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1.
To determine whether convergent or trans-specific evolution is responsible for the persistence of the ABO polymorphism in apes, we have sequenced segments of introns 5 and 6 of the ABO gene. Four substitutions and one insertion or deletion group human A, B, and O alleles together, separate from their chimpanzee A and gorilla B counterparts. No shared substitutions support a trans-species mode of evolution for any of the alleles examined. We conclude that the A and B antigens of the chimpanzee and gorilla,
respectively, have arisen by convergent evolution. Phylogenetic analysis suggests that the human A and B alleles are ancient, having diverged at least 3 million years ago. These alleles must have therefore been trans-specifically inherited within the genus Homo.
Received: 28 May 1997 / Accepted: 31 July 1997 相似文献
2.
Hubert Ammer Franz-Werner Schwaiger Clauda Kammerbauer Maria Gomolka Annette Arriens Sandor Lazary Jörg T. Epplen 《Immunogenetics》1992,35(5):332-340
Gene products encoded by the major histocompatibility complex often exhibit a high degree of polymorphism. In humans the HLA-DR polymorphism is due to more than 50 alleles with varying exon 2 sequences. Each group of DRB alleles contains a certain form of the basic simple repeat motif (gt)n(ga)m in intron 2. Identical alleles can be differentiated on the basis of the hypervariable repeat. In this study focused on cattle (Bos taurus) we identified different Bota-DRB alleles in a limited survey by amplification via polymerase chain reaction and sequencing. In addition DRB exon 2 sequences were also obtained from eight additional hoofed animal species (seven horned artiodactyls and one pig) revealing artiodactyl-specific polymorphic and nonpolymorphic substitutions. In the genus Bos the intronic simple repeat variability was compared with exonic DRB polymorphism. As in humans all Bota-DRB exons were always associated with specifically organized basic simple repeat structures. Yet the extent of simple repeat variability was lower in cattle compared to humans. Selective breeding in the process of domestication might be responsible for the diminished intronic hypervariability. Nevertheless, the hypermutable simple repeat sequences have been preserved in the same position and with the same principal structure for at least 70 × 106 years of evolution. Unexpectedly, the rate of intronic simple repeat and exonic changes appear quite similar. 相似文献
3.
MHC class I polymorphism improves the defense of vertebrate species against viruses and other intracellular pathogens. To
see how polymorphism at the same class I genes can evolve in different species we compared the MHC-A, MHC-B, and MHC-C loci of common chimpanzees and humans. Diversity in 23 Patr-A, 32 Patr-B, and 18 Patr-C alleles obtained from study of 48 chimpanzees was compared to diversity in 66 HLA-A, 149 HLA-B, and 41 HLA-C alleles obtained from a study of over 1 million humans. At each locus, alleles group hierarchically into families and then
lineages. No alleles or families are shared by the two species, commonality being seen only at the lineage level. The overall
nucleotide sequence diversity of MHC class I is estimated to be greater for modern chimpanzees than humans. Considering the
numbers of lineages, families, and alleles, Patr-B and Patr-C have greater diversity than the HLA-B and HLA-C, respectively. In contrast, Patr-A has less polymorphism than HLA-A, due to the absence of A2 lineage alleles. The results are consistent with ancestral humans having passed through a narrower population bottleneck
than chimpanzees, and with pathogen-mediated selection having favored either preservation of A2 lineage alleles on the human line and/or their extinction on the chimpanzee line.
Received: 8 December 1999 / Accepted: 30 December 1999 相似文献
4.
