Dissertation Research: Molecular Variation in Two Circumpolar Sea Urchins

小行星9423662 物种形成的动力学在广泛分布和广泛分散的生物体中继续挑战进化生物学家，特别是在海洋无脊椎动物中，地理隔离在许多情况下似乎是不可能的。 最近的研究表明，精子和卵子的分子相互作用可能在动物的生殖隔离中发挥重要作用，这些动物将配子自由地释放到水中。 特别是在海胆中，一种分子（蛋白质“结合蛋白”）的特征在于介导物种特异性受精。 DNA技术现在使我们能够研究这种生殖障碍进化背后的力量，并且可以很容易地在海胆中研究健康的后果。 结果表明，在自然产卵条件下，Droebachiensis和S.苍白球是细胞和发育生物学中主要模式生物的近亲，S.紫色的 它们在整个北方高纬度地区共存，并可能不对称杂交。 本研究将在DNA水平上研究它们的种群结构和结合分子的进化。 初步数据显示地理分化和有趣的分子进化模式。 该项目还将增加关于环北极物种种群结构和动态的稀缺数据。 这对S来说尤其重要。被越来越多地收获的droebachiensis。

9423662 EANES The dynamics of speciation in wide-ranging and widely dispersing organisms continues to challenge evolutionary biologists, especially in marine invertebrates where geographic isolation seems unlikely in many cases. Recent work suggests that the molecular interaction of sperm and eggs may play a major role in reproductive isolation in animals that release gametes freely into the water. In sea urchins in particular, a molecule (the protein "bindin") has been characterized that mediates species specific fertilization. DNA-techniques now permit us to examine the forces that underlie the evolution of this reproductive barrier, and the consequences for fitness can be easily studied in sea urchins. The free spawning echinoids Strongylocentrotus droebachiensis and S. pallidus are close relatives of a major model organism in cellular and developmental biology, S. purpuratus. They co-occur throughout northern high latitudes and may hybridize asymmetrically. This study will examine their population structure and the evolution of their bindin-molecules at the DNA level. Preliminary data show geographic differentiation and interesting patterns of molecular evolution. The project will also add to the scarce data on the population structure and dynamics of circumarctic species. This is particularly important for S. droebachiensis which is being harvested increasingly.