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Results for “Haplotype structures”

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PubMed2004

Genetic structure and population dynamics of Xanthomonas axonopodis pv. manihotis in Colombia from 1995 to 1999.

Restriction fragment length polymorphisms (RFLPs) were used to study the population genetics and temporal dynamics of the cassava bacterial pathogen Xanthomonas axonopodis pv. manihotis. The population dynamics were addressed by comparing samples collected from 1995 to 1999 from six locations, spanning four different edaphoclimatic zones (ECZs). Forty-five different X. axonopodis pv. manihotis RFLP types or haplotypes were identified between 1995 and 1999. High genetic diversity of the X. axonopodis pv. manihotis strains was evident within most of the fields sampled. In all but one site, diversity decreased over time within fields. Haplotype frequencies significantly differed over the years in all but one location. Studies of the rate of change of X. axonopodis pv. manihotis populations during the cropping cycle in two sites showed significant changes in the haplotype frequencies but not composition. However, variations in pathotype composition were observed from one year to the next at a single site in ECZs 1 and 2 and new pathotypes were described after 1997 in these ECZs, thus revealing the dramatic change in the pathogen population structure of X. axonopodis pv. manihotis. Disease incidence was used to show the progress of cassava bacterial blight in Colombia during the 5-year period in different ecosystems. Low disease incidence values were correlated with low rainfall in 1997 in ECZ 1.

Bacterial Proteins↗

PubMed2006

Testing introgressive hybridization hypotheses using statistical network analysis of nuclear and cytoplasmic haplotypes in the leaf beetle Timarcha goettingensis species complex.

Previous studies of leaf beetles (Chrysomelidae) in the Timarcha goettingensis species complex using mitochondrial (cox2) and nuclear (ITS-2 rRNA) markers revealed two main clades confined to the Iberian Peninsula and the rest of Europe but showing incongruent distributions indicative of gene exchange between both groups. Because of the anastomosing nature of hybridization, which disrupts the cladistic structure of character variation, phylogenetic trees might be inappropriate to represent and study this process. Here we test for evidence of hybridization in the T. goettingensis complex by analyzing the extra homoplasy arising in hybrid genomes from the simultaneous analysis of genetically independent markers. Haplotype networks obtained by Templeton's statistical parsimony analysis were generated for combined (concatenated) cox2 and ITS-2 sequences from 167 individuals of the T. goettingensis complex. Networks were used to detect runs of homoplasious characters physically clustered along a nucleotide sequence, as evidence for recombination between both gene partitions. A hypergeometric tail probability for the chance occurrence of physically clustered character changes on the connections linking networks of genotypes was applied. The test recognized two instances of statistically significant clustering, indicating the presence of cox2-ITS-2 mosaic genotypes and reticulation of both main T. goettingensis clades, supporting the reticulate origin of samples of T. maritima in southwestern France and T. sinuatocollis/T. monserratensis in the eastern Pyrenees. Although the assessment of reticulation in DNA sequences does not provide direct proof for hybridization, the geographical distribution of mosaic genotypes in the vicinity of "pure" genotypes supports the effect of gene flow between the two divergent lineages. The study demonstrates the utility of statistical parsimony networks for the detection of hybrids in the growing number of phylogeographic studies based on multiple gene markers.

Adaptor Proteins, Vesicular Transport↗

PubMed1991

Physical map of the 3' region of the human immunoglobulin heavy chain locus: clustering of autoantibody-related variable segments in one haplotype.

We have constructed the physical map of the 3' region of the human immunoglobulin heavy chain variable region (VH) genes. DNA segments extending to 200 kb upstream of the JH segment were isolated in two YAC clones. Five VH segments were identified in this region in the 5' to 3' order, V(II-5), V(IV-4), V(I-3), V(I-2), and V(VI-1) segments which were all structurally normal and orientated in the same direction as the JH segments. From DNA of a different cell line we have isolated a cosmid contig containing the same DNA region which has extraordinary polymorphism. The YAC and cosmid DNAs were called haplotypes A and B, respectively. Haplotype B contained an additional VH-I segment (V(I-4.1b)) between the V(II-5) and V(IV-4) segments. V(I-4.1b) segment is almost identical to a previously published VH sequence encoding a rheumatoid factor. Another VH segment in the B haplotype (V(I-3b)) corresponding to the V(I-3) segment also showed 99.7% nucleotide sequence homology with an anti-DNA autoantibody VH sequence. However, none of the VH sequences in haplotype A showed such strong homology with autoantibody VH sequences. The results suggest that VH haplotypes may have linkage with autoantibody production.