The genetic diversity of bovine class II DQB genes was investigated by polymerase chain reaction amplification and DNA sequencing. The first domain exon was amplified from genomic DNA samples representing 14 class II haplotypes, defined by restriction fragment length polymorphism (RFLP) analysis. The presence of a polymorphism in the copy number of DQB genes was confirmed since two DQB sequences were isolated from certain haplotypes. Four subtypes of bovine DQB genes were found. DQB1 is the major type and was found in almost all haplotypes. DQB2 is very similar DQB1 but was found only in the duplicated haplotypes DQ9 to 12. DQB3 and DQB4 are two quite divergent genes only present in certain duplicated haplotypes. The bovine DQB complexity thus resembles that in the human DRB region. Bovine DQB genes were found to be highly polymorphic as ten DQB1 alleles and four DQB2 alleles were identified. The observed sequence polymorphism correlated well with previously defined DQB RFLPs. Bovine and human DQB alleles show striking similarities at the amino acid level. In contrast, the frequency of silent substitutions is much higher in comparisons of DQB alleles between species than within species ruling out the possibility that any of the contemporary DQB alleles have been maintained since the divergence of humans and cattle. The frequency of silent substitutions between DQB alleles was markedly lower in cattle than in humans, in agreement with a previous comparison of human and bovine DRB alleles. 相似文献
5.
Like humans, non-human primates express the antigens A and B of the ABO histoblood group system. In chimpanzees, only A and
O types are found, while the types A, B, AB, and O are found in macaques. The sequences of exons 6 and 7 of two chimpanzee
O alleles (O
del
and O
x
), two macaque species O alleles (rhesus monkey and crab-eating macaque), and sequences of exon 7 of two major chimpanzee A alleles (A
1ch
and A
2ch
) were established. The sequences of cDNAs corresponding to the chimpanzee and rhesus monkey O alleles were characterized from exon 1 to 7 and from exon 4 to 7, respectively. A comparison of our results with ABO gene sequences already published by others demonstrates that human and non-human primate O alleles are species-specific and result from independent silencing mutations. These observations reinforce the hypothesis
that the maintenance of the ABO gene polymorphism in primates reflects convergent evolution more than transpecies inheritance of ancestor alleles.
Received: 30 July 1998 / Revised: 12 December 1998 相似文献
6.
Evolution ofMHC polymorphism: Extensive sharing of polymorphic sequence motifs between human and bovine DRB alleles 总被引:4,自引:0,他引:4
Leif Andersson Sunna Sigurdardóttir Carina Borsch Kenth Gustafsson 《Immunogenetics》1991,33(3):188-193
The evolution ofMHC polymorphism has been studied by comparing the amino acid and nucleotide sequences of 14 bovine and 32 humanDRB alleles. The comparison revealed an extensive sharing of polymorphic sequence motifs in the two species. Almost identical sets of residues were found at several highly polymorphic amino acid positions in the putative antigen recognition site. Consequently, certain bovine alleles were found to be more similar to certain human alleles than to other bovine alleles. In contrast, the frequencies of silent nucleotide substitutions were found to be much higher in comparisons between species than within species implying that none of the human or bovine DRB alleles originated before the divergence of these distantly related species. The results suggest that the observed similarity inDRB polymorphism is due to convergent evolution and possibly the sharing of short ancestral sequence motifs. However, the relative role of the latter mechanism is difficult to assess due to the biased base composition in the first domain exon of polymorphic class 11 genes. The frequency of silent substitutions betweenDRB alleles was markedly lower in cattle than in man suggesting that theDRB diversity has evolved more rapidly in the former species. 相似文献
7.
R. S. Pfau Ronald A. Van Den Bussche Karen McBee Robert L. Lochmiller 《Immunogenetics》1999,49(10):886-893
The cotton rat (Sigmodon hispidus) is a common murid rodent of the southern United States, Mexico, and Central America. Using single-stranded conformation
polymorphism analysis and DNA sequencing techniques, 11 DQA exon 2 alleles were detected among 180 S. hispidus from Caddo County, Oklahoma, USA. The alleles represent a single locus exhibiting a high level of polymorphism. Nucleotide
and amino acid distance values among DQA alleles of S. hispidus were higher than those within Mus musculus and species of Rattus. Although the distribution of polymorphic amino acid residues among alleles of S. hispidus was similiar to that of Mus and Rattus, some residues of the α-helix region were more variable in S. hispidus. Comparisons of nonsynonymous and synonymous substitutions indicated a trend toward higher numbers of nonsynonymous substitutions;
however, this difference was not significant statistically among S. hispidus alleles. To examine evolution of DQA alleleswithin Muridae, we performed a phylogenetic analysis that included DQA alleles from S. hispidus, Peromyscus leucopus, M. musculus, R. norvegicus, and six Australian species of Rattus. Results depicted monophyly for each genus, and this concordance between species and gene trees represents a lack of evidence
for trans-species persistence of alleles among these genera.
