Sequence of the dog immunoglobulin alpha and epsilon constant region genes

The immunoglobulin alpha (IGHAC) and epsilon (IGHEC) germline constant region genes were isolated from a dog liver genomic DNA library. Sequence analysis indicates that the dog IGHEC gene is encoded by four exons spread out over 1.7 kilobases (kb). The IGHAC sequence encompasses 1.5 kb and includes all three constant region coding exons. The complete exon/intron sequence of these genes is described.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers L 36871 (dog IGHAC) and L 36872 (dog IGHEC)     

Class II genes of miniature swine

Genomic clones corresponding to class II genes of theSLA ^c haplotype of miniature swine have been isolated and characterized. These genes have been grouped into seven non-overlapping clusters on the basis of restriction mapping. Ordering of exons within each cluster was accomplished by hybridization of Southern blots of restriction fragments with exon-specific probes. The two clusters (clusters 2 and 3) encoding theDRB andDQB genes were identified on the basis of hybridization with locus-specific 3 untranslated cDNA probes. Cluster 4 contained exons of bothDOB andDQB genes, the basis for which remains to be determined. The remaining four clusters (1, 5, 6, 7) were identified as containingDP, DR, andDO coding sequences, respectively, on the basis of sequence analysis. The porcine class II region appears very similar to that of man in number and nature of the class II genes identified and in the intron/exon organization of corresponding genes.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the association number M29944. Address correspondence and offprint requests to: C. LeGuern.     

Genetic polymorphisms ofQ region genes from wild-derived mice: Implications forQ region evolution

Both serological and DNA sequence analyses were performed to determine the extent of genetic polymorphism inQ region genes. A panel of Qa-2-specific monoclonal antibodies (mAbs) was tested on 35 wildderived and inbred mouse strains. Members of this reagent panel recognize multiple and distinct epitopes on the Qa-2-bearing molecule(s). Although quantitative variations in Qa-2 levels were observed, no structural polymorphisms were detected. All strains were either entirely positive or entirely negative with the complete set of reagents. Moreover, cell surface Qa-2 expression was not significantly affected by differences in age or sex of the mouse or cell cycle status. To confirm this apparent lack of genetic polymorphism, the polymerase chain reaction (PCR) technique was used to amplify a portion of the 3 end of theQ region genes,Q4 toQ9, from several independent wild-derived strains of mice. Sequence analysis of the amplified material revealed very little evidence of nucleotide divergence. All strains tested had aQ even DNA sequence identical to that ofQ6/Q8 in the B10 strain. Likewise, all tested strains had aQ odd DNA sequence identical toQ7/Q9 in the B10 strain. Two strains showed additionalQ even sequences, while all strains tested possessed additionalQ odd sequences. The observed lack of polymorphism suggests that theQ genes have evolved in a different manner fromH-2K andH-2D. Moreover, duplications of these genes appear to have arisen prior to nucleotide sequence divergence.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers M30896-30902.     

Structure and organization of pigMHC class IIDRB genes: evidence for genetic exchange between loci

The pig major histocompatibility complexDRB genes were studied by polymerase chain reaction (PCR) amplification of exon 2 from eight domestic pigs and two European wild boars. Sequence comparisons together with a phylogenetic analysis showed the existence of at least threeDRB genes of which only one appears to be expressed. The two putativeDRB pseudogenes contained delections in exon 2, making it possible to confirm the presence of three non-allelicDRB genes by analyzing the length polymorphism of the amplified PCR products. The expressed gene shows allelic polymorphism at the same positions as in the humanDRB1 gene. In addition this pig gene shows extensive allelic polymorphism at positions 84–88, whereas, e.g., humanDRB genes do not. Surprisingly, the the two putativeDRB pseudogenes also display a considerable amount of allelic polymorphism, albeit of a different character as compared with the expressedDRB gene. Short stretches of sequences are shared between individual alleles at different loci. These sequence similarities cannot be due to natural selection, since two of the threeDRB genes involved are polymorphic pseudogenes constituting allelic series that have diverged after the inactivation event. Instead, the results indicate that the sequences have been exchanged between theDRB genes by intergenic recombination. The nucleotide sequence data reported in this paper have been submitted to the EMBL/GenBank nucleotide sequence databases and have been assigned the accession numbers L36567 (DRB1 ^* 1) L36568 (DRB1 ^* 2), L36569 (DRB1 ^* 3), L36570 (DRB1 ^* 4), L36571 (DRB1 ^* 5), L36572 (DRB1 ^* 6), L36573 (DRB1 ^* 7), L36574 (DRB1 ^* 8), L36575 (DRB2 ^* 1), L36576 (DRB2 ^* 2A), L36577 (DRB2 ^* 2B), L36578 (DRB2 ^* 2C), L36579 (DRB1 ^* 2D), L36580 (DRB2 ^* 3), L36581 (DRB2 ^* 4), L36582 (DRB3 ^* 1A), L36583 (DRB3 ^* 1B), L36584 (DRB3 ^* 1C), L36585 (DRB3 ^* 1D)     

