A second generation radiation hybrid map to aid the assembly of the bovine genome sequence
- Oliver C Jann1Email author,
- Jan Aerts1,
- Michelle Jones1,
- Nicola Hastings1,
- Andy Law1,
- Stephanie McKay2,
- Elisa Marques2,
- Aparna Prasad2,
- Jody Yu2,
- Stephen S Moore2,
- Sandrine Floriot3,
- Marie-Françoise Mahé3,
- André Eggen3,
- Licia Silveri3, 4,
- Riccardo Negrini4,
- Elisabetta Milanesi4,
- Paolo Ajmone-Marsan4,
- Alessio Valentini5,
- Cinzia Marchitelli5,
- Maria C Savarese5,
- Michal Janitz6,
- Ralf Herwig6,
- Steffen Hennig7,
- Chiara Gorni4, 8,
- Erin E Connor9,
- Tad S Sonstegard9,
- Timothy Smith10,
- Cord Drögemüller11 and
- John L Williams1, 8
© Jann et al; licensee BioMed Central Ltd. 2006
Received: 04 August 2006
Accepted: 06 November 2006
Published: 06 November 2006
Several approaches can be used to determine the order of loci on chromosomes and hence develop maps of the genome. However, all mapping approaches are prone to errors either arising from technical deficiencies or lack of statistical support to distinguish between alternative orders of loci. The accuracy of the genome maps could be improved, in principle, if information from different sources was combined to produce integrated maps. The publicly available bovine genomic sequence assembly with 6× coverage (Btau_2.0) is based on whole genome shotgun sequence data and limited mapping data however, it is recognised that this assembly is a draft that contains errors. Correcting the sequence assembly requires extensive additional mapping information to improve the reliability of the ordering of sequence scaffolds on chromosomes. The radiation hybrid (RH) map described here has been contributed to the international sequencing project to aid this process.
An RH map for the 30 bovine chromosomes is presented. The map was built using the Roslin 3000-rad RH panel (BovGen RH map) and contains 3966 markers including 2473 new loci in addition to 262 amplified fragment-length polymorphisms (AFLP) and 1231 markers previously published with the first generation RH map. Sequences of the mapped loci were aligned with published bovine genome maps to identify inconsistencies. In addition to differences in the order of loci, several cases were observed where the chromosomal assignment of loci differed between maps. All the chromosome maps were aligned with the current 6× bovine assembly (Btau_2.0) and 2898 loci were unambiguously located in the bovine sequence. The order of loci on the RH map for BTA 5, 7, 16, 22, 25 and 29 differed substantially from the assembled bovine sequence. From the 2898 loci unambiguously identified in the bovine sequence assembly, 131 mapped to different chromosomes in the BovGen RH map.
Alignment of the BovGen RH map with other published RH and genetic maps showed higher consistency in marker order and chromosome assignment than with the current 6× sequence assembly. This suggests that the bovine sequence assembly could be significantly improved by incorporating additional independent mapping information.
The global importance of cattle production has resulted in considerable efforts to detect the genes controlling variations in economically important traits. This task is greatly facilitated by the availability of molecular markers ordered along chromosomes. In the last decade a number the bovine genome maps have been published, many of them based on genetic linkage between markers [1–3]. A major disadvantage of linkage maps is that only polymorphic loci can be included, whereas, RH maps can be constructed using sequence information from non-polymorphic loci. Therefore, RH maps potentially contain more coding loci than linkage maps facilitating comparative mapping across species. In contrast to linkage maps, which exploit the frequency of natural recombination between markers to calculate distances and orders of markers, RH maps are constructed using the probability of breaks between markers induced by radiation. Several whole genome radiation hybrid (WGRH) panels are available for cattle that have been used to construct RH maps [4–8]. These RH maps have been used to create comparative maps between bovine and human chromosomes through the alignment of the loci derived from coding sequences [9–15]. The RH maps can also be integrated with other bovine physical maps such as BAC maps constructed by fingerprinting methods by identifying the marker loci within e.g. BAC end sequences [16, 17]. This additional mapping information facilitates the ordering of fingerprint contigs and the construction of physical BAC maps covering whole chromosomes. Such physical BAC maps provide a valuable starting point for genome sequencing [18–21]. Fingerprint contig BAC maps have been constructed for cattle using clones from the INRA BAC library  and the CHORI-240 BAC library . The ultimate map for a species is the correctly assembled genome sequence. The bovine genome sequencing project started in 2003 and uses a combination of whole genome shotgun sequences (WGS) and sample sequencing of a minimum tiling path of BAC clones spanning the genome. The current, publicly available, bovine genomic sequence (Btau_2.0) has 6-fold genome coverage from WGS assembled into scaffolds and aligned on the chromosomes using limited mapping data. The use of RH and linkage map information  would greatly improve the genome sequence assembly .
