On 2015 May 12, University of Lausanne Genomics, Ecology and Evolution Journal Club commented:

The article nicely highlights the need for a reference genome panel consisting of African variants and understanding African population history. This is a summary of the discussion at our journal club. By sequencing a large number of single sperm DNA molecules, the authors showed that meiosis is an important source not only of genetic diversity of gametes with different alleles combinations as products of chromosomal crossovers (COs), but it is also the source of sequence variation, knowing that recombination may cause local mutagenic effect at crossover sites with recurrent double strand breaks (DSBs). This study contributes to the understanding of the sequence evolution at recombination hotspots. Observed de novo mutations changed strong (S) CG into weak (W) TA base pairs and they all occurred mainly at CpG sites. As it is shown that GC base pairs are preferentially transferred during crossover, the authors suggested that GC-biased gene conversion (gBGC) is the dominant force shaping the nucleotide composition at hotspots and potentially in other recombination products, which might explain the high GC content associated with recombination. It is possible that gBGC is an adaptation to reduce the opposing mutational load of recombination, knowing that mutation favors weak over strong nucleotides. Still, small sample size gives little power for detecting potential differences between COs and NCOs.

On 2015 May 12, University of Lausanne Genomics, Ecology and Evolution Journal Club commented:

The article nicely highlights the need for a reference genome panel consisting of African variants and understanding African population history. This is a summary of the discussion at our journal club. By sequencing a large number of single sperm DNA molecules, the authors showed that meiosis is an important source not only of genetic diversity of gametes with different alleles combinations as products of chromosomal crossovers (COs), but it is also the source of sequence variation, knowing that recombination may cause local mutagenic effect at crossover sites with recurrent double strand breaks (DSBs). This study contributes to the understanding of the sequence evolution at recombination hotspots. Observed de novo mutations changed strong (S) CG into weak (W) TA base pairs and they all occurred mainly at CpG sites. As it is shown that GC base pairs are preferentially transferred during crossover, the authors suggested that GC-biased gene conversion (gBGC) is the dominant force shaping the nucleotide composition at hotspots and potentially in other recombination products, which might explain the high GC content associated with recombination. It is possible that gBGC is an adaptation to reduce the opposing mutational load of recombination, knowing that mutation favors weak over strong nucleotides. Still, small sample size gives little power for detecting potential differences between COs and NCOs.