Cell and Developmental Biology Commons^™

Doublesex Target Genes In The Red Flour Beetle, Tribolium Castaneum, Jayendra Nath Shukla, Subba Reddy Palli

Entomology Faculty Publications

Sex determination cascade in insects terminates with the production of sex-specific protein, Doublesex (Dsx). We identified the dsx homolog (Tcdsx) in Tribolium castaneum. The pre-mRNA of Tcdsx is sex-specifically spliced into three female (Tcdsxf1, Tcdsxf2 and Tcdsxf3) and one male-specific (Tcdsxm) isoforms. Cis-regulatory elements potentially involved in sex-specific splicing of the Tcdsx pre-mRNA were identified in the female-specific exon and the adjoining intronic sequences. All the three female-specific TcDsx proteins share common OD1 and OD2 domains and differ in their C-terminal sequences. Knockdown of Tcdsx resulted in a reduction in the oocyte development, egg production and hatching of eggs laid. …

Sex Determination In Beetles: Production Of All Male Progeny By Parental Rnai Knockdown Of Transformer, Jayendra Nath Shukla, Subba Reddy Palli

Entomology Faculty Publications

Sex in insects is determined by a cascade of regulators ultimately controlling sex-specific splicing of a transcription factor, Doublesex (Dsx). We recently identified homolog of dsx in the red flour beetle, Tribolium castaneum (Tcdsx). Here, we report on the identification and characterization of a regulator of Tcdsx splicing in T. castaneum. Two male-specific and one female-specific isoforms of T. castaneum transformer (Tctra) were identified. RNA interference-aided knockdown of Tctra in pupa or adults caused a change in sex from females to males by diverting the splicing of Tcdsx pre-mRNA to male-specific isoform. All the pupa and adults developed from Tctra …

Inhibition Of Fatty Acid Synthase Attenuates Cd44-Associated Signaling And Reduces Metastasis In Colorectal Cancer, Yekaterina Y. Zaytseva, Piotr G. Rychahou, Pat Gulhati, Victoria Allison Elliott, William Conan Mustain, Kathleen O'Connor, Andrew J. Morris, Manjula Sunkara, Heidi L. Weiss, Eun Young Lee, B. Mark Evers

Markey Cancer Center Faculty Publications

Fatty acid synthase (FASN) and ATP-citrate lyase, key enzymes of de novo lipogenesis, are significantly upregulated and activated in many cancers and portend poor prognosis. Even though the role of lipogenesis in providing proliferative and survival advantages to cancer cells has been described, the impact of aberrant activation of lipogenic enzymes on cancer progression remains unknown. In this study, we found that elevated expression of FASN is associated with advanced stages of colorectal cancer (CRC) and liver metastasis, suggesting that it may play a role in progression of CRC to metastatic disease. Targeted inhibition of lipogenic enzymes abolished expression of …

The Linkage Between Transcription Control And Epigenetic Regulation: The Snail Story And Beyond, Yiwei Lin

Theses and Dissertations--Pharmacology and Nutritional Sciences

Epigenetic deregulation contributes significantly to the development of multiple human diseases, including cancer. While great effort has been made to elucidate the underlying mechanism, our knowledge on epigenetic regulation is still fragmentary, an important gap being how the diverse epigenetic events coordinate to control gene transcription. In the first part of our study, we demonstrated an important link between Snail-mediated transcriptional control and epigenetic regulation during cancer development. Specifically, we found that the highly conserved SNAG domain of Snail sequentially and structurally mimics the N-terminal tail of histone H3, thereby functions as a molecular “hook”, or pseudo substrate, for recruiting …

Rhodococcus Equi Infection And Interferon-Gamma Regulation In Foals, Lingshuang Sun

Theses and Dissertations--Veterinary Science

Rhodococcus equi (R. equi) is one of the most serious causes of pneumonia in young foals. The clinical disease is of great concern to breeding farms worldwide due to the impact of mortality on economic losses. While adult horses are resistant to R. equi, foals exhibit a distinct age-associated susceptibility. The mechanism underlying this susceptibility in foals is not well understood. Interferon-gamma (IFNg) plays an important role in the clearance of R. equi, but its expression is impaired in neonatal foals. Moreover, the regulation of this age-related IFNg expression in foals remains unknown. In humans, IFNg …

Development Of Novel Chemical Tools For Proteasome Biology & A New Approach To 1-Azaspirocyclic Ring System, Lalit Kumar

Theses and Dissertations--Chemistry

The proteasome, a multiprotease complex, is clinically validated as an anticancer target by the FDA approval of bortezomib and carfilzomib for the treatment of multiple myeloma. The emergence of resistance to proteasome inhibitors however remains a major clinical challenge. Recently, distinct types of proteasomes termed ‘intermediate proteasomes’, which contain unconventional mixtures of catalytic subunits, have been implicated with drug resistance of tumor cells. In elucidating the role of intermediate proteasomes in drug resistance, a crucial step is to unequivocally determine the subunit composition of intermediate proteasomes in cells. With this in mind, the goal of the studies reported in this …