Here we report a second generation RH map of the bovine genome which can be used to improve the construction of an integrated bovine genomic map. Sequences of the markers used to construct the map were aligned with the MARC 2004 linkage map and the Illinois-Texas (ILTX 2005) RH map  to investigate discrepancies. Loci that were unambiguously placed in all the maps were then aligned with the Btau_2.0 sequence to identify potential problems in the current sequence assembly.
Radiation hybrid map
Statistics of the BovGen RH map by chromosome
no of markers
The total length of the whole genome RH map, including all bovine autosomes and the X chromosome is 760 Rays (R). The map of BTA 28 is the shortest at 1141 cR and the longest is BTA 7 (4408 cR). The average marker interval, over the whole genome, is 19 cR ranging between 12 cR (BTA 29) to 29 cR (BTA 20). Distance comparisons between common markers on the RH map, MARC 2004 linkage map and the bovine sequence suggests, on average, 1 cR on the BovGen RH map is equivalent to 0.04 cM and 23 Kbp, respectively, although this varies considerably across the genome.
Comparison with the ILTX 2005 RH map
There are 160 marker loci in common between the BovGen RH map described here and the Illinois-Texas (ILTX 2005) RH map . All of these common loci were assigned to the same chromosomes on both maps (see Additional File 1).
Comparison with MARC 2004 linkage map
There are 885 marker loci in common between the BovGen RH and the MARC 2004 linkage map  which allows a detailed comparison of map order and chromosome assignment. Inconsistencies in chromosomal assignment are found for 5 of these 885 loci (see Additional File 2). In all these cases only individual markers are involved.
Comparison with the 6× bovine assembly
Inconsistent chromosome assignments between the BovGen RH map and Btau_2.0 sequence. Only the seven most significant cases are listed, involving at least three linked markers.
Assignment Bodge RH BTA
Assignment Btau_2.0 BTA
Other assignments species, chromosome [reference]
BTA 1 
BTA 5 
HSA 4a [42, 42, 43]
BTA 8 , MMU 15a , HSA 8a 
HSA 14a 
HSA 17a [44, 45]
On all but two chromosomes (BTA 9 and 14) there were many differences between the map order and the sequence: on many chromosomes large discrepancies involving groups of linked markers and/or large numbers of individual loci were seen, particularly on chromosomes 5, 7, 16, 22, 25 and 29. For example, on chromosome 7 two large groups of linked loci on the BovGen RH map locate to divergent positions in both the Btau_2.0 and MARC 2004 map, however, these latter two maps agree. This inconsistency is similar to an inconsistency observed between the BovGen RH and the MARC 2004 map, resulting in a good agreement with the Btau_2.0 sequence (Figure 4). Further information from the ILTX 2005 map does not help to resolve this inconsistency as there is only one marker in common with the BovGen RH map in this region.
The ability to determine the order of close markers on genome maps differs between approaches, and all approaches, including the assembly of a whole genome sequence, are prone to errors. In some cases insufficient information is available to assign the correct order or positioning of loci, while data errors can introduce distortions in the maps. The ultimate genome map of a species is the correctly ordered DNA sequence. Achieving the correct sequence assembly uses several sources of information. Sequence information from other species, including the human genome could be used as a template, but this approach should be treated with extreme caution as species specific variations are known . Therefore, direct sequence information is used for the local assembly of shotgun sequence reads into contigs, and these contigs are then assembled into scaffolds using additional information, such as overlapping clones, and sequences from paired clone ends. The ordering of these scaffolds on chromosomes and assembly of the final sequence relies on additional mapping information, including BAC fingerprint contig maps, linkage maps and RH maps. In this paper we describe an RH map with almost 4000 mapped loci which will contribute to the assembly of the bovine genome sequence.
Comparison with other linkage and RH maps
The consistency in ordering of common loci can be assessed across different maps, however, it is important that the information used when assembling the maps is independent, as circular arguments can give a false measure of agreement. The approach of e.g. Itoh et al.  was to use the linkage map as template for their RH map; in contrast we did not use any prior information to construct the RH map presented here. This was because the aim was to assemble the most likely map using completely independent data and so not to propagate potential errors across different maps. Resolving these inconsistencies often requires the use of additional independent evidence such as BAC FPC mapping data or cytogenetic (fluorescent in-situ hybridisation, FISH) information. We carried out an alignment of the BovGen RH map with the other available bovine genome maps and the Btau_2.0 sequence assembly, but only after the RH maps had been constructed. While this approach relies on only one source of information it may not result in the "best" possible map, however, it avoids bias and the resulting independent map can then be used to develop a combined map which carries a measure of map confidence based on similarity and differences between maps.