Evolution of the immunoglobulin M constant region genes of salmonid fish,rainbow trout (Oncorhynchus mykiss) and Arctic charr (Salvelinus alpinus): implications concerning divergence time of species

The nucleotide sequence data reported in this paper have been submitted to the EMBL nucleotide sequence database and have been assigned the accession numbers X83372 (Oncorhynchus mykiss) and X83373 (Salvelinus alpinus)     

Sequence analysis of the promoter regions of the classical class I gene RT1.A l and two other class I genes of the rat MHC

The nucleotide sequence data reported in this Papershave been submitted to the GenBank, EMBL, and DDBJ nucleotide sequence databases and have been assigned the accession numbers X79719 (RT1.A ¹), X79720 (RT1.C ¹), and X79721 (RT12.5)     

Identification of seven new humanMHC class I region genes around theHLA-F locus

Using cDNA hybridization selection techniques, we identified seven new genes in a 280 kilobase YAC coveting theHLA-F locus. The new genes were mapped back to the YAC by a combination of optical restriction mapping and pulse field gel electrophoresis. Northern analysis of individual clones demonstrated the presence of either different mRNA sizes or different expression patterns. Two of the cDNA clones were expressed only in lymphoid cell lines: one in Jurkat cells (T cell) and another in JY cells (B cell). All the genes lacked sequence similarity to any known classical and non-classical major histocompatibility complex (MHC) class I genes, indicating that theMHC class I region has more functions than anticipated. Of the seven new genes, one is highly similar (97%) to mouse 60S ribosomal protein, and another is homologous to diubiquitin proteins. Of the two G-coupled receptor-like cDNAs, one was fully sequenced and found to be an olfactory receptor-like gene. The study strengthens evidence that theMHC complex not only plays a key role in the immune system, but also contributes to non-immunological functions. The nucleotide sequence data reported in this paper have been submitted to the Genbank nucleotide sequence database and have been assigned the accession numbers U37229 (IB2), U37230 (IC4), U37231 (IF12), U37232 (IH9), U37233 (2D8), U37234 (2H6), and L35475 (IA8)     

Sequence and characterization of twoHSP70 genes in the colonial protochordateBotryllus schlosseri

Two genes belonging to the heat shock protein 70 gene family have been cloned from the colonial protochordateBotryllus schlosseri. The two intronless genes(HSP70.1 andHSP70.2) exhibit 93.6% sequence identity within the predicted coding region, and 83.3% and 81.7% sequence identity in the 5′ and 3′ flanking regions, respectively. The predicted amino acid sequences are 95% identical and contain several signatures characteristic of cytoplasmic eukaryoticHSP70 genes (Gupta et al. 1994; Rensing and Maier 1994). Northern blotting and sequence analysis suggest that both genes are heat-inducible merebees of theHSP70 gene family. Given these characteristics,HSP70.1 andHSP70.2 appear to be good candidates for protochordate homologues of the major histocompatibility complex-linkedHSP70 genes of human, mouse, and rat (Milner and Campbell 1990; Walter et al. 1994). Further experiments to determine whether there is functional evidence for such similarity are in progress. The nucleotide sequence data reported in this paper have been submitted to the EMBL/GenBank nucleotide sequence databases and have been assigned the accession numbers US 1901 (HSP70.1) and US 1902 (HSP70.2)     

Major histocompatibility complex class I genes of Peromyscus leucopus

Class I genes of the Peromyscus leucopus major histocompatibility complex (MhcPele) were examined by Southern blot hybridization, genomic cloning, and DNA sequencing. At least three distinct subtypes of Pele class I genes were discerned, which we have designated Pele-A, B, and C. The nucleotide sequences of exon 5-containing regions (encoding the transmembrane domain) suggested that Pele-A genes are homologs of mouse H-2K, D, L, and Q genes and that Pele-B genes correspond to mouse Tla genes. The Pele-C genes appeared similar to mouse M1 genes. The number of unique genes in each subtype cloned from an individual P. leucopus were 20 for Pele-A, 13 for Pele-B, and 2 for Pele-C. Three genomic clones showed cross-hybridization to both Pele-A and Pele-B gene-specific probes. Six genomic clones remained unclassified as they did not cross-hybridize to exon 5-containing probes from Pele-A, B, or C genes. The homology between the transmembrane domains of Pele class I gene subtypes was found to be similar to that observed between the transmembrane domains of H-2 subtypes (or groups). Interspecific similarity of exon 5 was found to be 81%–88% between Pele class I genes and their H-2 counterparts.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers M33983-5.     