Received: 22 October 1998 / Revised: 17 March 1999 相似文献
8.
The major histocompatibility complex (Mhc) encodes for highly variable molecules, responsible for foreign antigen recognition and subsequent activation of immune responses
in hosts. Mhc polymorphism should hence be related to pathogen resistance and immune activity, with individuals that carry either a higher
diversity of Mhc alleles or one specific Mhc allele exhibiting a stronger immune response to a given antigen. Links between Mhc alleles and immune activity have never been explored in natural populations of vertebrates. To fill this gap, we challenged
house sparrows (Passer domesticus) with two T-dependent antigens (phytohemagglutinin and sheep red blood cells) and examined both primary and secondary immune
responses in relation to their Mhc class I genotypes. The total number of Mhc alleles had no influence on either primary or secondary response to the two antigens. One particular Mhc allele, however, was associated with an increased response to both antigens. Our results point toward a contribution of the
Mhc, or of other genes in linkage disequilibrium with the Mhc, in the regulation of immune responses in a wild animal species. 相似文献
9.
10.
Genetic deversity at the highly polymorphic BoLA-DRB3 locus was investigated by DNA sequence analyses of 18 African cattle from two breeds representing the two subspecies of cattle, Bos primigenius indicus and Bos primigenius taurus. Yhe polymorphism was compared with that found in a sample ofd 32 European cattle from four breeds, all classified as B. p. taurus. Particularly extensive genetic diversity was found among African cattle, in which as many as 18 alleles were recognized in this small random sample of animals from two breeds. The observed similarity in allele frequency distribution between the two African populations, N'Dama and Zebu cattle, is consistent with the recent recognition of gene flow between B. p. indicus and B. P taurus cattle in Africa. A total of 30 DRB3 alleles were documented and as many as 26 of these were classified as major allelic types showing at least five amino acid substitutions compared with other major types. The observation of extensive genetic diversity at MHC loci in cattle, as well as in other farm animals, provides a compelling argument against matin-type preferences as a primary cause in maintaining major histocompatibility complex diversity, since the reproduction of these animals has been controlled by humans for many generations.The nucleotide sequence data reported in this paper have been submitted to the EMBL nucleotide sequence database and have been given the accession numbers X87641-X87670 相似文献
11.
The Pm blood group system in Peromyscus maniculatus was originally described by Rasmussen as consisting of two co-dominant alleles, PmA and PmB, responsible for the antigenic characteristics A and B. This paper describes two additional antisera, anti-C and anti-X, which expand this system and show it to be serologically complex. Anti-X is comprised of antibodies directed against at least two antigenic characteristics X‘ and X“. Four and possibly six alleles are described by the four antisera. Different subspecies exhibit different spectra of alleles at the Pm locus. A segregation distortion is evidenced. 相似文献
12.
Benzidine staining of starch gels after electrophoresis of sera to which haematin was added revealed polymorphism of haemopexin in sheep, mouflon and goat. In sheep three phenotypes were observed, Hpx A, Hpx AB and Hpx B. Pedigree data support the hypothesis of codominant inheritance from a single locus by two alleles, HpxA and HpxB. Neuraminidase treatment of haemopexin preparations showed that Hpx B covered two variants, B1 and B2, thus indicating genetic control by three alleles (HpxA, HpxB1 and HpxB2). In sheep populations the frequency of HpxB is low. In mouflon, in addition to the two variants that are like those of sheep, absence of haemopexin was observed in some animals, by using starch gel electrophoresis as well as immunoelectrophoresis. In goat, three phenotypes were detected, Hpx A, Hpx AB and Hpx B, differing in migration from those of sheep. Haemopexins of the studied species are heterogeneous. Sialic acid is responsible for electrophoretic heterogeneity of sheep haemopexin. Chemical. composition (amino acid and carbohydrate), molecular weight (56 060) and N-terminal sequence (Leu-Pro-Pro-) of sheep haemopexin were also determined. 相似文献
13.
