Medicine and Health Sciences Commons^™

Functional Analysis Of A Critical Glycine (Glycine 12) In Beta-Type Connexins Of Human Skin, Rasheed Bailey

Biology Theses

At least five beta-type connexins are expressed in various layers of the skin (Cx26, Cx30, Cx30.3, Cx31, and Cx32) and all include a glycine residue at position 12. Glycine12 (G12) is located about halfway through the cytoplasmic amino terminus and has been the focus of several studies related to connexin diseases and gap junction channel structure. The importance of this residue is evident in the severity and diversity of diseases associated with amino acid substitutions at G12 including hereditary forms of skin disease, deafness and neuropathy. This study uses bioinformatic analysis in combination with mutational analysis and electrophysiology to better …

Effect Of Supplementing Additives In Leptin-Enriched Maturation Medium During In Vitro Maturation And Vitrification Of Goat Oocytes, Reema Talukdar, Ranjan Kumar Biswas, Govindasamy Kadirvel, Bharat Chandra Deka, Sudip Sinha, Lukumoni Buragohain, Birina Bora

Turkish Journal of Veterinary & Animal Sciences

The present study aimed to evaluate the effect of supplementing epidermal growth factor (EGF), insulin-like growth factor-I (IGF-I), fetal bovine serum (FBS), and bovine serum albumin (BSA) in different combinations in a maturation medium (MM) comprising TCM-199 + 5 µg/mL 17-ß estradiol + 5 µg/mL ovine-luteinizing hormone (oLH) + 5 µg/mL pure follicle-stimulating hormone (pFSH) + 100 µM/mL cysteamine containing the best concentration of leptin among 10/20/25/30 ng/mL on in vitro maturation (IVM) and subsequent vitrification of matured goat oocytes. The IVM of oocytes was carried out in a CO2 incubator for 27 h at 38.5 °C. The percentage of …

A Xenopus Oocyte Model System To Study Action Potentials, Aaron Corbin-Leftwich, Hannah E Small, Helen H Robinson, Carlos A. Villalba-Galea, Linda M Boland

School of Pharmacy Faculty Articles

Action potentials (APs) are the functional units of fast electrical signaling in excitable cells. The upstroke and downstroke of an AP is generated by the competing and asynchronous action of Na+- and K+-selective voltage-gated conductances. Although a mixture of voltage-gated channels has been long recognized to contribute to the generation and temporal characteristics of the AP, understanding how each of these proteins function and are regulated during electrical signaling remains the subject of intense research. AP properties vary among different cellular types because of the expression diversity, subcellular location, and modulation of ion channels. These complexities, in addition to the …

Correlations Among Oocyte Quality, Hepatic Triacylglycerols, And Some Blood Metabolites In Carora Breed Cows During Early Postpartum, Leandro Rodriguez, Oswaldo Rosendo, Carlos Parraga, Armando Oropeza

Turkish Journal of Veterinary & Animal Sciences

The aim of this study was to assess the relationships of hepatic triacylglycerol (TAG), plasma glucose, plasma cholesterol, and plasma urea nitrogen (PUN) concentrations with the morphological quality of oocytes obtained from 20 Carora breed lactating cows at days 20 and 35 postpartum in a commercial farm. Oocytes were obtained through the technique of transvaginal ultrasound-guided follicle aspiration. Change in body condition score (0.35 vs. 0.44, P = 0.02) and mean plasma cholesterol (3.59 vs. 4.35 mmol/L, P = 0.01) significantly differed between the 2 periods, whereas mean TAG tended to be higher at day 35 after calving (2.29 vs. …

Survivability Of Caprine Oocytes Vitrified In Conventional And Open Pulled Straws, Rameez Ali, Waquar Razzaque, Utsav Sharma, Anil Pandey, Kafil Hussain

Turkish Journal of Veterinary & Animal Sciences

The aim of this study was to compare the efficacy of conventional straw vitrification with open pulled straw vitrification in terms of cryosurvivability and damages caused to the oocytes. Two hundred immature goat cumulus oocyte complexes (COCs) were vitrified in a solution of ethylene glycol, dimethyl sulfoxide, and sucrose using either conventional straws (100 COCs) or open pulled straws (100 COCs). The COCs were warmed and observed for morphological damages and viability after 7 days of preservation in liquid nitrogen. Among the 100 COCs cryopreserved in each case, only 83 COCs were recovered after warming in conventional straw vitrification as …

Menthol Binding And Inhibition Of A7-Nicotinic Acetylcholine Receptors, Abrar Ashoor, Jacob C. Nordman, Daniel Veltri, Keun-Hang Susan Yang, Lina T. Al Kury, Yaroslav M. Shuba, Mohamed Magoub, Frank Christopher Howarth, Bassem Sadek, Amarda Shehu, Nadine Kabbani, Murat Oz

Mathematics, Physics, and Computer Science Faculty Articles and Research

Menthol is a common compound in pharmaceutical and commercial products and a popular additive to cigarettes. The molecular targets of menthol remain poorly defined. In this study we show an effect of menthol on the α7 subunit of the nicotinic acetylcholine (nACh) receptor function. Using a two-electrode voltage-clamp technique, menthol was found to reversibly inhibit α7-nACh receptors heterologously expressed in Xenopus oocytes. Inhibition by menthol was not dependent on the membrane potential and did not involve endogenous Ca2+-dependent Cl− channels, since menthol inhibition remained unchanged by intracellular injection of the Ca2+ chelator BAPTA and perfusion with Ca2+-free bathing solution containing …

