1
|
Mapsembler, targeted and micro assembly of large NGS datasets on a desktop computer. BMC Bioinformatics 2012; 13:48. [PMID: 22443449 PMCID: PMC3514201 DOI: 10.1186/1471-2105-13-48] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 02/24/2012] [Indexed: 11/16/2022] Open
Abstract
Background The analysis of next-generation sequencing data from large genomes is a timely research topic. Sequencers are producing billions of short sequence fragments from newly sequenced organisms. Computational methods for reconstructing whole genomes/transcriptomes (de novo assemblers) are typically employed to process such data. However, these methods require large memory resources and computation time. Many basic biological questions could be answered targeting specific information in the reads, thus avoiding complete assembly. Results We present Mapsembler, an iterative micro and targeted assembler which processes large datasets of reads on commodity hardware. Mapsembler checks for the presence of given regions of interest that can be constructed from reads and builds a short assembly around it, either as a plain sequence or as a graph, showing contextual structure. We introduce new algorithms to retrieve approximate occurrences of a sequence from reads and construct an extension graph. Among other results presented in this paper, Mapsembler enabled to retrieve previously described human breast cancer candidate fusion genes, and to detect new ones not previously known. Conclusions Mapsembler is the first software that enables de novo discovery around a region of interest of repeats, SNPs, exon skipping, gene fusion, as well as other structural events, directly from raw sequencing reads. As indexing is localized, the memory footprint of Mapsembler is negligible. Mapsembler is released under the CeCILL license and can be freely downloaded from
http://alcovna.genouest.org/mapsembler/.
Collapse
|
2
|
Amorim CEG, Gontijo CC, Falcão-Alencar G, Godinho NMO, Toledo RCP, Pedrosa MAF, Luizon MR, Simões AL, Klautau-Guimãres MN, Oliveira SF. Migration in Afro-Brazilian rural communities: crossing demographic and genetic data. Hum Biol 2012; 83:509-21. [PMID: 21846207 DOI: 10.3378/027.083.0405] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Many studies have used genetic markers to understand global migration patterns of our species. However, there are only few studies of human migration on a local scale. We, therefore, researched migration dynamics in three Afro-Brazilian rural communities, using demographic data and ten Ancestry Informative Markers. In addition to the description of migration and marriage structures, we carried out genetic comparisons between the three populations, as well as between locals and migrants from each community. Genetic admixture analyses were conducted according to the gene-identity method, with Sub-Saharan Africans, Amerindians, and Europeans as parental populations. The three analyzed Afro-Brazilian rural communities consisted of 16% to 30% of migrants, most of them women. The age pyramid revealed a gap in the segment of men aged between 20 to 30 yrs. While endogamous marriages predominated, exogamous marriages were mainly patrilocal. Migration dynamics are apparently associated with matrimonial customs and other social practices of such communities. The impact of migration upon the populations' genetic composition was low but showed an increase in European alleles with a concomitant decrease in the Amerindian contribution. Admixture analysis evidenced a higher African contribution to the gene pool of the studied populations, followed by the contribution of Europeans and Amerindians, respectively.
Collapse
Affiliation(s)
- Carlos Eduardo G Amorim
- Departamento de Genética e Morfologia, Instituto de Ciências Biológicas, Universidade de Brasilia, Brasilia, DF, Brazil.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
3
|
Mixed origin of the current Tunisian population from the analysis of Alu and Alu/STR compound systems. J Hum Genet 2010; 55:827-33. [DOI: 10.1038/jhg.2010.120] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
4
|
Ennafaa H, Amor MB, Yacoubi-Loueslati B, Khodjet el-khil H, Gonzalez-Perez E, Moral P, Maca-Meyer N, Elgaaied A. Alu polymorphisms in Jerba Island population (Tunisia): Comparative study in Arab and Berber groups. Ann Hum Biol 2009; 33:634-40. [PMID: 17381061 DOI: 10.1080/03014460600931087] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Jerba Island represents an interesting area because four distinct ethnic groups have been cohabiting there until now: Arabs, Berbers, dark-skinned people of sub-Saharan origin and Jews. Religious and cultural differences seem to have constituted an obstacle to their intermixing. Our aim is to provide further information on the genetic structure of the Arab and Berber groups for whom previous data based on haploid markers confirmed their reproductive isolation. Five polymorphic Alu markers (HS 4.69, Sb 19.3, TPA-25, ACE and APO-A1) were analysed in a sample of 43 Arabs and 48 Berbers of Jerba. The genetic relationships among these groups and several populations from North Africa, sub-Saharan Africa and Europe were analysed using genetic distances based on allele frequencies. The results showed a homogeneous distribution of Alu insertions in the two geographically close groups, reflecting ancient relationships between them. This study also revealed that Arabs from Jerba present close genetic distances to other North African populations, whilst Berbers of Jerba occupy an intermediate position among Mediterranean populations.
Collapse
Affiliation(s)
- Hajer Ennafaa
- Laboratory of Genetics, Immunology and Human Pathologies, Faculty of Sciences of Tunis, Tunis, Tunisia.
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Kutuev I, Khusainova R, Karunas A, Yunusbayev B, Fedorova S, Lebedev Y, Hunsmann G, Khusnutdinova E. From East to West: Patterns of Genetic Diversity of Populations Living in Four Eurasian Regions. Hum Hered 2006; 61:1-9. [PMID: 16465065 DOI: 10.1159/000091309] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2004] [Accepted: 11/26/2005] [Indexed: 11/19/2022] Open
Abstract
We have analyzed the distribution and patterns of the genetic diversity of eight Alu loci (ACE, ApoA1, PV92, TPA25, NBC27, NBC102, NBC148, and NBC182) in 1,049 individuals representing 16 populations of the Volga-Ural region (Bashkirs, Tatars, Komis, Maris, Mordvins, and Udmurts), Central Asia (Kazakhs, Uzbeks, and Uighurs), the North Caucasus (Karachays, Kumyks, Kuban Nogays, and Karanogays), and Central South Siberia (Yakuts, Kalmyks and Evenks). Geographic divide between Europe and Asia, e.g. the Ural Mountains and the Caspian Sea, can also be considered as a genetic boundary. The data indicates that the populations of the two boundary regions between Europe and Asia, the Volga-Ural region of Russia, and populations of the North Caucasus are more similar to European than to Asian populations. Finally, Siberian and Central Asian populations are genetically closely related to each other.
