Ren X, Li R, Wei X, Bi Y, Ho VWS, Ding Q, Xu Z, Zhang Z, Hsieh CL, Young A, Zeng J, Liu X, Zhao Z.

Nucleic Acids Res. 2018 Feb 16;46(3):1295-1307. doi:10.1093/nar/gkx1277

Genomic basis of recombination suppression in the hybrid between Caenorhabditis briggsae and C. nigoni.

”the coding sequences of [the] one-to-one orthologs exhibited only around a 90% identity, and most of [the] introns and intergenic regions were not alignable” “we produced [15,157] one-to-one orthologous gene pairs between C. briggsae and C. nigoni.” “we extracted all of the best hits between the two genomes that were >1 kb in size [and] observed over 400 interchromosomal translocations” “[we produced] produce homozygous viable introgressions representing ∼28% of the C. briggsae genome” “We observed a significantly higher [alignment score] in recombination sites than in genomic background” “Nearly half of the reduced genome in C. briggsae could be explained by its lost repeats relative to the C. nigoni genome. These differences in genome size and repeat content are expected to create gaps in the sequence alignment or make the syntenic sequences not alignable.”