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Our laboratory is exploring the genetic basis of quantitative phenotypes. Two systems are being analyzed: an inbreeding plant, soybean, for which an extensive genetic and phenotypic database already is available; and an outcrossing mammal, the Portuguese Water Dog (PWD), for which a similar database is being developed. Both utilize inbred populations in which the underlying gene pool is narrow (few ancestors), but the phenotypic diversity is great. The two systems are related in that the soybean provides hypotheses on which to focus our investigation and serves as a model for the development of the PWD database. It provides technical tools and a simple, inexpensive, logistic approach to the acquisition of phenotypic data.

Research on Soybeans (click here for a more details)

We have used Recombinant Inbred (RI) populations of soybean segregants which we genotyped using molecular markers. Phenotypes (traits) measured by collaborators have been linked to these markers to identify QTLs. The database for these studies consists of three recombinant inbred populations derived from three parents. Traits have been measured with many replications in several environments. All three populations have been genetically characterized. We have developed statistical and computational methods with which we have identified QTLs and demonstrated that interactions between QTLs are common in soybean. We welcome collaborations with scientists who wish to analyze the genetic basis of new phenotypes using these genotyped, recombinant inbred populations.

Research on Portuguese Water Dogs (click here for more details)

As an outcrossing mammalian system, Portuguese Water Dogs (PWDs) are more complex. Although Portuguese Water Dogs derive from a narrow gene pool and have been highly inbred, they show extensive variation. In these respects, they resemble a recombinant inbred system. Molecular genetic markers for these animals are available and more are being developed. Accurate and complete records provide pedigrees, which make it possible to calculate relatedness between more than 6000 existing animals. We have used the pedigree data to choose useful sub-populations for genotypic and phenotypic analysis. Cooperation between our laboratories and owner-breeders through the Georgie project has made DNA available for genotyping and allowed measurement of trait values. These characteristics make the Portuguese water dog population ideal for the study of quantitative genetics. We plan to identify QTLs in this population and to determine the extent to which interactions between alleles play a role in determining quantitative trait values. We welcome collaborations with PWD breeders interested in genetically guided improvement of their breed; as well as with scientists interested in genetic analysis of biochemical, physiological, developmental or behavioral quantitative phenotypes.