C-bands produced by barium hydroxide using propidium iodide were observed in telomeres of the short arms of a large metacentric chromosome (
chromosome pair 3) and in the short arms of a submetacentric chromosome (
chromosome pair 5).
In both eytotypes, FISH with 5S rDNA probe produced hybridization signals in subtelomeric position of the short arm of the
chromosome pair No 3.
The ideogram was drawing on the basis of the averaged length of each homologous
chromosome pair (p) and their centromeric position.
One of each
chromosome pair is inherited from the mother and the other is inherited from the father.
The alleles controlling one trait can be on a different
chromosome pair from the alleles controlling the other trait, or both allele pairs can be on the same
chromosome pair.
Besides, both species are characterized by the absence of an m
chromosome pair. Within Corixidae, nine genera and 25 species belonging to the subfamilies Cymatinae (Cymatia borsdorfii (Sahlberg)) and Corixinae (24 species) have been cytogenetically analyzed (Table I) (Ituarte & Papeschi, 2004).
The total haploid complement length (TCL) in females was calculated by adding the mean value of each
chromosome pair (in arbitrary units).
They also showed a 4.3-fold increase in the mean number of sister chromatid exchanges (the number of crossover events in a
chromosome pair), from 6.1 to 26.3, and a 2.4-fold increase in micronuclei frequencies per 1,000 cells, from 3.6 to 8.5.
For each strain, a single
chromosome pair is depicted that is associated with three traits (i.e., A, B, and C).
This would also apply to the individual chromosomes of a pair, as suggested by Moritz and Hillis (1996: 9): "In cytogenetics, it is standard to refer to the respective chromosomes in a
chromosome pair of a diploid organism as homologs and to refer to the homologous pair of chromosomes in another species as homeologs, even though this is quite different from the use of homology in classical morphology (where homonomy is used to refer to a repeated structure in a single organism)." In the second scenario, the most likely prediction is that different proportions of genes, gene products, and fragments of genome brought together in the same zygote will violate different combinations of the three tests of homology, the similarity, conjunction, and congruence tests (see below).
This variation results from a Robertsonian polymorphism involving
chromosome pair 1.
1990), which showed a NOR cluster on
chromosome pair 11 ([NOR.sup.11]), in addition to the same five NOR-bearing chromosomes as in M.
