Time course of programmed cell death in Ciona intestinalis in relation to mitotic activity and MAPK signaling

• Published in: Developmental dynamics Vol. 230; no. 2; pp. 251 - 262
• Main Authors: Tarallo, Raffaella, Sordino, Paolo
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-06-2004
• Subjects: Animals; Apoptosis; Brain - cytology; Brain - enzymology; Brain - growth & development; Brain - metabolism; Cell Proliferation; Ciona intestinalis; Ciona intestinalis - cytology; Ciona intestinalis - growth & development; Ciona intestinalis - metabolism; Larva - cytology; Larva - enzymology; Larva - growth & development; Larva - metabolism; MAP Kinase Signaling System; MAPK signaling cascade; Mesoderm - cytology; Mitosis; programmed cell death; proliferation; secondary neurogenesis; Time Factors; TUNEL
• ISSN: 1058-8388; 1097-0177
• DOI: 10.1002/dvdy.20055

Programmed cell death (PCD) in the ascidian species Ciona intestinalis (Tunicata; Chordata) is investigated from early larvae to juvenile stages, by means of digoxigenin‐based terminal deoxynucleotidyl transferase‐mediated biotinylated UTP nick end labeling (TUNEL) technique. At first, PCD in the swimming larva affects trunk mesenchyme and central nervous system (CNS), then it participates extensively to metamorphosis, until it is restricted to developing organs of juveniles. Analysis of patterns of cell death and division in the larval CNS question old models on the genesis of the adult C. intestinalis brain. Upon performing immunochemical and functional assays for mitogen‐activated protein kinase (MAPK) kinase kinase‐1 (MEKK1), MAPK kinase 1/2 (MEK1/2), c‐Jun NH2‐terminal kinase (JNK), and dual phosphorylated extracellular regulated kinase 1/2 (dpERK1/2), the neurogenic competence of the larval brain appears to rely on a combinatorial regulation of PCD by the mitogen‐activated protein kinase signaling cascade. These results show that, in tunicates, PCD consists of a multistep program implicated in growth and patterning with various roles. Developmental Dynamics 230:251–262, 2004. © 2004 Wiley‐Liss, Inc.