Sarah Bedichek Pipkin Gilbert O. Ogonji Olajide O. Agbede 《Journal of molecular evolution》1972,2(1):56-71
Summary A comparative species study of octanol dehydrogenase (ODH) isozyme patterns of members of the genusDrosophila and six related genera has shown a rough correlation of these with taxonomic grouping at the level of subgenus or section within the subgeneraPholadoris, Sophophora, andDrosophila. Extensive polymorphism of ODH patterns occurs in thequinaria section of the subgenusDrosophila. In polymorphic strains ofD. pellewae andD. metzii, ODH pattern types of single females were shown to occur in frequencies expected on the hypothesis of a Hardy-Weinberg distribution of morphs depending on alleles at a single locus. However, patterns of homozygous B and A variants extracted from such populations differ from those expected if variants are due to alleles at a structural locus and indicate that such variants differ in alleles affecting the levels of particular isozymes. ODH patterns of monomorphic species strikingly resemble those of homozygous B, D, or A variants extracted from polymorphic populations ofD. pellewae, D. metzii, orD. albirostris which have been studied genetically by Pipkin (1968a, 1969) and Ogonji (1971). Based on these findings and previous work indicating that the ODH molecule is a polymer, an hypothesis is proposed that species differences in ODH patterns depend on differential activity of several ODH structural genes.This work was supported by NIH grant GM 18409-01 and NSF grant GB 8779. 相似文献
14.
Summary The reactivity was examined of horseradish peroxidase labelledUlex europaeus agglutinin-I (UEA-I) andGriffonia simplicifolia agglutinin I-B4 (GSAI-B4) with red blood cells and vascular endothelium in formalin-fixed, paraffin embedded tissues from 18 primate species. The expression of blood group ABH antigens in these cells as well as secretions from other tissues was also examined by the indirect immunoperoxidase method using monoclonal anti-ABH antibodies as primary antibodies. In Prosimians and New World monkeys which lack ABH antigens on both red blood cells and endothelial cells, but produce these antigens in other tissue secretions, GSAI-B4 always reacted with both red blood cells and endothelial cells. In Old World monkeys, which express blood group antigens on endothelial cells but not on red blood cells, neither GSAI-B4 nor UEA-I reactivity were observed, except the endothelial cells from blood group B or O individuals occasionally reacted with GSAI-B4 or UEA-I, respectively. Although UEA-I reactivity was not observed in the endothelial cells of gibbon, it reacted with these cells from chimpanzees. In these two anthropoid apes, both endothelial cells and red blood cells expressed ABH antigens as in humans. These results suggest the close evolutionary relationship between the expression of blood group ABH antigens and lectin binding properties of red blood cells and endothelial cells in primate species. 相似文献
15.