Collapse
Affiliation(s)
- I Kutuev
- Institute of Biochemistry and Genetics of Ufa Science Center of Russian Academy of Sciences, Ufa, Russia.
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Cordaux R, Lee J, Dinoso L, Batzer MA. Recently integrated Alu retrotransposons are essentially neutral residents of the human genome. Gene 2006; 373:138-44. [PMID: 16527433 DOI: 10.1016/j.gene.2006.01.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 01/18/2006] [Accepted: 01/21/2006] [Indexed: 10/24/2022]
Abstract
Alu elements represent the largest family of human mobile elements in copy number. A controversial issue with implications for both Alu biology and human genome evolution is whether selective pressures are affecting Alu elements on a large scale. To address this issue, we analyzed the genomic distribution of the three youngest known human Alu subfamilies (Ya5a2, Ya8 and Yb9) in conjunction with their insertion polymorphism status in the human population, since selection can only act on polymorphic elements. Our results indicate that: (i) polymorphic and fixed recently integrated Alu elements are found in genomic regions whose GC contents are statistically indistinguishable, and (ii) recently integrated Alu elements are inserted randomly, regardless of the GC content of the surrounding genomic DNA. These results provide strong evidence that recently integrated "young" Alu elements are not subject to positive or negative selection on a large scale. Therefore, young Alu elements can be regarded as essentially neutral residents of the human genome. These results also imply that selective processes specifically targeting Alu elements can be ruled out as explanations for the accumulation of Alu elements in GC-rich regions of the human genome.
Collapse
Affiliation(s)
- Richard Cordaux
- Department of Biological Sciences, Biological Computation and Visualization Center, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, USA
| | | | | | | |
Collapse
|
7
|
Thornburg BG, Gotea V, Makałowski W. Transposable elements as a significant source of transcription regulating signals. Gene 2006; 365:104-10. [PMID: 16376497 DOI: 10.1016/j.gene.2005.09.036] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2005] [Revised: 09/06/2005] [Accepted: 09/27/2005] [Indexed: 10/25/2022]
Abstract
Transposable elements (TEs) are major components of eukaryotic genomes, contributing about 50% to the size of mammalian genomes. TEs serve as recombination hot spots and may acquire specific cellular functions, such as controlling protein translation and gene transcription. The latter is the subject of the analysis presented. We scanned TE sequences located in promoter regions of all annotated genes in the human genome for their content in potential transcription regulating signals. All investigated signals are likely to be over-represented in at least one TE class, which shows that TEs have an important potential to contribute to pre-transcriptional gene regulation, especially by moving transcriptional signals within the genome and thus potentially leading to new gene expression patterns. We also found that some TE classes are more likely than others to carry transcription regulating signals, which can explain why they have different retention rates in regions neighboring genes.
Collapse
Affiliation(s)
- Bartley G Thornburg
- Institute of Molecular Evolutionary Genetics and Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
| | | | | |
Collapse
|
8
|
Abstract
Background Alu elements are short (~300 bp) interspersed elements that amplify in primate genomes through a process termed retroposition. The expansion of these elements has had a significant impact on the structure and function of primate genomes. Approximately 10 % of the mass of the human genome is comprised of Alu elements, making them the most abundant short interspersed element (SINE) in our genome. The majority of Alu amplification occurred early in primate evolution, and the current rate of Alu retroposition is at least 100 fold slower than the peak of amplification that occurred 30–50 million years ago. Alu elements are therefore a rich source of inter- and intra-species primate genomic variation. Results A total of 153 Alu elements from the Ye subfamily were extracted from the draft sequence of the human genome. Analysis of these elements resulted in the discovery of two new Alu subfamilies, Ye4 and Ye6, complementing the previously described Ye5 subfamily. DNA sequence analysis of each of the Alu Ye subfamilies yielded average age estimates of ~14, ~13 and ~9.5 million years old for the Alu Ye4, Ye5 and Ye6 subfamilies, respectively. In addition, 120 Alu Ye4, Ye5 and Ye6 loci were screened using polymerase chain reaction (PCR) assays to determine their phylogenetic origin and levels of human genomic diversity. Conclusion The Alu Ye lineage appears to have started amplifying relatively early in primate evolution and continued propagating at a low level as many of its members are found in a variety of hominoid (humans, greater and lesser ape) genomes. Detailed sequence analysis of several Alu pre-integration sites indicated that multiple types of events had occurred, including gene conversions, near-parallel independent insertions of different Alu elements and Alu-mediated genomic deletions. A potential hotspot for Alu insertion in the Fer1L3 gene on chromosome 10 was also identified.
Collapse
|
9
|
Salem AH, Ray DA, Batzer MA. Identity by descent and DNA sequence variation of human SINE and LINE elements. Cytogenet Genome Res 2004; 108:63-72. [PMID: 15545717 DOI: 10.1159/000080803] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2003] [Accepted: 11/21/2003] [Indexed: 11/19/2022] Open
Abstract
To test the hypothesis that Alu and L1 elements are genetic characters that are essentially homoplasy-free, we sequenced a total of five human L1 elements and eleven recently integrated Alu elements from 160 chromosomes (80 individuals representing four diverse human populations). Analysis of worldwide samples at L1 loci revealed 292 segregating sites and a nucleotide diversity of 0.0050. For Ya5 Alu loci, there were 129 segregating sites and nucleotide diversity was estimated at 0.0045. The Alu and L1 sequence diversity varied element to element. No completely or partially deleted Alu or L1 alleles were identified during the analysis. These data suggest that mobile element insertions are identical by descent characters for the study of human population genetics.
