[Illinois] CDB Student & Postdoc Seminar Series: Regulation of Histone mRNA by PIWI Homologs in Planarian Stem Cells
The well-known regenerative abilities of planarian flatworms are attributed to a population of adult stem cells called neoblasts, which
proliferate and differentiate to produce all cell types in their bodies. A characteristic feature of neoblasts is the presence of large
cytoplasmic ribonucleoprotein (RNP) granules named chromatoid bodies. These organelles are structurally and molecularly similar to
RNP granules present in the germline of many organisms. As such, they contain symmetrical dimethylarginine (sDMA) methylation
substrates of Protein Arginine Methyltransferase 5, such as PIWI and SmB homologs, as well as Tudor domain-containing proteins
that bind to sDMA. This study shows that the Schmidtea mediterranea PIWI family members SMEDWI-1 and SMEDWI-3 are
required for localization of germinal histone H4 (gH4)transcripts to chromatoid bodies. Regulation of histone mRNA by chromatoid
body components may go beyond gH4, since transcripts of every major histone gene family were also found in these structures.
Additionally, gH4 mRNA levels increased upon inhibition of SMEDWI-1 and SMEDWI-3 levels by RNAi, suggesting the
involvement of these PIWIs in histone mRNA turnover. PIWI proteins are better known for silencing transposable elements via
piRNA-mediated mRNA turnover and genomic silencing. Similar mechanisms may be involved in the regulation of histone gene
expression in planarians, where neoblasts are the only proliferating somatic cells and others are terminally differentiated.
University of Illinois at Urbana-Champaign
In addition, Labib recently was selected to participate in the Summer Leadership Institute (SLI). The SLI provides premier training to scientists from underrepresented backgrounds who wish to increase their ability to succeed as institutional and community leaders. This program hosted ten postdoctoral fellows, ten early career scientists, and ten mid-career professionals selected from a pool of approximately 150 participants. The SLI was developed by the Society for Advancement of Chicanos and Native Americans in Science (SACNAS) in collaboration with the American Association for the Advancement of Science (AAAS).
-Retrieved 12-30-12 From the MCB News website.
Dr. Rouhana is a member of the Newmark Lab at the University of Illinois at Urbana-Champaign.
Researchers should cite this work as follows:
Labib Rouhana; William Edward Nixon; Obaid Sarvana; George Michael Daley; NanoBio Node (2012), "[Illinois] CDB Student & Postdoc Seminar Series: Regulation of Histone mRNA by PIWI Homologs in Planarian Stem Cells," https://nanohub.org/resources/16005.