Amino Acid Sequence↗

PubMed1996

Mitochondrial DNA sequence variation in a sea star (Leptasterias spp.) species complex.

A 551-bp region of a PCR product containing the putative mitochondrial control region and flanking sequences was analyzed for sequence variation among 19 sea stars representing 10 previously described PCR-RFLP haplotypes within a cryptic species complex (Leptasterias spp.). Most (97%) of the sequence variation was interhaplotypic rather than intrahaplotypic, which greatly reduced the utility of sequence polymorphisms in this mtDNA region as markers of intrahaplotypic population structure and gene flow. The estimated number of transition and transversion substitutions per nucleotide site, corrected for multiple hits, was 0.0364 and 0.0158, respectively. Most of the sequence variation occurred in the first half of the putative control region. Phylogenetic analysis (both maximum parsimony and maximum likelihood) revealed three well-supported clades, but the position of two PCR-RFLP haplotypes was not completely resolved. Low intraspecific mtDNA sequence divergence over large geographic distances may be a general pattern for echinoderm species.

Animals↗

PubMed2005

High baseline serum total and LDL cholesterol levels are associated with MDR1 haplotypes in Brazilian hypercholesterolemic individuals of European descent.

The MDR1 gene encodes the P-glycoprotein, an efflux transporter with broad substrate specificity. P-glycoprotein has raised great interest in pharmacogenetics because it transports a variety of structurally divergent drugs, including lipid-lowering drugs. The synonymous single-nucleotide polymorphism C3435T and the nonsynonymous single-nucleotide polymorphism G2677T/A in MDR1 have been indicated as potential determinants of variability in drug disposition and efficacy. In order to evaluate the effect of G2677T/A and C3435T MDR1 polymorphisms on serum levels of lipids before and after atorvastatin administration, 69 unrelated hypercholesterolemic individuals from São Paulo city, Brazil, were selected and treated with 10 mg atorvastatin orally once daily for four weeks. MDR1 polymorphisms were analyzed by PCR-RFLP. C3435T and G2677T polymorphisms were found to be linked. The allelic frequencies for C3435T polymorphism were 0.536 and 0.464 for the 3435C and 3435T alleles, respectively, while for G2677T/A polymorphism allele frequencies were 0.580 for the 2677G allele, 0.384 for the 2677T allele and 0.036 for the 2677A allele. There was no significant relation between atorvastatin response and MDR1 polymorphisms (repeated measures ANOVA; P > 0.05). However, haplotype analysis revealed an association between T/T carriers and higher basal serum total (TC) and LDL cholesterol levels (TC: 303 +/- 56, LDL-C: 216 +/- 57 mg/dl, respectively) compared with non-T/T carriers (TC: 278 +/- 28, LDL-C: 189 +/- 24 mg/dl; repeated measures ANOVA/Tukey test; P < 0.05). These data indicate that MDR1 polymorphism may have an important contribution to the control of basal serum cholesterol levels in Brazilian hypercholesterolemic individuals of European descent.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1997

Comparative molecular phylogeography of two Xenopus species, X. gilli and X. laevis, in the south-western Cape Province, South Africa.

Xenopus gilli is a vulnerable anuran with a patchy distribution along the south-western coast of the Cape Province, South Africa. This species is sympatric with Xenopus laevis laevis, a widespread relative found over much of southern Africa. We examined the molecular phylogeography and population structure of the contact zone between these species to obtain information about historical biogeography and conservation management of this region. Analyses of the distribution, frequency, and cladistic and phenetic relationships among mitochondrial DNA haplotypes indicate that population subdivision is present in both taxa but that long-term isolation of sets of populations has occurred in X. gilli only. Haplotype and nucleotide diversity are also considerably higher within and among X. gilli ponds than X. l. laevis ponds in this region. We attribute the genetic segregation of X. gilli populations to ancient habitat fragmentation by ocean transgression into X. gilli habitat and to continued habitat alteration by human activity. The lower level of genetic diversity in X. L. laevis in this region is likely a result of a recent arrival of this taxon to the south-western Cape region relative to X. gilli. Population structure in X. l. laevis may be a result of isolation by distance. Clear evidence exists for at least two management units within X. gilli and strongly supports the establishment of protective measures east of False Bay in order to conserve a substantial portion of this species' extant genetic diversity.

