Xin Zhiguo Li, Ph.D.

Principle Investigator

The eternal youth of germ cells fascinates me. I started to think about how germ cells maintain genomic integrity when I worked as a joint Ph.D. student in Dr. Schimenti's and Dr. Tye’s laboratories at Cornell University. I studied how germ cells coordinate and monitor recombination and synapsis during meiosis, as well as the genetic errors created by defective replicative helicases. Aging and tumorigenesis seems to be inevitable as mutations accumulate in somatic cells. Therefore, germ cells must use special mechanisms to protect their genomes—the key reason for their immortality.

The discovery of piRNAs is a key step towards tracing the unique feature of germ cells. Very little is known about their regulation, biogenesis and function. During my postdoc training, I led the research to define the transcription units of piRNA genes and identify the first transcription factor that regulates piRNA precursor production. The follow-up work on post-transcriptional processing of piRNA precursors opens new revenue for piRNA research.