Platypus II Activation Code [serial Number]
the lf1 bac clone is specific for platypus y-specific sequences and crosses with a platypus male inbred line at 90% penetrance [ 36 ]. top row shows initial fish signals on a pachytene platypus xy bivalent; middle row shows the same bivalent hybridised with a pair of the lf1 dna probe, which is specific to the y chromosome. bottom row shows a representative pachytene xy bivalent hybridised with the lf1 dna probe and a second probe, df1-1, which is specific to the x chromosome. arrows indicate the y-specific hybridisation and a double arrow indicates the x-specific hybridisation. scale bars represent 5µm.
Platypus II Activation Code [serial number]
asynaptic autosome location within the xy bivalent. platypus spermatocytes were methanol:acetic acid fixed and then dual colour dna fish was performed. dual colour signals were recorded prior to additional dual colour fish experiments on the same slide. all signals are positioned within or immediately adjacent a dapi intense heterochromatic mass. bottom panel shows representative positions of collated signals from four experiments using four different bac probes linked by an arbitrarily drawn line. schematic at bottom is of sex chromosome chain with corresponding positions of bac probes. fish fluorescence in situ hybridisation, dapi 46-diamidino-2-phenylindole
unsynapsed autosomes and unpaired xy dna at pachytene triggers ddr machinery accumulation to protect the cell from meiotic progression until synaptic completion or to escape checkpoint surveillance, respectively [ 44, 50 ]. we used anti-rpa32 to determine whether platypus unpaired sex chromosome dna accumulates repair pathway components indicative of meiotic silencing. we hypothesised two scenarios: firstly our observations that platypus spermatocytes undergo a global phase of reduced transcription through pachytene when the sex chromosomes have extensive self-association resembles recent observations in chicken [ 12, 37 ].