A step to the gigantic genome of the desert locust: chromosome sizes and repeated DNAs
Symmetrical exchanges between non-homologous chromosomes were recovered following irradiation of germ-line cells of S. gregaria at different developmental stages. No X-Autosome exchanges were observed. It was found that the frequencies with which autosomes of the three size groups L, M and S participated in exchange agreed with the frequencies expected based on “effective” exchange lengths of polarized interphase chromosomes. All of the observed symmetrical exchanges were between euchromatic segments of the chromosomes and though many of the exchange points were close to the centromere, no exchanges were found with break points actually in the centric heterochromatin. None of the heterozygous symmetrical exchanges were seen to have an observable influence on the chiasma conditions of the cell.