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F Rougeon

Publications and source records attributed to F Rougeon.

At least 91 records · Page 5Linked to original sources
PubMed1984

Complex allotypes of the rabbit immunoglobulin kappa light chains are encoded by structural alleles.

We have isolated the rabbit immunoglobulin b9 Ck light chain gene and compared its nucleotide sequence with the b4, b4var , b5 and bas Ck sequences. In spite of the high number of substitutions found between the different rabbit Ck coding regions, only very few changes are silent. Furthermore, the nucleotide changes are clustered in segments which correlate with the bends and helical regions found in the tertiary structure of the Ck domain of the protein. The flanking regions present a higher degree of conservation than the coding regions. The two genomic EcoRI fragments hybridizing to a b4cDNA probe have been correlated with the two distinct loci, Ck1 and Ck2 : one encodes for the nominal b9 Ck allotype and the other contains the information for the bas Ck region. The b allotypes are true alleles which could have evolved by intergenic conversion.

Alleles↗
PubMed1984

Nucleotide sequence of a cDNA encoding the constant region of a rabbit immunoglobulin light chain of the lambda type.

A cDNA library has been constructed in the plasmid pBR322 using as template 12 S poly(A)-RNA isolated from spleen cells of a hyperimmunized Basilea rabbit. One of these cDNA-containing clones was used to determine the nucleotide sequence coding for the lambda light chain constant (C) region. The deduced amino acid sequence of this cDNA was found in good agreement with a Basilea rabbit C lambda region amino acid sequence previously determined. The nucleotide sequence of the rabbit C lambda-coding region was compared with man, mouse and chicken C lambda sequences and showed 78%, 72% and 66% homology, respectively. Southern blot hybridization analyses of liver DNA from various rabbits were carried out. The comparison of the restriction patterns suggests that a few C lambda-related genes occur in the rabbit genome. In addition, discrete differences in the restriction patterns may exist between rabbits of different genetic backgrounds.

Animals↗
PubMed1984

Evolution of aspartyl proteases by gene duplication: the mouse renin gene is organized in two homologous clusters of four exons.

Overlapping recombinant clones that appear to encompass the entire renin gene, named Ren 1, have been isolated from a library of BALB/c mouse genomic DNA fragments. Based on restriction endonuclease mapping and DNA sequence analysis, Ren 1 spans 9.6 kb and contains nine exons interrupted by eight intervening sequences of highly variable size. The first exon, encoding the signal peptide of preprorenin, is separated from the eight following exons by a 3-kb intron. These eight exons are organized into two clusters of four separated by a 2-kb intron. DNA stretches encoding the aspartyl residues, which are part of the active site of renin, are located at homologous positions in both clusters. Our results show that aspartyl protease genes have arisen by duplication and fusion of an ancestral gene containing five exons. The estimated date of the duplication event of the mouse renin genes Ren 1 and Ren 2 is discussed.

Amino Acid Sequence↗
PubMed1984

Mouse kidney and submaxillary gland renin genes differ in their 5' putative regulatory sequences.

The genomic DNAs that specify the renin mRNAs found in the submaxillary gland and in the kidney of Swiss mice have been isolated by molecular cloning in phage lambda. The Ren1 and Ren2 genes, encoding the kidney and submaxillary renins, respectively, span about 9.5 kilobases each. Restriction maps of both renin genes and their flanking sequences are presented. To correlate the differential expression of the renin genes with their structures, a sequence analysis of the putative 5' regulatory sequences of both genes was conducted. The results show that the leader sequences and promoter regions of both genes are highly homologous to a point located 179 nucleotides upstream from the transcription start point; the sequences diverge beyond this position.

Amino Acid Sequence↗
PubMed1983

Structural relationships among mouse and human immunoglobulin VH genes in the subgroup III.

The mouse VHIII subgroup is composed of four families which share sequence homology. We isolated a VH germ-line genomic clone, which cross hybridizes with a cDNA probe from one of these families, derived from a myeloma secreting an antigalactan antibody. We report here the nucleotide sequence of the cross hybridizing gene and show that very likely it has an anti-sheep red blood cell specificity. Comparison of its nucleotide sequence with those of the three other VHIII families shows that these genes share segmental homologies of variable lengths. This suggests that interchanges of sequence blocks between VH genes could be an important evolutionary mechanism for diversifying the germ-line repertoire. The strong homology (82%) with human VHIII genes suggests that efficient antibody sequences are strongly conserved. This conservation of homology is particularly striking when compared to the more limited homology (63%) between mouse and human C kappa genes.

Animals↗
PubMed1983

Molecular cloning and nucleotide sequence of a human renin cDNA fragment.

We have studied human renin messenger RNA by hybridization with the mouse submaxillary gland (SMG) renin cDNA probe. The human kidney messenger RNA is about 1.6 kilobase (kb) long, similarly to the mouse SMG renin mRNA. A kidney renin cDNA clone of 1.1 kb length was obtained. A comparison of nucleotide sequences of mouse and human cDNA clones reveals conservation of residues involved in catalytic mechanisms and a potential glycosylation site. The human renin molecular probe allowed us to study renin expression in human chorionic tissue. The chorionic and kidney renin messenger RNAs are similar in length. The Southern blot analysis reveals the presence of a single renin gene in human DNA.

Amino Acid Sequence↗
PubMed1983

Multiplicity of constant kappa light chain genes in the rabbit genome: a b4b4 homozygous rabbit contains a kappa-bas gene.

We have constructed a genomic library of homozygous b4b4 rabbit DNA in the pJB8 cosmid vector. Clones containing Ckappa-like sequences were screened with a b4 cDNA probe and were characterized by restriction mapping. One of the clones contained a Ckappa sequence different from the b4 allotype normally expressed by the animal. We report here the nucleotide sequence of this gene and show that it probably corresponds to a kappa-bas form of the Basilea allotype. It appears to be a structurally complete gene without any stop codons within the coding region and containing the dinucleotide AG as a splice site acceptor for the J-C junction, just 5' of the coding block. Comparison with the b4 cDNA nucleotide sequence shows a separate evolution of the Ckappa-coding and 3'-untranslated sequences, since the 3'-untranslated regions are more conserved than the coding regions. Genomic blot analysis would suggest that the kappa-bas gene is isotypic in the domestic rabbit population, since it lies within a genomic EcoRI or PstI restriction fragment, which was shown to be common to all homozygous b4, b5, b6 and b9 rabbit DNAs.

Amino Acid Sequence↗
PubMed1983

Kidney and submaxillary gland renins are encoded by two non-allelic genes in Swiss mice.

Two distinct phenotypic groups of inbred strains of mice, with different amounts of submaxillary gland (SMG) renin have been described. We have previously shown that strains with high levels of SMG renin, such as Swiss or AKR mice, have two renin genes, Rn1 and Rn2, per haploid genome, while strains with low levels of SMG, such as BALB/c or C57Bl/6, have only one renin gene. We now report the molecular cloning of cDNA copies of Swiss mouse kidney renin mRNA and present nucleotide sequence data of the recombinant clones. Comparison of these sequences with the sequence of Swiss mouse SMG renin mRNA we have previously reported, demonstrates that Swiss mice express the two non-allelic genes, Rn1 and Rn2.

Alleles↗
PubMed1983

Gene conversion and polymorphism: generation of mouse immunoglobulin gamma 2a chain alleles by differential gene conversion by gamma 2b chain gene.

We have determined the complete nucleotide sequence of the C57BL/6 allele of the mouse immunoglobulin gamma 2a chain gene. A comparison with the BALB/c gamma 2a gene for 1912 nucleotides reveals that the two alleles exhibit extensive divergence, since there are 138 single-base-pair differences and 8 insertions or deletions. We have compared the two gamma 2a alleles with the two corresponding gamma 2b alleles, which differ in only 12 positions. It appears that among the 134 differences between the two gamma 2a alleles, 70 are at positions where gamma 2a and gamma 2b are identical in the BALB/c haplotype and 54 are at positions where gamma 2a and gamma 2b are identical in the C57BL/6 haplotype. All these results suggest that nonreciprocal gene conversion between nonallelic genes can introduce sequence homogeneity in linked genes and can generate extensive divergence and polymorphism in allelic genes. We suggest that the gamma 2a and gamma 2b gene ancestors freely diverged after duplication, and that the conversion events were promoted by a deletion shortening the distance between the two loci.

