TY - JOUR
T1 - Muscle development and lineage-specific expression of CiMDF, the MyoD-family gene of Ciona intestinalis
AU - Meedel, Thomas H.
AU - Lee, James J.
AU - Whittaker, J. R.
N1 - Funding Information:
We thank Marv Ruona for preparing the figures in this manuscript. The Rhode Island College Faculty Research Committee, the Mayo Foundation, and the American Philosophical Society supported this research.
PY - 2002/1/15
Y1 - 2002/1/15
N2 - The expression pattern of CiMDF, the MyoD-family gene of Ciona intestinalis, was analyzed in unmanipulated and microsurgically derived partial embryos. CiMDF encodes two transcripts during development (coding for distinct proteins), the smaller of which, CiMDFa, was detected in maternal RNA. Zygotic activity of CiMDF initiated in cleaving embryos of 32-64 cells. Both CiMDFa and CiMDFb transcripts were detected at this time; however, CiMDFa accumulated more rapidly before declining in abundance such that, by the early tail-formation stage, CiMDFb was more prevalent. Microsurgical isolations of various lineage blastomeres from the eight-cell stage were used to analyze CiMDF expression in the two embryonic lineages that give rise to larval tail muscle-autonomously specified primary cells and conditionally specified secondary cells. CiMDFa and CiMDFb transcripts were detected in both lineages, suggesting that neither functioned in a lineage-specific manner. The data also demonstrated that CiMDF expression was autonomous in the primary lineage (i.e., cells derived from the B4.1 blastomeres) and correlated with histospecific differentiation of muscle. In the secondary lineage (i.e., cells derived from the A4.1 and b4.2 blastomeres), CiMDF expression was conditional and, as in the primary lineage, correlated with muscle differentiation. These experiments reveal similar patterns of CiMDF activity in the primary and secondary muscle lineages and imply a requirement for the expression of this gene in both lineages during larval tail muscle development.
AB - The expression pattern of CiMDF, the MyoD-family gene of Ciona intestinalis, was analyzed in unmanipulated and microsurgically derived partial embryos. CiMDF encodes two transcripts during development (coding for distinct proteins), the smaller of which, CiMDFa, was detected in maternal RNA. Zygotic activity of CiMDF initiated in cleaving embryos of 32-64 cells. Both CiMDFa and CiMDFb transcripts were detected at this time; however, CiMDFa accumulated more rapidly before declining in abundance such that, by the early tail-formation stage, CiMDFb was more prevalent. Microsurgical isolations of various lineage blastomeres from the eight-cell stage were used to analyze CiMDF expression in the two embryonic lineages that give rise to larval tail muscle-autonomously specified primary cells and conditionally specified secondary cells. CiMDFa and CiMDFb transcripts were detected in both lineages, suggesting that neither functioned in a lineage-specific manner. The data also demonstrated that CiMDF expression was autonomous in the primary lineage (i.e., cells derived from the B4.1 blastomeres) and correlated with histospecific differentiation of muscle. In the secondary lineage (i.e., cells derived from the A4.1 and b4.2 blastomeres), CiMDF expression was conditional and, as in the primary lineage, correlated with muscle differentiation. These experiments reveal similar patterns of CiMDF activity in the primary and secondary muscle lineages and imply a requirement for the expression of this gene in both lineages during larval tail muscle development.
KW - Ascidian
KW - Autonomous specification
KW - BHLH gene
KW - Chordate
KW - Conditional specification
KW - Myogenesis
KW - Troponin I
UR - http://www.scopus.com/inward/record.url?scp=0037081187&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037081187&partnerID=8YFLogxK
U2 - 10.1006/dbio.2001.0511
DO - 10.1006/dbio.2001.0511
M3 - Article
C2 - 11784108
AN - SCOPUS:0037081187
SN - 0012-1606
VL - 241
SP - 238
EP - 246
JO - Developmental Biology
JF - Developmental Biology
IS - 2
ER -