title: Leucomyosuppressin modulates cardiac rhythm in the cockroach Blattella germanica.
abstract: Several lines of evidence point to leucomyosuppressin (LMS) and myosuppressin-related peptides as inhibitory modulators of heartbeat frequency in arthropods. Previous studies in Blattella germanica demonstrated that heartbeat frequency decreases after ootheca formation, and remains low during the period of ootheca transport. Subsequent work in this cockroach resulted in the characterization of LMS and the cloning and sequencing of its precursor. The present paper describes the activity of LMS on modulation of heartbeat in B. germanica. Assays using semi-isolated heart preparations revealed that LMS reduces heartbeat frequency in a dose dependent manner, at physiological concentrations. Additional experiments showed that LMS inhibits heartbeat rates in vivo. Finally, injection of dsRNA for LMS elicited a decrease in LMS mRNA to virtually undetectable levels and heartbeat frequency increased significantly in females carrying oothecae. These data suggest that LMS contributes to the modulation of cardiac rhythm in B. germanica during the reproductive cycle.
authors.affiliation: Institut de Biologia Evolutiva (CSIC-UPF), Passeig Marítim de la Barceloneta 37, 08003 Barcelona, Spain. joseluis.maestro@ibe.upf-csic.es
authors.forename: José L
authors.initials: JL
authors.lastname: Maestro
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Tobe
authors.forename: Xavier
authors.initials: X
authors.lastname: Belles
mesh_terms: D000818:Animals; D020048:Blattellidae / Q000502:physiology*; D005260:Female; D055785:Gene Knockdown Techniques; D006321:Heart / Q000502:physiology; D006339:Heart Rate; D066298:In Vitro Techniques; D008297:Male; D009479:Neuropeptides / Q000502:physiology*; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D009479:Neuropeptides; D012333:RNA, Messenger; C058650:leucomyosuppressin