Counteraction by 20‐hydroxyecdysone of the effect of juvenile hormone on phosphorylation of ribosomal protein S6

Itoh, Kohji; Ueno, Kensuke; Natori, Shunji

doi:10.1016/0014-5793(87)81469-2

Cited by 7 publications

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“…In insects, S6 phosphorylation is stimulated by 20-hydroxyecdysone in the fat body of fly larvae (43,44) and by prothoracicotropic hormone in the prothoracic gland of moth larvae (45); in both cases, the stimulation is inhibited by juvenile hormone (44,45). Juvenile hormone treatment can cause a dramatic increase in frequency and earlier onset of melanotic tumor formation in'the tu-bw melanotic tumor strain (46) and can also induce such tumors in wild-type Drosophila (47).…”

Section: Resultsmentioning

confidence: 99%

Drosophila homolog of the human S6 ribosomal protein is required for tumor suppression in the hematopoietic system.

Watson

Konrad

Woods

et al. 1992

Proc. Natl. Acad. Sci. U.S.A.

155

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The tumor suppressor gene lethal(l)aberrant immune response 8 (air) of Drosophila melanogaster encodes a homolog of the human S6 rool protein. P element Insertons that prevent exprin ofthis gene cause overgowthofthe lymph glands (the hematopoletic organs), abnormal blood cell differentiatn, and meanoc tumor mation. Thalso cause delayed development, inbit growth of most of the larval organs, and lead to larval kthlity. Mitotic recombination experiments indiate that the normal S6 gene is r i for done survival in the germ line and imagial discs. The S6 gene produces a 1. Fs(1)K1237 can produce eggs, but in this experiment they were also homozygous for air8 and were thereby used to determine the effects of this mutation on germ-line clone development. y' w1 air8/Binsn or y' wl females were crossed to 24 Fs(1)K1237 males and the F1 progeny were irradiated (1000 rads; 1 rad = 0.01 Gy; Isomedix, Parsippany, NJ, 137Cs source) during the mid-to-late first instar of development to induce mitotic recombination. The resulting heterozygous 24 tTo whom reprint requests should be addressed. §The sequence reported in this paper has been deposited in the GenBank data base (accession no. L01658). 11302The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.Proc. Natl. Acad. Sci. USA 89 (1992) 11303 Fs(J)K1237/y' wl air8 or v24 Fs(J)K1237/y' w1 females were mated, examined for egg production, and dissected to search for vitellogenic ovaries, which would indicate the presence of homozygous germ-line clones.Hemocyte DNA Sequencing. Genomic DNA derived from AEMBL3-57 and AEMBL3-64 was subjected to dideoxynucleotide chain-termination sequencing with Sequenase (United States Biochemical) using a series of 17-to 20-mer oligonucleotide primers. S6 sequence information was obtained from sequencing cDNA clones isolated from an adult female library using probes A and B (see Fig. 3). The cDNAs were PCR amplified with oligonucleotide primers and the amplified products were subjected to double-stranded cycle sequencing. The locations of the P elements in the mutant strains were determined by PCR amplification and doublestranded cycle sequencing of the mutant genomic DNAs surrounding the P insertion sites. RESULTSring gland, salivary glands, gastric cecae, and most imaginal discs fail to reach normal size before the late-larval lethal phase (1). The ventral ganglion fails to condense and the brain hemispheres are undersized. Mutant animals die at a variety of larval stages, up to and including the late third larval instar when large melanotic tumors can be seen in the body cavity (Fig. 1). The melanotic tumor phenotype results from abnormalities in the production and differentiation of blood cells (hemocytes) in the mutant larvae. The hemocyte population in normal larvae consists almost entirely of small round cells called plasmatocytes, which differentiate into large flat lamello...

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