Circular Single-Stranded Synthetic DNA Delivery Vectors for MicroRNA

Single-stranded (ss) circular oligodeoxynucleotides were previously found to undergo rolling circle transcription (RCT) by phage and bacterial RNA polymerases (RNAPs) into tandemly repetitive RNA multimers. Here, we redesign them to encode minimal primary miRNA mimics, with the long term aim of intracellular transcription followed by RNA processing and maturation via endogenous pathways. We describe an improved method for circularizing ss synthetic DNA for RCT by using a recently described thermostable RNA ligase, which does not require a splint oligonucleotide to juxtapose the ligating ends. In vitro transcription of four templates demonstrates that the secondary structure inherent in miRNA-encoding vectors does not impair their RCT by RNAPs previously shown to carry out RCT. A typical primary-miRNA rolling circle transcript was accurately processed by a human Drosha immunoprecipitate, indicating that if human RNAPs prove to be capable of RCT, the resulting transcripts should enter the endogenous miRNA processing pathway in human cells. Circular oligonucleotides are therefore candidate vectors for small RNA delivery in human cells, which express RNAPs related to those tested here

mRNA Secondary Structures Fold Sequentially But Exchange Rapidly In Vivo

Self-cleavage assays of RNA folding reveal that mRNA structures fold sequentially in vitro and in vivo, but exchange between adjacent structures is much faster in vivo than it is in vitro

Women in STEM Majors and Professional Outcome Expectations: The Role of Living-Learning Programs and Other College Environments

Using data from the 2004-2007 National Study of Living Learning Programs, the only national dataset offering longitudinal information on outcomes associated with living-learning (L/L) program participation, this study investigated the role of L/L programs and other college environments in the professional outcome expectations of women in science, technology, engineering, and mathematics (STEM) majors. Specifically, we examined an overall measure of professional outcome expectations, along with participants' anticipation of the chances that they will "get a good job in their field," "achieve success in their career," and "combine a professional career with having a balanced personal life." Findings indicated that attending a coeducational STEM L/L program and discussing academic and career issues with peers were positively related with three of the outcome measures. Additional findings spoke to the importance of self-efficacy and interactions with diverse peers in the development of professional outcome expectations among women in STEM. Implications are presented for higher education institutions' efforts to support coeducational and women-only STEM-related L/L programs, peer and faculty interactions, and diverse peer interactions