Collapse
Affiliation(s)
- A-H Salem
- Department of Biological Sciences, Biological Computation and Visualization Center, Louisiana State University, Baton Rouge 70803, USA
| | | | | |
Collapse
|
10
|
Evolution and distribution of RNA polymerase II regulatory sites from RNA polymerase III dependant mobile Alu elements. BMC Evol Biol 2004; 4:37. [PMID: 15461819 PMCID: PMC524483 DOI: 10.1186/1471-2148-4-37] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2004] [Accepted: 10/04/2004] [Indexed: 11/24/2022] Open
Abstract
Background The primate-specific Alu elements, which originated 65 million years ago, exist in over a million copies in the human genome. These elements have been involved in genome shuffling and various diseases not only through retrotransposition but also through large scale Alu-Alu mediated recombination. Only a few subfamilies of Alus are currently retropositionally active and show insertion/deletion polymorphisms with associated phenotypes. Retroposition occurs by means of RNA intermediates synthesised by a RNA polymerase III promoter residing in the A-Box and B-Box in these elements. Alus have also been shown to harbour a number of transcription factor binding sites, as well as hormone responsive elements. The distribution of Alus has been shown to be non-random in the human genome and these elements are increasingly being implicated in diverse functions such as transcription, translation, response to stress, nucleosome positioning and imprinting. Results We conducted a retrospective analysis of putative functional sites, such as the RNA pol III promoter elements, pol II regulatory elements like hormone responsive elements and ligand-activated receptor binding sites, in Alus of various evolutionary ages. We observe a progressive loss of the RNA pol III transcriptional potential with concomitant accumulation of RNA pol II regulatory sites. We also observe a significant over-representation of Alus harboring these sites in promoter regions of signaling and metabolism genes of chromosome 22, when compared to genes of information pathway components, structural and transport proteins. This difference is not so significant between functional categories in the intronic regions of the same genes. Conclusions Our study clearly suggests that Alu elements, through retrotransposition, could distribute functional and regulatable promoter elements, which in the course of subsequent selection might be stabilized in the genome. Exaptation of regulatory elements in the preexisting genes through Alus could thus have contributed to evolution of novel regulatory networks in the primate genomes. With such a wide spectrum of regulatory sites present in Alus, it also becomes imperative to screen for variations in these sites in candidate genes, which are otherwise repeat-masked in studies pertaining to identification of predisposition markers.
Collapse
|
11
|
Otieno AC, Carter AB, Hedges DJ, Walker JA, Ray DA, Garber RK, Anders BA, Stoilova N, Laborde ME, Fowlkes JD, Huang CH, Perodeau B, Batzer MA. Analysis of the Human Alu Ya-lineage. J Mol Biol 2004; 342:109-18. [PMID: 15313610 DOI: 10.1016/j.jmb.2004.07.016] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2004] [Revised: 07/08/2004] [Accepted: 07/12/2004] [Indexed: 11/22/2022]
Abstract
The Alu Ya-lineage is a group of related, short interspersed elements (SINEs) found in primates. This lineage includes subfamilies Ya1-Ya5, Ya5a2 and others. Some of these subfamilies are still actively mobilizing in the human genome. We have analyzed 2482 elements that reside in the human genome draft sequence and focused our analyses on the 2318 human autosomal Ya Alu elements. A total of 1470 autosomal loci were subjected to polymerase chain reaction (PCR)-based assays that allow analysis of individual Ya-lineage Alu elements. About 22% (313/1452) of the Ya-lineage Alu elements were polymorphic for the insertion presence on human autosomes. Less than 0.01% (5/1452) of the Ya-lineage loci analyzed displayed insertions in orthologous loci in non-human primate genomes. DNA sequence analysis of the orthologous inserts showed that the orthologous loci contained older pre-existing Y, Sc or Sq Alu subfamily elements that were the result of parallel forward insertions or involved in gene conversion events in the human lineage. This study is the largest analysis of a group of "young", evolutionarily related human subfamilies. The size, evolutionary age and variable allele insertion frequencies of several of these subfamilies makes members of the Ya-lineage useful tools for human population studies and primate phylogenetics.
Collapse
Affiliation(s)
- Anthony C Otieno
- Department of Biological Sciences, Biological Computation and Visualization Center, Center for Bio-Modular Microsystems, Louisiana State University, 202 Life Sciences Building, Baton Rouge 70803, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Xing J, Salem AH, Hedges DJ, Kilroy GE, Watkins WS, Schienman JE, Stewart CB, Jurka J, Jorde LB, Batzer MA. Comprehensive analysis of two Alu Yd subfamilies. J Mol Evol 2004; 57 Suppl 1:S76-89. [PMID: 15008405 DOI: 10.1007/s00239-003-0009-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alu elements have inserted in the human genome throughout primate evolution. A small number of Alu insertions have occurred after the divergence of humans from nonhuman primates and therefore should not be present in nonhuman primate genomes. Most of these recently integrated Alu elements are contained with a series of discrete Alu subfamilies that are related to each other based upon diagnostic nucleotide substitutions. We have extracted members of the Alu Yd subfamily that are derivatives of the Alu Y subfamily that share a common 12-bp deletion that defines the Yd lineage from the draft sequence of the human genome. Analysis of the Yd Alu elements resulted in the recovery of two new Alu subfamilies, Yd3 and Yd6, which contain a total of 295 members (198 Yd3 and 97 Yd6). DNA sequence analysis of each of the Alu Yd subfamilies yielded age estimates of 8.02 and 1.20 million years old for the Alu Yd3 and Yd6 subfamilies, respectively. Two hundred Alu Yd3 and Yd6 loci were screened using polymerase chain reaction (PCR) assays to determine their phylogenetic origin and associated levels of human genomic diversity. The Alu Yd3 subfamily appears to have started amplifying relatively early in primate evolution and continued propagating albeit at a low level as many of its members are found in a variety of hominoid (humans, greater and lesser ape) genomes. Only two of the elements are polymorphic in the human genome and absent from the genomes of nonhuman primates. By contrast all of the members of the Alu Yd6 subfamily are restricted to the human genome, with 12% of the elements representing insertion polymorphisms in human populations. A single Alu Yd6 locus contained an independent parallel forward insertion of a paralogous Alu Sq sequence in the owl monkey. These Alu subfamilies are a source of genomic fossil relics for the study of primate phylogenetics and human population genetics.
