Role for calcium in the development of ovarial patency in Heliothis virescens.
Insect oocytes sequester nutritive proteins from the hemolymph under the regulation by juvenile hormone (JH), in a process called patency. Here, a pharmacological approach was used to decipher the role for calcium in ovarial patency in the moth, Heliothis virescens. Follicular epithelial cells were exposed in calcium-free or calcium-containing media to JH I, JH II or JH III alone, or in combination with various inhibitors of signal transduction. Protein kinase inhibitors, Na(+)/K(+) -ATPase inhibitor, ouabain, an inhibitor of voltage-dependent calcium channels in plasma membrane, omega-Conotoxin MVII, endoplasmic reticulum (ER) Ca(2+) -ATPase inhibitor, thapsigargin, ER inositol 1,4,5-triphosphate receptor (IP(3)R) inhibitor, 2-ABP and ER ryanodine receptor (RyR) inhibitor, ryanodine, were used. The results of our study suggest that JH II evokes patency via protein kinase C-dependent signaling pathway, and activation of Na(+)/K(+) -ATPase, similar to JH III. Response to JH II and JH III predominantly relies upon external and internal calcium stores, using voltage-dependent calcium channels, IP(3)Rs and RyRs. In contrast, regulation of patency by JH I appears to be largely calcium independent, and the calcium-dependent component of the signaling pathway likely does not use IP(3)Rs, but RyRs only. The JH II, JH III and calcium-dependent component of JH I signaling pathway probably utilize calcium/calmodulin-dependent kinase II for activation of Na(+)/K(+) -ATPase.
Department of Entomology, Kansas State University, Manhattan, KS 66506, USA. MPszczolkowski@missouristate.edu
Maciej A
MA
Pszczolkowski
Emily
E
Olson
Crystal
C
Rhine
Sonny B
SB
Ramaswamy
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001896:Boron Compounds / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D007605:Juvenile Hormones / Q000494:pharmacology; D009036:Moths / Q000187:drug effects / Q000502:physiology*; D010053:Ovary / Q000187:drug effects / Q000502:physiology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D012433:Ryanodine / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology; D020960:omega-Conotoxins / Q000494:pharmacology
D001896:Boron Compounds; D007605:Juvenile Hormones; D047428:Protein Kinase Inhibitors; D020960:omega-Conotoxins; D012433:Ryanodine; C063302:KN 62; D019284:Thapsigargin; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; C109986:2-aminoethoxydiphenyl borate; D002118:Calcium