Animals↗

PubMed2005

Cis-acting expression quantitative trait loci in mice.

We previously reported the analysis of genome-wide expression profiles and various diabetes-related traits in a segregating cross between inbred mouse strains C57BL/6J (B6) and DBA/2J (DBA). By considering transcript levels as quantitative traits, we identified several thousand expression quantitative trait loci (eQTL) with LOD score >4.3. We now experimentally address the problem of multiple comparisons by estimating the fraction of false-positive eQTL that are under cis-acting regulation. For this, we have utilized a classic cis-trans test with (B6 x DBA)F(1) mice to determine the relative levels of transcripts from the B6 and DBA alleles. The results suggest that at least 64% of cis-acting eQTL with LOD >4.3 are true positives, while the remaining 36% could not be confirmed as truly cis-acting. Moreover, we find that >96% of apparent cis-acting eQTL occur in regions that do not share SNP haplotypes. Cis-acting eQTL serve as an important new resource for the identification of positional candidates in QTL studies in mice. Also, we use the analysis of the correlation structures between genotypes, gene expression traits, and phenotypic traits to further characterize genes expressed in liver that are under cis-acting control, and highlight the advantages and disadvantages of integrating genetics and gene expression data in segregating populations.

Alleles↗

PubMed2026

Long-read sequencing resolves complex CYP21A2 variants and identifies 2+0 carriers in 21-hydroxylase deficiency.

The complex CYP21A2 variants arising from high homology with its pseudogene CYP21A1P challenge the diagnosis of 21-hydroxylase deficiency (21-OHD). This study systematically evaluated long-read sequencing (LRS) for identifying complex structural variants of the CYP21A2 gene in 21-OHD in comparison with conventional molecular diagnostic methods, including multiplex ligation-dependent probe amplification (MLPA), CNVplex, and SNaPshot. Twenty patients with suspected 21-OHD and defined CYP21A2 structural variants identified via initial MLPA screening were enrolled. Variants were further analyzed using CNVplex and SNaPshot, then all samples underwent LRS for comprehensive variant detection, breakpoint mapping, and haplotype resolution. LRS overcame key limitations of conventional methods. It reliably identified a novel large-fragment deletion and defined its boundaries. Notably, LRS identified "2+0" carriers, where deletions masked by duplications cause false-negatives with standard techniques. Moreover, LRS accurately distinguished CYP21A1P/CYP21A2_CH-4 and CH-9 chimera subtypes which were indistinguishable by the combined conventional assays. Furthermore, LRS enabled the precise identification and characterization of TNXA/TNXB chimeric deletions. These are frequently misclassified as CYP21A1P/CYP21A2 chimeras by conventional methods but are critical for diagnosing associated conditions such as CAH-X syndrome. LRS provides a superior, integrated solution for the molecular diagnosis of 21-OHD, offering precise structural variant characterization, accurate carrier detection, and reliable breakpoint mapping. Its application enhances diagnostic accuracy, supports advanced genetic counseling, and paves the way for genotype-informed clinical management.

Journal Article↗

PubMed1986

Immunogenicity in mice of the sequential polypeptides (Ala-Tyr-Glu-Gly)n, (Ala-Glu-Tyr-Gly)n, (Glu-Ala-Tyr-Gly)n and (Glu-Tyr-Ala-Gly)n and their linkage with the major histocompatibility complex.

The immunogenicity of the four sequential polymers of alpha-L-amino acids referred to below was studied in inbred strains of mice. The responses were linked to the H-2 haplotype, and the Ir genes controlling the responses were mapped to the IA region. The responses were restricted to two haplotypes as follows: (Ala-Tyr-Glu-Gly)n and (Ala-Glu-Tyr-Gly)n - H-2k; (Glu-Ala-Tyr-Gly)n - H-2b; (Glu-Tyr-Ala-Gly)n - H-2k and b. The absence of reciprocal crossreactions among all of these polymers, plus the sequential polymers (Tyr-Ala-Glu-Gly)n and (Tyr-Glu-Ala-Gly)n at both the antibody and T-cell levels, indicated that each of these six polymers was indeed structurally unique.

Amino Acid Sequence↗

PubMed1998

Positionally cloned gene for a novel glomerular protein--nephrin--is mutated in congenital nephrotic syndrome.

