Retinoic acid affects gene expression and morphogenesis without upregulating the retinoic acid receptor in the ascidian Ciona intestinalis.
Many chordate-specific morphological features develop depending on retinoic acid (RA). We isolated cDNA clones encoding a retinoic acid receptor (CiRAR) and a retinoid X receptor (CiRXR) in the ascidian Ciona intestinalis. CiRAR mRNA was detected in the anterior ectoderm and endoderm during gastrulation. The expression persists in the head endoderm and two discrete regions of the nerve cord in the tailbud embryo. CiRXR mRNA was ubiquitously expressed. RA affected closure of the neural tube and formation of the adhesive papillae. However, no obvious upregulation in CiRAR expression was observed. Expression of some, but not all, of the neural and papilla-specific genes was reduced in the RA-treated embryo. These results suggest limited roles of CiRAR in ascidian embryos.
Nagatomo
Kan-ichiro
K
Department of Biology, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
Ishibashi
Tomoko
T
Satou
Yutaka
Y
Satoh
Nori
N
Fujiwara
Shigeki
S
D000595:Amino Acid Sequence; D000818:Animals; D019521:Body Patterning / Q000235:genetics; D002938:Ciona intestinalis / Q000196:embryology* / Q000235:genetics*; D004625:Embryo, Nonmammalian / Q000187:drug effects; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D005819:Genetic Markers; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics; D018168:Receptors, Retinoic Acid / Q000235:genetics* / Q000378:metabolism; D047488:Retinoid X Receptors; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014212:Tretinoin / Q000378:metabolism* / Q000494:pharmacology; D015854:Up-Regulation
D005819:Genetic Markers; D018168:Receptors, Retinoic Acid; D047488:Retinoid X Receptors; D014157:Transcription Factors; D014212:Tretinoin