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Alexey Soshnev


alexey-soshnev@uiowa.edu
Mentor: Pamela Geyer, Ph.D.
Lab Room: 3159C MERF
Lab Phone: 319-335-7967

The role of insulators in genome organization and gene expression.

Cell differentiation is accompanied by dramatic changes in chromatin architecture that influence gene expression. One example is the differentiation of nurse cells (NCs) during Drosophila oogenesis. NCs are the synthetically active cells within the 16-cell germline cyst that support the oocyte maturation. NCs undergo genome amplification by endoreplication associated with changes in chromosome architecture from a condensed polytene to a dispersed polyploid state. The loss of the Suppressor of Hairy wing [Su(Hw)] protein causes female sterility and blocks changes in NC chromosome structure.

My studies combines the genome-wide analyses of transcriptional changes associated with the loss of Su(Hw) protein in the germline, identification of direct targets of Su(Hw) using next-gen sequencing technology, genetic and molecular methods to define the function of Su(Hw) in the germline. My recent findings suggest that Su(Hw) acts as a germline repressor of neural genes. Moreover, identification of key transcriptional target of Su(Hw) allowed us to rescue female sterility phenotype for the first time generating su(Hw) null embryos with no maternally deposited protein. Together, these studies reveal novel biological roles of a model insulator protein, suggesting that this factor has multiple roles in genome organization and transcriptional regulation.



Publications:

Soshnev AA, Baxley RM, Manak RJ, Tan K, Geyer PK. The Drosophila Suppressor of Hairy-wing insulator protein has an essential role as a transcriptional repressor in the ovary. Development, accepted/in press.

Hohl AM, Thompson M, Soshnev AA, Wu J, Morris J, Shih-Hsieh T, Wu CT, Geyer PK. Restoration of Topoisomerase 2 Function by Complementation of Defective Monomers in Drosophila. Genetics. 2012 Nov;192(3):843-56. PMID: 22923380.

Soshnev AA, He B, Baxley RM, Jiang N, Hart CM, Tan K, Geyer PK. Genome-wide studies of the multi-zinc finger Drosophila Suppressor of Hairy-wing protein in the ovary. Nucleic Acids Res. 2012 Jul;40(12):5415-31. PMID: 22406832.

Soshnev AA, Ishimoto H, McAllister BF, Li X, Wehling MD, Kitamoto T, Geyer PK. A conserved long non-coding RNA plays a role in sleep regulation in Drosophila. Genetics 2011 Oct 1;189(2):455-468. PMID: 21775470 (Featured on journal cover/in Issue highlights).

Baxley RM, Soshnev AA, Koryakov DE, Zhimulev IF, Geyer PK. The role of the Suppressor of Hairy-wing insulator protein in Drosophila oogenesis. Dev Biol. 2011 Aug 15;356(2):398-410. PMID: 21651900 (Artwork featured on journal cover).

Soshnev AA*, Li X*, Wehling MD, Geyer PK. Context differences reveal insulator and activator functions of a Su(Hw) binding region. PLoS Genet. 2008 Aug 15;4(8):e1000159. PMID: 18704163 (*, contributed equally).

Semiglazov VF, Aĭlamazian EK, Baĭliuk EN, Niauri DA, Ivanov VG, Manikhas AG, Kvetnoĭ IM, Soshnev AA. [Prophylaxis of breast cancer in patients with reproductive system hyperproliferative pathologies] Vopr Onkol. 2006;52(3):247-57. In Russian. PMID: 17191696.

Abstracts:

Soshnev AA, Geyer PK, Mechanisms of transcriptional regulation by a Drosophila insulator protein. 54th Annual Drosophila Research Conference, Washington, DC, 2013.

Soshnev AA, He B, Baxley RM, Manak RJ, Tan K, Geyer PK. Tissue-specific transcriptional regulation by a classic Drosophila insulator protein. FASEB SRC: Transcriptional Regulation During Cell Growth, Differentiation, & Development, Snowmass Village, CO, 2012 (platform presentation).

Soshnev AA, Baxley RM, He B, Tan K, Geyer PK. Tissue-specific transcriptional regulation by a Drosophila insulator protein. Michigan State University Summer Symposium on Transcriptional Dynamics, Evolution and Systems Biology, East Lansing, MI, 2011.

Soshnev AA, Baxley RM, Nilson KA, Tan K, He B, Geyer PK. Loss of Suppressor of Hairy-wing protein affects nuclear organization and gene expression during Drosophila oogenesis. 52nd Annual Drosophila meeting, San Diego, CA, 2011 (platform presentation).

Soshnev AA, Baxley RM, He B, Manak RJ, Tan K, Geyer PK. Investigations into the roles of the Suppressor of Hairy-wing insulator protein in nuclear organization and gene expression. ASBMB Special Symposium on Transcriptional Regulation by Chromatin and RNA Polymerase II, Lake Tahoe, CA, 2010.

Soshnev AA, Ishimoto H, McAllister BF, Li X, Wehling MD, Kitamoto T, Geyer PK. A long non-coding RNA gene is involved in the regulation of sleep homeostasis in Drosophila. 51st Annual Drosophila meeting, Washington D.C., 2010.

Baxley RM, Soshnev AA, Hohl AM, Klein MW, Liao A, Geyer PK. Elucidating the role of a Drosophila insulator protein in the female germline. 51st Annual Drosophila meeting, Washington D.C. 2010.

Soshnev AA, Baxley RM, and Geyer PK. Understanding the role of a Drosophila insulator protein in the female germline. 50th Annual Drosophila meeting, Chicago, IL, 2009 (platform presentation).

Marion DJ, Soshnev AA, Appleton K, Li X, Wehling MD, Baxley RM, Geyer PK. Understanding the function of insulators in the Drosophila genome. 49th Annual Drosophila meeting, San Diego, CA, 2008 (platform presentation).



Honors and Awards

  • 47th Annual Midwest Developmental Biology Research Conf., Iowa City, IA - 2nd place, poster presentation
  • 2009 Molecular and Cellular Biology Progrm Retreat – travel award, poster presentation
  • 2011 University of Iowa Department of Biochemistry Lois B. Gehring Award
  • 2012 University of Iowa Graduate Student Senate Travel Award
  • 2013 University of Iowa Research Week Award (Postdoc category)