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J H Nilson

Publications and source records attributed to J H Nilson.

63 records · Page 4Linked to original sources
PubMed1983

Developmental expression of growth hormone and prolactin genes in the bovine pituitary.

Cell-free translation was used to initially characterize the major mRNA species present in the bovine anterior pituitary as a function of development. The only detectable change in translation products, which occurred during the transition from fetus to adult, was a reversal in the relative ratio of pituitary growth hormone and prolactin. Subsequent hybridization analysis with cloned growth hormone and prolactin cDNA probes indicated that growth hormone mRNA comprised over 40% of the total fetal mRNA and was 50- to 100-fold higher than prolactin mRNA. The steady state levels of growth hormone mRNA remained relatively constant throughout gestation. In contrast, prolactin mRNA levels, which were low early in gestation, increased during development to become the principal mRNA in the adult pituitary. Since growth hormone and prolactin are synthesized and secreted by specialized cells (somatotrophs and mammotrophs, respectively) immunochemical staining was used to determine whether the changes in the mRNA levels for these two hormones were a reflection of specific cell proliferation. For growth hormone, there was a close correlation between the number of somatotrophs and the relative levels of growth hormone mRNA. In contrast, the increase in prolactin mRNA exceeded the increase in the number of mammotrophs. Thus, the cellular concentration of growth hormone mRNA remains relatively constant during development, while the cellular concentration of prolactin mRNA increases by more than an order of magnitude.

Aging↗
PubMed1982

Molecular cloning of gene sequences for avian fatty acid synthase and evidence for nutritional regulation of fatty acid synthase mRNA concentration.

A double-stranded cDNA library was constructed using total poly(A)+ RNA from the goose uropygial gland. Clones containing sequences complementary to fatty acid synthase mRNA were initially identified by colony hybridization with a 32P-labeled cDNA transcribed from RNA enriched for fatty acid synthase mRNA. Identity of the fatty acid synthase clones was confirmed by hybrid-selected translation. Mature fatty acid synthase mRNA is approximately 16 kilobases in length. When unfed neonatal goslings were fed for 24 hr, relative synthesis of hepatic fatty acid synthase increased more than 42-fold. Concomitantly, hepatic fatty acid synthase mRNA levels increased 70-fold. Thus, nutritional regulation of the synthesis of hepatic fatty acid synthase probably occurs at the pretranslational level. The availability of a specific probe for fatty acid synthase mRNA should allow us to analyze the regulation of expression of this gene during development, by nutrition and by hormones in both liver and uropygial gland.

Animals↗
PubMed1982

Nucleotide sequence of bovine prolactin messenger RNA. Evidence for sequence polymorphism.

Hybrid molecules containing DNA sequences complementary to bovine pituitary mRNA were constructed in the Pst I site of pBR322 by the dC . dG tailing technique. Recombinant plasmids containing bovine prolactin (bPRL) sequences were amplified in bacteria and identified by hybridization to purified [32P]bPRL cDNA sequences. Nucleotide sequence analysis was performed on the inserts from two of the positive clones. One clone, pBPRL72, contained a 982-base pair insert that included 67 nucleotides of the 5'-untranslated region, the complete coding region of the preprolactin protein (690 nucleotides), and the entire 3'-untranslated region (150 nucleotides) of bPRL mRNA. The nucleotide sequence analysis of clone pBPRL72 predicted the sequence of a 30-amino acid signal peptide and confirmed the published amino acid sequence of the protein with one exception. A comparison of the pBPRL72 cDNA sequence with a second bPRL clone, pBPRL4, revealed four silent nucleotide differences. Three of the base changes occurred in the third position of amino acid codons, and one occurred in the 3'-noncoding region. The sequence polymorphism suggests the existence of alleles or multiple loci for bPRL that do not alter the protein structure.

Amino Acid Sequence↗
PubMed1980

Ontogeny of pituitary hormone mRNAs in the bovine fetus. Quantitation of pre-prolactin mRNA as a function of gestation.

