Meiotic analysis of the XX/XY
system in Proechimys cf. longicaudatus Left: A diplotene in Proechimys cf longicaudatus with tip-to-tip pairing between the X and Y1, and a chiasma between X and Y2. The red arrow shows the connection point between the X and the translocated autosome. Right: schematic of the rearrangement and chromosome pairing of the sex trivalent seen in the diplotene. Abbreviations: PAR, pseudo-autosomal region; Centr, centromere of the autosome; and A, autosome.