A Shared Gene Expression Signature In Mouse Models Of Ebv-Associated And Non-Ebv-Associated Burkitt Lymphoma, Kathryn T. Bieging, Kamonwan Fish, Subbarao Bondada, Richard Longnecker

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The link between EBV infection and Burkitt lymphoma (BL) is strong, but the mechanism underlying that link has been elusive. We have developed a mouse model for EBV-associated BL in which LMP2A, an EBV latency protein, and MYC are expressed in B cells. Our model has demonstrated the ability of LMP2A to accelerate tumor onset, increase spleen size, and bypass p53 inactivation. Here we describe the results of total gene expression analysis of tumor and pretumor B cells from our transgenic mouse model. Although we see many phenotypic differences and changes in gene expression in pretumor B cells, the transcriptional …

Investigating A Conformational Change In The Enzyme Neurolysin, Fei Xiong

Kaleidoscope

No abstract provided.

Investigating Calmodulin-Long Qt Syndrome Restorative Interactions Through Combinatorial Approaches, Michael Bricken

Kaleidoscope

No abstract provided.

An Evolutionarily Conserved Rit Gtpase-P38 Mapk Signaling Pathway Mediates Oxidative Stress Resistance, Weikang Cai, Jennifer L. Rudolph, Susan M. W. Harrison, Ling Jin, Aubrey L. Frantz, Douglas A. Harrison, Douglas A. Andres

Molecular and Cellular Biochemistry Faculty Publications

Ras-related small GTP-binding proteins control a wide range of cellular processes by regulating a variety of effector pathways, including prominent roles in the control of mitogen-activated protein kinase (MAPK) cascades. Although the regulatory role(s) for many Ras family GTPases are well established, the physiological function for the Rit/Rin subfamily has been lacking. Here, using both knockout mice and Drosophila models, we demonstrate an evolutionarily conserved role for Rit subfamily GTPases (mammalian Rit and Rin, and the Drosophila RIC homologue) in governing survival in response to oxidative stress. Primary embryonic fibroblasts derived from Rit knockout mice display increased apoptosis and selective …

Origin Of Amphibian And Avian Chromosomes By Fission, Fusion, And Retention Of Ancestral Chromosomes, Stephen R. Voss, D. Kevin Kump, Srikrishna Putta, Nathan Pauly, Anna Reynolds, Rema J. Henry, Saritha Basa, John A. Walker, Jeramiah J. Smith

Biology Faculty Publications

Amphibian genomes differ greatly in DNA content and chromosome size, morphology, and number. Investigations of this diversity are needed to identify mechanisms that have shaped the evolution of vertebrate genomes. We used comparative mapping to investigate the organization of genes in the Mexican axolotl (Ambystoma mexicanum), a species that presents relatively few chromosomes (n = 14) and a gigantic genome (>20 pg/N). We show extensive conservation of synteny between Ambystoma, chicken, and human, and a positive correlation between the length of conserved segments and genome size. Ambystoma segments are estimated to be four to 51 times longer than homologous …

Sonic Hedgehog Dependent Phosphorylation By Ck1Α And Grk2 Is Required For Ciliary Accumulation And Activation Of Smoothened, Yongbin Chen, Noriaki Sasai, Guoqiang Ma, Tao Yue, Jianhang Jia, James Briscoe, Jin Jiang

Markey Cancer Center Faculty Publications

Hedgehog (Hh) signaling regulates embryonic development and adult tissue homeostasis through the GPCR-like protein Smoothened (Smo), but how vertebrate Smo is activated remains poorly understood. In Drosophila, Hh dependent phosphorylation activates Smo. Whether this is also the case in vertebrates is unclear, owing to the marked sequence divergence between vertebrate and Drosophila Smo (dSmo) and the involvement of primary cilia in vertebrate Hh signaling. Here we demonstrate that mammalian Smo (mSmo) is activated through multi-site phosphorylation of its carboxyl-terminal tail by CK1α and GRK2. Phosphorylation of mSmo induces its active conformation and simultaneously promotes its ciliary accumulation. We demonstrate that …

Cooperative And Antagonistic Roles For Heterochromatin Proteins In Transcriptional Regulation Of The Drosophila Sex Determination Masterswitch Gene, Hui Li

University of Kentucky Doctoral Dissertations

HOAP was originally identified as a component of an ORC-containing multi-protein complex of Heterochromatin Protein 1 (HP1) from early Drosophila embryos. HOAP immunostaining showed prominent association of it with telomeres, and mutants for HOAP (cav¹) showed it functions along with HP1 in forming a telomere capping complex that prevents telomeric fusions.

