Publication Type: Poster
Abstract: Ectopic expression of the homeobox transcription factor HOXB4 has been shown to enhance hematopoietic stem cell (HSC) self-renewal and expansion ex vivo and in vivo. However, the mechanism(s) by which HOXB4 promotes HSC self-renewal is not well understood. In order to identify early downstream targets of HOXB4 in such cells, we have overexpressed a conditionally active HOXB4 protein fused to a truncated estrogen receptor (ER) in the primitive hematopoietic progenitor cell line, EML. We transduced KLS (c-Kit+, Sca-1+, Lin-)-EML cells with the MSCV-HOXB4/ER-IRES-GFP retroviral vector producing EML cells overexpressing HOXB4 (EML-B4/ER) the activity of which can be induced by exposure to tamoxifen. In order to identify early downstream targets, EML-B4/ER cells were treated with 100nM of tamoxifen for 8hrs and KLS cells were then harvested for gene expression profiling experiments. Preliminary results indicate that the differential expression of erythroid specific genes that was previously observed in EML cells constitutively overexpressing active HOXB4 (EML-B4) is not observed in these EML-B4/ER cells. Of the 878 gene products that are observed to be differentially expressed in the EML-B4/ER cells after short-term tamoxifen induction, about 108 of these genes are also shown to be differentially expressed in the EML-B4 cells when compared to controls. These results indicate that HOXB4 may regulate many other genes early on that may not be observed after HOXB4 has been constitutively active after a certain amount of time. We are now planning experiments to hopefully identify which of these targets are also direct downstream targets of HOXB4.

Publication Type: Conference Paper/Unpublished Manuscript
Abstract: Leo Marx’s landmark book, The Machine in the Garden, has had an enormous influence on both the study of the American popular imaginary and on the image of the environment in popular culture. Rather than a definitive text on the state of the environment in the American mind, a state characterized by a “tragic ambivalence” between pastoral and industrial ideals, I suggest that Leo Marx's study ought to be read as an investigation into the symbolic form of the environment at the specific historical juncture of mid-19th century America. Contemporary thinkers concerning the environment have had to confront this heritage of tension between cultivated landscape and technological development. In the context of post-industrial America, Maya Lin's use of the environment as a symbolic resource in her art and architecture overcomes the sense of tragic ambivalence between the 'machine' and the 'garden.' Her use of technology as a supplement to the perspective of the human eye, along with concern with landscape as an aesthetic object of value in the design of built forms (in art and in architecture), synthesizes technology with the complex pastoral that values human work on (and contact with) the physical environment. Lin’s work, viewed as an important symbolic form which gives insight into contemporary values concerning human’s relation to the environment, ought to aid scholars in making sense of American social beliefs about the commensurability between environmental protection and technological development.