Alleles↗
PubMed1983

Diversity in the rabbit immunoglobulin kappa chain variable regions is amplified by nucleotide deletions and insertions at the V-J junction.

To analyze the rabbit immunoglobulin kappa locus, we isolated, from a phenotypically homozygous b4/b4 rabbit genomic library, a C kappa gene corresponding to the b4 var allelic form of the b4 C kappa gene. We also determined the nucleotide sequence of the J kappa cluster 3 kb upstream of the b4 var C kappa gene. Southern blot experiments with rabbit J kappa probes indicate that the bas C kappa gene is an isotype probably associated with its own J kappa segment(s). The rabbit b4 J kappa gene region contains a cluster of five J kappa segments, homologous to the human J kappa cluster, and two remnant J kappa segments approximately 5 kb upstream of the b4 C kappa gene. Nucleotide sequence analyses of the coding J kappa segments and their recombination signal sequences show only one functional J kappa segment. Comparisons with the protein data indicate that the rabbit kappa gene family, unlike its human and mouse homologs, increases kappa light chain variability by deletions and insertions at the V-J junction.

Amino Acid Sequence↗
PubMed1983

Mouse submaxillary renin: a useful model for the study of renal renin.

The submaxillary gland of mouse contains a renin-like enzyme which represents as much as 5% of the total protein content. Its physico-chemical and enzymatic characteristics are similar to those of renal renin. Recently, the amino-acid sequence of the submaxillary pre-prorenin molecule has been deduced from the nucleotide sequence of the renin structural gene. A model for pre-prorenin processing into active renin has been proposed. Comparison of the structures of mouse submaxillary renin and of aspartyl proteases shows that renin belongs to this class of proteins and shares a similar catalytic site. Although the structure of renal renin is not yet known, preliminary studies suggest that the renal pro-enzyme is processed as the submaxillary enzyme. However, glycosylation would occur in the case of renal renin, whereas submaxillary renin is not glycosylated. Genetic studies and DNA hybridization experiments in mouse with high or low renin content in the submaxillary gland show that submaxillary renin in high renin producing strains results from a gene duplication. Submaxillary renin is therefore an isoenzyme and a useful model for the study of renal renin.

Amino Acid Sequence↗
PubMed1982

Molecular cloning of rabbit gamma heavy chain mRNA.

A cDNA library of rabbit spleen mRNA was screened for immunoglobulin heavy chain sequences. In this paper we report the nucleotide sequence of two cDNA clones containing part of the constant region of the rabbit gamma heavy chain mRNA. The sequence encodes part of the CH2 domain (amino acids 268 to 340), the entire CH3 domain (amino acids 341 to 447) and the 3' untranslated region. This nucleotide sequence has been compared to the corresponding sequences of mouse gamma 1, gamma 2a and gamma 2b genes. The homologies between rabbit gamma chain gene sequence and each of the mouse gamma chain gene sequences are of the same magnitude order. This comparison shows that the CH2 domains are more homologous to each other than CH3 domains or 3' untranslated sequences. The presence of species specific nucleotide positions suggests that mouse gamma chain genes could have evolved from a common ancestor shortly after the mouse-rabbit species separation. Genomic blot analysis of rabbit liver DNA with the rabbit C gamma probes shows a limited number of related sequences, with little restriction site polymorphism between individual rabbits.

Animals↗
PubMed1982

Identification of a cDNA clone coding for the acetylcholine binding subunit of Torpedo marmorata acetylcholine receptor.

