Multiple mRNAs are generated from the chicken lysozyme gene

We have determined the DNA sequence of a 770 by Pst I fragment containing 450 nucleotides of the 5′ flanking region of the chicken lysozyme gene. S1-nuclease mapping was performed to localize the 5′ end of nuclear RNA containing lysozyme-specific sequences and of the mRNA. We present evidence that the 5′ noncoding region of the chicken lysozyme mRNA is heterogeneous in length. The 5′ termini of the different mRNAs map 29, 31 and 53 nucleotides upstream from their common initiation codon. The 5′ ends of lysozyme-specific nuclear RNAs map at positions similar to that of the mRNA. AT-rich regions and sequences similar to the E. coli RNA polymerase recognition sequence are found around 30 and 70 nucleotides upstream from each of these 5′ termini. The AT-rich regions differ, however, from the canonical Goldberg-Hogness box in that they do not contain the extremely conserved TATA sequence motif. Sequence comparison at the 5′ end of the lysozyme, conalbumin and ovalbumin genes reveals only one region of partial homology, 140 nucleotides upstream from the mRNA start sites.     

Cloning of the Atlantic salmon (Salmo salar) estrogen receptor-alpha gene

A cDNA clone encoding most of an Atlantic salmon (Salmo salar) estrogen receptor (ER) was obtained from a liver cDNA library and the remainder of the coding sequence from the gene was isolated from a genomic library. Sequence comparisons showed that the cloned gene represents ER-alpha. Expression of the ER-alpha gene in male and female salmon parr was analysed by RT-PCR. Highest expression was found in brain and liver, with lower levels of ER-alpha mRNA present in all other tissues tested. There was little difference in expression of ER-alpha between male and female.     

Polymorphism within the bovine estrogen receptor-alpha gene 5'-region

Due to the functions that estrogens play in the regulation of reproduction, development of the mammary gland, growth and differentiation of cells, estrogen receptors and their genes are considered candidates for the markers of production and functional traits in farm animals, including cattle. In the present study, on the basis of the sequences of the human, ovine, and porcine ER genes, available in the GenBank database, sets of PCR primers were designed and used to amplify the bovine ERalpha gene 5'-region. Seven overlapping fragments of the 5' region of the bovine ERalpha gene were amplified and then sequenced. Altogether, these fragments were composed in the 2853-bp sequence which was deposited in the GenBank database under accession no. AY340597. The sequenced fragment included the noncoding exons A, B, C, their putative promoters, and a part of the coding exon 1. A polymorphism within the 5' region of the bovine ERalpha gene-A/G transition, which could be recognized with RFLP-BglI, lying upstream to the exon C, was identified for the first time using this sequence.     

Nonmuscle and smooth muscle myosin light chain mRNAs are generated from a single gene by the tissue-specific alternative RNA splicing

We have isolated two cDNA clones for myosin alkali light chain (MLC) mRNA from two respective cDNA libraries of chick gizzard and fibroblast cells by cross-hybridization to the previously isolated cDNA of skeletal muscle MLC. Sequence analysis of the two cloned cDNAs revealed that both of them are homologous to but distinct from the cDNA sequence used as the probe so that they may be classified into members of the MLC family, that they are identical with each other in the 3' and 5' untranslated sequence as well as in the coding sequence with a notable exception of a 39-nucleotide insertion in the fibroblast cDNA, 26 nucleotides of which are used for encoding the C-terminal amino acid sequence, and, therefore, that they encode the identical 142-amino acid sequence with different C-terminals of nine amino acids, each specific for fibroblast and gizzard smooth muscle MLC. The position of the inserted block corresponds exactly to one of the exon-intron junctions in the other MLC genes whose structures have so far been elucidated. DNA blot analysis suggested that the two MLC mRNAs of gizzard (smooth muscle) and fibroblast cells (nonmuscle) are generated from a single gene, probably through alternative RNA splicing mechanisms. RNA blot analysis and S1 nuclease mapping analysis using RNA preparations from fibroblast and gizzard tissues showed that the fibroblast MLC mRNA is expressed predominantly in fibroblast cells, but not, or very scantily if at all, in the gizzard, whereas the reverse is true for the gizzard smooth muscle MLC mRNA.     

Aromatase (estrogen synthetase) gene expression in human leukocytes

Extragonadal aromatization plays an important role in many physiological and pathological conditions. It has been found that incubation of the peripheral blood mononuclears in the RPMI-1640 medium with 10% fetal calf serum during 48 hrs is able to induce the aromatase gene expression. The latter did not occur in 11 samples of mononuclears of the intra-tissue leukocyte infiltration which finding needs further investigation. The data obtained suggest that the possibility of the aromatase gene induction in leukocytes is associated with the cellular fraction capable of the substrate adhesion.     

Chromosomal localization of the human interleukin 1 alpha (IL-1 alpha) gene

The human interleukin 1 alpha gene was assigned to chromosome 2 using Southern transfer analysis of human-rodent somatic cell hybrid DNAs. The gene was regionally localized to 2q12-21 using in situ hybridization to metaphase chromosomes. These results indicate that the IL-1 alpha gene maps to the same general region on the long arm of chromosome 2 as the IL-1 beta gene, which has been previously assigned.