Collapse
Affiliation(s)
- Jinchuan Xing
- Department of Biological Sciences, Biological Computation and Visualization Center, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Carter AB, Salem AH, Hedges DJ, Keegan CN, Kimball B, Walker JA, Watkins WS, Jorde LB, Batzer MA. Genome-wide analysis of the human Alu Yb-lineage. Hum Genomics 2004; 1:167-78. [PMID: 15588477 PMCID: PMC3525081 DOI: 10.1186/1479-7364-1-3-167] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2003] [Accepted: 12/10/2003] [Indexed: 11/10/2022] Open
Abstract
The Alu Yb-lineage is a 'young' primarily human-specific group of short interspersed element (SINE) subfamilies that have integrated throughout the human genome. In this study, we have computationally screened the draft sequence of the human genome for Alu Yb-lineage subfamily members present on autosomal chromosomes. A total of 1,733 Yb Alu subfamily members have integrated into human autosomes. The average ages of Yb-lineage subfamilies, Yb7, Yb8 and Yb9, are estimated as 4.81, 2.39 and 2.32 million years, respectively. In order to determine the contribution of the Alu Yb-lineage to human genomic diversity, 1,202 loci were analysed using polymerase chain reaction (PCR)-based assays, which amplify the genomic regions containing individual Yb-lineage subfamily members. Approximately 20 percent of the Yb-lineage Alu elements are polymorphic for insertion presence/absence in the human genome. Fewer than 0.5 percent of the Yb loci also demonstrate insertions at orthologous positions in non-human primate genomes. Genomic sequencing of these unusual loci demonstrates that each of the orthologous loci from non-human primate genomes contains older Y, Sg and Sx Alu family members that have been altered, through various mechanisms, into Yb8 sequences. These data suggest that Alu Yb-lineage subfamily members are largely restricted to the human genome. The high copy number, level of insertion polymorphism and estimated age indicate that members of the Alu Yb elements will be useful in a wide range of genetic analyses.
Collapse
Affiliation(s)
- Anthony B Carter
- Department of Biological Sciences, Biological Computation and Visualization Center, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, USA
| | - Abdel-Halim Salem
- Department of Biological Sciences, Biological Computation and Visualization Center, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, USA
- Department of Anatomy, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | - Dale J Hedges
- Department of Biological Sciences, Biological Computation and Visualization Center, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, USA
| | - Catherine Nguyen Keegan
- Department of Pathology, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112, USA
| | - Beth Kimball
- Department of Pathology, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112, USA
| | - Jerilyn A Walker
- Department of Biological Sciences, Biological Computation and Visualization Center, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, USA
| | - W Scott Watkins
- Department of Human Genetics, University of Utah Health Sciences Center, Salt Lake City, UT 84112, USA
| | - Lynn B Jorde
- Department of Human Genetics, University of Utah Health Sciences Center, Salt Lake City, UT 84112, USA
| | - Mark A Batzer
- Department of Biological Sciences, Biological Computation and Visualization Center, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, USA
- Department of Pathology, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112, USA
| |
Collapse
|
14
|
Salem AH, Ray DA, Xing J, Callinan PA, Myers JS, Hedges DJ, Garber RK, Witherspoon DJ, Jorde LB, Batzer MA. Alu elements and hominid phylogenetics. Proc Natl Acad Sci U S A 2003; 100:12787-91. [PMID: 14561894 PMCID: PMC240696 DOI: 10.1073/pnas.2133766100] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2003] [Indexed: 01/12/2023] Open
Abstract
Alu elements have inserted in primate genomes throughout the evolution of the order. One particular Alu lineage (Ye) began amplifying relatively early in hominid evolution and continued propagating at a low level as many of its members are found in a variety of hominid genomes. This study represents the first conclusive application of short interspersed elements, which are considered nearly homoplasy-free, to elucidate the phylogeny of hominids. Phylogenetic analysis of Alu Ye5 elements and elements from several other subfamilies reveals high levels of support for monophyly of Hominidae, tribe Hominini and subtribe Hominina. Here we present the strongest evidence reported to date for a sister relationship between humans and chimpanzees while clearly distinguishing the chimpanzee and human lineages.
Collapse
Affiliation(s)
- Abdel-Halim Salem
- Department of Biological Sciences, Biological Computation and Visualization Center, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Callinan PA, Hedges DJ, Salem AH, Xing J, Walker JA, Garber RK, Watkins WS, Bamshad MJ, Jorde LB, Batzer MA. Comprehensive analysis of Alu-associated diversity on the human sex chromosomes. Gene 2003; 317:103-10. [PMID: 14604797 DOI: 10.1016/s0378-1119(03)00662-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A comprehensive analysis of the human sex chromosomes was undertaken to assess Alu-associated human genomic diversity and to identify novel Alu insertion polymorphisms for the study of human evolution. Three hundred forty-five recently integrated Alu elements from eight different Alu subfamilies were identified on the X and Y chromosomes, 225 of which were selected and analyzed by polymerase chain reaction (PCR). From a total of 225 elements analyzed, 16 were found to be polymorphic on the X chromosome and one on the Y chromosome. In line with previous research using other classes of genetic markers, our results indicate reduced Alu-associated insertion polymorphism on the human sex chromosomes, presumably reflective of the reduced recombination rates and lower effective population sizes on the sex chromosomes. The Alu insertion polymorphisms identified in this study should prove useful for the study of human population genetics.