A recombinant DNA plasmid has been constructed that contains sequences of the gene coding for the acetylcholine binding subunit (alpha-subunit, 40 000 daltons) of Torpedo marmorata acetylcholine receptor protein (AChR). Polyadenylated RNA purified from Torpedo electric organ was used to construct a cDNA library. The AChR alpha-subunit cDNA clone was then identified by a two-step screening of 700 recombinant clones. As AChR is present in Torpedo electric organ but not in Torpedo liver or spleen, differential screening led to the selection of 12 clones specific for the electric organ. We then tested the ability of cDNA inserts to hybridize alpha-subunit mRNA specifically, as judged by cell-free translation and immunoprecipitation. The insert from one clone, p alpha-1, selectively hybridized with a mRNA species which elicited the synthesis of a 38 000 mol. wt. polypeptide. This polypeptide was precipitated by: (1) a rabbit serum raised against purified denatured alpha-subunit (the pure alpha-subunit displaced the complex); and (2) a rat monoclonal antibody specific for the denatured alpha-subunit. It was thus identified as a precursor of the alpha chain. Blot hybridization analysis of polyadenylated RNA from Torpedo electric organ with the p alpha-1 probe revealed a major species of 2.0 kb, which thus contains approximately 800 non-coding nucleotides.

Animals↗
PubMed1982

The mouse Rn locus: S allele of the renin regulator gene results from a single structural gene duplication.

Inbred strains of mice have been divided into two distinct phenotypic groups having different levels of renin activity regulated by androgen in the submaxillary gland (SMG). Strains carrying the Rnrs allele of the renin gene regulator, located on chromosome 1, have a high level of renin activity; strains carrying the Rnrb allele have a low level of renin activity. The level of SMG renin activity correlates with the level of renin mRNA. We have analyzed, by Southern blot hybridization, the organization of renin genes in both strains. Strains carrying the Rnrb allele, such as BALB/c or C57 Bl/6, or CH3 mice, have one renin structural gene per haploid genome, while those having the Rnrs allele, such as AKR or Swiss mice, have two renin genes. We have also identified renin genes in mice belonging to different biochemical groups: Mus spretus has one renin gene while M. vrania and M. musculus brevirostris have two renin genes.

Alleles↗
PubMed1982

Multiple sequences related to a constant-region kappa light chain gene in the rabbit genome.

Four allelic genes control kappa light chain allotypes in the rabbit. Amino acid sequence studies have revealed an extensive divergence (22%--33%) in the alternative forms of the kappa constant region (b4, b5, b6 and b9). Furthermore, independent studies have shown that a rabbit could express a wrong allotype. To assess the hypothesis that b allotypes are encoded by duplicated genes with a polymorphic control mechanism, we have analyzed the DNAs of four different homozygous rabbits using the Southern blot hybridization technique, with a cloned b4 C kappa probe. DNAs of individual b4, b5, b6 and b9 rabbits were cleaved with Eco RI, Kpn I and Pst I restriction endonucleases. Comparative analysis of restriction patterns shows that all four rabbit DNAs contain multiple DNA fragments hybridizing with the probe under low- and high-stringency washing conditions. In addition, each restriction pattern is distinct, suggesting that the C kappa genes are organized differently in animals expressing different allotypes.

Alleles↗
PubMed1981

Mouse heavy chain variable regions: nucleotide sequence of a germ-line VH gene segment.

We have constructed a library of Balb/c mouse embryo DNA in the vector Charon 4A. The library was searched for sequences homologous to the VH region of a cloned cDNA of the UPC10 heavy chain mRNA. In this paper, we describe the structure and the partial nucleotide sequence of one of such clones (VH441). The nucleotide sequence of this germ-line gene indicates that it encodes amino-acids 1-98 of the X44 and J601 galactan-binding VH regions, but that it differs from the UPC10 VH segment by four single base changes. The VH gene appears to contain a 101 bases long intervening sequence within a precursor sequence identical to the precursor sequence of UPC10. The 3' non coding sequence of the V gene contains the two conserved sequences found in embryonic V DNA segments, CACAGTG and ACATGAACC, separated by 23 nucleotides and a sequence CACTGTG separated by 33 nucleotides from the first heptamer.

Animals↗