Skip to page navigation menu Skip entire header
Brown University
Skip 13 subheader links

An Investigation of miRNA Repertoires in Bdelloid Rotifers

Description

Abstract:
An exceptional group of aquatic invertebrates makes up Class Bdelloidea. Bdelloid rotifers are the only group of ancient asexual animals known. A second distinction that sets them apart from all other metazoans is their outstanding DNA repair abilities. <br/> <br/> A class of small noncoding regulatory RNAs known as microRNAs (miRNAs) has been implicated in numerous cellular processes. The role of miRNAs in responding to DNA damage and asexual reproduction prompted an investigation of the bdelloid miRNA repertoire. A comparative approach was used for the investigation. The miRNA repertoire of a facultatively sexual sister clade of bdelloids, the monogononts, was also surveyed. Examination of small RNA libraries from a bdelloid and monogonont species revealed the absence of two widely conserved miRNAs: let-7 and miR-100. These results were rigorously evaluated through an additional small RNA library survey of a second species of bdelloid rotifers along with qPCR and Northern blot assays. The apparent loss of let-7 and miR-100 in bdelloids suggested that other conserved miRNAs may exhibit sequence divergence. A program designed with flexible stringency parameters was created to identify all conserved miRNAs with varying levels of sequence divergence. In addition, accessory programs were created to identify miRNA sequence variants. This software revealed several divergent miRNA homologs in bdelloid rotifers that could not be identified with existing software. Potentially edited variants of some conserved miRNAs were also identified.<br/> <br/> The conserved miRNA repertoire of bdelloids does indeed reflect the unique aspects of bdelloid biology, as let-7 is an integral part of the DNA damage response and also shown to be suppressed in other asexual species. The miRNA editing phenomenon may be a compensatory mechanism for the absence of conserved miRNAs. Cumulatively, these findings suggest that the unique miRNA evolution of bdelloid rotifers has contributed to their successful asexual evolution.
Notes:
Thesis (Ph.D. -- Brown University (2013)

Access Conditions

Rights
In Copyright
Restrictions on Use
Collection is open for research.

Citation

Dutta, Anupriya, "An Investigation of miRNA Repertoires in Bdelloid Rotifers" (2013). Molecular Biology, Cell Biology, and Biochemistry Theses and Dissertations. Brown Digital Repository. Brown University Library. https://doi.org/10.7301/Z0J38QV0

Relations

Collection: