Congress Abstracts - Society for Developmental Biology

understanding the mechanisms that underlie the transcription control of muscle development can provide insight into human
myopathies and ailments.
Program/Abstract # 148
Withdrawn
Program/Abstract # 149
Alteration of MMP9 and TIMP1 expression by high glucose in mouse blastocysts is dependent on oxidative stress
Sánchez Santos, Alajandra; Martínez Hernández, María Guadalupe; Baiza Gutman, Luis Arturo (FES Iztacala, UNAM, Mexico)
Hyperglycemia during diabetes has been associated with enhanced oxidative stress and metabolic alterations that lead to changes in
gene expression. High concentration of glucose induce the formation of reactive oxygen species (ROS), which can alter the expression
of matrix metalloproteinases (MMPs), producing changes in the synthesis and degradation of the extracellular matrix (ECM). MMP9
is secreted by the mouse blastocyst during implantation, and it has been involved in the invasive behavior of trophoblast in vivo and in
vitro. However, few studies have been focus in MMP9 expression on blastocyst during implantation. In the present work we
determined the effect of oxidative stress caused by high concentration of glucose on the expression of MMP9 and TIMP1 in mouse
blastocysts developing in culture. Gestational day (GD) 4 blastocysts were cultured in HAM-F10 and treated after 2 days of culture
(GD7), with glucose 25 mmol/L or H 2 O 2 10 μmol/L. The antioxidant N-acetylcysteine (NAC) or ROS inhibitors (apocynin, rotenone)
were added to some groups of glucose treated embryos. Mmp9 and Timp1 mRNAs were measured using real time RT-PCR. MMP9
levels were analyzed by zymography in SDS-PAGE-gels co-polymerized with gelatin. Glucose 25 mmol/L and H 2 O 2 10 μmol/L
induced higher levels of MMP9 protein and mRNA. Both conditions also cause diminished levels of Timp1 mRNA. NAC and ROS
inhibitors restored Mmp9 mRNA, MMP9 protein and Timp1 mRNA concentration to levels similar to control group (embryos cultured
with glucose 6 mM). We concluded that oxidative stress caused by high concentration of glucose may regulate the invasiveness of
trophoblast during embryo implantation, through the control of MMP9 and TIMP1 expression. Supported by PAPIT, DGAPA,
UNAM, grant IN230611.
Program/Abstract # 150
Spalt major directly regulates seven-up expression in Drosophila oenocytes
Ryan, Kathryn M.; Mason, Grace; Cripps, Richard (University of New Mexico, USA)
Oenocytes are hepatocyte-like cells oriented bilaterally in the Drosophila embryo and larva. These cells function in lipid metabolism
as well as pheromone secretion. The focus of our work is to understand the developmental genetic program controlling the formation
of these cells. We have identified a minimal enhancer responsible for expression of the seven-up (svp) gene in the oenocytes. Svp is
orthologous to the vertebrate COUP-TF proteins (Chicken Ovalbumin Upstream Promotor Transcription Factors. These proteins have
been shown to be important in vertebrate development. Here we demonstrate that Spalt major (Salm) is a direct regulator of the svp
enhancer. We also show that Svp is upstream of mirror, another important gene in oenocyte development. Understanding the
relationship of these genes in the context of the simpler Drosophila model may lead to a better understanding of the genetic regulation
of COUP-TFs, which have been shown to be involved in many of the same biological functions in vertebrates, as flies.
Program/Abstract # 151
A Genetic and Chemical Genetic Approach to Study Cell Fate Decisions via JAK/STAT Attenuation
Monahan, Amanda J.; Seley-Radtke, Katherine; Starz-Gaiano, Michelle (Univ of Maryland-Baltimore, USA)
Throughout development cells undergo precise spatio-temporal patterning governed genetically, which generally involves a signal
transduction cascade, such as the Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) pathway. Border cell
migration during Drosophila oogenesis provides a powerful system to study JAK/STAT regulation. The egg chamber is composed of
the germ line encased by somatic epithelial follicle cells. At mid-oogenesis, a subset of anterior follicle cells (AFC) receive graded
STAT activity. The 4-6 AFC with the highest level of STAT signaling form motile border cells. STAT activation must be precisely
regulated as too few or too many motile cells results in migration defects. We have utilized two approaches to study STAT regulation.
In the first, we establised Socs36E is necessary to limit STAT signaling in the AFC. We found STAT and the STAT feedback inhibitor
Apontic (APT) regulate Socs36E. Genetic interactions suggest Socs36E functions with Cullin-2 in an E3 ubiquitin ligase complex.
Thus, APT attenuates STAT at the protein level - via Socs36E - to limit migratory cell fate and post transcriptionally via miR-279 to
facilitate detachment. In our second approach, we have modified the synthetic scheme of a known JAK ATP-competive inhibitor and
are synthesizing novel analogs that have altered interactions in the catalytic domain. In vitro and in vivo assays allow us to interrogate
the importance of specific interactions between JAK and its substrates, as well as study the transcriptional and developmental effects
of inhibiting STAT signaling. Through fly and chemical genetics our work demonstrates the importance of proper JAK/STAT
regulation in developmental and disease contexts.
Program/Abstract # 152
Comparative transgenic analysis of enhancers near the human and mouse short-stature genes SHOX and Shox2
Cobb, John A.; Rosin, Jessica; Abassah-Oppong, Samuel (University of Calgary, Canada)
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