The BovGen and ILTX 2005 RH map appear to be more consistent with each other than with the MARC 2004 linkage map. Some inconsistencies between linkage and RH maps may be due to the different mapping approaches. However, the observation of the apparently higher consistency between the RH maps must be treated with care as the BovGen RH map has fewer loci in common with the ILTX 2005 map than with the MARC 2004 linkage map, and so fewer discrepancies could be detected. The ILTX 2005 map was constructed on the basis of the first-generation map (ILTX 2004) by increasing the marker density and a subsequent rigorous removal of markers which did not pass a quality control procedure . In this process a significant number of markers common to both the BovGen RH and the ILTX 2004 map were removed and as a result there are fewer correspondences of our map with ILTX 2005 than with the old ILTX 2004. It can be assumed that this process improved the ILTX map enormously. Therefore, we used the ILTX 2005 map for comparison despite fewer correspondences. Nevertheless, the ILTX 2004 map has a similarly high marker order consistency and chromosomal assignment with the BovGen RH map (data not shown).
Comparison with the sequence assembly
Sequence similarity search algorithms used to align maps with Btau_2.0 have a considerable risk of errors as they may also detect gene duplications or similar motifs in different genes. To minimize this problem we used very stringent parameters for minimum homology and maximized the required length of overlap between sequences. In addition, sequence matches were assessed manually. Thus the loci we aligned between the different maps and the bovine sequence carry a very high probability of correctly assigned homology. Differences in the position of individual markers between different maps could be the result of technical variations explained by using different parameters and algorithms to construct the multipoint maps. Inconsistencies in the chromosomal assignment of individual markers may also have simple explanations, such as poor primer design resulting in amplification of related loci and not the target locus. Of greater importance for the interpretation of the map information are inconsistencies affecting whole groups of linked markers. To minimise the propagation of errors in individual maps we eliminated individual markers that were inconsistently placed between BovGen RH, ILTX 2005 and MARC 2004 maps from a further combined analysis against the sequence assembly.
While the BovGen RH map is in general agreement with the ILTX map and the MARC 2004 map, there is poor agreement with the Btau_2.0 sequence at specific chromosomal regions. In such regions, e.g. those described above on chromosomes 7, 25 and 29, the assembled Btau_2.0 sequence is most consistent with the linkage map. This is not surprising, because, among other sources of information, the MARC 2004 map was used to order the sequence scaffolds in Btau_2.0. Recalculating the BovGen data for these chromosomes and forcing the markers into the order they appear in the sequence assembly significantly increases the map length and reduces the probability showing that our data are not consistent with the sequence order. Further information must be generated to resolve such inconsistencies.
Assignment of markers to different chromosomes
A problem in the genome assembly is that of erroneous assignments of sequence scaffolds. By comparing assignments among the different RH and linkage maps [1, 39, 40] and also using comparative human [30, 31, 41–45] or mouse  information, it seems likely that the assignment in the bovine assembly is most often at fault (Table 2). For example the markers PTK2B, BZ948637 and B4GALT1 (Table 2, case 4) are closely linked on the BovGen RH map of BTA 8 and the linkage map of Barendse et al.  which also places these genes on BTA 8. This is also consistent with data from Fiedorek & Kay  who mapped PYK2B (alias PTK2B or Fadk) on murine chromosome 15 and Inazawa et al.  who mapped the gene on human chromosome 8 at positions which share conservation of synteny with BTA 8 . However, these marker loci are placed on chromosome 5 in the Btau_2.0 sequence assembly. All three markers are located on a single sequence scaffold (chr5.80), suggesting that the chromosomal assignment of this scaffold is likely to be incorrect.
A group of neighbouring markers formed by KIAA0284, Q9Y4F5, KNS2 and BTBD6 were assigned to BTA 11 on the BovGen RH map; however, this assignment is not consistent with other mapping data (Table 2, case 5). The human homologues of these loci are located on human chromosome 14 , suggesting that this group is correctly assigned in the Btau_2.0 sequence to chromosome 21 and that in this case the BovGen RH assignment is incorrect. Nevertheless, the linkage of this group to other markers on BTA 11 is convincing with LOD linkage values up to 13.8 between the extreme marker KIAA0284 and the neighbouring markers on the BovGen RH map. If this marker group is tested with the markers located on BTA 21 using the BovGen RH datasets it shows no linkage. In the Btau_2.0 assembly this marker group is at an extreme telomeric position which suggests that the statistical support for this assignment is weak. This chromosomal assignment may have been made on the expected position derived from the supposed conservation of synteny between human and cattle chromosomes and should be tested using independent evidence.
The markers BZ850749, CC517527 and CC471629 are assigned to BTA 14 on the BovGen RH map and to BTA 25 in the Btau_2.0 sequence assembly (Table 2, case 6). These markers are derived from BAC end sequences of clones from the CHORI-240 library and are not present on other maps. All these markers are assigned to the scaffold Chr25.84 and are in a chromosomal region of the assembly with a low density of corresponding markers. In contrast on the BovGen RH map, the markers in the same region are at a higher density. This suggests that these markers are more tightly linked on the BovGen RH map. No further information is available to resolve this inconsistency.
