Genetic Basis of Morphological Evolution in Stickleback

北卡罗来纳州立大学的LeBlanc博士获得了一项资助，以阐明蜗牛物种(泥螺：Ilyanassa obsoleta)性别分化的基本内分泌控制，并确定杀生剂三丁基锡导致海洋蜗牛性别歧义的机制。三丁基锡是一种用于海洋涂料的防污剂。这种物质在海洋环境中普遍存在，与全球海洋蜗牛生殖系统异常的发生有因果关系。将进行研究，以确定负责蜗牛生殖系统发育的激素。最初，将进行实地调查，以确定激素或激素受体水平与季节性繁殖周期中蜗牛生殖系统发育之间的关系。在这些研究之后，将进行实验室实验，以控制暂时重要的荷尔蒙水平，并确定对生殖系统发育的影响。一旦最终确定了相关的激素，三丁基锡对这些激素水平和活性的影响将得到证实。这项研究的结果将极大地促进我们对软体动物基本内分泌学的理解。许多亚洲和南美国家正在发展蜗牛养殖，将其作为当地消费和出口的可持续食物来源。了解蜗牛繁殖周期的规律将极大地提高此类作业的经济可行性。此外，由于三丁基锡对海洋生态系统的不利影响，国际海事组织已实施逐步淘汰海洋涂料中的三丁基锡。通过使用防污剂将对远洋轮船的拖累降至最低的经济动机将使开发和使用三丁基锡替代品成为必要。阐明三丁基锡干扰蜗牛性发育的机制将有助于确保替代防污剂不具有这种隐蔽的特性。

A grant has been awarded to Dr. LeBlanc (North Carolina State University) to elucidate the basic endocrine control of sexual differentiation in a snail species (mud snail: Ilyanassa obsoleta) and to determine the mechanism by which the biocide tributyltin causes sexual ambiguity in marine snails. Tributyltin is an antifoulant used in marine paints. The material is ubiquitous in the marine environment and has been causally associated with the global occurrence of reproductive system abnormalities in marine snails. Studies will be performed to identify the hormones that are responsible for the development of the snail reproductive system. Initially, field surveys will be performed to establish relationships between hormone or hormone receptor levels and development of the snail reproductive system over the seasonal reproductive cycle. These investigations will be followed by laboratory experiments where levels of tentatively important hormones will be manipulated and consequences to reproductive system development will be established. Once the relevant hormones have been conclusively identified, the effect of tributyltin on those hormone levels and activity will be established. Results from this study will significantly advance our understanding of basic molluscan endocrinology. Many Asian and South American countries are developing snail culture as a sustainable food source for local consumption as well as export. Understanding the regulation of the reproductive cycle of snails would greatly enhance the economic feasibility of such operations. In addition, the International Maritime Organization has implemented a phase-out of tributyltin in marine paints owing to its adverse effects on marine ecosystems. The economic incentive to minimize drag on ocean-going vessels through the use of antifoulants will necessitate the development and use of tributyltin alternatives. Elucidation of the mechanism by which tributyltin interferes with sexual development of snails will help ensure that alternative antifoulants do not share this insidious property.