PURPOSE An early-onset retinal degenerative disease has been identified in Persian cats. This study genetically, clinically, and histologically characterized the disease. A breeding colony was established to assist with identification of the causative gene and to provide a resource for vision research. METHODS Cats were produced from testcross breedings. Kittens underwent serial ophthalmic an...

Epistasis seems to play a significant role in the manifestation of heterosis. However, the power of detecting epistatic interactions among quantitative trait loci (QTL) in segregating populations is low. We studied heterosis in Arabidopsis thaliana hybrid C24 x Col-0 by testing near-isogenic lines (NILs) and their triple testcross (TTC) progenies. Our objectives were to (i) provide the theoreti...

Interpretation of experimental results from quantitative trait loci (QTL) mapping studies on the predominant type of gene action can be severely affected by the choice of statistical model, experimental design, and provision of epistasis. In this study, we derive quantitative genetic expectations of (i) QTL effects obtained from one-dimensional genome scans with the triple testcross (TTC) desig...

Transmission ratio distortion (TRD) is frequently observed in inter- and intraspecific hybrids of plants, leading to a violation of Mendelian inheritance. Sex-independent TRD (siTRD) was detected in a hybrid between Asian cultivated rice and its wild ancestor. Here we examined how siTRD caused by an allelic interaction at a specific locus arose in Asian rice species. The siTRD is controlled by ...

The genetic architecture of hybrid fitness characters can provide valuable insights into the nature and evolution of postzygotic reproductive barriers in diverged species. We determined the genome-wide distribution of barriers to introgression in an F(1) hybrid of two Eucalyptus tree species, Eucalyptus grandis (W. Hill ex Maiden.) and E. globulus (Labill.). Two interspecific backcross families...

Triple-testcross experiments (Kearsey and Jinks 1968) were employed to investigate the mode of gene action affecting pupa weight in Tribolium castaneum. Their experimental design involves two inbred lines, the F1 progeny and a segregating population derived from the cross of the inbred lines. In the present experiments, four segregating populations were used. These populations included the F2 g...

A natural male sterile mutant of Salvia miltiorrhiza (Labiatae, Sh-B) was found during field survey in 2002. Our objective was to analyze its genetic mechanism for producing F1 hybrid seeds and to develop a molecular marker linked to male sterile gene for selection of a hybrid parent line. The segregation ratios of male sterile plants to fertile plants in the progenies of both testcross and bac...

Recent molecular data using resynthesized polyploids of Brassica napus established that genome changes can occur rapidly after polyploid formation. In this study we present data that de novo phenotypic variation for flowering time also occurs rapidly after polyploidization. Two initial polyploid plants were developed by reciprocal crosses of B. rapa and B. oleracea followed by chromosome doubli...

Rice (Oryza sativa L.) blast disease is one of the most destructive rice diseases in the world. The fungal pathogen, Magnaporthe oryzae, is the causal agent of rice blast disease. Development of resistant cultivars is the most preferred method to achieve sustainable rice production. However, the effectiveness of resistant cultivars is hindered by the genetic plasticity of the pathogen genome. T...