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Regulation of hemoglobin and vitellogenin synthesis during chironomus development
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128 DEVELOPMENTAL PATTERN OF STORAGE PROTEIN GENE EXPRESSION IN GALLERIA. A.K. Kumaran, N.A. Memmel and A. Ray. Department of Biology, Marquette University, Milwaukee, WI 53233. The pattern of production of storage proteins (SP) and of putative SP mRNA suggests developmental stage specific SP gene expression in Galleria mellonella larvae. We prepared a cDNA library in pBR322 starting from day-5 larval fat body mRNA. Differential screening of the cDNA library with labeled RNAs from day5 and day-O larvae yielded 39 clones, out of 690, that were regarded as putative SP cDNA clones, cDNA inserts from 4 of these putative SP clones which range from 1200 to 1500 bp were used in further analysis. Identity of the purified cDNA was established by hybrid arrested and hybrid selected translation. Northern and dot blot analyses of RNA extracted from fat body from larvae of diverse ages and following different hormonal treatments and from other larval tissues are under study. The developmental regulation of an insect storage protein gene expression is under study. Supported by N.S.F. and Fulbright Foundation.
EMBRYONIC MOUSE LUNG MORPHOGENESIS IN SERLgiLESS, CHEMICALLY-DEFINED MEDIUM IN VITRO. T.Jaskoll, R.Johnson, G.Don and H.C.Slavkin. Lab. Develop. Biol., School of Dentistry, Univ. of Southern California, Los Angeles, California 90089-0191. Hormonal regulation mediated lung morphogenesis. Thyroxin and glucocorticoids, for example, enhance alveolar type II cell differentiation. Present studies were designed to evaluate embryonic mouse lung development using serumless, chemically-defined organ culture. Light and transmission electron microscopy were used to evaluate in vitro as compared with in situ morphogenesis. BI0.A mouse lung rudiments (12-days gestation) were cultured for periods up to 15 days in BGJB medium supplemented with ascorbic acid and maintained at pH 7.4 in a 95%/ 5% atmosphere. We observed type II and Clara cells, as well as elastogenesis within mesenchyme during serumless culture. These observations suggest epithelial-mesenchymal interactions, without exogenous supplements, result in epithelial as well as mesenchymal differentiation during morphogenesis in vitro. HL-28325 (USPHS).
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130 REGULATION OF HEMOGLOBIN AND VITELLOGENIN SYNTHESIS DURING CHIRONOMUS DEVELOPMENT. H. Laufer and X. Vafopoulou-Mandalos, Univ. of Connecticut, Storrs, CT, USA. Hemoglobins (Hbs) exist as a multigene family and are characteristic of larval stages; vitellogenins (Vgs) are restricted to the pupal-adult transformation. Ecdysteroids and juvenile hormone (JH) play a significant role in the fluctuations of 9 Hbs seen as soluble hemolymph proteins. The JH analogue, methoprene, activates synthesis of Hbs 2 and 3 by initiating transcription in the fat body. At larval and pupal molts ecdysteroid concentrations increased, while Hb synthesis decreased. Ecdysteroids administered to short-term fat body organ cultures reduced Hb synthesis by regulating post transcriptional events. Methoprene also induces the precocious onset of Vg synthesis in larvae in an increasing ecdysteroid titer. Vgs are synthesized in normal females in the presence of endogenous ecdysteroid and JH. It is concluded that in Chironomus, both are needed for normal vitellogenin synthesis, as well as for Hb synthesis and degradation. The target of regulation is the fat body which persists from the larva to the adult.
HORMONES AND PERINATAL ADAPTATION IN RAT AND SPINY MOUSE. W.H.Lamers and R. Charles, Dept. of AnatomyandEmbryology, University of Amsterdam, AMC, Amsterdam, The Netherlands. The rates of organ-specific gene-expression are lower in fetuses than in neonates, suggesting that immaturety of the fetus or differences in the circulating levels of hormones are responsible. By comparing organ-specific enzyme inducibility in the term, but comparatively immature rat fetus with that in the term and muchmore mature spiny mouse fetus, we have shown that the intra-uterine environment rather than the (more or less advanced) state of development at birth or the fetal hormone production is responsible for the limited synthetic capacity ofparenchymal cells before birth. Contributing factors were found to b e t h e combined presence of relatively high progesteroneand estrogen levels beforebirth. The spiny mouse condition with its relatively long gestation period, its transient T 3 p e a k a n d relatively low insulin/glucagon ratio at birthand cortisol as the circulatingglucocorticosteroid hormone resembled the humanperinatal situation more than the rat condition.
