Homing in on chromosomal activity in meiosis using super-resolution microscopy
We inherit a blend of mum and dad’s genetic traits, but our DNA was a jumble even before sperm met egg. Mum’s DNA, for example, was 'mixed' during meiosis, when corresponding or homologous regions of DNA came together to swap bits, giving each egg a blend of her parent’s genes. Here synaptonemal complex (SC) proteins help this crossing over to happen – these tiny biological machines are carefully ‘expanded’ after bathing in stretchy chemicals, so they're visible under sensitive structured illumination microscopy. A bit like a magician holding two balloon animals before they twist together, 'arms' of the SC (highlighted in red) attach to homologous regions of DNA called chromosomes, while green ‘filaments’ attached to a central 'body' (purple) help bring them together. This vital stage of meiosis is one of the reasons we are who we are, a unique combination of our parents, and grandparents too.
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