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Characterization and expression of C/EPB-like genes in the liver of Rana catesbeiana tadpoles during spontaneous and thyroid hormone-induced metamorphosis.
Dev Genet. 1994; 15(4):366-77.DG

Abstract

Tissue-specific changes in gene expression occur in the liver of Rana catesbeiana tadpoles undergoing metamorphosis. Many of these changes can be induced precociously by administration of thyroid hormone (TH) to a tadpole or to cultured tadpole liver. While the precise molecular means by which TH exerts a tissue-specific response is unknown, recent studies suggest that the expression of genes which are liver-specific and characteristic of the adult liver phenotype may rely on TH-induction of tissue-specific transcription factors, as well as the thyroid hormone receptor proteins. Guided by this notion, we screened our Rana catesbeiana liver cDNA library and isolated clones, RcC/EBP-1 and -2, encoding Rana homologues of a mammalian transcription factor, C/EBP (CCAAT/enhancer core binding protein), implicated in the expression of liver-specific genes and terminal differentiation of hepatocytes. Gel mobility shift assays demonstrate that the proteins synthesized from these cDNAs bind specifically to the consensus binding site for C/EBP-related proteins. Characterization of the amino acid sequence in the bZIP DNA-binding domains of these proteins suggests that RcC/EBP-1 and -2 encode Rana homologues of C/EBP alpha and delta, respectively. Hybridization analyses demonstrate that the amount of RcC/EBP-2 mRNAs in tadpole liver remains constant throughout metamorphosis, whereas RcC/EBP-1 mRNAs are up-regulated during both spontaneous and TH-induced metamorphosis. The TH-induced up-regulation of RcC/EBP-1 mRNAs precedes the up-regulation of liver-specific urea cycle enzyme mRNAs by 6 to 12 hours. These results, coupled with in situ hybridization studies, suggest that RcC/EBP-1 mRNAs encode a transcription factor which may play an early role(s) in the terminal differentiation and/or reprogramming of gene expression in this tadpole's liver cells during both spontaneous and TH-induced metamorphosis.

Authors+Show Affiliations

Department of Zoology, University of Western Ontario, London, Canada.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

7923939

Citation

Chen, Y, et al. "Characterization and Expression of C/EPB-like Genes in the Liver of Rana Catesbeiana Tadpoles During Spontaneous and Thyroid Hormone-induced Metamorphosis." Developmental Genetics, vol. 15, no. 4, 1994, pp. 366-77.
Chen Y, Hu H, Atkinson BG. Characterization and expression of C/EPB-like genes in the liver of Rana catesbeiana tadpoles during spontaneous and thyroid hormone-induced metamorphosis. Dev Genet. 1994;15(4):366-77.
Chen, Y., Hu, H., & Atkinson, B. G. (1994). Characterization and expression of C/EPB-like genes in the liver of Rana catesbeiana tadpoles during spontaneous and thyroid hormone-induced metamorphosis. Developmental Genetics, 15(4), 366-77.
Chen Y, Hu H, Atkinson BG. Characterization and Expression of C/EPB-like Genes in the Liver of Rana Catesbeiana Tadpoles During Spontaneous and Thyroid Hormone-induced Metamorphosis. Dev Genet. 1994;15(4):366-77. PubMed PMID: 7923939.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Characterization and expression of C/EPB-like genes in the liver of Rana catesbeiana tadpoles during spontaneous and thyroid hormone-induced metamorphosis. AU - Chen,Y, AU - Hu,H, AU - Atkinson,B G, PY - 1994/1/1/pubmed PY - 1994/1/1/medline PY - 1994/1/1/entrez SP - 366 EP - 77 JF - Developmental genetics JO - Dev Genet VL - 15 IS - 4 N2 - Tissue-specific changes in gene expression occur in the liver of Rana catesbeiana tadpoles undergoing metamorphosis. Many of these changes can be induced precociously by administration of thyroid hormone (TH) to a tadpole or to cultured tadpole liver. While the precise molecular means by which TH exerts a tissue-specific response is unknown, recent studies suggest that the expression of genes which are liver-specific and characteristic of the adult liver phenotype may rely on TH-induction of tissue-specific transcription factors, as well as the thyroid hormone receptor proteins. Guided by this notion, we screened our Rana catesbeiana liver cDNA library and isolated clones, RcC/EBP-1 and -2, encoding Rana homologues of a mammalian transcription factor, C/EBP (CCAAT/enhancer core binding protein), implicated in the expression of liver-specific genes and terminal differentiation of hepatocytes. Gel mobility shift assays demonstrate that the proteins synthesized from these cDNAs bind specifically to the consensus binding site for C/EBP-related proteins. Characterization of the amino acid sequence in the bZIP DNA-binding domains of these proteins suggests that RcC/EBP-1 and -2 encode Rana homologues of C/EBP alpha and delta, respectively. Hybridization analyses demonstrate that the amount of RcC/EBP-2 mRNAs in tadpole liver remains constant throughout metamorphosis, whereas RcC/EBP-1 mRNAs are up-regulated during both spontaneous and TH-induced metamorphosis. The TH-induced up-regulation of RcC/EBP-1 mRNAs precedes the up-regulation of liver-specific urea cycle enzyme mRNAs by 6 to 12 hours. These results, coupled with in situ hybridization studies, suggest that RcC/EBP-1 mRNAs encode a transcription factor which may play an early role(s) in the terminal differentiation and/or reprogramming of gene expression in this tadpole's liver cells during both spontaneous and TH-induced metamorphosis. SN - 0192-253X UR - https://www.unboundmedicine.com/medline/citation/7923939/Characterization_and_expression_of_C/EPB_like_genes_in_the_liver_of_Rana_catesbeiana_tadpoles_during_spontaneous_and_thyroid_hormone_induced_metamorphosis_ L2 - https://doi.org/10.1002/dvg.1020150408 DB - PRIME DP - Unbound Medicine ER -