Collapse
Affiliation(s)
- Pauline A Callinan
- Department of Biological Sciences, Biological Computation and Visualization Center, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Abstract
The eukaryotic genome has undergone a series of epidemics of amplification of mobile elements that have resulted in most eukaryotic genomes containing much more of this 'junk' DNA than actual coding DNA. The majority of these elements utilize an RNA intermediate and are termed retroelements. Most of these retroelements appear to amplify in evolutionary waves that insert in the genome and then gradually diverge. In humans, almost half of the genome is recognizably derived from retroelements, with the two elements that are currently actively amplifying, L1 and Alu, making up about 25% of the genome and contributing extensively to disease. The mechanisms of this amplification process are beginning to be understood, although there are still more questions than answers. Insertion of new retroelements may directly damage the genome, and the presence of multiple copies of these elements throughout the genome has longer-term influences on recombination events in the genome and more subtle influences on gene expression.
Collapse
Affiliation(s)
- Prescott L Deininger
- Tulane Cancer Center, Department of Environmental Health Sciences, Tulane University Health Sciences Center, New Orleans, Louisiana 70112, USA.
| | | |
Collapse
|
17
|
Abstract
During the past 65 million years, Alu elements have propagated to more than one million copies in primate genomes, which has resulted in the generation of a series of Alu subfamilies of different ages. Alu elements affect the genome in several ways, causing insertion mutations, recombination between elements, gene conversion and alterations in gene expression. Alu-insertion polymorphisms are a boon for the study of human population genetics and primate comparative genomics because they are neutral genetic markers of identical descent with known ancestral states.
Collapse
Affiliation(s)
- Mark A Batzer
- Department of Biological Sciences, Biological Computation and Visualization Center, Louisiana State University, 202 Life Sciences Building, Baton Rouge, Louisiana 70803, USA.
| | | |
Collapse
|
18
|
Romualdi C, Balding D, Nasidze IS, Risch G, Robichaux M, Sherry ST, Stoneking M, Batzer MA, Barbujani G. Patterns of human diversity, within and among continents, inferred from biallelic DNA polymorphisms. Genome Res 2002; 12:602-12. [PMID: 11932244 PMCID: PMC187513 DOI: 10.1101/gr.214902] [Citation(s) in RCA: 164] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Previous studies have reported that about 85% of human diversity at Short Tandem Repeat (STR) and Restriction Fragment Length Polymorphism (RFLP) autosomal loci is due to differences between individuals of the same population, whereas differences among continental groups account for only 10% of the overall genetic variance. These findings conflict with popular notions of distinct and relatively homogeneous human races, and may also call into question the apparent usefulness of ethnic classification in, for example, medical diagnostics. Here, we present new data on 21 Alu insertions in 32 populations. We analyze these data along with three other large, globally dispersed data sets consisting of apparently neutral biallelic nuclear markers, as well as with a beta-globin data set possibly subject to selection. We confirm the previous results for the autosomal data, and find a higher diversity among continents for Y-chromosome loci. We also extend the analyses to address two questions: (1) whether differences between continental groups, although small, are nevertheless large enough to confidently assign individuals to their continent on the basis of their genotypes; (2) whether the observed genotypes naturally cluster into continental or population groups when the sample source location is ignored. Using a range of statistical methods, we show that classification errors are at best around 30% for autosomal biallelic polymorphisms and 27% for the Y chromosome. Two data sets suggest the existence of three and four major groups of genotypes worldwide, respectively, and the two groupings are inconsistent. These results suggest that, at random biallelic loci, there is little evidence, if any, of a clear subdivision of humans into biologically defined groups.
Collapse
Affiliation(s)
- Chiara Romualdi
- Department of Biology, University of Ferrara, via L. Borsari 46, I-44100 Ferrara, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Roy-Engel AM, Carroll ML, El-Sawy M, Salem AH, Garber RK, Nguyen SV, Deininger PL, Batzer MA. Non-traditional Alu evolution and primate genomic diversity. J Mol Biol 2002; 316:1033-40. [PMID: 11884141 DOI: 10.1006/jmbi.2001.5380] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Alu elements belonging to the previously identified "young" subfamilies are thought to have inserted in the human genome after the divergence of humans from non-human primates and therefore should not be present in non-human primate genomes. Polymerase chain reaction (PCR) based screening of over 500 Alu insertion loci resulted in the recovery of a few "young" Alu elements that also resided at orthologous positions in non-human primate genomes. Sequence analysis demonstrated these "young" Alu insertions represented gene conversion events of pre-existing ancient Alu elements or independent parallel insertions of older Alu elements in the same genomic region. The level of gene conversion between Alu elements suggests that it may have a significant influence on the single nucleotide diversity within the genome. All the instances of multiple independent Alu insertions within the same small genomic regions were recovered from the owl monkey genome, indicating a higher Alu amplification rate in owl monkeys relative to many other primates. This study suggests that the majority of Alu insertions in primate genomes are the products of unique evolutionary events.
