A whole genome duplication occurred in the ancestor of all salmonid fishes some 50-100 million years ago. Early inheritance studies with allozymes indicated that loci in the salmonid genome are inherited disomically in females. However, some pairs of duplicated loci showed patterns of inheritance in males indicating pairing and recombination between homeologous chromosomes. Nearly 20% of loci i...

In the chicken, the nucleolus organizer regions, or sites of the genes encoding 18S, 5.8S, and 28S ribosomal RNA (rRNA), map to one pair of microchromosomes that can be identified by silver nitrate cytochemistry. This nucleolar organizer chromosome also contains the major histocompatibility complex. Chickens aneuploid for this chromosome have been identified and reproduced for over seven genera...

Polyploidy, ploidal variation between populations, and aneuploidy within some populations complicate population genetic analyses in switchgrass. We report 21 genic-simple sequence repeat marker loci with single-locus disomic segregation in tetraploids and apparently tetrasomic inheritance in octoploids, thus allowing population genetic analyses across ploidy levels. Based on 472 individuals sam...

We describe our studies of the genetics of allelic variation for NADP-dependent isocitrate dehydrogenase (IDH) in rainbow trout (Salmo gairdneri). Five populations of rainbow trout were studied to determine the phenotypic distribution of IDH; 453 progeny from a number of controlled matings were examined to determine the nature of inheritance of these alleles. The variation was found to be the r...

Abstract The principal cultivated potato ( Solanum tuberosum ) has mainly been vegetatively propagated through its tubers. Potato breeders have therefore made planned artificial hybridizations to generate genetically unique seedlings and their clonal descendants from which select new cultivars for tuber propagation. After the initial hybridizations, no more sexual reproduction was required prod...

Meiotic pairing in homothallic S. cerevisiae was studied by tetrad analysis, using strains that were trisomic or tetrasomic for chromosomes. I. The disomic segregants of these strains produce tetrasomic spore colonies that can be distinguished by their phenotype. Results indicated the existence of preferential pairing and nonrandom assortment of chromosomes at meisosis I. The frequency of cross...