Congenital nephrotic syndrome of the Finnish type (NPHS1) is an autosomal-recessive disorder, characterized by massive proteinuria in utero and nephrosis at birth. In this study, the 150 kb critical region of NPHS1 was sequenced, revealing the presence of at least 11 genes, the structures of 5 of which were determined. Four different mutations segregating with the disease were found in one of the genes in NPHS1 patients. The NPHS1 gene product, termed nephrin, is a 1241-residue putative transmembrane protein of the immunoglobulin family of cell adhesion molecules, which by Northern and in situ hybridization was shown to be specifically expressed in renal glomeruli. The results demonstrate a crucial role for this protein in the development or function of the kidney filtration barrier.

Amino Acid Sequence↗

PubMed2004

Putative ancestral origins of chromosomal segments in individual african americans: implications for admixture mapping.

Theoretically, markers that distinguish European from West African ancestry can be used to examine the origin of chromosomal segments in individual African Americans. In this study, putative ancestral origin was examined by using haplotypes estimated from genotyping 268 African Americans for 29 ancestry informative markers spaced over a 60-cM segment of chromosome 5. Analyses using a Bayesian algorithm (STRUCTURE) provided evidence that blocks of individual chromosomes derive from one or the other parental population. In addition, modeling studies were performed by using hidden real marker data to simulate patient and control populations under different genotypic risk ratios. Ancestry analysis showed significant results for a genotypic risk ratio of 2.5 in the African American population for modeled susceptibility genes derived from either putative parental population. These studies suggest that admixture mapping in the African American population can provide a powerful approach to defining genetic factors for some disease phenotypes.

Black or African American↗

PubMed2006

Mitochondrial phylogeography and genetic diversity of Tibetan gazelle (Procapra picticaudata): implications for conservation.

The Tibetan gazelle (Procapra picticaudata) is a threatened species and distributed on the Qinghai-Tibet Plateau of China (Qinghai Province, Tibet Autonomous Region and the adjacent Gansu Province, Sichuan Province, and Xinjiang Uigur Autonomous Region). Small peripheral populations of Tibetan gazelle were once found in northern Sikkim and Ladakh, but now these are close to extinction. To describe the evolutionary history and to assess the genetic diversity within this monotypic species and population structure among different geographic locations in China, we sequenced mitochondrial DNA from the control region (CR) and cytochrome (cyt) b gene for 46 individuals from 12 geographic localities in Qinghai, Tibet, Xinjiang, Gansu, and Sichuan. A total of 25 CR haplotypes and 16 cyt b haplotypes were identified from these gazelle samples. CR haplotype diversity (0.98+/-0.01) and nucleotide diversity (0.08+/-0.009) were both high. Phylogenetic trees indicate that the Tibetan gazelle in China can be divided into three main clades: Tibet, Sichuan (SCH) and Qinghai-Arjin Shan-Kekexili (QH-ARJ-KKXL). Analysis of molecular variance (AMOVA) and network analysis consistently support this geographic structure in both datasets. Significant differentiation between populations argues for the presence of management units (MUs). Such differentiation may reflect a geographic separation resulting from the uplift of the Qinghai-Tibet Plateau during the Late Pliocene and Pleistocene. Mismatch distribution analysis implies that Tibetan gazelle has undergone complex population changes. We suggest that the present population structure has resulted from habitat fragmentation during the recent glacial period on the Qinghai-Tibet Plateau and population expansion from glacial refugia after the glacial period. It is likely that the present populations of Tibetan gazelle exhibit a pattern reminiscent of several bottlenecks and expansions in the recent past.

Animals↗

PubMed1994

Determination of amino acids on agretopes of pigeon cytochrome c-related peptides specifically bound to I-A allelic products.

