GENES DIFFERENTIALLY EXPRESSED IN DEVELOPING EMBRYONIC LIMB BUDS

建立模式所需基因的鉴定 形态发生过程中的形成及其调控的研究， 这些问题是脊椎动物生物学许多方面的核心问题。 许多 形态发生的关键过程，包括对营养刺激的反应， 细胞-细胞相互作用，迁移，差异细胞增殖， 程序性细胞死亡等等，在病理学上也被概括为 在肿瘤发生过程中。 小鸡四肢发育是一个有吸引力的 系统研究模式形成的分子基础，因为 组织/细胞相互作用水平上的关键事件， 图案形成已经被很好地表征，并且看起来非常 类似于哺乳动物系统中的那些，并且该系统易于 适合于生物化学和分子分析以及显微外科手术 操纵 这个长期项目的目的是分离出 调节鸡胚肢芽的形态发生。 两个一般 正在开发的方法：1）产生消减cDNA 富集潜在调控和诱导基因的文库;和2） 鉴定保守基因家族的相关/新成员， 在其他的发育调节过程中也有牵连， 系统. 目前，同源异型盒基因家族的两个新成员， 在早期发育过程中， 发展 这些基因之一是表达在一个梯度的方式沿着 在肢的A-P轴上，翅芽比腿芽丰富， 提出了在图案形成和/或确定中的可能作用 肢体类型的身份。 第二个基因似乎选择性地 在发育中的肢芽中表达较晚，可能在以后的发育中发挥作用。 形态发生事件，如重塑。 研究正在进行中， 阐明这些调控基因的功能，使用遗传和 生物化学方法。

The identification of genes necessary for establishing pattern formation during morphogenesis and the study of their regulation are problems which are central to many aspects of vertebrate biology. Many key processes in morphogenesis, including responses to trophic stimuli, cell-cell interactions, migration, differential cell multiplication, programmed cell death, etc., are also recapitulated in a pathologic manner during oncogenesis. Chick limb development is an attractive system for studying the molecular basis of pattern formation because critical events at the level of tissue/cellular interactions involved in pattern formation have been well characterized and appear to be very similar to those in mammalian systems, and this system is readily amenable to biochemical and molecular analysis as well as microsurgical manipulation. It is the aim of this long-term project to isolate genes that regulate morphogenesis in the chick embryo limb bud. Two general approaches are being developed: 1) the generation of subtracted cDNA libraries enriched for potential regulatory and induced genes; and 2) the identification of related/new members of conserved gene families that have been implicated in developmental regulatory processes in other systems. Currently, two new members of the homeobox gene family have been identified which are selectively expressed in limb buds during early development. One of these genes is expressed in a graded fashion along the A-P axis of the limb and is more abundant in wing than leg buds, suggesting possible roles in pattern formation and/or the determination of limb-type identity. The second gene appears to be selectively expressed later in developing limb buds and might play a role in later morphogenetic events such as remodeling. Studies are underway to elucidate the function of these regulatory genes, using both genetic and biochemical approaches.