Three extra copies of a C4-related gene in H-2 w7 mice are C4/Slp hybrid genes generated by multiple recombinational events

Mice bearing the H-2 _w7 haplotype have five C4-related genes and constitutively express the Slp antigen. To understand the structure and evolution of the five C4-related genes of the C3H.W7 mouse, we have determined nucleotide sequences of the 5 end region of these genes. A C4/Slp hybrid nature was confirmed for three of five C4-related genes as predicted previously by restriction enzyme analysis. The nucleotide sequences of the 5 flanking regions of these three hybrid genes showed close similarity to that of the C4 gene, while the 3 side of the ninth exon of the three hybrid genes showed close similarity to that of the Slp gene. In contrast, the regions between the first exon and the middle of the ninth exon of the three hybrid genes showed a mosaic structure of C4-like and Slp-like sequences. Moreover, the boundaries of the C4-like and Slp-like sequences were quite different among the three hybrid genes. The pattern of nucleotide sequence diversity in this region among the five C4-related sequences could be mainly explained not by point mutations but by gene conversions or unequal crossovers. These results suggest that multiple genetic recombinational events between two homologous sequences played an important role in the generation and diversification of the extra copies of the C4/Slp gene in the H-2 ^w7 mouse.The nucleotide sequence data reported in this paper have been submitted to the DDBJ, EMBL, and GenBank nucleotide sequence databases and have been assigned the accession numbers D90167-71.     

Major histocompatibility complex class II A gene polymorphism in the striped bass

Adaptions of the polymerase chain reaction were used to isolate cDNA sequences encoding the Major histocompatibility complex(Mhc) class II A gene(s) of the striped bass (Morone saxatilis). Four complete Mhc class II A genes were cloned and sequenced from a specimen originating in the Roanoke River, North Carolina, and another three A genes from a specimen originating from the Santee-Cooper Reservoir, South Carolina, identifying a total of seven unique sequences. The sequence suggests the presence of at least two Mhc class II A loci. The extensive sequence variability observed between the seven different Mhc class II clones was concentrated in the 1 encoding domain. The encoded 2, transmembrane, and cytoplasmic regions of all seven striped genes correlated well with those of known vertebrate Mhc class II proteins. Overall, the striped bass sequences showed greatest similarity to the Mhc class II A genes of the zebrafish. Southern blot analysis demonstrated extensive polymorphism in the Mhc class II A genes in members of a Roanoke river-caught population of striped bass versus a lesser degree of polymorphism in an aquacultured Santee-Cooper population of striped bass.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers (Mosa-A-S5) L35062, (Mosa-A-S8) L35066, (Mosa-A-R7) L35067, and (Mosa-A-S7) L35072 L35066, (Mossa-A-R7) L35067, and (Mosa-A-S7) L35072     

Sequence and diversity of variable gene segments coding for rabbit T-cell receptor beta chains

The nucleotide sequences of 11 variable gene segments coding for rabbit T-cell receptor beta (Tcrb-V) chains were determined by directly sequencing fragments amplified by the cassette-ligation mediated polymerase chain reaction (CLM-PCR) and by modified anchor PCR without the cloning procedure. The nucleotide sequences in two of these 11 rabbit Tcrb-V gene segments coincided with those in two of the four rabbit Tcrb-V gene segments previously reported; the others have not been described. The percentage similarity of each nucleotide sequence of the 11 rabbit Tcrb-V gene segments was analyzed and the segments were divided into nine families, which were homologous to nine human families (Vb 2, 3, 4, 5, 7, 8, 10, 18, and 22), respectively.The nucleotide sequence data reported in this paper have been submitted to the DDBJ, EMBL, and GenBank nucleotide sequence databases and have been assigned the accession numbers D17416-D17426.     

