• Title/Summary/Keyword: knockout

Search Result 377, Processing Time 0.039 seconds

Gene Expression Analysis of Gα13-/- Knockout Mouse Embryos Reveals Perturbations in Gα13 Signaling Related to Angiogenesis and Hypoxia

  • Park, Ji-Hwan;Choi, Sang-Dun
    • Genomics & Informatics
    • /
    • v.9 no.4
    • /
    • pp.161-172
    • /
    • 2011
  • Angiogenesis is regulated by a large number of molecules and complex signaling mechanisms. The G protein $G{\alpha}_{13}$ is a part of this signaling mechanism as an endothelial cell movement regulator. Gene expression analysis of $G{\alpha}_{13}$ knockout mouse embryos was carried out to identify the role of $G{\alpha}_{13}$ in angiogenesis signaling during embryonic development. Hypoxia-inducible response factors including those acting as regulators of angiogenesis were over expressed, while genes related to the cell cycle, DNA replication, protein modification and cell-cell dissociation were under expressed. Functional annotation and network analysis indicate that $G{\alpha}_{13}{^{-/-}}$ embryonic mice were exposed to hypoxic conditions. The present analysis of the time course highlighted the significantly high levels of disorder in the development of the cardiovascular system. The data suggested that hypoxia-inducible factors including those associated with angiogenesis and abnormalities related to endothelial cell division contributed to the developmental failure of $G{\alpha}_{13}$ knockout mouse embryos.

Differential Effects of Two Period Genes on the Physiology and Proteomic Profiles of Mouse Anterior Tibialis Muscles

  • Bae, Kiho;Lee, Kisoo;Seo, Younguk;Lee, Haesang;Kim, Dongyong;Choi, Inho
    • Molecules and Cells
    • /
    • v.22 no.3
    • /
    • pp.275-284
    • /
    • 2006
  • The molecular components that generate and maintain circadian rhythms of physiology and behavior in mammals are present both in the brain (suprachiasmatic nucleus; SCN) and in peripheral tissues. Examination of mice with targeted disruptions of either mPer1 or mPer2 has shown that these two genes have key roles in the SCN circadian clock. Here we show that loss of the clock gene mPer2 affects forced locomotor performance in mice without altering muscle contractility. A proteomic analysis revealed that the anterior tibialis muscles of the mPer2 knockout mice had higher levels of glycolytic enzymes such as triose phosphate isomerase and enolase than those of either the wild type or mPer1 knockout mice. In addition, the level of expression of HSP90 in the mPer2 mutant mice was also significantly higher than in wildtype mice. These results suggest that the reduced locomotor endurance of the mPer2 knockout mice reflects a greater dependence on anaerobic metabolism under stress conditions, and that the two canonical clock genes, mPer1 and mPer2, play distinct roles in the physiology of skeletal muscle.

Shade Avoidance and the Regulation of Leaf Inclination in Rice

  • Shin, Juhee;Park, Phun Bum
    • Rapid Communication in Photoscience
    • /
    • v.3 no.3
    • /
    • pp.53-55
    • /
    • 2014
  • The shade avoidance syndrome is a morphological and physiological response when plants are exposed to shade. Recent work in Arabidopsis had begun to define the molecular components of the shade avoidance syndrome in dicotyledonous model plant. However, little is known about the shade avoidance response networks in agriculturally important monocotyledon crops such as rice. Here, we found that the degree of bending at the lamina joint is inversely proportional to the R:FR ratio. To elucidate which phytochrome is involved in this response, we did lamina joint inclination assay with the rice phytochrome-deficient mutants (osphyA, osphyB, and osphyC) and the wild type plants. Whereas the osphyA and osphyC knockout mutants bent at the lamina joint in the far-red rich condition as the wild type plants, the osphyB knockout mutants no longer bent at the lamina joint in the far-red rich condition. These results suggest that PHYB acts as a sole photoreceptor in the lamina joint inclination response in rice.

Normal Anxiety, Fear and Depression-related Behaviors in Mice Lacking ${\alpha}-Calcitonin$ Gene-Related Peptide

  • Lee, Jong-Ho
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.6 no.6
    • /
    • pp.299-304
    • /
    • 2002
  • Calcitonin gene-related peptide (CGRP) expressing neurons are distributed widely throughout the central and peripheral nervous systems. Due to its distribution and pharmacological studies, CGRP has been implicated to be involved in anxiety, fear and depression. In this study, ${\alpha}CGRP-knockout$ mice were used to assess the consequences of removing this neuropeptide to the mice behaviors. ${\alpha}CGRP-knockout$ mice performed equally as well as wild type mice in the light-dark transition test and in the elevated plus maze test of anxiety. ${\alpha}CGRP-null$ mice behaved similarly as wild-type mice in the Porsolt swim test of depression. They also exhibited normal learning and memory in the fear conditioning tasks. It is concluded that ${\alpha}CGRP$ is not essential for mice to be able to perform these tests, despite the presence of ${\alpha}CGRP$ in the relevant regions of the brain.

Regulatory roles of NKT cells in Anaplasma phagocytophilum infection

  • Choi, Kyoung-Seong;Chae, Joon-Seok
    • Korean Journal of Veterinary Research
    • /
    • v.49 no.2
    • /
    • pp.167-172
    • /
    • 2009
  • Human granulocytic anaplasmosis (HGA) is caused by the obligate intracellular bacterium Anaplasma (A.) phagocytophilum. Natural killer T (NKT) cells are key players in host defense against various microbial infections. We investigated the role of NKT cells in immune response to A. phagocytophilum infection using NKT-knockout ($J\alpha$18-/-) mice. $J\alpha$18-/- and wild-type (WT) mice were infected with low-passage A. phagocytophilum and assayed for hepatic histopathology and cytokine production during 7 days post-infection. Compared to WT controls, the infected $J\alpha$18 -/- mice had much less histopathologic lesions and less apoptosis through day 7, and lower concentrations of ${IFN\gamma}$ and IL- 12, but not of IL-10. This result suggests that NKT cells are major components in the pathogenesis of HGA.

Attenuation of nicotine-induced locomotor sensitization in $\mu$-opioid receptor knockout mice

  • Yoo, Ji-Hoon;Yang, Eun-Mi;Kim, Kyung-In;Lee, Seok-Yong;Jang, Choon-Gon
    • Proceedings of the PSK Conference
    • /
    • 2003.04a
    • /
    • pp.130.2-130.2
    • /
    • 2003
  • The present study was undertaken to examine the hypothesis that $\mu$-opioid receptors play a crucial role in behavioral sensitization to nicotine using $\mu$-opioid receptor knockout mice. All mice were treated acutely or repeatedly with nicotine 0.05 mg/kg twice daily for 7 consecutive days. The mice were challenged with nicotine on day 11. And locomotor activity was measured for 30min. (omitted)

  • PDF