Microinjection system for manipulation of yolk and lipids in developing fish embryos

大多数种类的鱼产生许多卵（r-选择）。例如，一只雌性美洲拟鲽（Pseudopleuronectes americanus）每年可以产下多达300万个卵，平均繁殖期为7年。然而，很少有胚胎能够存活下来繁殖。这些r-选择的物种，在野外和水产养殖环境中，在生命的第一年死亡率极高。 这种生活史策略对于我们理解鱼类种群动态具有根本重要性，也是水产养殖发展的一个重大挑战。母亲提供的卵黄和脂质储备的质量对于这些早期生命史阶段的生存极其重要。最近，我们开发了第一种成功的显微注射方法来控制发育中的鱼胚胎的蛋黄和脂质的质量和数量。这一进展是重要的，因为通过控制蛋黄和脂质的大小在一个女性的批次，我们可以检查鸡蛋质量对生存的影响。具体而言，我们将研究幼虫大小（由蛋黄大小控制），年龄大小（发育阶段或经验），家庭和股票起源对性能性状和生存在自然和水产养殖环境中的重要性。 使用我们的新的显微注射系统，我们已经设计并提出在这里，我们将采取两种方法来确定卵黄质量对幼虫生长和存活的影响。首先，我们将注入特定的常量营养素，以确定它们的重要性。例如，DHA是幼鱼发育的重要脂肪酸。我们将通过直接将不同数量的DHA注射到发育中的胚胎的蛋黄中，然后检查它们的生长，存活和性能来研究其重要性。 第二，我们将修改我们的显微注射技术，使我们能够操纵几乎所有的蛋黄;在发育中的胚胎与“设计”或“标准”蛋黄交换蛋黄将提供更大的控制非遗传母体对性能的影响。这些方法将使我们能够在生态和水产养殖环境中解决蛋黄和脂质质量对生存和生长的影响。这里要求的设备将使我们能够在这一新开发的研究领域保持领导地位。

Most species of fish produce many eggs (r-selected). For example, a female winter flounder (Pseudopleuronectes americanus) can produce up to 3 million eggs per year and is reproductive for an average of 7 years. However, very few embryos survive to reproduction. Mortality rates for these r-selected species, both in field and aquaculture setting, are extremely high during the first year of life.  This life-history strategy is of fundamental importance to our understanding of fish population dynamics and a significant challenge to aquaculture development. The quality of the yolk and lipid reserves provided by the mother is extremely important for survival during these early life history stages. Recently, we developed the first successful microinjection approach to control yolk and lipid quality and quantity in developing fish embryos. This advance is important because by controlling yolk and lipid size within a female's batch we can examine the effect of egg quality on survival. Specifically, we will examine the importance of larval size (controlled by yolk size), size at age (developmental stage or experience), family and stock origin on performance traits and survival in both natural and aquaculture contexts.  Using our new microinjection system that we have designed and proposed here, we will take two approaches to determine the effect of yolk quality on larval growth and survival. First, we will inject specific macronutrients to determine their importance. For example, DHA is an important fatty acid for larval fish development. We will examine its importance by directly injecting various amounts of DHA into the yolk of developing embryos and then examining their growth, survival and performance.  Second, we will modify our microinjection technique to allow us to manipulate almost all of the yolk; swapping the yolk within developing embryos with a "designed" or "standard" yolk will provide greater control of non-genetic maternal effects on performance. These approaches will allow us to address the effect of yolk and lipid quality on survival and growth in both ecological and aquaculture settings. The equipment requested here will allow us to maintain a leadership role in this newly developed area of research.