DISSERTATION RESEARCH: Determining anucleated sperm function in Lepidoptera

精子细胞的功能传统上被认为是雄性将DNA转移到卵子并创造后代的一种方式。不携带DNA的精子细胞不能使卵子受精，因此蝴蝶和飞蛾中存在这样的精子细胞是令人费解的。几乎所有这些昆虫都产生两种类型的精子：一种是传统的、带有DNA的精子，另一种是缺乏DNA的精子。在所有这些情况下，男性产生的这种缺乏DNA的精子比传统精子多得多。这种精子类型的绝对丰富意味着它在生殖中发挥着一些未知的功能作用。这项提案旨在揭示这些缺乏DNA的精子细胞的进化意义。这项研究还将有助于开发技术，使科学家能够以一种比传统饲养方法更便宜、更不易失败的方式维持重要的转基因谱系。这种协议甚至可以扩展到受威胁的物种，以创建一个基因库。通过夏季科学研讨会向公众进行宣传。在许多动物谱系中，一只雄性动物产生多种精子的现象已经独立出现。在所有研究充分的情况下，证据表明只有一种类型的精子保留了使卵子受精的能力，但这些非精子的功能仍不清楚。这一点在蝴蝶和蛾类中表现得最为明显;这一目的雄性产生一种缺乏核DNA的次级精子类型。这些无核细胞代表了男性的一项重大投资，其数量超过有核精子的20比1，但不可能使卵子受精以直接增加男性健康。自从发现无核精子以来，已经提出了几种假说来解释无核精子的存在，但迄今为止还没有进行过严格的测试。该项目将在两种不同交配策略的鳞翅目物种中开发和完善人工授精方案，以彻底测试无核精子在不同选择背景下的功能。

The function of sperm cells is traditionally thought to be a way for males to transfer DNA to eggs and create offspring. Sperm cells that do not carry DNA cannot fertilize an egg, thus the existence of such sperm cells in butterflies and moths is puzzling. Almost all of these insects make two types of sperm: both traditional, DNA-bearing sperm, and a second type that lacks DNA. In all of these cases, males make far more of this DNA-lacking sperm than traditional sperm. The sheer abundance of this sperm type implies it plays some yet-unknown functional role in reproduction. This proposal aims to uncover the evolutionary significance of these DNA-lacking sperm cells. The research will also aid in the development of technologies that will allow scientists to maintain important genetically modified lineages in a way that is both cheaper and less vulnerable to failure than traditional rearing methods. Such protocols could even be extended to threatened species to create a gene bank. Outreach to the public will occur via summer science workshops.Production of multiple sperm types by a single male has independently arisen in many animal lineages. In all well-studied cases, evidence suggests that only one type of sperm retains its ability to fertilize eggs but the function of these non-fertilizing sperm remains unclear. Nowhere is this more apparent than in butterflies and moths; males of this order produce a secondary sperm type that lacks nuclear DNA. These anucleated cells represent a significant investment for a male, outnumbering their nucleated sperm by 20-to-1, but cannot possibly fertilize eggs to directly increase male fitness. Several hypotheses have been proposed since the discovery of anucleated sperm to explain the existence of anucleated sperm, but to-date no rigorous tests have been undertaken. This project will develop and refine artificial insemination protocols in two lepidopteran species that differ in mating strategy in order to thoroughly test the function of anucleated sperm in different selective backgrounds with a common framework.