Polymorphism and phylogeny of dinucleotide repeats in human T-cell receptor Vb6 genes

The Vb6 subfamily is the largest reported subfamily of human T-cell receptor (Tcr) genes with as many as 14 possible members based on variation in reported DNA sequences. A study of the genomic organization of four distinct Vb6 genes indicated that they contained within their introns theuniterrupted dinucleotide repeat (GT)_n, with n>8. DNA amplification primers and conditions were determined which amplified the intron of these four different Vb6 gene segments. All four Vb6 genes tested showed length polymorphism when examined in a group of unrelated individuals. Careful sizing and DNA sequencing showed that the alleles of each gene differed in size by multiples of two base pairs (bp), due to different repeat numbers of the dinucleotide (GT)_n. These four microsatellite polymorphisms had from three to ten alleles, and individual heterozygosities of 26% to 83%. The large number of alleles and the high heterozygosity make these polymerase chain reaction (PCR)-based polymorphisms very attractive genetic markers for segregation studies which postulate the presence of autoimmune susceptibility genes within the Tcrb region. Vb6 hybridization to genomic DNA confirmed the relatively large size of the Vb6 subfamily in several hominoid species. Nucleotide sequencing of an intron of the Vb6 genes from other primates revealed the presence of dinucleotide repeats similar to those found in human Vb6 genes. Thus, the (GT)_n microsatellite was not only present in the Vb6 intron before Vb6 gene duplication, but was present before speciation of the hominoids.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers L07638, L07640, and X07641.     

The nucleotide sequence and evolution of ovine MHC class II B genes: DQB and DRB

The nucleotide sequences of one Ovar-DQB gene, excluding exon 1 and parts of the introns, and one Ovar-DRB pseudogene are presented. The structure of the Ovar-DQB gene is typical of a major histocompatibility complex (MHC) class II B gene and demonstrats considerable sequence similarity with that of humans including such characteristics as the less common polyadenylation signal, ATTAAA. The ovine sequence has a typical 5' acceptor splice signal for exon 5, thus potentially encoding a full length cytoplasmic tail. The Ovar-DRB gene identified in this study was found to be a pseudogene, lacking a defined exon 2 and containing premature termination codons in both exons 3 and 4. The 3' donor splice site of exon 3 is also atypical. A purine-pyrimidine microsatellite repeat, (dCdA)₁₅, in the 3' region of the pseudogene may be a hotspot for recombination within the ovine DR subregion.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers M33306 and M33307. Address correspondence and offprint requests to: M. R. Brandon.     

Sequence and diversity of rabbit T-cell receptor gamma chain genes

The nucleotide sequences of one constant (C), six variable (V), and two joining (J) gene segments coding for the rabbit T-cell receptor gamma chain (Tcrg) were determined by directly sequencing fragments amplified by the cassette-ligation mediated polymerase chain reaction. The Tcrg-C gene segment did not encode a cysteine residue for connection to the Tcr delta chain in the connecting region, and two variant forms of the Tcrg-C gene segment were generated by alternative splicing, like the human Tcrg-C2 gene. Five of six rabbit Tcrg-V gene segments belonged to the same family and displayed similarity to five productive human Tcrg-V1 family genes as well as the mouse Tcrg-V5 gene. The remaining rabbit Tcrg-V gene segment displayed similarity to the human Tcrg-V3 gene. Both rabbit Tcrg-J gene segments displayed similarity to the human Tcrg-J2.1 and 2.3, respectively. These findings suggested that the genomic organization of rabbit Tcrg genes is more similar to that of human than of mouse Tcrg genes.The nucleotide sequence data reported in this paper have been submitted to the GSDB, DDBJ, EMBL, and NCBI nucleotide sequence databases and have been assigned the accession numbers D38134-D38144 and D42090     

Structural characterization of protein secretion genes of the bacterial phytopathogen Xanthomonas campestris pathovar campestris: relatedness to secretion systems of other gram-negative bacteria

Summary The nucleotide sequence was determined of a 5.3 kb region of the Xanthomonas campestris pathovar campestris genome carrying a gene cluster encoding protein secretion and pathogenicity functions. A putative promoter sequence and five open reading frames (ORF) which may be part of an operon were revealed. The five predicted primary translation products comprise 531, 390, 147, 169 and 138 amino acids with M_r values of 58854, 42299, 15548, 18214 and 15108 respectively. A sixth, partial ORF is also present. Between ORF1 and ORF2 is a sequence of unknown function showing 7 by duplications. The deduced amino acid sequence of ORF1 is related to the Klebsiella pneumoniae PulE protein, to the Bacillus subtilis ComG ORF1 and to the Agrobacterium tumefaciens VirB ORF11 products. In addition, the deduced amino acid sequence of ORF2 showed homology to the Pu1F and to the ComG ORF2 products. The proteins encoded by ORF3, 4 and 5 showed amino acid homology to PulG, H and I products respectively. The proteins encoded by ORF2, 3, 4 and 5 showed significant hydrophobic domains which may represent membrane-spanning regions. By contrast the protein encoded by ORF1 was largely hydrophilic and had two putative nucleoside triphosphate binding sites.The nucleotide sequence data in this paper have been deposited in the EMBL, Genbank and DDBJ nucleotide sequence databases under the accession number X59079     

