title: His-Purkinje lineages and development.
abstract: The heartbeat is initiated and coordinated by a multi-component set of specialized muscle tissues collectively referred to as the pacemaking and conduction system. Over the last few years, impetus has gathered into unravelling the cellular and molecular processes that regulate differentiation and integration of this essential cardiac network. One focus of our collective work has been the developmental history of cells comprising His-Purkinje tissues of the conduction system. This interest in part arose from studies of the expression of connexins in periarterial Purkinje fibres of the chick heart. Using lineage-tracing strategies, including those based on replication-defective retroviruses and adenoviruses, it has been shown that conduction cells are derived from multipotent, cardiomyogenic progenitors in the tubular heart. Moreover, heterogeneity within myocardial clones has indicated that the elaboration of the conduction system in the chick embryo occurs by progressive, localized recruitment from within this pool of cardiomyogenic cells. Cell birth dating has revealed that inductive conscription of cells to central elements of the conduction system (e.g. the His bundle) precedes recruitment to the peripheral components of the network (i.e. subendocardial and periarterial Purkinje fibres). Birth dating studies in rodents suggest an analogous recruitment process is occurring in this species. In addition to summarizing earlier work, this chapter provides information on ongoing studies of cell-cell signalling and transcriptional mechanisms that may regulate the development of His-Purkinje tissues.
authors.affiliation: Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston, SC 29425, USA.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Gourdie
authors.forename: Brett S
authors.initials: BS
authors.lastname: Harris
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Bond
authors.forename: Angela M
authors.initials: AM
authors.lastname: Edmondson
authors.forename: Gang
authors.initials: G
authors.lastname: Cheng
authors.forename: David
authors.initials: D
authors.lastname: Sedmera
authors.forename: Terrence X
authors.initials: TX
authors.lastname: O'Brien
authors.forename: Takashi
authors.initials: T
authors.lastname: Mikawa
authors.forename: Robert P
authors.initials: RP
authors.lastname: Thompson
mesh_terms: D000818:Animals; D002036:Bundle of His / Q000166:cytology / Q000254:growth & development*; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage; D002642:Chick Embryo; D017630:Connexins / Q000378:metabolism; D003326:Coronary Circulation; D006321:Heart / Q000033:anatomy & histology* / Q000254:growth & development; D006331:Heart Diseases; D009024:Morphogenesis; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D011690:Purkinje Fibers / Q000166:cytology / Q000254:growth & development*; D015398:Signal Transduction / Q000502:physiology; D000097003:Gap Junction alpha-5 Protein
chemical_list: D017630:Connexins; D000097003:Gap Junction alpha-5 Protein