Cell death

Smith, Kathy Beckingham; Tata, Jamshed R.

doi:10.1016/0014-4827(76)90335-9

Cited by 32 publications

(8 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3 are for whole tadpole RNA for premetamorphic stages (up to stage 53), the middle region of the tadpole (which contains the liver) during mid-metamorphosis and metamorphic climax (stages 55-59) and for liver RNA upon completion of metamorphosis. The increase in liver-type arginase mRNA coincides with the morphological and biochemical changes associated with liver development during metamorphosis (Beckingham Smith and Tata, 1976;Gilbert and Frieden, 1981). …”

Section: Developmental Regulation Of Xenopus Liver-type Arginase Tranmentioning

confidence: 99%

“…It is well known that exogenous thyroid hormone will precociously induce metamorphosis in pre-metamorphic tadpoles, with all the normal morphological and biochemical changes (Beckingham Smith and Tata, 1976;Cohen et al, 1978;Gilbert and Frieden, 1981). The above experiments on the developmental regulation of arginase mRNA accumulation were therefore extended to Northern analysis of RNA from Xenopus tadpoles treated with triiodothyronine at different developmental stages.…”

Section: Thyroid-hormone-dependent Regulation Of the Xenopus Liver-tymentioning

confidence: 99%

“…During metamorphosis, the nitrogen excretion pathway switches from the conversion of toxic ammonia to non-toxic urea. This switch is brought about by a substantial induction in the liver of arginase and other urea cycle enzymes, which accompanies a structural and functional reorganisation of the amphibian liver to adapt to life in a terrestrial environment (Cohen et al, 1978;Beckingham Smith and Tata, 1976;Gilbert and Frieden, 1981;Tata, 1983). The response of the liver, in turn, constitutes just one of the diverse structural, functional and morphogenetic alterations occurring in virtually every tissue of the tadpole during metamorphosis, such as the reorganisation of the brain, gut and pancreas, limb and lung morphogenesis, switching to adult haemoglobin, and cell death resulting in the loss of tail and gills (Tata, 1983;Yoshizato, 1989).…”

mentioning

confidence: 99%

“…All the above post-embryonic developmental changes, largely at the level of gene expression, are obligatorily under control of thyroid hormones (Beckingham Smith and Tata, 1976;Gilbert and Frieden, 1981 ;Tata, 1983). The fact that thyroid hormones administered to pre-metamorphic anuran tadpoles induce metamorphosis and urea cycle enzyme activity precociously has been exploited over many years as a valuable tool in analyzing this important post-embryonic developmental process.…”

mentioning

confidence: 99%

“…mone-induced metamorphosis in amphibia (Beckingham Smith and Tata, 1976;Cohen et al, 1978;Gilbert and Frieden, 1981 ;Galton, 1983). During metamorphosis, the nitrogen excretion pathway switches from the conversion of toxic ammonia to non-toxic urea.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Developmental and hormonal regulation of the Xenopus liver‐type arginase gene

Baker

Tata

1993

European Journal of Biochemistry

View full text Add to dashboard Cite

Liver-type L-arginase is a major urea-cycle enzyme which is strongly induced during amphibian metamorphosis, but little is known about the molecular mechanisms underlying this induction. As a first step towards elucidating the possible mechanisms, we have isolated a cDNA clone for Larginase from an adult Xenopus luevis liver cDNA library. Sequence comparison of Xenopus livertype L-arginase cDNA shows a strong conservation at the amino acid level with those of human, rat and yeast. Using a Xenopus arginase cDNA fragment as a hybridization probe, we have shown by Northern blotting that the gene is highly expressed in the liver, and very slightly in kidney and spleen, of adult Xenopus. The expression is developmentally regulated. Only traces of arginase mRNA can be detected in pre-metamorphic tadpoles, but its accumulation increases very markedly at the onset of natural metamorphosis, being maintained at a high concentration constitutively upon completion of this developmental process. Amphibian metamorphosis is under the strict control of thyroid hormones. It is therefore significant that exposure of pre-metamorphic tadpoles (at stages before endogenous thyroid hormone secretion) to exogenous hormone (1 nM triiodothyronine) precociously activated the L-arginase gene. The time course of this precocious hormonal induction paralleled that of serum albumin gene in the liver. Polyclonal antibodies were raised against recombinant Xenopus L-arginase expressed in Escherichiu coli as a fusion protein with glutathione S-transferase in the plasmid expression vector pGEX. Western blotting using this antibody showed that, although arginase mRNA is present in high concentration in Xenopus tadpole liver at the onset of natural metamorphosis, the protein is detected only upon its completion. Our results show a complex transcriptional and post-transcriptional regulation of the Xenopus liver-type L-arginase gene during post-embryonic development. They also demonstrate that this gene can be exploited as a target for thyroid hormones in further studies to analyze the mechanisms underlying the establishment of the adult phenotype during amphibian metamorphosis.

show abstract

Section: Developmental Regulation Of Xenopus Liver-type Arginase Tranmentioning

confidence: 99%

Section: Thyroid-hormone-dependent Regulation Of the Xenopus Liver-tymentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Developmental and hormonal regulation of the Xenopus liver‐type arginase gene

Baker

Tata

1993

European Journal of Biochemistry

View full text Add to dashboard Cite

show abstract

Programmed cell death during metamorphosis in the blow-flyCalliphora vomitoria

Bowen

Mullarkey

Morgan

1996

Microsc. Res. Tech.

View full text Add to dashboard Cite

An analysis of the influence of thyroid hormone on the synthesis of proteins in the tail fin of bullfrog tadpoles

Ray

Dent

1986

J. Exp. Zool.

View full text Add to dashboard Cite

By incubation of explants of tail fin from tadpoles of Rana catesbeiana in a solution of 35S-methionine for 4 h, newly synthesized proteins were labeled isotopically. After separation by two-dimensional polyacrylamide gel electrophoresis, those proteins were visualized by fluorography. Exposure of explants to culture medium containing thyroxine (T4) (150 nM) increased the incorporation of 35S-methionine into several proteins with 48 h. Effects of T4 on the relative abundance of two of these newly synthesized proteins were detected after 8 h of hormonal treatment. Very similar patterns of newly synthesized proteins were observed when proteins from explants of tail fin removed from tadpoles at metamorphic climax and immediately incubated with 35S-methionine were compared with proteins produced in fin derived from premetamorphic animals. These results are interpreted to indicate that both treatment of explants with T4 and elevation of endogenous levels of thyroid hormones during spontaneous metamorphosis increased the relative rates of synthesis of several identical proteins. The potential involvement of those proteins in early phases of metamorphic action which eventually lead to cell death and resorption is discussed.

show abstract

Cell death

Cited by 32 publications

References 35 publications

Developmental and hormonal regulation of the Xenopus liver‐type arginase gene

Developmental and hormonal regulation of the Xenopus liver‐type arginase gene

Programmed cell death during metamorphosis in the blow-flyCalliphora vomitoria

An analysis of the influence of thyroid hormone on the synthesis of proteins in the tail fin of bullfrog tadpoles

Contact Info

Product

Resources

About