Independent information is essential to produce the best maps of the bovine genome and to assemble the most accurate sequence. In addition to the RH mapping approach and linkage mapping that have been discussed here the refinement of the sequence should use additional sources of information such as BAC FPC maps, comparative mapping, fluorescent in situ hybridization, and somatic cell hybrid mapping.
There is reasonable consistency between the RH map presented here, the MARC 2004 linkage map and the ILTX 2005 map. However, where the maps differed it is usually not possible to determine which order of markers is correct. Manipulating the data to make the different maps match is not productive. When the major discrepancies are removed a number of inconsistencies with the Btau_2.0 bovine sequence assembly still remain. Using the various mapping information it is possible to identify potential errors in the assembly of the current bovine genome sequence which should be investigated further to aid the improvement of the next sequence build.
Using the information presented here it will not be possible to reach a final version of the sequence. The Btau_2.0 sequence assembly contains more than 100,000 scaffolds of which only 4409 are anchored to chromosomes using markers from the genetic map, and about half of the anchored scaffolds contain two mapped markers allowing them to be orientated. The data presented here will increase the number of scaffolds that can be assigned and orientated. Nevertheless it will be necessary to use additional information such as fingerprinting or BAC skim data and physical maps, such as FISH based techniques, which in addition to comparative mapping data will help to finalize the assembly and yield a reliable sequence.
Sequencing of ESTs
A non-redundant "unigene" set of ESTs was selected by oligo-nucleotide fingerprinting and clustering of cDNAs from a brain library (Herwig et al., manuscript in preparation). This non-redundant cDNA clone set contains 23040 bovine clones grouped by sequence assembly of ESTs into 14989 unique cDNA clusters and singletons. The cDNA clones of the "unigene" set were amplified in a 384-well microplate format by PCR consisting of an initial denaturing for 2 min at 95°C, denaturing for 45 sec at 94°C, annealing and elongation for 4 min at 65°C in 30 cycles. PCR primers were complementary to the insert-flanking vector sequences. The PCR mix contained 5 pmol forward primer (GGA TCT ATC AAC AGG AGT CCA AGC TCA GCT), 5 pmol reverse primer (TCA CCA TCA CGG ATC CTA TTT AGG TGA CAC), 0.1 mM dNTP's, 1.5 M Betain, 1× PCR buffer, 0.1 mM Cresol Red and 1 U per reaction Taq DNA polymerase. PCR buffer consisted of 0.5 M KCl, 1% Tween20, 15 mM MgCl2, 350 mM TrisBase, 150 mM Tris/HCl pH 8.3. PCR fragments were subjected to sequence analysis using BigDye-terminator chemistry (Applied Biosystems) and a 3700 DNA sequencer (Applied Biosystems). Average sequence read length was 750 bp. The individual EST sequence data were submitted to GenBank and are publicly available under accession numbers CO871676–CO897060.
Maximum sequence information for annotation was achieved by aligning the EST data with available public cattle transcript sequences contained in the TIGR bovine gene index. TIGR clusters and corresponding ESTs cattle sequences produced here were aligned and the resulting 14989 cluster sequences (consensus) used for the subsequent construction of primers. Cluster sequences were aligned with bovine genomic sequences and only those showing clear splicing were used to define the precise exon-intron boundaries for the final primer selection (see below).
The primer design was carried out using dedicated software now in the public domain . The software uses the nearest-neighbour method  to predict the complimentarily of primers and secondary structures (dimers, hairpin etc.) and is able to process large number of sequences in batches, picking primers in designated regions. To minimize the amplification of hamster DNA contained within the RH panel cell lines, primer pairs were designed with one primer within exon, the other within the adjacent intron or non-coding sequence.
The primer design was standardized to achieve a maximum of uniformity in amplification conditions. Primer details are available to the public in the ArkDB database .
Screening of the Roslin RH panel
2473 marker loci were successfully typed on the 94 cell lines of a 3000-rad bovine/hamster RH panel as described by Williams et al. . Vectors of 262 AFLP markers  were added to the dataset. Resulting vectors for the 3966 marker loci used (including 1231 previously mapped loci ) are available in the Additional File 4 for download.
RH data analysis
RH vectors were assigned to chromosomes by analysing 2-pt linkage with mapped loci  using RH mapper . Multipoint maps were constructed using the default algorithm of the Carthagene software . The initial multi-point map was improved by an iterative process of inspection of marker loci and removal and alternative addition of badly linked or disrupting loci. This process resulted in the removal of 122 loci that could not be reliably fitted into the chromosome maps with the highest probability. The best maps generated by this process were compared to the ComRad RH-map  and the MARC 2004 linkage map  and regions showing discrepancies examined in detail to identify the presence of problem markers. Marker positions on the maps are available from the ArkDB database .
