EXTRACELLULAR MATRIX AND PRIMARY MESENCHYME DIFFERENTIATION

海胆的微粒-初级间充质细胞系是一种 用于研究细胞的细胞和分子方面的模型系统 分化 这一谱系产生了钙质骨骼 胚胎的（骨针）。 骨针的形成需要密切的联系 在初级间充质和细胞外基质之间（E 的 胚胎 我们已经开发了一种利用外源性ECM或 促进体外间充质分化的血清。 我们的首要目标 是分离、鉴定和产生针对针状物诱导的抗体， ECM中的活性（SIA）。 我们的第二个目标是识别转录本， 由血清或细胞外基质诱导的微粒。 这些转录本可能代表了早期基因产物， 这一谱系的明显分化。 第二个目标是独立于 第一，我们不需要确定SIA以隔离 诱导基因及其mRNA。

The micromere-primary mesenchyme cell lineage of the sea urchin is a model system for investigating cellular and molecular aspects of cell differentiation. This lineage gives rise to the calcareous skeleton (spicule) of the embryo. Spicule formation requires intimate association between the primary mesenchyme and the extracellular matrix (E of the embryo. We have developed a model system utilizing an exogenous ECM or serum which promotes mesenchyme differentiation in vitro. Our first aim is to isolate, characterize and raise antibodies to the spicule inducing activity (SIA) in the ECM. Our second aim is to identify transcripts in the micromeres which are induced by the serum or extracellular matrix. These transcripts presumably represent early gene products necessary for overt differentiation of this lineage. The second aim is independent of the first in that we need not identify the SIA in order to isolate the induced genes and their mRNAs.