ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:3/4<181::AID-ARCH1>3.0.CO;2-W

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractThis review examines the signal transduction pathways which regulate the contraction of an insect visceral muscle, namely the oviduct of the locust,Locusta migratoria. Detailed studies based upon neurophysiology, neurochemistry, and neuropharmacology have defined the neural control over contraction of locust oviducts. The identification of a variety of neuroactive chemicals which are associated with the innervation of this muscle, including peptides, an amine, and an amino acid, has allowed examination of second messenger systems which lead to an intricate control over muscle contraction. Thus, it is known that these neuroactive chemicals are involved with G‐proteins, membrane lipid systems, cyclic nucleotides, calcium, and calmodulin as well as protein phosphorylation, thereby allowing these extracellular neuroactive chemicals to initiate and modulate contractile events within the individual muscle cells. Each of these systems is reviewed in the context of locust oviduct contraction and the possibilities of cross‐talk regulation between these second messengers discussed. © 1996 Wiley‐Lis

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:3/4<183::AID-ARCH2>3.0.CO;2-U

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractOf the approximately 400 described insect cell lines, only three are derived 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 (Nf)‐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 Irisphosphate (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 cells are capable of producing spontaneous action potentials, while others may be photosensitive. Taken together, the findings reported here suggest that IPLB‐CPB2 cells 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 receptor‐mediated calcium signaling. Thus, the IPLB‐CPB2 cell line may prove to be an excellent model system for studies of insect neurobiology and calcium‐based signal transductio

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:3/4<197::AID-ARCH3>3.0.CO;2-Q

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractThe development of theDrosophilaoocyte depends upon a sequential series of interactions between the germline cells and the somatically derived follicle cells to produce individual follicles with appropriate polarities. In the germarium the control of germline cell division depends upon a proper interaction with somatic cells adjacent to the germline stem cells. Bothgurkenandbrainiacare required in the germline, and theEgfr, daughterless, Notch, andDeltagenes are required in the somatic cells to produce individual egg chambers with a continuous follicular epithelium. After a follicle forms, components in these same signaling pathways, plus additional genes, are then required for the establishment of the anterior‐posterior polarity, followed by the dorsal‐ventral polarity of the developing follicle. Initially,gurkenmRNA is localized to the posterior edge of the oocyte, where it signals the posterior polar follicle cells to differentiate as posterior. The anterior‐posterior assymmetry of the oocyte is then established by a reorganization of the microtubule network, which requires aNotch‐Delta‐dependent signal sent from the posterior polar follicle cells to the oocyte and the activity of protein kinase A in the germ line. This reorganization leads to the localization of the maternal anterior‐posterior determinantsbicoidandoskarto opposite poles of the oocyte and the repositioning of the oocyte nucleus to the anterior‐dorsal surface of the oocyte,gurkenmRNA and protein are now concentrated between the oocyte nucleus and the adjacent anterior‐dorsal follicle cells, where, in combination with Rhomboid, it locally activates the EGF receptor and its downstream cascade to direct the adjoining cells to adopt a dorsal fate. This process is thought to restrict the action of three follicle cell gene functions, encoded bywindbeutel, nudal, and,pipe, to the ventral follicle cells, where they lead to the localized activation of a serine protease cascade required to produce the active Spätzle ligand to activate the Toll receptor. Finally, the termini of the embryo are dependent upon the activation of the Torso receptor, and this requires the localized expression oftorso‐likein a subset of follicle cells at the anterior and posterior poles of the follicle, which leads to the activation of Trunk, the putative ligand for Torso. In summary, the normal development of the oocyte requires a continuous sequence of germline‐follicle cell interactions to provide the polarities responsible for normal development. ©

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:3/4<211::AID-ARCH4>3.0.CO;2-V

