The genetic map of Xiphophorus fishes represented by 24 multipoint linkage groups.
Hybrids between distinct Xiphophorus species have been utilized for over 70 years to study melanoma and other neoplasms that can develop spontaneously in hybrid offspring. Genetic linkage mapping has proven to be important in delineating genomic areas that harbor oncogenes and tumor suppressors. Within this report, two parallel backcrosses have been utilized to generate a genetic linkage map for Xiphophorus fishes. Isozyme/allozyme, RFLP and PCR-based mapping techniques, including AP-PCR/RAPDs and microsatellite loci were utilized. The derived linkage map provides a total of 403 mapped polymorphisms distributed among 24 linkage groups, representative of 24 acro- and telocentric chromosome pairs. Genomic coverage is approximately one marker per 5.8 cM. Detailed genotypic analysis of the utilized hybrids revealed two areas of the genome that show significant segregation distortion. Loci within the linkage group harboring the sex determining locus (LG 24) and an autosomal linkage group (LG 21) show highly significant deviations from Mendelian expectations. This phenomenon is not present in a hybrid cross that utilizes a different backcross hybrid progenitor species. The derived map with sequence-tagged markers provides a framework for physical map generation, large-scale genomic sequencing and will further enable cross-genome comparisons of vertebrate genomes.
Kazianis
Steven
S
Wistar Institute, Program of Molecular and Cellular Oncogenesis, Philadelphia, Pennsylvania 19104, USA. skazianis@wistar.upenn.edu
Nairn
Rodney S
RS
Walter
Ronald B
RB
Johnston
Dennis A
DA
Kumar
Jay
J
Trono
David
D
Della-Coletta
Luis
L
Gimenez-Conti
Irma
I
Rains
J Douglas
JD
Williams
Earlanda L
EL
Pino
Brian M
BM
Mamerow
Madonna M
MM
Kochan
Kelli J
KJ
Schartl
Manfred
M
Vielkind
Juergen R
JR
Volff
Jean-Nicolas
JN
Woolcock
Bruce
B
Morizot
Donald C
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