Mapping of marker associated sequences against the bovine sequence assembly
ESTs sequences used to design the primers for mapped loci were aligned with the assembled 6× bovine sequence assembly (Btau_2.0) using BLAST  and SPIDEY . To filter out incorrect alignments the BLAST e-value was set to a maximum of 1e-20 and minimum percent identity to 90%. In addition, the relative length of the BLAST hit (i.e. coverage, or length of the hit divided by the length of the query sequence) had to be at least 80%. Where ambiguous alignments were observed higher stringency filters were applied (sequence similarity higher than 97.5% and coverage higher than 90%).
Diagrammatic representation of chromosomal maps
Visual representation of map alignments was achieved using cMap .
This work was funded by the European Community (BovGen QLRT-CT-2002-02744 project) and the Biotechnology and Biological Sciences Research Council (BBS/B13454). Contributions by the University of Alberta were supported through Grant Number 2003A245R awarded to S.S. Moore by the Alberta Agriculture Research Institute. The authors thank Sandra Nejezchleb for technical assistance and John W. Keele and Gregory P. Harhay for the help to annotate primers designed previously at MARC.
- Barendse W, Vaiman D, Kemp SJ, Sugimoto Y, Armitage SM, Williams JL, Sun HS, Eggen A, Agaba M, Aleyasin SA, Band M, Bishop MD, Buitkamp J, Byrne K, Collins F, Cooper L, Coppettiers W, Denys B, Drinkwater RD, Easterday K, Elduque C, Ennis S, Erhardt G, Ferretti L, Flavin N, Gao Q, Georges M, Gurung R, Harlizius B, Hawkins G, Hetzel J, Hirano T, Hulme D, Jorgensen C, Kessler M, Kirkpatrick BW, Konfortov B, Kostia S, Kuhn C, Lenstra JA, Leveziel H, Lewin H, Leyhe B, Lil L, Martin Burriel I, McGraw RA, Miller JR, Moody DE, Moore SS, Nakane S, Nijman IJ, Olsaker I, Pomp D, Rando A, Ron M, Shalom A, Teale AJ, Thieven U, Urquhart BGD, Vage DI, Van de Weghe A, Varvio S, Velmala R, Vilkki J, Weikard R, Woodside C, Womack JE: A medium-density genetic linkage map of the bovine genome. Mamm Genome. 1997, 8: 21-28. 10.1007/s003359900340. Erratum in: Mamm Genome 1997, 8:798.PubMedView ArticleGoogle Scholar
- Kappes SM, Keele JW, Stone RT, McGraw RA, Sonstegard TS, Smith TP, Lopez-Corrales NL, Beattie CW: A second-generation linkage map of the bovine genome. Genome Res. 1997, 7: 235-249.PubMedView ArticleGoogle Scholar
- Ihara N, Takasuga A, Mizoshita K, Takeda H, Sugimoto M, Mizoguchi Y, Hirano T, Itoh T, Watanabe T, Reed KM, Snelling WM, Kappes SM, Beattie CW, Bennett GL, Sugimoto Y: A comprehensive genetic map of the cattle genome based on 3802 microsatellites. Genome Res. 2004, 14: 1987-1998. 10.1101/gr.2741704.PubMedPubMed CentralView ArticleGoogle Scholar
- Womack JE, Johnson JS, Owens EK, Rexroad CE, Schlapfer J, Yang YP: A whole-genome radiation hybrid panel for bovine gene mapping. Mamm Genome. 1997, 8: 854-856. 10.1007/s003359900593.PubMedView ArticleGoogle Scholar
- Rexroad CE, Schlapfer JS, Yang Y, Harlizius B, Womack JE: A radiation hybrid map of bovine chromosome one. Anim Genet. 1999, 30: 325-332. 10.1046/j.1365-2052.1999.00504.x.PubMedView ArticleGoogle Scholar
- Band MR, Larson JH, Rebeiz M, Green CA, Heyen DW, Donovan J, Windish R, Steining C, Mahyuddin P, Womack JE, Lewin HA: An ordered comparative map of the cattle and human genomes. Genome Res. 2000, 10: 1359-1368. 10.1101/gr.145900.PubMedPubMed CentralView ArticleGoogle Scholar
- Williams JL, Eggen A, Ferretti L, Farr CJ, Gautier M, Amati G, Ball G, Caramorr T, Critcher R, Costa S, Hextall P, Hills D, Jeulin A, Kiguwa SL, Ross O, Smith AL, Saunier K, Urquhart B, Waddington D: A bovine whole-genome radiation hybrid panel and outline map. Mammalian Genome. 2002, 13: 469-474. 10.1007/s00335-002-3001-x.PubMedView ArticleGoogle Scholar
