SHORT COMMUNICATION Consensus and comprehensive linkage maps of bovine chromosome 7 Z Gu, L Gomez-Raya, D I Va Êge, K Elo, W Barendse, G Davis, M Grosz, G Erhardt, E Kalm, N Reinsch, S M. Kappes, R T Stone, S K Davis, J F Taylor, B W Kirkpatrick Summary The objective of this project was to integrate the currently available linkage maps for bovine chromosome 7 (BTA7) by combining data sets from eight research groups. A total of 54 unique markers were typed in eight pedigrees. Multi- locus linkage analysis with CRI-MAP produced a bovine chromosome 7 consensus framework map of 27 loci ordered with odds greater than 1000 : 1. Furthermore, we present a bovine chromosome 7 comprehensive map integrating 54 loci. The locus order is in general agreement with the recently published linkage maps except for one discrepancy. The order of loci BM9289, BMS713, and ILSTS001 was reversed in the consensus framework map relative to the published USDA-MARC bovine chromosome 7 linkage map. Keywords: cattle, framework map, genetic mar- ker, genetics Several bovine linkage maps have been con- structed using independent pedigrees and a partially overlapping set of markers. Integration of these maps is of great importance. An integrated map serves as a bridge of commu- nication among mapping research groups by working out discrepancies in locus order between the various maps and building statis- tical support for the location of markers that are less supported in just one data set. In 1995, Eggen and Fries integrated the bovine cytogenetic map with the two most comprehensive linkage maps at that time (Barendse et al. 1994; Bishop et al. 1994). Unfortunately, the number of commonly mapped loci between the two linkage maps was so limited that most of the genome regions were not integrated. For bovine chromosome 7, RASA was the only coding gene mapped by Bishop et al. (1994) that was also physically mapped. There were three markers on the Barendse et al. (1994) chromosome 7 map, and two of them were also mapped by Bishop et al. (1994). Most regions of the bovine chromosome 7 linkage and physical maps were left unconnected (Eggen & Fries 1995). Subsequent efforts to create a more decent linkage map (Barendse et al. 1997) and to physically map additional loci (Ferretti et al. 1997) have extended the tie between physical and linkage maps for bovine chromosome 7. The subsequent availability of more dense linkage maps (Barendse et al. 1997; Kappes et al. 1997) increases the need for building the consensus linkage map for each bovine chromo- some. Most typed markers were not in common between the most comprehensive bovine link- age maps and there is some disagreement in locus order between maps. Thus a consensus map serves as a way of integrating linkage maps and helps to solve locus order discrepancies. In this study, we present the results of analysis of data submitted by eight research groups. The goal was to construct a consensus framework map of bovine chromosome 7 and a compre- hensive map including all polymorphic loci. Eight genotype data sets were submitted by research groups from around the world as part of an International Society for Animal Genet- ics-sponsored effort to develop consensus bovine linkage maps. Data were provided for the International Bovine Reference Pedigrees (IBRP), USDA Meat Animal Research Centre Bovine Pedigrees (USDA-MARC), Texas A & M University Angleton Families (TAMU), Agri- cultural Research Centre MTT pedigrees (MTT), CSIRO Tropical Agriculture pedigrees (CSIRO-TROP), USDA ARS Fort Keogh LARRL pedigrees (USDA-LARRL), German Cattle Breeding Organisation pedigrees (ADR), and Norwegian Cattle Pedigrees (NCM). The data were provided in CRI-MAP format. Among the data sets, the number of offspring varied from 152 to 1716 and the number of markers typed ranged from 6 to 43. For each data set, a framework map consisting only of loci whose location could be mapped Animal Genetics, 2000, 31, 206±209 Z Gu B W Kirkpatrick Department of Animal Sciences, University of Wisconsin-Madison, WI 53706 USA L Gomez-Raya D I Va Êge Department of Animal Science, Agricultural University of Norway, N-1432 Aas, Norway K Elo Agricultural Research Centre MTT, Animal Production Research, Animal Breeding, FIN- 31600 Jokioinen, Fin- land W Barendse CSIRO Molecular Ani- mal Genetics Centre, Brisbane, Australia G Davis CSIRO Tropical Agricul- ture, Molecular Animal Genetics Centre, Bris- bane, QLD 4072, Austra- lia M Grosz USDA ARS Fort Keogh LARRL, Miles City, MT, USA G Erhardt E Kalm Department of Animal Breeding and Genetics, Justus-Liebig-University Giessen, Ludwigstr. 21, D-35390 Giessen, Ger- many N Reinsch Institut fu Èr Tierzucht und Tierhaltung der Christian-Albrechts- Universita Èt, D-24098 Kiel, Germany S M Kappes R T Stone USDA Meat Animal Re- search Center, Clay Cen- ter, NE, USA S K Davis J F Taylor Texas A & M University, College Station TX 77843-2471, USA Correspondence: B W Kirkpatrick. Accepted 12 January 2000 ã 2000 International Society for Animal Genetics 206