Class of 2009 Abstract / OBJECTIVES: The objective of this study was to characterize the Hyaluronidase (HYA) gene family throughout gestational development of murine hearts to provide greater insight regarding its role in cardiac morphogenesis. METHODS: Microdissection of murine embryos was accomplished to extract embryonic heart tissue. RNA was extracted using the standard Trizol protocol. cDNA templates were created using a standard protocol. Polymerase chain reaction (PCR) was used to verify presence of HYA, isolate a sample for insertion into a cloning plasmid to make a recombinant clone. A TOPO cloning reaction followed by a double DNA digest was accomplished to verify gene sequencing and orientation in the clone. SYBR Green real time RT- PCR was used to quantify gene expression relative to 18S RNA. RESULTS: RT-PCR provided qualitative data indicating HYA1, HYA2, and HYA3 are present at all observed time points (E8.5, E9.5, E10.5, E11.5, E12.5, E13.5, E14.5, E15.5, and E16.5). Real time RT-PCR data results characterizing relative expression for HYA2: E9.0 (Rel. Exp. = 1.00; SD = 0), E10.5 (Rel. Exp. = 1.33; SD = 0.577), E12.5 (Rel. Exp. = 2.00; SD = 0), E13.5 (Rel. Exp. = 2.66; SD = 0.577), E14.5 (Rel. Exp. = 3.00; SD = 0), E15.0 (Rel. Exp. = 2.00; SD = Error). CONCLUSIONS: HYA1, HYA2, and HYA3 are present at al time points observed in embryonic heart tissue. Relative expression of HYA2 progressively increased from E9.0 until E14.5 and then started tapering downward at time point E15.0.

We have obtained new images of the protoplanetary disk orbiting TW Hya in visible, total intensity light with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST), using the newly commissioned BAR5 occulter. These HST/STIS observations achieved an inner working angle of similar to 0."2, or 11.7 au, probing the system at angular radii coincident with recent images of the disk obtained by ALMA and in polarized intensity near-infrared light. By comparing our new STIS images to those taken with STIS in 2000 and with NICMOS in 1998, 2004, and 2005, we demonstrate that TW Hya's azimuthal surface brightness asymmetry moves coherently in position angle. Between 50 au and 141 au we measure a constant angular velocity in the azimuthal brightness asymmetry of 22 degrees.7. 7 yr(-1) in a counterclockwise direction, equivalent to a period of 15.9. yr assuming circular motion. Both the (short) inferred period and lack of radial dependence of the moving shadow pattern are inconsistent with Keplerian rotation at these disk radii. We hypothesize that the asymmetry arises from the fact that the disk interior to 1 au is inclined and precessing owing to a planetary companion, thus partially shadowing the outer disk. Further monitoring of this and other shadows on protoplanetary disks potentially opens a new avenue for indirectly observing the sites of planet formation.

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