Editing Genetic recombination (section)

==Achiasmy and heterochiasmy==
'''[[Achiasmate Meiosis|Achiasmy]]''' is the phenomenon where autosomal recombination is completely absent in one sex of a species. Achiasmatic chromosomal segregation is well documented in male ''[[Drosophila melanogaster]]''. The '''"Haldane-Huxley rule"''' states that achiasmy usually occurs in the [[heterogametic sex]].<ref name="Lenormand" />

'''[[Heterochiasmy]]''' occurs when recombination rates differ between the sexes of a species.<ref name="Lenormand">{{cite journal | vauthors = Lenormand T | title = The evolution of sex dimorphism in recombination | journal = Genetics | volume = 163 | issue = 2 | pages = 811–22 | date = February 2003 | doi = 10.1093/genetics/163.2.811 | pmid = 12618416 | pmc = 1462442 }}</ref> In humans, each oocyte has on average 41.6 ± 11.3 recombinations, 1.63-fold higher than sperms. This sexual dimorphic pattern in recombination rate has been observed in many species. In mammals, females most often have higher rates of recombination. <ref>{{Cite journal |last1=Ottolini |first1=Christian S. |last2=Newnham |first2=Louise J. |last3=Capalbo |first3=Antonio |last4=Natesan |first4=Senthilkumar A. |last5=Joshi |first5=Hrishikesh A. |last6=Cimadomo |first6=Danilo |last7=Griffin |first7=Darren K. |last8=Sage |first8=Karen |last9=Summers |first9=Michael C. |last10=Thornhill |first10=Alan R. |last11=Housworth |first11=Elizabeth |last12=Herbert |first12=Alex D. |last13=Rienzi |first13=Laura |last14=Ubaldi |first14=Filippo M. |last15=Handyside |first15=Alan H. |date=July 2015 |title=Genome-wide maps of recombination and chromosome segregation in human oocytes and embryos show selection for maternal recombination rates |journal=Nature Genetics |language=en |volume=47 |issue=7 |pages=727–735 |doi=10.1038/ng.3306 |pmid=25985139 |issn=1546-1718|pmc=4770575 }}</ref>