- Itoh T, Watanabe T, Ihara N, Mariani P, Beattie CW, Sugimoto Y, Takasuga A: A comprehensive radiation hybrid map of the bovine genome comprising 5593 loci. Genomics. 2005, 85: 413-424. 10.1016/j.ygeno.2004.12.007.PubMedView ArticleGoogle Scholar
- Amaral ME, Kata SR, Womack JE: A radiation hybrid map of bovine X chromosome (BTAX). Mamm Genome. 2002, 13: 268-271. 10.1007/s00335-001-2100-4.PubMedView ArticleGoogle Scholar
- Goldammer T, Kata SR, Brunner RM, Dorroch U, Sanftleben H, Schwerin M, Womack JE: A comparative radiation hybrid map of bovine chromosome 18 and homologous chromosomes in human and mice. Proc Natl Acad Sci USA. 2002, 99: 2106-2111. 10.1073/pnas.042688699.PubMedPubMed CentralView ArticleGoogle Scholar
- Gautier M, Hayes H, Eggen A: An extensive and comprehensive radiation hybrid map of bovine Chromosome 15: comparison with human Chromosome 11. Mamm Genome. 2002, 13: 316-319. 10.1007/s00335-001-3069-8.PubMedView ArticleGoogle Scholar
- Gautier M, Hayes H, Bonsdorff T, Eggen A: Development of a comprehensive comparative radiation hybrid map of bovine chromosome 7 (BTA 7) versus human chromosomes 1 (HSA 1), 5 (HSA 5) and 19 (HSA 19). Cytogenet Genome Res. 2003, 102: 25-31. 10.1159/000075720.PubMedView ArticleGoogle Scholar
- Larkin DM, Everts-van der Wind A, Rebeiz M, Schweitzer PA, Bachman S, Green C, Wright CL, Campos EJ, Benson LD, Edwards J, Liu L, Osoegawa K, Womack JE, de Jong PJ, Lewin HA: A cattle-human comparative map built with cattle BAC-ends and human genome sequence. Genome Res. 2003, 13: 1966-1972.PubMedPubMed CentralGoogle Scholar
- Everts-van der Wind A, Kata SR, Band MR, Rebeiz M, Larkin DM, Everts RE, Green CA, Liu L, Natarajan S, Goldammer T, Lee JH, McKay S, Womack JE, Lewin HA: A 1463 gene cattle-human comparative map with anchor points defined by human genome sequence coordinates. Genome Res. 2004, 14: 1424-1437. 10.1101/gr.2554404.PubMedPubMed CentralView ArticleGoogle Scholar
- Everts-van der Wind A, Larkin DM, Green CA, Elliott JS, Olmstead CA, Chiu R, Schein JE, Marra MA, Womack JE, Lewin HA: A high-resolution whole-genome cattle-human comparative map reveals details of mammalian chromosome evolution. Proc Natl Acad Sci USA. 2005, 102: 18526-18531. 10.1073/pnas.0509285102.PubMedView ArticleGoogle Scholar
- Coulson A, Waterston R, Kiff J, Sulston J, Kohara Y: Genome linking with yeast artificial chromosomes. Nature. 1988, 335: 184-186. 10.1038/335184a0.PubMedView ArticleGoogle Scholar
- Olson MV, Dutchik JE, Graham MY, Brodeur GM, Helms C, Frank M, MacCollin M, Scheinman R, Frank T: Random-clone strategy for genomic restriction mapping in yeast. Proc Natl Acad Sci USA. 1986, 83: 7826-7830. 10.1073/pnas.83.20.7826.PubMedPubMed CentralView ArticleGoogle Scholar
- Cao Y, Kang HL, Xu X, Wang M, Dho SH, Huh JR, Lee BJ, Kalush F, Bocskai D, Ding Y, Tesmer JG, Lee J, Moon E, Jurecic V, Baldini A, Weier HU, Doggett NA, Simon MI, Adams MD, Kim UJ: A 12-Mb complete coverage BAC contig map in human chromosome 16p13.1-p11.2. Genome Res. 1999, 9: 763-774.PubMedPubMed CentralGoogle Scholar
- Hoskins RA, Nelson CR, Berman BP, Laverty TR, George RA, Ciesiolka L, Naeemuddin M, Arenson AD, Durbin J, David RG, Tabor PE, Bailey MR, DeShazo DR, Catanese J, Mammoser A, Osoegawa K, de Jong PJ, Celniker SE, Gibbs RA, Rubin GM, Scherer SE: A BAC-based physical map of the major autosomes of Drosophila melanogaster. Science. 287: 2271-2274. 10.1126/science.287.5461.2271. 2000, Mar 24, Erratum in: Science 2000, 288:1751.Google Scholar
- McPherson JD, Marra M, Hillier L, Waterston RH, Chinwalla A, Wallis J, Sekhon M, Wylie K, Mardis ER, Wilson RK, Fulton R, Kucaba TA, Wagner-McPherson C, Barbazuk WB, Gregory SG, HumphR SJ, French L, Evans RS, Bethel G, Whittaker A, Holden JL, McCann OT, Dunham A, Soderlund C, Scott CE, Bentley DR, Schuler G, Chen HC, Jang W, Green ED, Idol JR, Maduro VV, Montgomery KT, Lee E, Miller A, Emerling S, Kucherlapati , Gibbs R, Scherer S, Gorrell JH, Sodergren E, Clerc-Blankenburg K, Tabor P, Naylor S, Garcia D, de Jong PJ, Catanese JJ, Nowak N, Osoegawa K, Qin S, Rowen L, Madan A, Dors M, Hood L, Trask B, Friedman C, Massa H, Cheung VG, Kirsch IR, Reid T, Yonescu R, Weissenbach J, Bruls T, Heilig R, Branscomb E, Olsen A, Doggett N, Cheng JF, Hawkins T, Myers RM, Shang J, Ramirez L, Schmutz J, Velasquez O, Dixon K, Stone NE, Cox DR, Haussler D, Kent WJ, Furey T, Rogic S, Kennedy S, Jones S, Rosenthal A, Wen G, Schilhabel M, Gloeckner G, Nyakatura G, Siebert R, Schlegelberger B, Korenberg J, Chen XN, Fujiyama A, Hattori M, Toyoda A, Yada T, Park HS, Sakaki Y, Shimizu N, Asakawa S, Kawasaki K, Sasaki T, Shintani A, Shimizu A, Shibuya K, Kudoh J, Minoshima S, Ramser J, Seranski P, Hoff C, Poustka A, Reinhardt R, Lehrach H, International Human Genome Mapping Consortium: A physical map of the human genome. Nature. 2001, 409: 934-941. 10.1038/35057157.PubMedView ArticleGoogle Scholar
- Gregory SG, Sekhon M, Schein J, Zhao S, Osoegawa K, Scott CE, Evans RS, Burridge PW, Cox TV, Fox CA, Hutton RD, Mullenger IR, Phillips KJ, Smith J, Stalker J, Threadgold GJ, Birney E, Wylie K, Chinwalla A, Wallis J, Hillier L, Carter J, Gaige T, Jaeger S, Kremitzki C, Layman D, Maas J, McGrane R, Mead K, Walker R, Jones S, Smith M, Asano J, Bosdet I, Chan S, Chittaranjan S, Chiu R, Fjell C, Fuhrmann D, Girn N, GR C, Guin R, Hsiao L, Krzywinski M, Kutsche R, Lee SS, Mathewson C, McLeavy C, Messervier S, Ness S, Pandoh P, Prabhu AL, Saeedi P, Smailus D, Spence L, Stott J, Taylor S, Terpstra W, Tsai M, Vardy J, Wye N, Yang G, Shatsman S, Ayodeji B, Geer K, Tsegaye G, Shvartsbeyn A, Gebregeorgis E, Krol M, Russell D, Overton L, Malek JA, Holmes M, Heaney M, Shetty J, Feldblyum T, Nierman WC, Catanese JJ, Hubbard T, Waterston RH, Rogers J, de Jong PJ, Fraser CM, Marra M, McPherson JD, Bentley DR: A physical map of the mouse genome. Nature. 2002, 418: 743-750. 10.1038/nature00957.PubMedView ArticleGoogle Scholar
- Eggen A, Gautier M, Billaut A, Petit E, Hayes H, Laurent P, Urban C, Pfister-Genskow M, Eilertsen K, Bishop MD: Construction and characterization of a bovine BAC library with four genome-equivalent coverage. Genet Sel Evol. 2001, 33: 543-548. 10.1051/gse:2001132.PubMedPubMed CentralView ArticleGoogle Scholar
- CHORI-240 Bovine BAC Library. [http://bacpac.chori.org/bovine240.htm]
- Snelling WM, Gautier M, Keele JW, Smith TP, Stone RT, Harhay GP, Bennett GL, Ihara N, Takasuga A, Takeda H, Sugimoto Y, Eggen A: Integrating linkage and radiation hybrid mapping data for bovine chromosome 15. BMC Genomics. 2004, 5: 77-10.1186/1471-2164-5-77.PubMedPubMed CentralView ArticleGoogle Scholar
- Weikard R, Goldammer T, Laurent P, Womack JE, Kuehn C: A gene-based high-resolution comparative radiation hybrid map as a framework for genome sequence assembly of a bovine chromosome 6 region associated with QTL for growth, body composition, and milk performance traits. BMC Genomics. 2006, 7: 53-10.1186/1471-2164-7-53.PubMedPubMed CentralView ArticleGoogle Scholar
- Gorni C, Williams JL, Heuven HCM, Negrini R, Valentini A, van Eijk MJT, Waddington D, Zevenbergen M, Ajmone Marsan P, Peleman JD: Application of AFLP® technology to radiation hybrid mapping. Chromosome Research. 2004, 12: 285-297. 10.1023/B:CHRO.0000021912.22552.ff.PubMedView ArticleGoogle Scholar
