形状的，以及异速生长基因是如何影响这些变化的。这将涉及类似于医学CAT扫描和延时摄影的方法来成像生长器官。因为叶子，特别是花瓣不是完全平坦的，我们将开发计算机软件来导航和记录这些图像的3D形状。我们还将研究是否相同的基因负责其他金鱼草物种之间的叶片和花瓣的差异，以及这些基因如何共同作用以控制器官的最终形状和大小。由于植物通常会从茎的底部到顶部产生不同形状和大小的叶子（这种现象称为异胚性），一个有趣的问题是异胚性和异速生长是否相关（例如，它们是否由相似的基因控制）。最后，我们将尝试确定至少两个异速生长基因的DNA序列。稍后，这将使我们能够研究这些基因产生的蛋白质如何影响生长，并研究基因突变如何使叶子和花瓣进化出不同的形状和大小。与BB/D522089/1和BB/D522438/1连接

As living organisms grow, they also change shape. The human head, for instance, grows more slowly than the rest of the body, and so makes up less of the total size of an adult than a baby. Similar changes in shape and size have been important in the evolution of new species and are important in the breeding of crops and livestock (e.g. plants with bigger fruits). Although the importance of changes in both size and shape was recognised over 80 years ago, when the phenomenon was named allometry (from the Greek allo ` different¿ and metron `measure¿), its causes are still mostly unknown. We have used plant leaves and petals as examples of growing shapes to understand how allometry is controlled. We hybridised two snapdragon (Antirrhinum) species with different sized leaves and petals. By comparing the size of these organs in each of the offspring with the genes it had inherited, we were able to locate the genes responsible for differences in organ size. These genes also affected shape (i.e. controlled allometry). We will use this finding along with new techniques and plant varieties that we have developed, to make the first integrated study of the causes of natural variation in allometry. We will attempt to discover how leaves and petals change shape as they grow and how allometry genes affect these changes. This will involve approaches similar to medical CAT scanning and time-lapse photography to image growing organs. Because leaves and particularly petals are not completely flat, we will develop computer software to navigate and record 3D shapes from these images. We will also examine whether the same genes are responsible for differences in leaves and petals between other snapdragon species and how the genes act together to control the final shape and size of organs. Because a plant normally produces leaves with different shapes and sizes from the bottom of the stem to the top (a phenomenon known as heteroblasty), one intriguing question is whether heteroblasty and allometry are related (e.g. are they controlled by similar genes). Finally, we will try to identify the DNA sequences of at least two of the allometry genes. Later this will allow us to study how the proteins produced by these genes influence growth and to examine how mutations in the genes have allowed evolution of leaves and petals with different shapes and sizes. Joint with BB/D522089/1 and BB/D522438/1