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractPulses of the steroid hormone 20‐hydroxyecdysone (ecdysone) regulate diverse biological responses during the life history of insects. Studies of the fruit fly,Drosophila melanogaster, have provided significant insights into the mechanisms underlying ecdysone mediated regulation of development. During the dramatic metamorphosis ofDrosophila, ecdysone induces the histolysis of nearly all of the larval tissues and differentiation and morphogenesis of the structures composing the adult fly. These changes are mediated by a genetic signaling cascade that was first recognized as puffs in the giant polytene chromosomes of the salivary gland. This genetic regulatory cascade is composed of early and late genes that are intricately coordinated by changes in hormone titer. Early genes encode regulatory proteins that are involved in the proper regulation of late genes, which are thought to play a more direct role in development. The regulation and function of these genes is discussed in the context of the cell‐ and tissue‐specific changes required for the reorganization of a larva to form an adult fly. © 1996 Wiley‐L

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:3/4<231::AID-ARCH5>3.0.CO;2-V

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractPheromone production in most moths is regulated by pheromone biosynthesis activating neuropeptides (PBAN) produced in the subesophageal ganglion. This paper will review the current concepts related to how PBAN stimulates the pheromone biosynthetic pathway at the level of the pheromone gland cell. Data will be presented using pharmacological compounds that help determine the mode of action of PBAN at the cellular level. Current concepts on the signal transduction pathways involved in PBAN mode of action will be discussed. © 1996 Wiley‐Liss, I

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:3/4<245::AID-ARCH6>3.0.CO;2-R

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractJuvenile hormone (JH) biosynthesis is regulated by both peptidergic and aminergic inputs. Depending upon the species and developmental stage, these signals may be either inhibitory or stimulatory (allatostatins and allatotropins). Signal transduction within corpus allatum cells occurs by way of known second messengers, including the cyclic nucleotides, Ca2+, and the phosphoinositides. We review the role of signal transduction in the regulation of JH biosynthesis in the locust,Locusta migratoria, the hornworm,Manduca sexta, and the cockroach,Diploptera punctata. Differences in signal transduction between the species reflect in part differences in the signals which regulate the corpus allatum. For example, JH biosynthesis in locusts appears to be regulated principally by allatotropic signals, whereas in the cockroach allatostatic signals appear to predominate. InM. sexta, both types of signals appear to function and are stage‐dependent. This may reflect the complex nature of the juvenile hormone products in this species, whereas in locusts and cockroaches only JH III is produced. Modulation of intracellular calcium (CA2+) levels by drugs (ionophores, Ca2+chelators and releasing agents, CA2+channel blockers) or depolarizing agents including current injection dramatically alters JH biosynthesis, as do agents that activate the phosphoinositide pathway. Modulation of intracellular cAMP levels is associated with changes in JH production, with increases in JH biosynthesis occurring as a consequence of the stimulation of the adenylate cyclase system in locusts but with an inhibition of JH biosynthesis in cockroaches. The situation inM. sextais more complex and appears to be both stage‐ and product‐dependent. The effects of second messengers in the three species differ, probably as a consequence of the differences in the peptide signals that regulate JH biosynthesis and in the intrinsic state of the corpora allata (either switched on or switched off, in the absence of external signals). © 1996 Wiley‐L

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:3/4<259::AID-ARCH7>3.0.CO;2-N

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractThe hypertrehalosemic hormone of the cockroach,Blaberus discoidalis(Bld‐HTH), stimulates trehalose biosynthesis by the fat body and is a member of the adipokinetic hormone/red pigment‐concentrating hormone family of arthropods. Bld‐HTH also stimulates expression of the gene for cytochrome P4504C1 (CYP4C1) in the fat body. The present studies were undertaken to determine if simultaneous stimulation of trehalose biosynthesis andCYP4C1expression by Bld‐HTH occurs in response to independent signal transduction cascades or if they are sequential events of a common cascade. The Bld‐HTH signal transduction cascade does not involve cyclic nucleotides but appears to employ inositol 1,4,5‐triphosphate (IP3) to release intracellular Ca2+for activation of phosphorylase which increases trehalose biosynthesis andCYP4C1expression. Trehalose‐6‐phosphate synthase activity was also stimulated by Bld‐HTH. Both phosphorylase activation andCYP4C1expression appear regulated by a common, IP3/Ca2+‐based signal transduction cascade. ©

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:3/4<283::AID-ARCH8>3.0.CO;2-T

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/1520-6327(1996)33:3/4<::AID-ARCH940330301>3.0.CO;2-F

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY