The appearance of recombination between homologous chromosomes in meiosis is, along with mutations, a significant parameter of the variability in nature, and furthermore, selection itself (and its efficiency and success). The frequency of recombination affects many different population-wise genetic parameters like genome inbreeding structure and the appearance of LD (linkage disequilibrium). PRDM9 is a zinc finger protein that binds DNA at specific locations in the genome where it trimethylates H3K4 and H3K36 at surrounding nucleosomes. During meiosis in many species, these actions determine the location of recombination hotspots. It also reorganizes local nucleosomal structure, creating a nucleosome-free center where the DNA DSB required for DNA exchange between chromosomes is formed. Although this mechanism wasn't completely clarified, the newest technologies helped discover parts of it and therefore suggest that this process is more complex than what was previously thought. A lot of things yet remain unknown in the process of meiotic recombination, but with rapid development of technology more questions will be asked and hopefully answers unveiled with further research. Furthermore, PRDM9 gene has a big role in inheritance and recombination frequencies. As an example, PRDM9 alleles influence human chromosomal rearrangements, causing hereditary diseases.