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128 DEVELOPMENTAL PATTERN OF STORAGE PROTEIN GENE EXPRESSION IN GALLERIA. A.K. Kumaran, N.A. Memmel and A. Ray. Department of Biology, Marquette University, Milwaukee, WI 53233. The pattern of production of storage proteins (SP) and of putative SP mRNA suggests developmental stage specific SP gene expression in Galleria mellonella larvae. We prepared a cDNA library in pBR322 starting from day-5 larval fat body mRNA. Differential screening of the cDNA library with labeled RNAs from day5 and day-O larvae yielded 39 clones, out of 690, that were regarded as putative SP cDNA clones, cDNA inserts from 4 of these putative SP clones which range from 1200 to 1500 bp were used in further analysis. Identity of the purified cDNA was established by hybrid arrested and hybrid selected translation. Northern and dot blot analyses of RNA extracted from fat body from larvae of diverse ages and following different hormonal treatments and from other larval tissues are under study. The developmental regulation of an insect storage protein gene expression is under study. Supported by N.S.F. and Fulbright Foundation.
EMBRYONIC MOUSE LUNG MORPHOGENESIS IN SERLgiLESS, CHEMICALLY-DEFINED MEDIUM IN VITRO. T.Jaskoll, R.Johnson, G.Don and H.C.Slavkin. Lab. Develop. Biol., School of Dentistry, Univ. of Southern California, Los Angeles, California 90089-0191. Hormonal regulation mediated lung morphogenesis. Thyroxin and glucocorticoids, for example, enhance alveolar type II cell differentiation. Present studies were designed to evaluate embryonic mouse lung development using serumless, chemically-defined organ culture. Light and transmission electron microscopy were used to evaluate in vitro as compared with in situ morphogenesis. BI0.A mouse lung rudiments (12-days gestation) were cultured for periods up to 15 days in BGJB medium supplemented with ascorbic acid and maintained at pH 7.4 in a 95%/ 5% atmosphere. We observed type II and Clara cells, as well as elastogenesis within mesenchyme during serumless culture. These observations suggest epithelial-mesenchymal interactions, without exogenous supplements, result in epithelial as well as mesenchymal differentiation during morphogenesis in vitro. HL-28325 (USPHS).
129
130 REGULATION OF HEMOGLOBIN AND VITELLOGENIN SYNTHESIS DURING CHIRONOMUS DEVELOPMENT. H. Laufer and X. Vafopoulou-Mandalos, Univ. of Connecticut, Storrs, CT, USA. Hemoglobins (Hbs) exist as a multigene family and are characteristic of larval stages; vitellogenins (Vgs) are restricted to the pupal-adult transformation. Ecdysteroids and juvenile hormone (JH) play a significant role in the fluctuations of 9 Hbs seen as soluble hemolymph proteins. The JH analogue, methoprene, activates synthesis of Hbs 2 and 3 by initiating transcription in the fat body. At larval and pupal molts ecdysteroid concentrations increased, while Hb synthesis decreased. Ecdysteroids administered to short-term fat body organ cultures reduced Hb synthesis by regulating post transcriptional events. Methoprene also induces the precocious onset of Vg synthesis in larvae in an increasing ecdysteroid titer. Vgs are synthesized in normal females in the presence of endogenous ecdysteroid and JH. It is concluded that in Chironomus, both are needed for normal vitellogenin synthesis, as well as for Hb synthesis and degradation. The target of regulation is the fat body which persists from the larva to the adult.
HORMONES AND PERINATAL ADAPTATION IN RAT AND SPINY MOUSE. W.H.Lamers and R. Charles, Dept. of AnatomyandEmbryology, University of Amsterdam, AMC, Amsterdam, The Netherlands. The rates of organ-specific gene-expression are lower in fetuses than in neonates, suggesting that immaturety of the fetus or differences in the circulating levels of hormones are responsible. By comparing organ-specific enzyme inducibility in the term, but comparatively immature rat fetus with that in the term and muchmore mature spiny mouse fetus, we have shown that the intra-uterine environment rather than the (more or less advanced) state of development at birth or the fetal hormone production is responsible for the limited synthetic capacity ofparenchymal cells before birth. Contributing factors were found to b e t h e combined presence of relatively high progesteroneand estrogen levels beforebirth. The spiny mouse condition with its relatively long gestation period, its transient T 3 p e a k a n d relatively low insulin/glucagon ratio at birthand cortisol as the circulatingglucocorticosteroid hormone resembled the humanperinatal situation more than the rat condition.
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