Weaker HOAP immunostaining is also observed in regions of pericentric heterochromatin and euchromatin. To examine the role of HOAP at these non-telomeric sites, we applied Affymetric Drosophila Genome Arrays to undertake a microarray expression profiling study of genes that are mis-expressed in cav¹ mutant larvae. The …

Loss Of Bloom Syndrome Protein Causes Destabilization Of Genomic Architecture And Is Complemented By Ectopic Expression Of Escherichia Coli Recg In Human Cells, Michael Wayne Killen

University of Kentucky Doctoral Dissertations

Genomic instability driven by non-allelic homologous recombination (NAHR) provides a realistic mechanism that could account for the numerous chromosomal abnormalities that are hallmarks of cancer. We recently demonstrated that this type of instability could be assayed by analyzing the copy number variation of the human ribosomal RNA gene clusters (rDNA). Further, we found that gene cluster instability (GCI) was present in greater than 50% of the human cancer samples that were tested. Here, data is presented that confirms this phenomenon in the human GAGE gene cluster of those cancer patients. This adds credence to the hypothesis that NAHR could be …

Cyanidin-3-Glucoside Inhibits Ethanol-Induced Invasion Of Breast Cancer Cells Overexpressing Erbb2, Mei Xu, Kimberly A. Bower, Siying Wang, Jacqueline A. Frank, Gang Chen, Min Ding, Shiow Wang, Xianglin Shi, Zunji Ke, Jia Luo

Internal Medicine Faculty Publications

BACKGROUND: Ethanol is a tumor promoter. Both epidemiological and experimental studies suggest that ethanol may enhance the metastasis of breast cancer cells. We have previously demonstrated that ethanol increased the migration/invasion of breast cancer cells expressing high levels of ErbB2. Amplification of ErbB2 is found in 20-30% of breast cancer patients and is associated with poor prognosis. We sought to identify agents that can prevent or ameliorate ethanol-induced invasion of breast cancer cells. Cyanidin-3-glucoside (C3G), an anthocyanin present in many vegetables and fruits, is a potent natural antioxidant. Ethanol exposure causes the accumulation of intracellular reactive oxygen species (ROS). This …

The Distribution Of Unpaired During Drosophila Oogenesis, Travis Sexton

University of Kentucky Doctoral Dissertations

Janus Kinase (JAK) activity specifies the cell fates of the follicular epithelium during Drosophila oogenesis by establishing a gradient of JAK activity with highest levels at the A/P poles. Unpaired (Upd), a ligand for the pathway, is expressed and secreted exclusively from the polar cells potentially establishing the JAK activity gradient. This project proposed that Upd acts as a morphogen to directly establish the JAK activity gradient, specifying the fates of the follicular epithelium. The aims of this work were to investigate the extracellular distribution of Upd and, in addition, factors that may be involved. Furthermore, upd3, a gene …

Towards Cloning The Clk-3 Gene In Caenorhabditis Elegans, Suchita Umesh Desai

University of Kentucky Master's Theses

Mutations in the clk-1, clk-2, clk-3 and gro-1 genes in Caenorhabditis elegans show alterations in developmental and behavioral timing and lifespan, collectively termed the Clk phenotype. While the clk-1, clk-2, and gro-1 genes have been cloned, clk-3 gene has not been identified. Gene expression changes in clk-3 mutant worms were determined using microarray expression data. I examined genes in the region to which clk-3 gene maps, for strongly reduced expression in the clk-3 mutants and identified thirteen clk-3 candidate genes. RNAi feeding vectors for all these candidate genes were picked and cultured from the RNAi library. …

Teratogenic Effects Of Zinc On Embryo-Larval Stages Of The Fathead Minnow (Pimephales Promelas), Barbara A. Ramey

KWRRI Research Reports

The effects of zinc on embryos and larvae of the fathead minnow (Pimephales promelas) were studied using standard 8-day embryo-larval bioassay techniques. The objective was to determine if there was a period in embryonic development which would be the most sensitive to the toxic and teratogenic effects of zinc. Five developmental stages were exposed to 0.5, 1.0 and 3.0 mg/L. After 96 hr, all animals exposed to 3.0 mg Zn/L were dead. The hatching stage was the most affected by 1.0 mg/L, with only 59% surviving after 96 hr, while the tailbud stage showed essentially control-level survival. However, virtually all …

Algal Growth And Decomposition: Effects On Water Quality, Edward G. Foree, John S. Tapp Jr.

KWRRI Research Reports

The chemical composition of algae grown in batch culture depends mainly on environmental conditions, nutrient availability, presence of predators, cell age, and species. The effects of nutrient availability and cell age on the composition of three unialgal cultures (algae + bacteria) and one hetergeneous culture (algae + bacteria + microscopic animals) were evaluated. The cultures were grown in batch culture under both nutrient-abundant and nutrient deficient conditions and the changes in compositions were observed. Luxurious uptake where nutrients are incorporated into cellular protoplasm at levels greater than those necessary for growth, and super-luxurious uptake, where some nutrients are stored rather …