Author
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SHEPPARD, CAROL - UNIVERSITY OF SCRANTON |
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LYNN, DWIGHT |
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Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/15/1996 Publication Date: N/A Citation: N/A Interpretive Summary: The Colorado potato beetle is the most serious pest of potatoes in the United States. In order to develop improved methods for controlling this pest, greater knowledge of the insect's basic biology is necessary. A cell line previously developed from eggs of this insect has been shown through elaborate biochemical techniques in the current study to be of nerve origin. Other tests show that some of the cells respond to light by forming an electrical pulse. These results mean that these cells are the first from insect nerve tissue to be grown in continuous culture and that they probably consist, at least in part, of precursors of light sensitive (photoreceptor) cells. Since current studies on insect nerves require difficult procedures to isolate cells for study, this cell line will now provide scientists with a simpler method to study the biology of the nerve cells of insects. Also, these cells can be used for screening chemicals in attempts to isolate more specific methods of controlling the Colorado potato beetle and other insects. These results will be of interest to scientists studying neurophysiology and to chemical companies screening for chemicals with insecticidal activities. Technical Abstract: Of the approximately 400 described insect cell lines, only 3 derive from beetles (Coleoptera) and none are neural in origin. The present work was undertaken to characterize further a new cell line, designated IPLB-CPB2, derived from eggs of the Colorado potato beetle, Leptinotarsa decimlineata. Indirect immunofluorescent studies reported here indicate that these cells express neurofilament-like immunoreactivities to antibodies directed against mammalian Nf-medium (MW 150,000), and a heavily phosphorylated form of Nf Heavy (MW 200,000; detected using the axonal monoclonal antibody SMI 31). This appears to be the first report of neurofilament-like immunoreactivity in an arthropod. Immunofluorescent analyses also indicate that IPLB- CPB2 cells express: an antigenic epitope characteristic of the mammalian type 1 inositol trisphosphate IP3) receptor; the ryanodine receptor (Ryr; also termed calcium-induced calcium release receptor channel, or CICR); and the sarco(endo)plasmic reticulum Ca2* pump (SERCA). Patch-clamp recordings indicate that some IPLB-CPB2 cens are capable of producing spontaneous action potentials, while others may be photosensitive. Taken together, the findings reported here suggest that IPLB-CPB2 cefls are of neural origin, and that they express the major receptor channels and pumps known to be localized in the ER of the cell, which are required for receptormediated calcium signafing. Thus, the IPLB-CPB2 cell line may prove to be an exceflent model system for studies of insect neurobiology and calcium-based signal transduction. |
