Parental origin of chromosomes influences crossover activity within the Kcnq1 transcriptionally imprinted domain of Mus musculus.
BACKGROUND
Among the three functions of DNA, mammalian replication and transcription can be subject to epigenetic imprinting specified by the parental origin of chromosomes, and although there is suggestive indication that this is also true for meiotic recombination, no definitive evidence has yet been reported.


RESULTS
We have now obtained such evidence on mouse chromosome 7 by assaying meiotic recombination as it occurs in reciprocal F1 mice. A 166 kb region near the Kcnq1 transcriptionally imprinted domain showed significantly higher recombination activity in the CAST x B6 parental direction (p < 0.03). Characterizing hotspots within this domain revealed a cluster of three hotspots lying within a 100 kb span, among these hotspots, Slc22a18 showed a definitive parent of origin effect on recombination frequency (p < 0.02). Comparing recombination activity in the mouse Kcnq1 and neighboring H19-Igf2 imprinted domains with their human counterparts, we found that elevated recombination activity in these domains is a consequence of their chromosomal position relative to the telomere and not an intrinsic characteristic of transcriptionally imprinted domains as has been previously suggested.


CONCLUSIONS
Similar to replication and transcription, we demonstrate that meiotic recombination can be subjected to epigenetic imprinting and hotspot activity can be influenced by the parental origin of chromosomes. Furthermore, transcriptionally imprinted regions exhibiting elevated recombination activity are likely a consequence of their chromosomal location rather than their transcriptional characteristic.
Center for Genome Dynamics, The Jackson Laboratory, 600 Main Street, Bar Harbor, Maine, USA. siemon.ng@jax.org
Siemon H
SH
Ng
Rose
R
Madeira
Emil D
ED
Parvanov
Lorin M
LM
Petros
Petko M
PM
Petkov
Kenneth
K
Paigen
D000818:Animals; D002874:Chromosome Mapping; D033481:Chromosomes, Mammalian / Q000737:chemistry / Q000235:genetics*; D003434:Crossing Over, Genetic; D005260:Female; D018392:Genomic Imprinting; D051657:KCNQ1 Potassium Channel / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008297:Male; D051379:Mice / Q000235:genetics* / Q000378:metabolism; D008810:Mice, Inbred C57BL; D014158:Transcription, Genetic
D051657:KCNQ1 Potassium Channel; C496910:Kcnq1 protein, mouse