Collapse
Affiliation(s)
- Astrid M Roy-Engel
- Department of Environmental Health Sciences, Tulane Cancer Center SL-66, Tulane University Medical Center, 1430 Tulane Ave., New Orleans, LA 70112, USA
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Belle EMS, Eyre-Walker A. A test of whether selection maintains isochores using sites polymorphic for Alu and L1 element insertions. Genetics 2002; 160:815-7. [PMID: 11898794 PMCID: PMC1461991 DOI: 10.1093/genetics/160.2.815] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
21
|
Ovchinnikov I, Troxel AB, Swergold GD. Genomic characterization of recent human LINE-1 insertions: evidence supporting random insertion. Genome Res 2001; 11:2050-8. [PMID: 11731495 PMCID: PMC311227 DOI: 10.1101/gr.194701] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
LINE-1 (L1) elements play an important creative role in genomic evolution by distributing both L1 and non-L1 DNA in a process called retrotransposition. A large percentage of the human genome consists of DNA that has been dispersed by the L1 transposition machinery. L1 elements are not randomly distributed in genomic DNA but are concentrated in regions with lower GC content. In an effort to understand the consequences of L1 insertions, we have begun an investigation of their genomic characteristics and the changes that occur to them over time. We compare human L1 insertions that were created either during recent human evolution or during the primate radiation. We report that L1 insertions are an important source for the creation of new microsatellites. We provide evidence that L1 first strand cDNA synthesis can occur from an internal priming event. We note that in contrast to older L1 insertions, recent L1s are distributed randomly in genomic DNA, and the shift in the L1 genomic distribution occurs relatively rapidly. Taken together, our data indicate that strong forces act on newly inserted L1 retrotransposons to alter their structure and distribution.
Collapse
Affiliation(s)
- I Ovchinnikov
- Division of Molecular Medicine, Department of Medicine, Mailman School of Public Health, Columbia University New York, New York 10032, USA
| | | | | |
Collapse
|
22
|
Abstract
A few months ago the International Human Genome Sequencing Consortium (IHGSC) published a 61-page paper on the human genome (IHGSC, Nature 409 (2001) 860). Here comments will be presented on some points of the paper that were previously investigated in our laboratory, and some misunderstandings and misconceptions about the organization and the evolutionary history of the human genome will be discussed. A very recent article on the same subject (Eyre-Walker and Hurst, Nat. Rev. Genet. 2 (2001) 549) will also be addressed. The present paper is a complement to two review articles which were published last year (Bernardi, Gene 241 (2000) 3; Gene 259(1) (2000) 31).
Collapse
Affiliation(s)
- G Bernardi
- Laboratory of Molecular Evolution, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy.
| |
Collapse
|
23
|
Pavlícek A, Jabbari K, Paces J, Paces V, Hejnar JV, Bernardi G. Similar integration but different stability of Alus and LINEs in the human genome. Gene 2001; 276:39-45. [PMID: 11591470 DOI: 10.1016/s0378-1119(01)00645-x] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Alus and LINEs (LINE1) are widespread classes of repeats that are very unevenly distributed in the human genome. The majority of GC-poor LINEs reside in the GC-poor isochores whereas GC-rich Alus are mostly present in GC-rich isochores. The discovery that LINES and Alus share similar target site duplication and a common AT-rich insertion site specificity raised the question as to why these two families of repeats show such a different distribution in the genome. This problem was investigated here by studying the isochore distributions of subfamilies of LINES and Alus characterized by different degrees of divergence from the consensus sequences, and of Alus, LINEs and pseudogenes located on chromosomes 21 and 22. Young Alus are more frequent in the GC-poor part of the genome than old Alus. This suggests that the gradual accumulation of Alus in GC-rich isochores has occurred because of their higher stability in compositionally matching chromosomal regions. Densities of Alus and LINEs increase and decrease, respectively, with increasing GC levels, except for the telomeric regions of the analyzed chromosomes. In addition to LINEs, processed pseudogenes are also more frequent in GC-poor isochores. Finally, the present results on Alu and LINE stability/exclusion predict significant losses of Alu DNA from the GC-poor isochores during evolution, a phenomenon apparently due to negative selection against sequences that differ from the isochore composition.
Collapse
Affiliation(s)
- A Pavlícek
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Flemingovo 2, CZ-16637, Prague, Czech Republic
| | | | | | | | | | | |
Collapse
|
24
|
Watkins WS, Ricker CE, Bamshad MJ, Carroll ML, Nguyen SV, Batzer MA, Harpending HC, Rogers AR, Jorde LB. Patterns of ancestral human diversity: an analysis of Alu-insertion and restriction-site polymorphisms. Am J Hum Genet 2001; 68:738-52. [PMID: 11179020 PMCID: PMC1274485 DOI: 10.1086/318793] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2000] [Accepted: 01/17/2001] [Indexed: 11/04/2022] Open
Abstract
We have analyzed 35 widely distributed, polymorphic Alu loci in 715 individuals from 31 world populations. The average frequency of Alu insertions (the derived state) is lowest in Africa (.42) but is higher and similar in India (.55), Europe (.56), and Asia (.57). A comparison with 30 restriction-site polymorphisms (RSPs) for which the ancestral state has been determined shows that the frequency of derived RSP alleles is also lower in Africa (.35) than it is in Asia (.45) and in Europe (.46). Neighbor-joining networks based on Alu insertions or RSPs are rooted in Africa and show African populations as separate from other populations, with high statistical support. Correlations between genetic distances based on Alu and nuclear RSPs, short tandem-repeat polymorphisms, and mtDNA, in the same individuals, are high and significant. For the 35 loci, Alu gene diversity and the diversity attributable to population subdivision is highest in Africa but is lower and similar in Europe and Asia. The distribution of ancestral alleles is consistent with an origin of early modern human populations in sub-Saharan Africa, the isolation and preservation of ancestral alleles within Africa, and an expansion out of Africa into Eurasia. This expansion is characterized by increasing frequencies of Alu inserts and by derived RSP alleles with reduced genetic diversity in non-African populations.
