Plant & Animal Genome VI Conference Plant & Animal Genome VI Conference
W12
Genomic Variation Laboratory, Department of Animal Science, Meyer Hall, University of California, Davis, Davis, CA 95616
The Agricultural Research Organization in Israel in conjunction with
scientists at U. C. Davis and VPI are developing a synthetic stock of
tilapia (an artificial center of origin) as a new approach to genetic
improvement of fish for economically important quantitative traits,
particularly salinity tolerance and cold tolerance. The synthetic is
being creating by crossing four tilapine species: Oreochromis niloticus
(wild-type and red strains), O. aureus, O. mossambicus, and
Serathodon galileus. We at U. C. Davis are constructing a composite
linkage map for tilapia using a fluorescence-based approach to amplified
fragment length polymorphisms (AFLP). We have exchanged the
radiolabeled primer amplification originally described by Vos et al.
with a Fluorescein label. The autoradiographs have been replaced with
a Molecular Dynamics Fluorimager 595 imaging system. The genetic map
will be created using species-specific markers. These markers will allow
monitoring of the proportion of genome contributed by each species to
high performing lines that are extracted from the synthetic. In addition,
the linkage map will provide an excellent source of markers for the
identification and localization of alleles contributing to salinity or cold
tolerance in later generations of the synthetic. Markers associated with
performance loci are known as quantitative trait loci (QTLs). Segregation
data is being obtained from three-way crossed progeny. Currently, data
is being collected for progeny set obtained from an O. niloticus x O. aureus
female and an O. mossambicus male. Several individuals of each of the
pure parental species have been screened using AFLP to identify markers
that are species-specific.