Extensive polymorphism of the FUT2 gene in an African (Xhosa) population of South Africa 总被引:2,自引:0,他引:2
Yuhua Liu Yoshiro Koda Mikiko Soejima H. Pang Terry Schlaphoff Ernette D. du Toit H. Kimura 《Human genetics》1998,103(2):204-210
The human secretor type α(1,2)fucosyltrans-ferase gene (FUT2) polymorphism was investigated in Xhosa and Caucasian populations of South Africa by polymerase chain reaction–restriction
fragment length polymorphism and DNA sequencing. Six new base substitutions were found in the coding region of FUT2. A single base (C) deletion at nucleotide 778, which led to a frame shift and produced a stop codon at codon 275, was responsible
for the enzyme inactivation. Three nonsynonymous base substitutions, A40G (Ile14Val), C379T (Arg127Cys), and G481A (Asp161Asn), and two synonymous base substitutions, A375G (Glu125) and C480T (His160), were also identified in functional alleles. As a result, seven new alleles, Se
40
, Se
481
, Se
40,481
, Se
357,480
, Se
357,379,480
, Se
375
, and se
357,480,778
were identified. Population studies revealed that an allele containing a nonsense mutation G428A (Trp143stop) (se
428
) was the common null allele in both Xhosa and Caucasian populations, whereas an allele containing a missense A385T (Ile129Phe) mutation (se
357,385
), which is the common null allele in Orientals, was found to be absent from both populations. The heterozygosity rates of
FUT2 genotypes were as high as 0.75 in the Xhosa population and 0.65 in the Caucasian population. Therefore, the extensive polymorphism
and race specificity of the FUT2 gene make it suitable for application as a new tool in genetic studies of modern human evolutionary history.
Received: 23 March 1998 / Accepted: 9 May 1998 相似文献
16.
R. Bernardo 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,85(8):1055-1062
Summary The coefficient of coancestry (fAB) between individuals A and B is the classical measure of genetic relationship. fAB is determined from pedigree records and is the probability that random alleles at the same locus in A and B are copies of the same ancestral allele or identical by descent (ibd). Recently, the proportion of molecular marker variants shared between A and B (SAB) has been used to measure genetic relationship. But SAB is an upwardly-biased estimator of fAB, especially between distantly-related lines. fAB, SAB, and adjusted (to remove bias) estimates of molecular marker similarity (f
AB
M
) were compared. RFLP banding patterns at 46 probe-restriction enzyme combinations were obtained for 23 maize inbred lines derived from the Iowa Stiff Stalk Synthetic (BSSS) maize (Zea mays L.) population, and for 4 non-BSSS lines. f
AB
M
was estimated as
, where
A (or
B) was the average proportion of RFLP variants shared between inbred A (or inbred B) and the non-BSSS lines. The average fAB among 253 pairwise combinations of BSSS lines was 0.212, whereas the average SAB was 0.397. The average f
AB
M
was 0.162, indicating that the upward bias in SAB was effectively removed. SAB and fAB were significantly different ( = 0.05) in 76.3% of the comparisons, whereas 24.9% of the f
AB
M
values differed significantly from fAB. The latter result suggests that selection and/or drift were present during inbred line development and that fAB may not be an accurate measure of the true proportion of ibd alleles between two lines. Cluster analyses based on S
AB
M
and f
AB
M
grouped lines according to pedigree, although several exceptions were noted. The presence of shared molecular marker variants between unrelated lines must be considered when setting SAB-based minimum distances for varietal protection. Under simplified conditions, more than 250 molecular marker loci are necessary to obtain sufficiently precise estimates of coefficient of coancestry using molecular markers.A contribution from Limagrain Genetics, a Group Limagrain company 相似文献
17.
M Matsui S Machida S M Feinstone T Akatsuka 《Biochemical and biophysical research communications》1999,261(1):46-52
In order to study the origin of the polymorphism of MHC class I molecules, we have cloned and sequenced five new Patr-A, -B, and -C loci alleles from two chimpanzees. Previous studies of sequence comparison between Patr and HLA class I alleles revealed that many of the sequence motifs were shared and the origin of class I molecules predated the divergence of chimpanzees and humans. These findings are confirmed by our current study. Additionally, our data suggest significant differences between mechanisms of evolution of the A, B, and C loci: (1) The B locus is characterized by frequent nucleotide substitutions, whereas the A and C loci are relatively more conserved; (2) However, unlike the A locus, the alpha2 domains of the C locus sequenced appear to produce MHC polymorphism between these species. These differences might imply the distinctive contributions of each locus during the evolutionary history. 相似文献
18.