Collapse
Affiliation(s)
- W S Watkins
- Department of Human Genetics, University of Utah Health Sciences Center, Salt Lake City, UT, 84112, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Lander ES, Linton LM, Birren B, Nusbaum C, Zody MC, Baldwin J, Devon K, Dewar K, Doyle M, FitzHugh W, Funke R, Gage D, Harris K, Heaford A, Howland J, Kann L, Lehoczky J, LeVine R, McEwan P, McKernan K, Meldrim J, Mesirov JP, Miranda C, Morris W, Naylor J, Raymond C, Rosetti M, Santos R, Sheridan A, Sougnez C, Stange-Thomann Y, Stojanovic N, Subramanian A, Wyman D, Rogers J, Sulston J, Ainscough R, Beck S, Bentley D, Burton J, Clee C, Carter N, Coulson A, Deadman R, Deloukas P, Dunham A, Dunham I, Durbin R, French L, Grafham D, Gregory S, Hubbard T, Humphray S, Hunt A, Jones M, Lloyd C, McMurray A, Matthews L, Mercer S, Milne S, Mullikin JC, Mungall A, Plumb R, Ross M, Shownkeen R, Sims S, Waterston RH, Wilson RK, Hillier LW, McPherson JD, Marra MA, Mardis ER, Fulton LA, Chinwalla AT, Pepin KH, Gish WR, Chissoe SL, Wendl MC, Delehaunty KD, Miner TL, Delehaunty A, Kramer JB, Cook LL, Fulton RS, Johnson DL, Minx PJ, Clifton SW, Hawkins T, Branscomb E, Predki P, Richardson P, Wenning S, Slezak T, Doggett N, Cheng JF, Olsen A, Lucas S, Elkin C, Uberbacher E, Frazier M, Gibbs RA, Muzny DM, Scherer SE, Bouck JB, Sodergren EJ, Worley KC, Rives CM, Gorrell JH, Metzker ML, Naylor SL, Kucherlapati RS, Nelson DL, Weinstock GM, Sakaki Y, Fujiyama A, Hattori M, Yada T, Toyoda A, Itoh T, Kawagoe C, Watanabe H, Totoki Y, Taylor T, Weissenbach J, Heilig R, Saurin W, Artiguenave F, Brottier P, Bruls T, Pelletier E, Robert C, Wincker P, Smith DR, Doucette-Stamm L, Rubenfield M, Weinstock K, Lee HM, Dubois J, Rosenthal A, Platzer M, Nyakatura G, Taudien S, Rump A, Yang H, Yu J, Wang J, Huang G, Gu J, Hood L, Rowen L, Madan A, Qin S, Davis RW, Federspiel NA, Abola AP, Proctor MJ, Myers RM, Schmutz J, Dickson M, Grimwood J, Cox DR, Olson MV, Kaul R, Raymond C, Shimizu N, Kawasaki K, Minoshima S, Evans GA, Athanasiou M, Schultz R, Roe BA, Chen F, Pan H, Ramser J, Lehrach H, Reinhardt R, McCombie WR, de la Bastide M, Dedhia N, Blöcker H, Hornischer K, Nordsiek G, Agarwala R, Aravind L, Bailey JA, Bateman A, Batzoglou S, Birney E, Bork P, Brown DG, Burge CB, Cerutti L, Chen HC, Church D, Clamp M, Copley RR, Doerks T, Eddy SR, Eichler EE, Furey TS, Galagan J, Gilbert JG, Harmon C, Hayashizaki Y, Haussler D, Hermjakob H, Hokamp K, Jang W, Johnson LS, Jones TA, Kasif S, Kaspryzk A, Kennedy S, Kent WJ, Kitts P, Koonin EV, Korf I, Kulp D, Lancet D, Lowe TM, McLysaght A, Mikkelsen T, Moran JV, Mulder N, Pollara VJ, Ponting CP, Schuler G, Schultz J, Slater G, Smit AF, Stupka E, Szustakowki J, Thierry-Mieg D, Thierry-Mieg J, Wagner L, Wallis J, Wheeler R, Williams A, Wolf YI, Wolfe KH, Yang SP, Yeh RF, Collins F, Guyer MS, Peterson J, Felsenfeld A, Wetterstrand KA, Patrinos A, Morgan MJ, de Jong P, Catanese JJ, Osoegawa K, Shizuya H, Choi S, Chen YJ, Szustakowki J. Initial sequencing and analysis of the human genome. Nature 2001; 409:860-921. [PMID: 11237011 DOI: 10.1038/35057062] [Citation(s) in RCA: 14712] [Impact Index Per Article: 639.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.
Collapse
Affiliation(s)
- E S Lander
- Whitehead Institute for Biomedical Research, Center for Genome Research, Cambridge, MA 02142, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Sheen FM, Sherry ST, Risch GM, Robichaux M, Nasidze I, Stoneking M, Batzer MA, Swergold GD. Reading between the LINEs: human genomic variation induced by LINE-1 retrotransposition. Genome Res 2000; 10:1496-508. [PMID: 11042149 PMCID: PMC310943 DOI: 10.1101/gr.149400] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2000] [Accepted: 08/11/2000] [Indexed: 11/25/2022]
Abstract
The insertion of mobile elements into the genome represents a new class of genetic markers for the study of human evolution. Long interspersed elements (LINEs) have amplified to a copy number of about 100,000 over the last 100 million years of mammalian evolution and comprise approximately 15% of the human genome. The majority of LINE-1 (L1) elements within the human genome are 5' truncated copies of a few active L1 elements that are capable of retrotransposition. Some of the young L1 elements have inserted into the human genome so recently that populations are polymorphic for the presence of an L1 element at a particular chromosomal location. L1 insertion polymorphisms offer several advantages over other types of polymorphisms for human evolution studies. First, they are typed by rapid, simple, polymerase chain reaction (PCR)-based assays. Second, they are stable polymorphisms that rarely undergo deletion. Third, the presence of an L1 element represents identity by descent, because the probability is negligible that two different young L1 repeats would integrate independently between the exact same two nucleotides. Fourth, the ancestral state of L1 insertion polymorphisms is known to be the absence of the L1 element, which can be used to root plots/trees of population relationships. Here we report the development of a PCR-based display for the direct identification of dimorphic L1 elements from the human genome. We have also developed PCR-based assays for the characterization of six polymorphic L1 elements within the human genome. PCR analysis of human/rodent hybrid cell line DNA samples showed that the polymorphic L1 elements were located on several different chromosomes. Phylogenetic analysis of nonhuman primate DNA samples showed that all of the recently integrated "young" L1 elements were restricted to the human genome and absent from the genomes of nonhuman primates. Analysis of a diverse array of human populations showed that the allele frequencies and level of heterozygosity for each of the L1 elements was variable. Polymorphic L1 elements represent a new source of identical-by-descent variation for the study of human evolution. [The sequence data described in this paper have been submitted to the GenBank data library under accession nos. AF242435-AF242451.]