- ArkDB Public database browser. [http://www.thearkdb.org]
- Ranz JM, Casals F, Ruiz A: How malleable is the eukaryotic genome? Extreme rate of chromosomal rearrangement in the genus Drosophila. Genome Res. 2001, 11: 230-239. 10.1101/gr.162901.PubMedPubMed CentralView ArticleGoogle Scholar
- Fiedorek FT, Kay ES: Mapping of the focal adhesion kinase (Fadk) gene to mouse chromosome 15 and human chromosome 8. Mamm Genome. 1995, 6: 123-6. 10.1007/BF00303256.PubMedView ArticleGoogle Scholar
- Inazawa J, Sasaki H, Nagura K, Kakazu N, Abe T, Sasaki T: Precise localization of the human gene encoding cell adhesion kinase beta (CAK beta/PYK2) to chromosome 8 at p21.1 by fluorescence in situ hybridization. Hum Genet. 1996, 98: 508-510. 10.1007/s004390050249.PubMedView ArticleGoogle Scholar
- Goedert M, Marsh S, Carter N: Localization of the human kinesin light chain gene (KNS2) to chromosome 14q32.3 by fluorescence in situ hybridization. Genomics. 1996, 32: 173-175. 10.1006/geno.1996.0102.PubMedView ArticleGoogle Scholar
- Polyprimers. [http://www.unitus.it/SAG/primers.zip]
- SantaLucia J, Allawi HT, Seneviratne PA: Improved nearest-neighbor parameters for predicting DNA duplex stability. Biochemistry. 1996, 35: 3555-3562. 10.1021/bi951907q.PubMedView ArticleGoogle Scholar
- Slonim D, Kruglyak L, Stein L, Lander E: Building human genome maps with radiation hybrids. J of Computational Biology. 1997, 4: 487-504.View ArticleGoogle Scholar
- Schiex T, Gaspin C: Carthagene: constructing and joining maximum likelihood genetic maps. Proceedings of ISMB'97, Halkidiki, Greece Porto Carras. 1997, 258-267.Google Scholar
- Altschul SF, Gish W, Miller W, Myers EW, Lipman DJ: Basic local alignment search tool. J Mol Biol. 1990, 215: 403-410. 10.1006/jmbi.1990.9999.PubMedView ArticleGoogle Scholar
- Wheelan SJ, Church DM, Ostell JM: Spidey: a tool for mRNA-to-genomic alignments. Genome Res. 2001, 11: 1952-1957.PubMedPubMed CentralGoogle Scholar
- GMOD Generic Software Components for Model Organism Databases. [http://www.gmod.org/cmap/]
- Sonstegard TS, Abel Ponce de Leon F, Beattie CW, Kappes SM: A chromosome-specific microdissected library increases marker density on bovine chromosome 1. Genome Res. 1997, 7: 76-80.PubMedView ArticleGoogle Scholar
- Dietz AB, Womack JE, Swarbrick PA, Crawford AM: Assignment of five polymorphic ovine microsatellites to bovine syntenic groups. Anim Genet. 1993, 24: 433-436.PubMedView ArticleGoogle Scholar
- Yokoyama H, Baraona E, Lieber CS: Molecular cloning and chromosomal localization of the ADH7 gene encoding human class IV (sigma) ADH. Genomics. 1996, 31: 243-245. 10.1006/geno.1996.0040.PubMedView ArticleGoogle Scholar
- Xu YL, Xue JL, Qiu XF, Qi M, Xu Y: Regional assignment of human alcohol dehydrogenase (ADH) gene to 4pter----4q21. Sci Sin [B]. 1987, 30: 720-726.Google Scholar
- Tsukahara M, Yoshida A: Chromosomal assignment of the alcohol dehydrogenase cluster locus to human chromosome 4q21-23 by in situ hybridization. Genomics. 1989, 4: 218-220. 10.1016/0888-7543(89)90304-2.PubMedView ArticleGoogle Scholar
- Couch FJ, Abel KJ, Brody LC, Boehnke M, Collins FS, Weber BL: Localization of the gene for ATP citrate lyase (ACLY) distal to gastrin(GAS) and proximal to D17S856 on chromosome 17q12-q21. Genomics. 1994, 21: 444-446. 10.1006/geno.1994.1293.PubMedView ArticleGoogle Scholar
- De Marchis L, Cropp C, Sheng ZM, Bargo S, Callahan R: Candidate target genes for loss of heterozygosity on human chromosome 17q21. Br J Cancer. 2004, 90: 2384-2389. 10.1038/sj.bjc.6601848. Erratum in: Br J Cancer 2004, 91:1001.PubMedView ArticleGoogle Scholar
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