In our prior study it was demonstrated that residues 46 and 54 on a synthetic peptide, AEGFSYTVANKNKGIT (50V), work as an agretope (site contacts with major histocompatibility complex molecules) and residues 50 and 52 function as an epitope (site contacts with T cell receptor), when tri-molecular complexes are formed among 50V,I-Ab and the T cell receptor. 50V was composed of residues 43 to 58 of pigeon cytochrome c (p43-58) except that the aspartic acid (D) at residue 50 was substituted by valine (V). Substitution of agretopic residues on 50V changed this I-Ab-binding peptide to an I-Ak-binding peptide, suggesting that positions 46 and 54 work as an agretope in I-Ak-restricted T cell responses. In the present study we examined whether residues 46 and 54 of 50V worked as agretopes in T cell responses restricted to other I-A haplotypes. The 50V-related peptides with phenylalanine (F) at position 46 and alanine (A) at position 54 bound tightly to I-Ab, I-Ad, I-Aq and I-As molecules and stimulated T cells most potently in mice bearing these I-A haplotypes. In contrast, 50V-related peptides carrying D at position 46 and A at position 54 bound most potently to I-Ak molecules, and the peptides with arginine (R) at position 46 and A at position 54 bound most efficiently to I-Av molecules. The present findings, thus, demonstrate that the agretopic positions on the p43-58 related peptides are preserved in T cell responses restricted to each I-A haplotype studied, and that the specific amino acids on the agretopic positions exist a priori for each I-A allele-specific structure.

Amino Acid Sequence↗

PubMed1999

Phylogeny, biogeography, and processes of molecular differentiation in Quercus subgenus Quercus (Fagaceae).

Quercus is one of the most abundant and economically important genera of woody plants in the Northern Hemisphere. To infer phylogenetic relationships within Quercus subgenus Quercus, chloroplast DNA (cpDNA) restriction sites and nucleotide sequences of the internal transcribed spacers (ITS) and the 5.8S coding region of the nuclear ribosomal DNA repeat were obtained for 44 individuals, including 25 species, intraspecific samples, and three outgroups. Separate parsimony analyses of each data set showed that individual gene trees were congruent and often complementary in supporting clades that generally corresponded to previously recognized taxonomic groups. Only one instance of strongly supported gene tree incongruence was detected and this anomalous pattern was explained best by ancient introgression of cpDNA across sectional boundaries. Simultaneous parsimony analysis of the pruned data sets supported the recognition of the strictly Eurasian section Cerris and resolved a novel hypothesis for the major infrageneric groups (Cerris- (Lobatae- (Protobalanus + Quercus sensu stricto))). The biogeographic hypothesis that all major oak lineages evolved locally at middle latitudes within the general distribution of their fossil ancestors was fully supported. This set of relationships also suggested a New World origin for the widespread white oaks of the Northern Hemisphere (section Quercus s. s.). For both data sets, inter- and intraspecific sampling within section Protobalanus showed little correspondence to morphological species. Greater cladistic structure among the samples was obtained by cpDNA restriction sites and two well-delimited plastomes types comprising a total of 15 distinct haplotypes were resolved. Haplotypes of 2 of the peripheral species in this species complex occupy terminal portions of one of the plastome clades, suggesting a more recent origin relative to those of more widespread species. The phylogeography of the two divergent plastome types suggested a north-south pattern, consistent with a Late Tertiary disjunction in the ancestral distribution of section Protobalanus.

Cell Nucleus↗

PubMed1995

Karyomegalic interstitial nephritis: further support for a distinct entity and evidence for a genetic defect.

Karyomegalic interstitial nephritis was first described in 1979 by Mihatsch, who was reporting three such cases. We report here four additional cases as well as two family investigations. Our findings support the association of karyomegaly and interstitial nephritis as a distinct entity. Typical clinical features are asymptomatic progressive renal failure in the third decade of life and recurrent infections, mostly of the upper respiratory tract. Histologic alterations consist of markedly enlarged and hyperchromic nuclei in many tubular epithelial cells throughout the nephron accompanied by interstitial fibrosis in the surrounding atrophic tubules. Karyomegaly is not limited to the kidneys. In one case, autopsy revealed karyomegaly in epithelial and mesenchymal cells of many other organs. However, no association of karyomegaly with further histologic damage is evident except in the kidneys. Because of the familial clustering, karyomegalic interstitial nephritis seems to be an inherited disease. Examination of the nuclear proliferation-associated structures proliferating cell nuclear antigen/cyclin, Ki 67, and p53 suggests an inhibition of mitosis in karyomegalic cells. The finding of the same HLA haplotype, A9/B35, in four of six HLA-typed cases suggests the possibility of a genetic defect on chromosome 6, which is inherited and linked to the HLA locus.

Adult↗

PubMed2005

Gene flow across linguistic boundaries in Native North American populations.