Collapse
Affiliation(s)
- F M Sheen
- Promega Corporation, Madison, Wisconsin 53711, USA
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Apoil PA, Roubinet F, Despiau S, Mollicone R, Oriol R, Blancher A. Evolution of alpha 2-fucosyltransferase genes in primates: relation between an intronic Alu-Y element and red cell expression of ABH antigens. Mol Biol Evol 2000; 17:337-51. [PMID: 10723735 DOI: 10.1093/oxfordjournals.molbev.a026314] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Coding sequences of the paralogous FUT1 (H), FUT2 (Se), and Sec1 alpha 2-fucosyltransferase genes were obtained from different primate species. Analysis of the primate FUT1-like and FUT2-like sequences revealed the absence of the known human inactivating mutations giving rise to the h null alleles of FUT1 and the se null alleles of FUT2. Therefore, most primate FUT1-like and FUT2-like genes potentially code for functional enzymes. The Sec1-like gene encodes for a potentially functional alpha 2-fucosyltransferase enzyme in nonprimate mammals, New World monkeys, and Old World monkeys, but it has been inactivated by a nonsense mutation at codon 325 in the ancestor of humans and African apes (gorillas, chimpanzees). Human and gorilla Sec1's have, in addition, two deletions and one insertion, respectively, 5' of the nonsense mutation leading to proteins shorter than chimpanzee Sec1. Phylogenetic analysis of the available H, Se, and Sec1 mammalian protein sequences demonstrates the existence of three clusters which correspond to the three genes. This suggests that the differentiation of the three genes is rather old and predates the great mammalian radiation. The phylogenetic analysis also suggests that Sec1 has a higher evolutionary rate than FUT2 and FUT1. Finally, we show that an Alu-Y element was inserted in intron 1 of the FUT1 ancestor of humans and apes (chimpanzees, gorillas, orangutans, and gibbons); this Alu-Y element has not been found in monkeys or nonprimate mammals, which lack ABH antigens on red cells. A potential mechanism leading to the red cell expression of the H enzyme in primates, related to the insertion of this Alu-Y sequence, is proposed.
Collapse
Affiliation(s)
- P A Apoil
- Laboratoire d'Immunogénétique Moléculaire, Hôpital Purpan, Toulouse, France
| | | | | | | | | | | |
Collapse
|
28
|
Jorde LB, Watkins WS, Bamshad MJ, Dixon ME, Ricker CE, Seielstad MT, Batzer MA. The distribution of human genetic diversity: a comparison of mitochondrial, autosomal, and Y-chromosome data. Am J Hum Genet 2000; 66:979-88. [PMID: 10712212 PMCID: PMC1288178 DOI: 10.1086/302825] [Citation(s) in RCA: 276] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
We report a comparison of worldwide genetic variation among 255 individuals by using autosomal, mitochondrial, and Y-chromosome polymorphisms. Variation is assessed by use of 30 autosomal restriction-site polymorphisms (RSPs), 60 autosomal short-tandem-repeat polymorphisms (STRPs), 13 Alu-insertion polymorphisms and one LINE-1 element, 611 bp of mitochondrial control-region sequence, and 10 Y-chromosome polymorphisms. Analysis of these data reveals substantial congruity among this diverse array of genetic systems. With the exception of the autosomal RSPs, in which an ascertainment bias exists, all systems show greater gene diversity in Africans than in either Europeans or Asians. Africans also have the largest total number of alleles, as well as the largest number of unique alleles, for most systems. GST values are 11%-18% for the autosomal systems and are two to three times higher for the mtDNA sequence and Y-chromosome RSPs. This difference is expected because of the lower effective population size of mtDNA and Y chromosomes. A lower value is seen for Y-chromosome STRs, reflecting a relative lack of continental population structure, as a result of rapid mutation and genetic drift. Africa has higher GST values than does either Europe or Asia for all systems except the Y-chromosome STRs and Alus. All systems except the Y-chromosome STRs show less variation between populations within continents than between continents. These results are reassuring in their consistency and offer broad support for an African origin of modern human populations.
Collapse
Affiliation(s)
- L B Jorde
- Department of Human Genetics, University of Utah Health Sciences Center, Salt lake City, UT, 84112, USA.
| | | | | | | | | | | | | |
Collapse
|
29
|
Abstract
The bulk of the human genome is ultimately derived from transposable elements. Observations in the past year lead to some new and surprising ideas on functions and consequences of these elements and their remnants in our genome. The many new examples of human genes derived from single transposon insertions highlight the large contribution of selfish DNA to genomic evolution.
Collapse
Affiliation(s)
- A F Smit
- Axys Pharmaceuticals, Inc., La Jolla, 92037-1029, USA.
| |
Collapse
|