The main cause of the sterility of mules and hinnies is probably related to failure of pairing of homologous chromosomes
at meiosis during spermatogenesis (Wodsedalek, 1966; Taylor and Short, 1973; Chandley et al.
Humans are diploid organisms; they have paired homologous chromosomes
in their somatic cells, which contain two copies of each gene.
Of these, 44 are known as autosomes and consist of matched pairs of chromosomes, known as homologous chromosomes
This demonstration further reinforces the idea that the synapse of homologous chromosomes
is a hallmark of meiosis because the bi-orientation of nonsister kinetochores (two kinetochores from homologous chromosomes
) results in the physical separation of the homologous chromosomes
The average size of the 60 pairs of telocentric (T) monoarm homologous chromosomes
that comprise the karyotype of P.
Thus, the expression of each trait is controlled by two genetic messages; two homologous chromosomes
control one gene from each trait.
Variants of a single gene that occupy the same locus on the two homologous chromosomes
are known as an allele.
i1] can be considered as the allelic interaction effect (heterozygous dominance effect) due to the specific substituted chromosome or arm from 3-79 and the homologous chromosome
or arm in female cultivar parent i.
Further, it has recently been shown that the homologous chromosome
arms of Hordeum marinum Hudson carrying rDNA segments have a lower chiasma frequency than all other chromosome arms (I.
Moreover, the banding patterns were consistent between members of homologous chromosome
Nevertheless, in nature there may be breakdown of strict homologous chromosome
pairing, and the wheat and jointed goatgrass hybrids may exhibit an array of chromosome numbers (Zemetra et al.
Efficacy of the image analysis system for differentiating among homologous chromosome
sets averaged across four nondormant alfalfa germplasm populations.
The bivalent pairing observed in the hybrids indicates that there is a high degree of homology between chromosomes of the upland and lowland genomes; thus, the transfer of genes between cytotypes likely is possible by recombination resulting from meiotic pairing between homologous chromosome
This suggests that soybean may possess a gene similar to the Ph (pairing homoeologous) gene in wheat, which suppresses homoeologous chromosome pairing and regulates homologous chromosome
pairing (Okamoto, 1957; Riley and Chapman, 1958).
Recombination between homologous chromosome
segments, structurally separated by an interchange difference, was estimated by a CRR locus and an interchange breakpoint as genetic markers.