Exceptionally high levels of recombination across the honey bee genome.
The first draft of the honey bee genome sequence and improved genetic maps are utilized to analyze a genome displaying 10 times higher levels of recombination (19 cM/Mb) than previously analyzed genomes of higher eukaryotes. The exceptionally high recombination rate is distributed genome-wide, but varies by two orders of magnitude. Analysis of chromosome, sequence, and gene parameters with respect to recombination showed that local recombination rate is associated with distance to the telomere, GC content, and the number of simple repeats as described for low-recombining genomes. Recombination rate does not decrease with chromosome size. On average 5.7 recombination events per chromosome pair per meiosis are found in the honey bee genome. This contrasts with a wide range of taxa that have a uniform recombination frequency of about 1.6 per chromosome pair. The excess of recombination activity does not support a mechanistic role of recombination in stabilizing pairs of homologous chromosome during chromosome pairing. Recombination rate is associated with gene size, suggesting that introns are larger in regions of low recombination and may improve the efficacy of selection in these regions. Very few transposons and no retrotransposons are present in the high-recombining genome. We propose evolutionary explanations for the exceptionally high genome-wide recombination rate.
Beye
Martin
M
Institute of Genetics, Heinrich Heine Universität Duesseldorf, Duesseldorf 40225, Germany. Martin.Beye@uni.duesseldorf.de
Gattermeier
Irene
I
Hasselmann
Martin
M
Gempe
Tanja
T
Schioett
Morten
M
Baines
John F
JF
Schlipalius
David
D
Mougel
Florence
F
Emore
Christine
C
Rueppell
Olav
O
Sirviö
Anu
A
Guzmán-Novoa
Ernesto
E
Hunt
Greg
G
Solignac
Michel
M
Page
Robert E
RE
D000818:Animals; D001482:Base Composition; D001516:Bees / Q000235:genetics*; D002875:Chromosomes / Q000235:genetics; D004247:DNA / Q000737:chemistry / Q000235:genetics; D017344:Genes, Insect; D049750:Genome, Insect; D018598:Minisatellite Repeats; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D011995:Recombination, Genetic
D004247:DNA