DISSERTATION RESEARCH: The Origin and Evolution of Recently Gained Introns in Daphnia Populations

内含子是一种非编码DNA序列，在高等生物体中中断基因，在蛋白质产生之前被移除。一些物种的整个基因组中只有两个内含子，而另一些物种几乎在每个基因中都插入了许多内含子。这些差异的原因尚不清楚，尽管之前在这个问题上做了很多工作，解决这个问题仍然是进化遗传学的一个主要挑战。目前，我们对新的内含子是如何产生的知之甚少；这是因为在几乎所有被研究过的物种中，所有的内含子都有古老的起源。内含子的主动损失和获得只在一种水蚤中已知，即水蚤。pi将对该物种和内含子稳定的相关物种进行基因组分析。他们将在基因组水平上对种群进行广泛的调查，以了解新的内含子来自何处，插入机制，新插入的内含子是否持续存在，以及新内含子产生和丢失的速率。这个项目很有可能大大提高我们对水蚤中新内含子的起源、机制和命运的理解，这些结果将适用于一般的高等生物。pi将通过独立监督的项目指导本科生使用分子实验和生物信息学分析，并为学生提供发展沟通技巧的机会。这项研究也将为国际合作提供机会。

Introns are noncoding DNA sequences that interrupt genes in higher organisms, and are removed prior to the manufacture of a protein. Some species have just a couple of introns in their entire genome, and others have many introns inserted into almost every gene. The causes of these differences are unknown despite much prior work on the subject, and solving the problem remains a major challenge for evolutionary genetics. Currently, we know very little about how new introns arise; this is because in nearly all species that have been studied, all the introns are of ancient origin. Active loss and gain of introns is known in only one species, the waterflea Daphnia pulex. The PIs will conduct genomic analyses of this species and a related one in which introns are stable. They will use extensive surveys of populations at the genomic level to learn where the new introns come from, the mechanisms of insertion, whether newly inserted introns persist, and rates at which new introns arise and are lost. This project has a high likelihood of substantially improving our understanding of the origin, mechanisms, and fates of new introns in Daphnia - results that will be applicable to higher organisms in general. The PIs will mentor undergraduates through independent supervised projects using molecular bench work and bioinformatic analyses, as well as giving the students opportunities to develop communication skills. This research will also provide opportunities for international collaboration.