Functional Morphology of Reproduction in Mollusca

我对软体动物繁殖的研究，结合了连续切片和透射电子显微镜（TEM），揭示了细胞事件的新细节，例如受精时或细胞分泌物质时发生的事件。此外，激光共聚焦光学显微镜与荧光抗体结合使用，能够以无与伦比的清晰度检查活细胞或死细胞中的微观事件。 我实验室最近的研究揭示了动物细胞如何从表面分泌物质的新信息。在大多数蜗牛中，雌性接受的废精子被交配囊消化。在山鸡科动物中，这个器官通过一种不寻常的大顶浆分泌过程分泌消化酶。大约十年前，在人类男性的前列腺和附睾中首次观察到这种机制，它与精子的寿命和卵子结合特性有关。我对小顶浆分泌也很感兴趣，我们发现它是石鳖卵船体形成的原因。这种分泌方式，在某些情况下完全通过内膜系统，鲜为人知，我们在软体动物中发现。我们计划首次对顶浆分泌物进行三维重建，方法是使用计算机对在此过程中拍摄的连续顶浆切片的数字图像进行处理。 有些蜗牛在动物中是不寻常的，因为它们既能产生能育的真精子，又能产生不育的副精子。在某些物种中，外胚乳不是“错误”，而是占射精量的50%。Parasperm通过程序性核死亡消除细胞核，但细胞继续存活并使用细胞质中储存的分子产生复杂的分泌物。通过像这样失去细胞核，人眼的透镜细胞变得更加透明，红细胞提高了它们的携氧能力。但是蜗牛精子的功能是什么呢？我们计划通过电泳分离独特的蛋白质来研究这一点，然后部署定制的抗体来跟踪它们在雌性中的命运，并开始了解它们的目的。

My research on molluscan reproduction, which combines serial ultrathin sectioning with transmission electron microscopy (TEM), is revealing new details of cellular events, such as those occuring at fertilization or during the secretion of substances from cells. Furthermore, Laser Confocal light microscopes, used in conjunction with fluorescent antibodies, are enabling examination of microscopic events in cells, living or dead, with unparalleled clarity. Recent studies in my lab have revealed new information about how animal cells secrete substances from their surfaces. In most snails, waste sperm received by the female are digested by the bursa copulatrix. In littorinids this organ secretes digestive enzymes by an unusual process of macroapocrine secretion. This mechanism was observed for the first time in human males about a decade ago, in the prostate gland and epididymis, where it has been linked to the longevity and egg-binding properties of sperm. I am also interested in microapocrine secretion, which we have found to be responsible for egg hull formation in chitons. This method of secretion, which bi-passes the endomembrane system completely in some cases, is little known and was discovered by us in molluscs. We plan to do 3D reconstruction of apocrine secretion in action for the first time, by using computers to superimpose digital images of serial ultrathin sections taken during this process. Some snails are unusual among animals in that they produce both fertile eusperm and sterile parasperm. The parasperm are not 'mistakes' but rather make up 50% of the ejaculate in some species. Parasperm eliminate the nucleus by programmed nuclear death and yet the cells continue to live and produce complex secretions using stored molecules in the cytoplasm. By losing their nuclei like this, lens cells of the human eye become more transparent and red blood cells improve their oxygen carrying capacity. But what is the function of snail parasperm? We plan to investigate this by isolating unique proteins with electrophoresis, followed by deployment of custom-made antibodies to track their fate in the female and begin to understand their purpose.