The mRNA coding for pre-prolactin (pPRL) of the adult bovine anterior pituitary was purified to 85% homogeneity and used as a template for cDNA synthesis with reverse transcriptase from avian myeloblastosis virus. The cDNA sequences complementary to pPRL mRNA were further purified by employing a limited back-hybridization step and treatment with S1 nuclease. The pPRL cDNA preparation was judged to be homogeneous by comparing its hybridization kinetics to those of ovalbumin and globin mRNA standards and by thermal melt analysis of the pPRL mRNA:cDNA hybrids. Total cellular RNA was extracted from individual bovine fetal pituitaries of either sex, ranging from 90 to 200 days of gestation, and examined for its pPRL mRNA concentration by hybridization with an excess of pPRL cDNA. The hybridization assay was capable of detecting picogram amounts of pPRL mRNA, e.g. amounts less than 0.002% of input total cellular RNA. These results indicated that from 90 to 200 days of gestation, the levels of pPRL mRNA relative to total cellular RNA in bovine fetal pituitaries increase exponentially. This increase in pPRL mRNA occurs to the same extent in either sex, with the most dramatic shift (over 10-fold) occurring between 120 and 145 days of gestation.

Animals↗
PubMed1980

Use of oligodeoxynucleotide primers to determine poly(adenylic acid) adjacent sequences in messenger ribonucleic acid. 3'-Terminal noncoding sequence of bovine growth hormone messenger ribonucleic acid.

Twelve synthetic oligodeoxynucleotide primers of the general sequence d(pT8-N-N') were tested in a reverse transcriptase reaction for specific initiation of complementary deoxyribonucleic acid (cDNA) synthesis at the poly(adenylic acid) junction of a messenger ribonucleic acid (mRNA) template. Only the sequence d(pT8-G-C) functioned as a specific primer of cDNA synthesis with an enriched fraction of bovine growth hormone mRNA from the anterior pituitary gland and produced unique fragments in a dideoxy sequencing reaction. The nucleotide sequence obtained by this method extended into the protein coding region of bovine growth hormone mRNA and was confirmed by chemical sequencing of the cDNA initiated with [5'-32P]d(pT8-G-C). The 3'-untranslated region of bovine growth hormone mRNA is 104 nucleotides in length and contains regions of significant homology with both rat and human growth hormone mRNAs, including the region surrounding the common AAUAAA hexanucleotide. The method presented here for selection of the d(pT8-N-N') primer complementary to the poly(A) junction of mRNA is of general applicability for nucleotide sequence analysis of partially purified mRNAs.

Animals↗
PubMed1980

Construction and characterization of a cDNA clone containing a portion of the bovine prolactin sequence.

Poly(A)-containing RNA from the bovine anterior pituitary has been used as a template for the enzymatic synthesis of double-stranded cDNA. The resulting double-stranded cDNA was inserted into the Pst I site of pBR322 with the oligo(dG)-oligo(dC) tailing technique and subsequently cloned in E. coli chi 1776. Clones containing sequences complementary to prolactin mRNA were identified by colony hybridization with partially purified prolactin cDNA. A 250 base pair sequence from one prolactin positive clone was extensively characterized and shown to contain the coding information for amino acids 119-192 of authentic bovine prolactin. The recombinant DNA from this clone was covalently attached to diazotized aminocellulose and used to purify prolactin mRNA from a mixture of mRNAs.

Animals↗
PubMed1979

Purification of pre-prolactin mRNA from bovine anterior pituitary glands.

Total cytoplasmic RNA, isolated from bovine anterior pituitary glands, directed the synthesis of primarily two proteins in a wheat germ cell-free system. Analysis of wheat germ cell-free products by sodium dodecyl sulfate-slab gel electrophoresis, direct immunoprecipitation with prolactin aatibody, and prolactin- and growth hormone-specific radioimmunoassay indicated that the two proteins were pre-prolactin and pre-growth hormone. Agarose-urea-gel electrophoresis of poly(A)-containing RNA revealed the presence of a large symmetrical RNA peak with an estimated size of approximately 15 S. The RNA contained in this peak was eluted from the gel and translated in the wheat germ cell-free system. Analysis of the translation products by electrophoresis, direct immunoprecipitation, and radioimmunoassay resulted in the detection of only pre-prolactin. The extent of pre-prolactin mRNA purification was assessed by synthesizing DNA complementary to gel-purified pre-prolactin mRNA and then following the hybridization of this cDNA to gel purified pre-prolactin mRNA. The result of this hybridization is consistent with the cell-free translation studies, namely that pre-prolactin mRNA is the predominant mRNA component of pituitary poly(A)-containing RNA.

Animals↗