Rat Chromosome 2: assignment of the genes encoding cyclin B1,
interleukin 6 signal transducer, and proprotein convertase 1 to the
Mcs1-containing region and identification of new
Pascale Van Vooren,
De´partement de Biologie Mole´culaire, Universite´ Libre de Bruxelles, Rue des Chevaux, 67; B-1640 Rhode-Saint-Gene`se, Belgium
Laboratory of Health Effects Research, National Institutes of Public Health and The Environment, Bilthoven 3720 BA, The Netherlands
CMB-Genetics, Go¨teborg University, S-405 30 Gothenburg, Sweden
Received: 21 July 1998 / Accepted: 28 August 1998
Abstract. The rat Chromosome (Chr) 2 harbors several genes
controlling tumor growth or development, blood pressure, and
non-insulin-dependent diabetes mellitus. We report that the region
(2q1) containing the mammary susceptibility cancer gene Mcs1
also harbors the genes encoding cyclin B1, interleukin 6 signal
transducer (gp130), and proprotein convertase 1. We also gener-
ated 13 new anonymous microsatellite markers from Chr 2-sorted
DNA. These markers, as well as a microsatellite marker in the
cyclin B1 gene, were genetically mapped in combination with
known markers. A cyclin B1-related gene was also cytogenetically
assigned to rat Chr 11q22-q23.
The rat provides one with interesting genetic models for complex
traits, including cancer susceptibility, hypertension, and diabetes
mellitus. Previous studies genetically defined several loci control-
ling these traits, some of which were assigned to rat Chromosome
(Chr) 2 (for a review, see Szpirer et al. 1997). The Mcs1 locus,
controlling mammary cancer susceptibility, was assigned to the rat
Chromosome region 2q1 by Hsu and coworkers (Hsu et al. 1994).
Two loci controlling pituitary tumor growth, Epdm2-1 and Edpm2-
2, were mapped in more distal regions, in intervals centered on
D2Mit4 (2q16-q24) and D2Mgh15 (probably 2q25-26), respec-
tively (Wendel and Gorski 1997). At least two quantitative trait
loci (QTL) controlling blood pressure also map on rat Chr 2: one
is located in the 2q24 region, near the genes Cpb (carboxypepti-
dase) and Agtr1b (angiotensin receptor 1B; Dubay et al. 1993;
Clark et al. 1996; see Bp6 and Bp13 in RATMAP 1998), while
another one maps more distally, in the 2q34-43 region, which
contains the genes Npr (סGca: natriuretic peptide receptor A/gua-
nylate cyclase A), Atp1a (סNak␣l, ATPase, Na+K+ transporting,
␣1 polypeptide), and Camkd (Ca++/calmodulin-dependent protein
kianse II, ␦ subunit; Schork et al. 1995; Samani et al. 1996; Deng
et al. 1997a). This region might harbor more than one blood pres-
sure QTL (see Bp10, Bp14, Bp16, Bp17, Bp19 in RATMAP
1998). This distal part of rat Chr 2 also includes at least one gene
controlling non-insulin-dependent diabetes mellitus (Galli et al.
1996; Gauguier et al. 1996).
Despite remarkable progress in the number of anonymous ge-
netic markers mapped on rat Chr 2 (Bihoreau et al. 1997; Shepel
et al. 1997, 1998; Deng et al. 1997b; Brown et al. 1998; RATMAP
1998; http://www.genome.wi.mit.edu/rat/public/), more markers
are needed to better define the genetic position of the above QTL
and, ultimately, to identify the relevant genes. Also, relatively few
genes are localized in the rat in general, and on Chr 2 in particular
(Szpirer et al. 1997; RATMAP 1998).
In order to improve the rat Chr 2 map, we generated new
microsatellite markers from chromosome-sorted DNA. We report
here the characterization of 13 new anonymous markers, which
were incorporated into a Chr 2 linkage map also including already
known markers. In addition, we report three new cytogenetic lo-
calizations of genes in the Mcs1-containing region, 2q1.
Materials and methods
Cell hybrids and fluorescence in situ hybridization (FISH).
panel of mouse × rat cell hybrids segregating rat chromosomes has been
described previously and used to map numerous rat genes (J. Szpirer et al.
1984; C. Szpirer et al. 1996). Fluorescence in situ hybridization (FISH) was
done as described previously (Pinkel et al. 1988; Stephanova et al. 1996).
The probes used were: a 1.4-kb rat cyclin B1 cDNA (Trembley et al. 1994)
and two lambda clones (clones B and F) we isolated from a rat genomic
library (Ccnb1 and Ccnb1rs); a rat gp130 cDNA (pCMVgp130: Il6st;
Wang et al. 1992); a 2.6-kb rat prohormone convertase 1 cDNA (prPC1:
Pcsk1; Bloomquist et al. 1991). Images were captured and treated with the
ISIS imaging system (MetaSystems, D-68804 Althussheim, Germany).
Generation of markers from Chr 2-sorted DNA and genotyping.
DNA from rat Chr 2 was obtained as described previously (Hoebee
et al. 1994; Deng et al. 1997b), except that the last PCR reaction
was done using the polymerase Pfu and the PCR products were
cloned in pKIL-PCRII (Gabant et al. 1997). The library was then
screened with a mixture of end-labeled [CA]
and the positive clones were sequenced (Dracopoli et al. 1997).
Primers flanking the repeats were designed with the Oligo 5.0
software (National Bioscience, Inc., Plymouth, MN55447-5434,
USA). PCR reactions on genomic DNA were done as described by
Dracopoli and colleagues (1997). BN/Mol and LE/Mol inbred rats
were purchased from M&B (Lille-Skensred, Denmark), and the
genotype of the markers was determined in a (BN × LE) × BN
backcross (Sjo¨ling et al. 1996). Ninety-six animals were tested,
except for the following markers, tested on 156 animals: D2U1bl,
D2Wox2, D2U1b3, D2Mgh2, D2Wox4, D2U1b6, D2Mit5,
D2U1b9, D2Mit7, D2Mit11, D2Mit12, D2Mgh12, D2Mit15,
D2Mit16. The PCR products were analyzed on standard non-
denaturing 6–10% polyacrylamide gels. The genotyping data are
available from RATMAP.
Correspondence to: C. Szpirer
Mammalian Genome 10, 30–34 (1999).
© Springer-Verlag New York Inc. 1999