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Small regulatory RNAs (and their associated proteins) are dynamic and active participants in controlling the genome and phenotype of cells and animals.  Germ cells have a special role in the perpetuation of organisms, but they have also become the richest environment for the study of small regulatory RNAs.  In addition to microRNAs, which are vital gene regulators conserved from plants to people, germ cells express endogenous small interfering RNAs (endo-siRNAs) and Piwi-interacting RNAs (piRNAs).  

In animal germ cells, such as spermatocytes and oocytes, piRNAs are the most abundant class of small RNAs, and together with Piwi proteins, they suppress the mobilization of transposable elements and specify the organization of mRNAs and proteins in the germ cell, which impacts the expression of certain genes.


Our group is interested in dissecting the molecular mechanisms of Piwi proteins and piRNAs, with a focus on particular outstanding questions.  How exactly do Piwi proteins and piRNAs silence transposons and organize asymmetrically in germ cells?   What is the impact of these molecules on global gene expression and chromatin organization and how does this affect germ cell and embryonic development? How do piRNAs get generated and what triggers their specific expression in germ cells? 

We hope to address these questions with molecular, cell biology, and biochemical approaches in specific model systems, such as Xenopus oocytes and Insect ovary-derived cell lines, which are repositories and “living test tubes” of Piwi proteins and piRNAs.  Insights we gain from piRNA studies will complement our examinations of other RNAi pathways, like microRNAs and endo-siRNAs.


Our biochemical and cell biology approaches seek to dissect the molecular function of the piRNAs and the piRNA Complex (piRC) through these specific aims: 1) Functional analysis of the piRNA Complex; 2) Regulation of piRNA cluster transcription; 3) Understanding the Genesis of piRNAs. 

We will apply our current biochemical techniques to probe the piRC’s functional activity, and develop genetic and cell biology methodologies to understand the role of piRNA clusters.  Piwi proteins have been shown to be essential for proper germ cell development in animals, including mammals.   However, the mechanistic understanding and gene regulatory potential of this ribonucleoprotein is still uncharted.  These research projects aim to develop systems that will drive progress in a subject relevant to child health and human development.


page updated 20150531