Cultural and linguistic groups are often expected to represent genetic populations. In this article, we tested the hypothesis that the hierarchical classification of languages proposed by J. Greenberg [(1987) Language in the Americas (Stanford Univ. Press, Stanford, CA)] also represents the genetic structure of Native North American populations. The genetic data are mtDNA sequences for 17 populations gleaned from literature sources and public databases. The hypothesis was rejected. Further analysis showed that departure of the genetic structure from the linguistic classification was pervasive and not due to an outlier population or a problematic language group. Therefore, Greenberg's language groups are at best an imperfect approximation to the genetic structure of these populations. Moreover, we show that the genetic structure among these Native North American populations departs significantly from the best-fitting hierarchical models. Analysis of median joining networks for mtDNA haplotypes provides strong evidence for gene flow across linguistic boundaries. In principle, the language of a population can be replaced more rapidly than its genes because language can be transmitted both vertically from parents to children and horizontally between unrelated people. However, languages are part of a cultural complex, and there may be strong pressure to maintain a language in place whereas genes are free to flow.

DNA, Mitochondrial↗

PubMed1984

HLA-linked congenital adrenal hyperplasia results from a defective gene encoding a cytochrome P-450 specific for steroid 21-hydroxylation.

We have determined the molecular genetic basis of congenital adrenal hyperplasia due to 21-hydroxylase (21-OHase) deficiency. This common disorder of cortisol biosynthesis is HLA-linked. The haplotype HLA-(A3);Bw47;DR7 is strongly associated with 21-OHase deficiency and always carries a null allele at the locus encoding the C4A (Rodgers) form of the fourth component (C4) of complement. It seemed likely that this haplotype carries a deletion encompassing the genes encoding both C4A and 21-OHase. We hypothesized that the HLA-linked defect involved a structural gene for the adrenal microsomal cytochrome P-450 specific for steroid 21-hydroxylation. Using a plasmid with a 520-base-pair bovine adrenal cDNA insert encoding the middle third of the cytochrome P-450 polypeptide, we compared hybridization patterns in DNA from normal and 21-OHase-deficient individuals. Normal human DNA yielded two fragments that hybridized with the probe after digestion with either restriction endonuclease EcoRI [12- and 14-kilobase (kb) fragments] or Taq I (3.7 and 3.2 kb). One of these bands (the first mentioned in each digest) was absent in DNA from a cell line derived from a patient homozygous for HLA-Bw47. DNA from six unrelated patients homozygous for 21-OHase deficiency who were heterozygous for HLA-Bw47 yielded diminished relative intensity of the 3.7-kb Taq I band in five patients, consistent with a heterozygous deletion, and complete disappearance of the 3.7-kb band in one. This deletion segregated with HLA-Bw47 in a large pedigree carrying 21-OHase deficiency and HLA-Bw47. Thus, 21-OHase deficiency sometimes results from the deletion of a specific cytochrome P-450 gene and sometimes, presumably, from smaller mutations. This gene is probably located very near the C4A gene.

Adrenal Hyperplasia, Congenital↗

PubMedDate not supplied

Molecular identification of evolutionarily significant units in the Amazon River dolphin Inia sp. (Cetacea: Iniidae).

The Amazon river dolphin, genus Inia, is endemic to the major river basins of northern South America. No previous studies have focused on the genetic structure of this genus. In this work, 96 DNA samples from specimens of this genus were collected in the Orinoco basin (four rivers), the Putumayo River, a tributary of the Colombian Amazon and the Mamoré, and the Tijamuchí and Ipurupuru rivers in theBolivian Amazon. These samples were used to amplify a fragment of 400 bp of the mitochondrial DNA (mtDNA) control region. In addition, 38 of these samples were also used to sequence 600 bp of the mitochondrial cytochrome b gene. The analysis of the population structure subdivision with an analysis of molecular variance (AMOVA) revealed important aspects about the genetic structure of Inia groups fromthese three geographically separate regions. By comparing the control region DNA and cytochrome b sequences, distinct types of nonshared haplotypes were observed. The net genetic divergence of control region sequences was 6.53% between the Orinoco and Bolivian rivers, 5.32% between the Putumayo and Bolivian rivers, and 2.50% between the Orinoco and Putumayo rivers. For the cytochrome b gene, these values were 2.48%, 2.98%, and 0.06%, respectively. The nucleotide sequences were analyzed phylogenetically using several genetic distance matrices and applying neighbor-joining, maximum likelihood, and maximum parsimony procedures. The results support the proposal to subdivide the Inia genus into at least two evolutionarily significant units: one confined to the Bolivian river basin and the other widely distributed across the Amazon and Orinoco basins.

Animals↗