TY - JOUR
T1 - Unequal Sister Chromatid and Homolog Recombination at a Tandem Duplication of the a1 Locus in Maize
AU - Yandeau-Nelson, Marna D
AU - Xia, Yiji
AU - Li, Jin
AU - Neuffer, M. Gerald
AU - Schnable, Patrick S.
N1 - Funding information:
We thank the late John R. Laughnan for encouraging this research direction, James Bradeen (University of Minnesota) for sharing his long-range PCR protocol and related advice, and undergraduate students Brian Brand, Timothy Dunham, Ryan Manser, John Tenhunfeld, and George Weber for technical assistance. This research was supported in part by the National Research Initiative of the U.S. Department of Agriculture Cooperative State Research, Education, and Extension Service, grant nos. 9701407 and 9901579 to P.S.S. and Basil J. Nikolau and 0101869, 0300940, and 0500962 to P.S.S.; additional support was provided by Hatch Act and State of Iowa funds.
Publisher copyright:
© 2006 by the Genetics Society of America
PY - 2006/8/1
Y1 - 2006/8/1
N2 - Tandemly arrayed duplicate genes are prevalent. The maize A1-b haplotype is a tandem duplication that consists of the components, α and β. The rate of meiotic unequal recombination at A1-b is ninefold higher when a homolog is present than when it is absent (i.e., hemizygote). When a sequence heterologous homolog is available, 94% of recombinants (264/281) are generated via recombination with the homolog rather than with the sister chromatid. In addition, 83% (220/264) of homolog recombination events involved α rather than β. These results indicate that: (1) the homolog is the preferred template for unequal recombination and (2) pairing of the duplicated segments with the homolog does not occur randomly but instead favors a particular configuration. The choice of recombination template (i.e., homolog vs. sister chromatid) affects the distribution of recombination breakpoints within a1. Rates of unequal recombination at A1-b are similar to the rate of recombination between nonduplicated a1 alleles. Unequal recombination is therefore common and is likely to be responsible for the generation of genetic variability, even within inbred lines.
AB - Tandemly arrayed duplicate genes are prevalent. The maize A1-b haplotype is a tandem duplication that consists of the components, α and β. The rate of meiotic unequal recombination at A1-b is ninefold higher when a homolog is present than when it is absent (i.e., hemizygote). When a sequence heterologous homolog is available, 94% of recombinants (264/281) are generated via recombination with the homolog rather than with the sister chromatid. In addition, 83% (220/264) of homolog recombination events involved α rather than β. These results indicate that: (1) the homolog is the preferred template for unequal recombination and (2) pairing of the duplicated segments with the homolog does not occur randomly but instead favors a particular configuration. The choice of recombination template (i.e., homolog vs. sister chromatid) affects the distribution of recombination breakpoints within a1. Rates of unequal recombination at A1-b are similar to the rate of recombination between nonduplicated a1 alleles. Unequal recombination is therefore common and is likely to be responsible for the generation of genetic variability, even within inbred lines.
UR - http://www.scopus.com/inward/record.url?scp=33747840024&partnerID=8YFLogxK
U2 - 10.1534/genetics.105.052712
DO - 10.1534/genetics.105.052712
M3 - Journal article
C2 - 16751673
AN - SCOPUS:33747840024
SN - 0016-6731
VL - 173
SP - 2211
EP - 2226
JO - Genetics
JF - Genetics
IS - 4
ER -