SGER: Establishing the Parthenogentic "Marmorkrebs" Crayfish as a Model Organism in North America

上世纪90年代末，在德国鱼类爱好者的水族馆里发现了一种不同寻常的动物：一种小龙虾，即使与其他小龙虾隔离长大，也能产卵。这种小龙虾在德语中被昵称为“Marmorkrebs”，大致翻译为“大理石纹蟹”，该物种尚未被赋予正式的科学名称。Marmorkrebs在小龙虾、龙虾、虾和螃蟹中是独一无二的：每一个个体都是雌性，可以无性繁殖。Marmorkrebs与北美小龙虾有密切的关系，但在北美没有发现野生的Marmorkrebs，所以这些小龙虾的来源仍然是一个谜。此后，Marmorkrebs被引入欧洲和马达加斯加水域。由于Marmorkrebs繁殖迅速（每个个体都能产卵），它们可能是一种严重的有害物种，它们的引入可能会威胁到本地物种。除了它们神秘的起源和潜在的生态威胁外，Marmorkrebs是实验室研究的一种优秀的新模式生物。Marmorkrebs很容易照顾，繁殖率也很高。更重要的是，因为它们的繁殖没有性别，所以女儿在基因上与母亲是相同的。因此，对母亲所做的任何基因改变（例如，突变，转基因技术）将忠实地传递给女儿，这将允许为特定类型的研究建立稳定的菌株。所有个体在基因上相同也是非常可取的，因为它消除了基因变异作为实验中必须考虑的因素。例如，许多人知道的白色实验室老鼠是白色的，因为它们是近亲繁殖的，试图使它们尽可能相似。Marmorkrebs在发育、基因表达、神经生物学和生态生理学的实验室研究中具有很高的前景。这个项目将有助于把Marmorkrebs介绍给北美的研究人员。

In the late 1990s, a remarkable animal was discovered in the aquaria of German fish hobbyists: a type of crayfish that could generate eggs even if they had grown up in isolation from other crayfish. This crayfish was nicknamed "Marmorkrebs" in German, which roughly translates as "marbled crab", the species has yet to be given a formal scientific name. Marmorkrebs are unique among crayfish, lobsters, shrimp, and crabs: every individual is female and can reproduce without sex. Marmorkrebs are closely related to North American crayfish, but no Marmorkrebs have been found in the wild in North America, so the source of these crayfish remains a mystery. Marmorkrebs have since been introduced into the waters of Europe and Madagascar. Because Marmorkrebs reproduce rapidly (every individual can generate eggs), they could be a serious pest species whose introduction could threaten native species. In addition to their mysterious origin and potential to be an ecological threat, Marmorkrebs are an excellent new model organism for lab research. Marmorkrebs are easy to care for and reproduce at high rates. More importantly, because they reproduce without sex, daughters are genetically identical to their mothers. Thus, any genetic change made to a mother (e.g., mutation, transgenic techniques) will be passed along faithfully to the daughters, which would allow stable strains to be established for specific types of research. That all individuals are genetically identical is also highly desirable, as it removes genetic variation as a factor that has to be accounted for in experiments. For example, the white lab rats that many people know are white because they have been inbred in an attempt to make them as similar as possible. Marmorkrebs are highly promising for laboratory studies of development, gene expression, neurobiology, and ecological physiology. This project will help introduce Marmorkrebs to North American researchers.