Analysis in Neisseria meningitidis and other Neisseria species of genes homologous to the FKBP immunophilin family

The immunophilin family of FK506-binding proteins (FKBPs), involved in eukaryotic protein folding and cell regulation, have recently been found to have prokaryotic homologues. Genes with sequences homologous to those encoding human FKBPs were examined in Neisseria species. An FKBP DNA sequence was present, as shown by the polymerase chain reaction and Southern blotting experiments, in the chromosome of Neisseria meningitidis (14 strains) and in all 11 different commensal Neisseria spp. studied, but was not found in Neisseria gonorrhoeae (11 strains tested) or in Moraxella catarrhalis. The nucleotide and predicted protein sequences of the FKBP-encoding domain from five of the meningococcal strains were highly conserved (e.g. ≥97% homologous). The meningococcal nucleotide sequence was ≥93% homologous and the consensus meningococcal protein sequence was ≥97% homologous to FKBP sequences found in seven different commensal Neisseria spp. The meningococcal nucleotide and predicted protein sequences were ≥59% homologous to the conserved C-terminus of the human FKBP gene family. The FKBP nucleotide sequence was present as a single copy in the chromosome of commensal Neisseria spp. and in most strains of N. meningitidis. The FKBP gene was linked to the silent pilin locus, pilS, in class II-piliated meningococcal strains. In meningococcal strains expressing class I pili, the FKBP gene was linked to one of several pilS loci but not the pilE locus present in these strains. FKBP genes found in commensal Neisseria spp. were not linked to known pilin loci.     

A new Igk-V gene family in the mouse

We have identified and characterized a novel mouse Igk-V gene family, which we have designated Igk-V34. Southern hybridization and nucleotide sequence analysis indicate that this family is comprised of either one or two members in mice of different Igk haplotypes. The gene family members share between 95% and 98% sequence similarity, indicating that they diverged only recently during the evolution of the Igk locus. Sequence relationships between members of this family are discussed.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers M35154-7. Offprint requests to: A. J. Caton.     

The nucleotide sequence of bovine MHC class IIDQB andDRB genes

The nucleotide sequences of most of the exons and parts of the introns of twoBoLA-DQB genes and twoBoLA-DRB genes have been determined. The structure of these genes is very similar to that of human major histocompatibility complex (MHC) class II genes. The twoDQB genes probably represent true alleles. Based on the exons sequenced, bothDQB genes and one of theDRB genes seem to be functional. The otherDRB gene is a pseudogene; stopcodons are found in the exons encoding the second and transmembrane domain and, furthermore, a 2 base pair (bp) deletion has occured in the leader exon which places the initiation start codon out of frame. Also in this pseudogene, an almost perfect inverted repeat of 200 bp is found flanking the exon encoding the first domain, which might have been the result of a duplication/inversion event. The sequences presented in this paper do not contain any repetitions. Therefore, DNA fragments containing these sequences can be used as homologous bovine probes in restriction fragment length polymorphism (RFLP) analysis to study disease association in cattle.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers M30002–M30014. Address correspondence and offprint requests to: M. A. M. Groenen.     

The immunoglobulin repertoire of the rainbow trout (Oncorhynchus mykiss): definition of nine Igh-V families

An Igh-V library was constructed from the head kidney cytoplasmic RNA of an 8.5-month-old non-immunized rainbow trout, Oncorhynchus mykiss, using the 5 RACE polymerase chain reaction. Six new Igh-V segments were identified, bringing to nine the number of Igh-V families actually defined in that species. A phylogenetic analysis shows that these nine Igh-V families can be classified into three major groups. The first includes the Igh-V1, Igh-V3, Igh-V4, and Igh-V7 families, and is homologous to the human and mouse Group III Igh-V families. The second includes the Igh-V5, Igh-V8, and Igh-V9 families and is more closely related to the Group I and Group II human and mouse Igh-V families. The third group includes the Igh-V2 and Igh-V6 families, which are not closely related to any other vertebrate Igh-V gene. Six Igh-J segments were characterized. They can recombine with Igh-V segments belonging to different families and there is a high level of junctional diversity between the Igh-V and Igh-J segments.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers L28741 (Igh-V4), L28742 (Igh-V5.1), L28744 (Igh-V6), L28745 (Igh-V7), L28746 (Igh-V8), L28747 (Igh-V9), and L28805 (Igh-V5.2)