A Human Phospholipid Phosphatase Activated By A Transmembrane Control Module, Christian R. Halaszovich, Michael G. Leitner, Angeliki Mavrantoni, Audrey Le, Ludivine Frezza, Anja Feuer, Daniela N. Schreiber, Carlos A. Villalba-Galea, Dominik Oliver

School of Pharmacy Faculty Articles

In voltage-sensitive phosphatases (VSPs), a transmembrane voltage sensor domain (VSD) controls an intracellular phosphoinositide phosphatase domain, thereby enabling immediate initiation of intracellular signals by membrane depolarization. The existence of such a mechanism in mammals has remained elusive, despite the presence of VSP-homologous proteins in mammalian cells, in particular in sperm precursor cells. Here we demonstrate activation of a human VSP (hVSP1/TPIP) by an intramolecular switch. By engineering a chimeric hVSP1 with enhanced plasma membrane targeting containing the VSD of a prototypic invertebrate VSP, we show that hVSP1 is a phosphoinositide-5-phosphatase whose predominant substrate is PI(4,5)P(2). In the chimera, enzymatic activity …

Efficient Activation Of Reconstructed Rat Embryos By Cyclin-Dependent Kinase Inhibitors, Robin L. Webb, Kirk A. Findlay, Michael A. Green, Tina L. Beckett, M. Paul Murphy

Molecular and Cellular Biochemistry Faculty Publications

Background

Over the last decade a number of species, from farm animals to rodents, have been cloned using somatic cell nuclear transfer technology (SCNT). This technique has the potential to revolutionize the way that genetically modified animals are made. In its current state, the process of SCNT is very inefficient (<5% success rate), with several technical and biological hurdles hindering development. Yet, SCNT provides investigators with powerful advantages over other approaches, such as allowing for prescreening for the desired level of transgene expression and eliminating the excess production of undesirable wild-type animals. The rat plays a significant role in biomedical research, but SCNT has been problematic for this species. In this study, we address one aspect of the problem by evaluating methods of activation in artificially constructed rat embryos.

Principal Findings

We demonstrate that treatment with a calcium ionophore (ionomycin) combined with a variety of cyclin-dependent kinase inhibitors is an effective way to activate rat embryos. This is in contrast to methods developed for the mouse embryo, which tolerates much less specific chemical treatments. Methods developed to activate …

Coupling Between The Voltage-Sensing And Phosphatase Domains Of Ci-Vsp, Carlos A. Villalba-Galea, Francesco Miceli, Maurizio Taglialatela, Francisco Bezanilla

School of Pharmacy Faculty Articles

The Ciona intestinalis voltage sensor-containing phosphatase (Ci-VSP) shares high homology with the phosphatidylinositol phosphatase enzyme known as PTEN (phosphatase and tensin homologue deleted on chromosome 10). We have taken advantage of the similarity between these proteins to inquire about the coupling between the voltage sensing and the phosphatase domains in Ci-VSP. Recently, it was shown that four basic residues (R11, K13, R14, and R15) in PTEN are critical for its binding onto the membrane, required for its catalytic activity. Ci-VSP has three of the basic residues of PTEN. Here, we show that when R253 and R254 (which are the homologues …

Effects Of Oocyte Source On The Developmental Competence Of In Vitro Matured Goat Oocytes Fertilized By The Intracytoplasmic Sperm Injection Technique, Abu Nasar Md. Aminoor Rahman, Ramli Bin Abdullah, Wan Embong Wan-Khadijah

Turkish Journal of Veterinary & Animal Sciences

This study evaluated the effects of oocyte source on in vitro maturation (IVM) and embryo developmental competence in goats by the intracytoplasmic sperm injection (ICSI) technique. Oocytes were obtained either by laparoscopic ovum pick-up (LOPU) or by slicing of abattoir ovaries. The donor does used for LOPU were superstimulated and their estrus was synchronized. Recovered oocytes from both sources were cultured in microdrops of IVM medium in the presence of CO2 (5%) at 38.5 °C in a CO2 incubator for 27 h. The ICSI was performed with immobilized sperm on the lid of a culture dish (35 mm) under an …

Expression, Isolation And Purification Of Human Zona Pellucida Protein 3, Ting-Fung Chi

Theses and Dissertations in Biomedical Sciences

Mammalian fertilization involves interactions of sperm surface receptors with the ligands of the zona pellucida, an extracellular matrix surrounding the ovulated oocytes. In humans, the zona pellucida is composed of three major glycoproteins. One of them, ZP3, participates in the primary sperm binding and in the subsequent triggering of the spermatozoa's acrosome reaction. Studies on the role of this specific protein in the human fertilization process are hampered by the limited amount of available biologically functional proteins.

By use of a pcDNA 3.1(+) expression vector, a transfecting-vector was constructed containing a 1.3 kb histidine tagged hZP3 cDNA. This histidine tagged …