In Xiphophorus, the causative genetic information for melanoma formation has been assigned by classical genetics to chromosomal loci, which are located on the sex chromosomes. In our attempts to molecularly clone these melanoma-determining loci, named Tu, we have looked for restriction-fragment-length markers (RFLMs) linked to the Tu loci. These RFLMs should be useful in obtaining a physical ma...

Cytological and immunochemical studies were carried out on dioecious Coccinia indica to understand the genetic control of sex expression. The somatic chromosome number of both the sex forms of C. indica was found to be 2n = 24 and the karyotype shows high homogeneity, though a distinct heteromorphic pair of sex chromosomes is found in male sex forms of C. Indica. Soluble protein profile from th...

The identification of molecular markers linked to leaf curl virus (CLCuV) disease resistance in cotton has the potential to improve both the efficiency and the efficacy of selection in cotton breeding programs. Genetic analysis suggested that CLCuV resistance is controlled by a single dominant gene. In this study, an interspecific F2 population derived from a cross of Gossypium barbadense and G...

We develop models that describe the cytonuclear structure for either a cytoplasmic and nuclear marker in a haplodiploid species or a cytoplasmic and X-linked marker in a diploid species. Sex-specific disequilibrium statistics that summarize nonrandom cytonuclear associations in such systems are defined, and their basic Hardy-Weinberg dynamics and admixture formulae are delimited. We focus on th...

The Arvicolidae is a widely distributed rodent group with several interesting characteristics in their sex chromosomes. Here, we summarize the actual knowledge of some of these characteristics. This mammalian group has species with abnormal sex determination systems. In fact, some species present the same karyotype in both males and females, with total absence of a Y chromosome, and hence of SR...

Datisca glomerata is an androdioecious plant species containing male and hermaphroditic individuals. Molecular markers and crossing data suggest that, in both D. glomerata and its dioecious sister species D. cannabina, sex is determined by a single nuclear locus, at which maleness is dominant. Supporting this conclusion, an amplified fragment length polymorphism (AFLP) is heterozygous in males ...