• Title/Summary/Keyword: Postembryonic development

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Postembryonic Changes of Locustatachykinin I-immunoreactive Neurons in the Brains of the Moth Spodoptera litura

  • Kang, Hyun-O;Lee, Jeong-Oon;Lee, Bong-Hee
    • Animal cells and systems
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    • v.1 no.3
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    • pp.475-482
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    • 1997
  • The antiserum against locustatachykinin I, originally isolated from brain and retrocerebral complex of the locust Locusta migratoria, has been used to investigate changes in number, localization, and structure of locustatachykinin I-immunoreactive (LomTK I-IR) neurons in the brains of the common cutworm, Spodoptera Iitura, during postembryonic development. These neurons are found at larval, pupal, and adult stages. In the larval stages, the first instar larva shows the first appearance of about 8 LomTK I-IR neurons. These neurons gradually increase in number from the second to fourth instar larvae which have the largest number of about 92 in all postembryonic stages. Thereafter, these neurons decrease to about 28 in number in the 5-day-old pupa. However, they begin to rise again from the 7-day-old pupal stage, eventually reaching to about 90 in the l-day-old adult. The developing larval brains contain cell bodies of these neurons in most neuromeres. After the metamorphosis of larva to pupa and adult, localization of these neuronal cell bodies is confined to the specific cerebral neuromeres. The 7-day-old pupal brain shows the location of these neuronal cell bodies in pars intercerebralis, pars lateralis of protocerebrum, deutocerebrum, tritocerebrum, optic lobe-near region, and subesophageal ganglion. In the l-day-old adult, however, the brain has these cell bodies only in some neuromeres of protocerebrum, deutocerebrum, and subesophageal ganglion. Throughout the postembryonic life, changes in structure of these neurons coincide with changes in number and localization of these neurons. These findings suggest that changes in number, localization, and structure of these neurons reflect differentiation of these neurons to adult type.

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LIN-23, an E3 Ubiquitin Ligase Component, Is Required for the Repression of CDC-25.2 Activity during Intestinal Development in Caenorhabditis elegans

  • Son, Miseol;Kawasaki, Ichiro;Oh, Bong-Kyeong;Shim, Yhong-Hee
    • Molecules and Cells
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    • v.39 no.11
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    • pp.834-840
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    • 2016
  • Caenorhabditis elegans (C. elegans) utilizes two different cell-cycle modes, binucleations during the L1 larval stage and endoreduplications at four larval moltings, for its postembryonic intestinal development. Previous genetic studies indicated that CDC-25.2 is specifically required for binucleations at the L1 larval stage and is repressed before endoreduplications. Furthermore, LIN-23, the C. elegans ${\beta}$-TrCP ortholog, appears to function as a repressor of CDC-25.2 to prevent excess intestinal divisions. We previously reported that intestinal hyperplasia in lin-23(e1883) mutants was effectively suppressed by the RNAi depletion of cdc-25.2. Nevertheless, LIN-23 targeting CDC-25.2 for ubiquitination as a component of E3 ubiquitin ligase has not yet been tested. In this study, LIN-23 is shown to be the major E3 ubiquitin ligase component, recognizing CDC-25.2 to repress their activities for proper transition of cell-cycle modes during the C. elegans postembryonic intestinal development. In addition, for the first time that LIN-23 physically interacts with both CDC-25.1 and CDC-25.2 and facilitates ubiquitination for timely regulation of their activities during the intestinal development.