Featured Faculty: Christine Byrum

Christine ByrumChristine Byrum, PhD, College of Charleston

PROJECT TITLE: Sorting it out: An in vivo model examining roles of importins in neurogenesis

The Byrum lab successfully cloned all of the KAP-β importins and transportins in embryos of the sea urchin Lytechinus variegatus (as well as many of the exportins) and performed wholemount in situ hybridization analysis (WMISH) to better characterize distribution these products. Spatial distributions for KPNB1, IPO5, IPO9, IPO11, and TNPO1/2 were reported at two national conferences (Society of Integrative and Comparative Biology; Developmental Biology of the Sea Urchin and Other Basal Deuterostomes) and results of these studies were also presented at several regional or local meetings (School of Sciences and Mathematics Poster Session, College of Charleston; Celebration of Scholars Poster Session, College of Charleston; South Carolina Academy of Sciences Meeting; Southeastern Regional Society of Developmental Biology Meeting). These findings showed that the KAP-β forms KPNB1, IPO5, and TNPO1/2 are broadly distributed in the developing sea urchin and that expression of the importin IPO9, although broadly expressed, is temporally restricted (evident at 10, 12, 15, and 24hpf, but absent at 18hpf). Similarly, IPO11 expression was clearly present at 8, 16, and 22hpf, but was absent at 12.5 and 14hpf. It is spatially restricted and broadly distributed at 8hpf, however, by the late gastrula (16hpf) and prism stages (22hpf), expression is highest in the gut, oral, and vegetal regions.

SC INBRE provided funding to support supplies and equipment as well as student research, travel and teaching releases for the PI.

Availability of transcription factors (TFs) in the nucleus influences gene expression and is critical to the growth and development of any cell. Therefore, understanding roles of nuclear transport on TF segregation would offer great medical benefits.Human health conditions associated with defects in nuclear transport include autism (Perry & Fainzilber, 2009), DiGeorge syndrome (Stoller & Epstein, 2005), congenital heart defects (Hatayama et al., 2008), and several disorders of the nervous system (Perry & Fainzilber, 2009). KAP-α nuclear transport proteins also import disease- and tumor-inducing viruses (Puntener & Greber, 2009), and increased expression of the KAP-α gene KPNA2 predicts poor prognosis in 12 forms of cancer (Christiansen & Dyrskjot, 2013). This study could impact public health because: A) It develops a valuable model for nuclear transport studies, B) It identifies transcription factors binding to the KAP-α proteins, C) it increases understanding of early neurogenesis, and D) it offers insights into signals regulating distribution of nuclear transport factors.


November 22, 2017