Therefore, homologous chromosomes are similar and pairing behaviour is the empirical observation needed to infer homology.
Viewed through the light microscope, the karyotype and individual chromosomes may be described in traditional morphological terms, but the visible features of chromosomes are few, and the level of description has changed little since Sutton (1903) remarked that homologous chromosomes were "those that correspond in size.
the reciprocal exchange of parts of the chromatids of the homologous chromosomes - can take place, and it ensures that bivalents are formed from the homologous parental chromosomes and are held together by chiasmata until first meiotic division.
However, it is likely that homologous chromosomes or chromosome segments are identified and contact established between them during or before early meiotic prophase.
DNA sequences that serve the mutual recognition of homologous chromosomes probably reside in autonomously functioning individual sites (e.
The MER2 product seems, however, not to be a structural component of the synaptonemal complex, but is suggested to play a role in the initiation of genetic exchange; in MER2 mutants homologous chromosomes fail to synapse and the alignment of homologous chromosomes is reduced (Rockmill et al.