An extensive and comprehensive radiation hybrid map of bovine
Chromosome 15: comparison with human Chromosome 11
Mathieu Gautier, He´l`ène Hayes, Andre´ Eggen
Laboratoire de Ge´ne´tique Biochimique et de Cytoge´ne´tique, De´partement de Ge´ne´tique Animale, INRA-CRJ, 78350 Jouy-en-Josas, France
Received: 24 Sepbember 2001 / Accepted: 13 February 2002
Abstract. An extensive and comprehensive radiation hybrid map
of bovine Chromosome 15 (BTA15) was built with 42 anonymous
markers, 3 ESTs, and 49 genes. This work allows us to refine the
comparative map between human Chromosome (Chr) 11 (HSA11)
and BTA15. Four blocks with a similar gene content and relatively
good gene order conservation were identified. The discrepancies
are concentrated on closely positioned genes for which discrimi-
nation is not possible between mapping resolution limits in either
the human or the bovine maps and true local inversions. Using the
gene order similarity and the human physical map as starting point,
we estimated the overall physical length of BTA15 to be around
75.3 Mb. The INRA bovine BAC library was screened for all the
markers ordered on the bovine map, which will provide anchors
for future efforts in the construction of a physical map of the
Finally, this map contains the majority of publicly available
polymorphic markers described for BTA15 and integrates those
with comparative mapping information. It should, therefore, con-
stitute a powerful tool in the identification of relevant candidate
genes in regions of BTA15 harboring economic trait loci.
By identifying similarities among gene maps of different species,
comparative mapping allows geneticists working on mammalian
genomes and particularly on the bovine genome to take advantage
of the growing accuracy of the knowledge and available resources
on the human genome (O’Brien et al. 1999). Indeed, drawing
detailed comparative maps constitutes a straightforward prerequi-
site for identifying relevant candidate genes in regions harboring
economic trait loci suggested from genome scan programs in the
last few years (Georges and Andersson 1996).
Although heterologous chromosome painting of bovine chro-
mosomes with human paints provided a global framework of the
extent and distribution of conserved synteny blocks (i.e., segments
with similar gene contents; Hayes 1995; Solinas-Toldo et al. 1995;
Chowdhary et al. 1996), these techniques were not sufficiently
accurate to point at gene order reshuffling. As demonstrated by the
recent large-scale survey initiated by Band and coworkers (2000),
refined mapping by using radiation hybrid mapping is a powerful
tool to address this question (Yang and Womack 1998).
ZooFISH experiments and subsequent analysis have shown
that human Chr 11 (HSA11) shares alternative blocks of conserved
synteny with bovine Chrs 15 (BTA15) and BTA29 (Gautier et al.
2001). Using a linkage mapping approach, Rexroad and coworkers
(2001) have recently attempted to describe more precisely the
correspondence in the linear order of genes mapped to BTA15 and
HSA11, concentrating on a region containing a QTL for meat
Here we present a comprehensive 3000-rad radiation hybrid
map of BTA15 with 49 genes localized on HSA11, 3 ESTs, and 42
microsatellite markers. The aim of the present study was to in-
crease the resolution of the comparative map and to help the in-
tegration of this information in other genetic maps by mapping
anonymous markers. Moreover the bovine BAC library con-
structed in our laboratory (Eggen et al. 2001) was screened for
each marker to provide anchors for future efforts in the construc-
tion of a physical map of the bovine genome.
Materials and methods
Primer sets for microsatellite markers were obtained from the
BOVMAP database (http://locus.jouy.inra.fr/). Primer pairs for 11 genes
were designed from available bovine sequences stored in Genbank (see
primer sequences and accession numbers in http://locus.jouy.inra.fr/).
Other genes were mapped with primers described in the literature. Descrip-
tions and references of the gene loci are given in http://locus.jouy.inra.fr/.
PCR reactions were performed on a PTC-100 thermo-
cycler (MJ Research) in a 15-l reaction volume with 1× standard Taq
polymerase buffer supplemented with 0.125 m
dNTP, 1.5 m
of each primer, and 0.035 U Taq polymerase (Promega, Madison, WI).
Samples were preheated for 5 min at 94°C, subjected to 35 cycles (94°C for
20 s, 52°–60°C for 30 s, and 72°C for 30 s), and a final extension step of
5 min at 72°C. Primer references and sequences are given in http://
Bovine BAC identification.
PCR-based screening was performed on the
four-genome equivalent INRA bovine BAC library containing 105,984
clones as previously described (Eggen et al. 2001).
Bovine whole-genome radiation hybrid panel genotyping and map
PCR reactions were performed on the 94 radiation hybrid
cell lines that constitute the newly developed 3000 Rad bovine panel by
using Wg3H as recipient (Williams et al. 2002).
The Carthagene software (Schiex et al. 2002) was used to perform
two-point and multipoint analyses of the radiation hybrid data and to pro-
vide a comprehensive map of the BTA15. The distances between markers
on the most likely map were calculated with RHMAP3.0 software (Lange
et al. 1995) under the equal retention probability model.
Radiation hybrid mapping. Each marker was directly mapped on
the panel by PCR except for three genes (CAT, PAX6, and
PPP2R1B). As described in Gautier et al. (2001), mapping of CAT,
PAX6, and PPP2R1B genes corresponds respectively to the map-
ping of three marker pairs [respectively (SP608B5 / T608B5),
(SP935F11 / T935F11) and (SP441F4 / T441F4)], each derived
from the two end-sequences of a specific BAC containing the gene
Correspondence to: A. Eggen; E-mail: email@example.com
Mammalian Genome 13, 316–319 (2002).
© Springer-Verlag New York Inc. 2002
Incorporating Mouse Genome