Estela Paz-Artal Alfredo Corell Miguel Alvarez Pilar Varela Luis Allende Augustín Madroño Manuel Rosal Antonio Arnaiz-Villena 《Immunogenetics》1994,40(6):381-396
Eleven new C4d genomic primate sequences of the fourth complement factor (C4) have been obtained. Seven of them belong to five species not yet explored for this gene: Pan paniscus (pygmy chimpanzee), Cercopithecus aethiops (green monkey), Macaca mulatta (rhesus monkey), Macaca fascicularis (cynomolgus), and Saguinus oedipus (cotton top tamarin). The New World monkeys (tamarins, four individuals) sequenced for C4 have a single C4d sequence only, which shows a B isotypic specificity and a Rodgers 3 (Rg3), Chido 1 (Ch1) antigenicity. Rg3 and Ch1 could thus be the oldest Rg/Ch specificity (at least 50 million years old) and Rg1, Rg2, Ch3, and Ch6 could be more recent human-specific antigens. Mechanisms of C4d polymorphism generation were analyzed by compiling all the presently available sequences. Examples of both point mutations and crossing-over events among C4d primate sequences could be detected. The problem of a possible trans-species inheritance of C4d polymorphism was addressed and two apparently contradicting dendrograms were obtained. One of them, constructed by using both exon and intron sequences, does not support trans-species evolution, but supports the proposed theory of extensive homogenization of the C4 genes occurring within each species, because alleles from each primate species cluster together. Another completely different dendrogram, obtained by using exon sequences only, suggests the existence of trans-species evolution for C4d polymorphism, because alleles belonging to different species cluster together in a way similar to that found for HLA class I or II alleles. However, orangutan sequences group together in both kinds of C4d sequence dendrograms and seem to have arisen from an ancestor different from that of chimpanzee, gorilla and man C4d sequences. Finally, further data have been obtained that support trans-species conservation of A-ness and B-ness and the existence of trans-specifically conserved allelic motifs, both in intronic and exonic sequences. 相似文献
19.
Koichi Suzuki Misa Iwata Shigenori Ito Kiyoshi Matsui Atsuko Uchida Yasuhiko Mizoi 《Human genetics》1994,94(2):129-135
The “a” subunit of human coagulation factor XIII (F13A) exhibits genetic polymorphism defined by four common alleles, F13A*1A, *1B, *2A, and *2B. We have previously suggested on the basis of the isoelectric focusing patterns of the four allele products that point mutations at two separate sites and one intragenic crossing over might be involved in the genes of F13A polymorphism. Here, we report nucleotide substitutions associated with F13A polymorphism. A C/T transition of the second nucelotide of codon 564 in exon 12 is responsible for the difference between F13A*1A and *1B and that between F13A*2A and *2B, and a set of two base changes in codons 650 and 651 in exon 14 leads to the differences between F13A*1A and *2A and those between F13A*1B and *2B. The four combinations of the point mutations at the two exons thus correspond to the four alleles, two of which were generated by the point mutations from ancestral monomorphic gene. The results suggest strongly that intragenic crossing over must be involved in the genesis of the fourth allele. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods discriminating these base changes in exons 12 and 14 are also presented. 相似文献
20.
The I-region gene products of 29 wild-derivedH-2 haplotypes on a B10 background (B10.W congenic lines) were typed with alloantisera which detect 17 inbred I-region antigens. Five new I-region antigens were defined by expanding the inbred line panel ofH-2 haplotypes to includeH-2
u
, H-2v, andH-2
j
. Based on serological analyses of the inbred and B10.W lines, the polymorphism of theIA gene (or genes) is estimated to be at a minimum of 15 alleles and theIE gene (or genes) at a minimum of 4 alleles. These results indicate that theIA subregion is more polymorphic than theIE subregion. By combining the I-region typing data with theH-2K andH-2D region typing data reported previously, a total of 11 new natural recombinants of inbredH-2 alleles were detected among the B10.W lines. 相似文献