遺傳重組（它涉及DNA股的斷開和重接以產(chǎn)生新的基因組合）是真核細(xì)胞生物中的一種基本的生物學(xué)過(guò)程。在哺乳動(dòng)物減數(shù)分裂的時(shí)候,，在這一專門化的細(xì)胞分裂過(guò)程中,，來(lái)自母系和父系的染色體被一分為二并產(chǎn)生出精子細(xì)胞和卵子細(xì)胞，而重組過(guò)程則將同源染色體的不同部分連接在了一起,，從而導(dǎo)致了后代中的基因變化,。
在2010年2月12日刊的《科學(xué)》雜志中，有3個(gè)研究小組報(bào)告發(fā)現(xiàn)了控制發(fā)生在被稱作“熱點(diǎn)”的優(yōu)先染色體位置的基因重組程度的哺乳動(dòng)物基因（含有9或Prdm9的PR結(jié)構(gòu)域）,。
Parvanov等人發(fā)現(xiàn),，在小鼠中，*Prdm9*（它編碼的是一種功能為組蛋白甲基轉(zhuǎn)移酶的鋅指蛋白）會(huì)在雄性和雌性動(dòng)物的早期減數(shù)分裂時(shí)表達(dá),，而其表達(dá)的不足會(huì)導(dǎo)致雌雄兩性的不育,。研究人員還對(duì)小鼠和人類的該基因進(jìn)行了測(cè)序并對(duì)其序列變異進(jìn)行了分析。
Baudat等人將小鼠和人體中不同的*Prdm9*變異株和PRDM9 蛋白變異株與預(yù)計(jì)的不同DNA序列特異性和基因組中不同模式的熱點(diǎn)“使用”進(jìn)行了相關(guān)研究,。
最后,，Myers 等人對(duì)人類和黑猩猩基因組中的重組熱點(diǎn)位置進(jìn)行了比較并發(fā)現(xiàn)了一個(gè)過(guò)去與40%的人類熱點(diǎn)（而PRDM9蛋白質(zhì)就是與其結(jié)合的）有關(guān)的序列基元；而該重組過(guò)程導(dǎo)致了一種自我破壞的驅(qū)動(dòng)力,，使得該吸收熱點(diǎn)的序列基元從我們的基因組中被清除了出去,。
在一篇附隨的Perspective中,，Cheung寫道，這些發(fā)現(xiàn)開啟了人們了解成功配子形成的平衡與維護(hù)基因多元性的大門,。（生物谷Bioon.com）
生物谷推薦原始出處：
Science 12 February 2010: DOI: 10.1126/science.1181495
Prdm9 Controls Activation of Mammalian Recombination Hotspots
Emil D. Parvanov, Petko M. Petkov,* Kenneth Paigen*
Mammalian meiotic recombination, which preferentially occurs at specialized sites called hotspots, ensures the orderly segregation of meiotic chromosomes and creates genetic variation among offspring. A locus on mouse chromosome 17, which controls activation of recombination at multiple distant hotspots, has been mapped within a 181-kilobase interval, three of whose genes can be eliminated as candidates. The remaining gene, Prdm9, codes for a zinc finger containing histone H3K4 trimethylase that is expressed in early meiosis and whose deficiency results in sterility in both sexes. Mus musculus exhibits five alleles of Prdm9; human populations exhibit two predominant alleles and multiple minor alleles. The identification of Prdm9 as a protein regulating mammalian recombination hotspots initiates molecular studies of this important biological control system.
The Jackson Laboratory, Bar Harbor, ME 04609, USA.
Science 12 February 2010: DOI: 10.1126/science.1183439
PRDM9 Is a Major Determinant of Meiotic Recombination Hotspots in Humans and Mice
F. Baudat,1,* J. Buard,1,* C. Grey,1,* A. Fledel-Alon,2 C. Ober,2 M. Przeworski,2,3 G. Coop,4 B. de Massy1,
Meiotic recombination events cluster into narrow segments of the genome, defined as hotspots. Here, we demonstrate that a major player for hotspot specification is the Prdm9 gene. First, two mouse strains that differ in hotspot usage are polymorphic for the zinc finger DNA binding array of PRDM9. Second, the human consensus PRDM9 allele is predicted to recognize the 13-mer motif enriched at human hotspots; this DNA binding specificity is verified by in vitro studies. Third, allelic variants of PRDM9 zinc fingers are significantly associated with variability in genome-wide hotspot usage among humans. Our results provide a molecular basis for the distribution of meiotic recombination in mammals, in which the binding of PRDM9 to specific DNA sequences targets the initiation of recombination at specific locations in the genome.
1 Institut de Génétique Humaine, UPR1142, CNRS, Montpellier, France.
2 Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA.
3 Howard Hughes Medical Institute, University of Chicago, Chicago, IL 60637, USA.
4 Department of Evolution and Ecology and the Center for Population Biology, University of California, Davis, CA 95616, USA.
Science 12 February 2010: DOI: 10.1126/science.1182363
Drive Against Hotspot Motifs in Primates Implicates the PRDM9 Gene in Meiotic Recombination
Simon Myers,1,2,*, Rory Bowden,1,2,* Afidalina Tumian,1 Ronald E. Bontrop,3 Colin Freeman,2 Tammie S. MacFie,4, Gil McVean,1,2, Peter Donnelly1,2,
Although present in both humans and chimpanzees, recombination hotspots, at which meiotic crossover events cluster, differ markedly in their genomic location between the species. We report that a 13–base pair sequence motif previously associated with the activity of 40% of human hotspots does not function in chimpanzees and is being removed by self-destructive drive in the human lineage. Multiple lines of evidence suggest that the rapidly evolving zinc-finger protein PRDM9 binds to this motif and that sequence changes in the protein may be responsible for hotspot differences between species. The involvement of PRDM9, which causes histone H3 lysine 4 trimethylation, implies that there is a common mechanism for recombination hotspots in eukaryotes but raises questions about what forces have driven such rapid change.
1 Department of Statistics, Oxford University, 1 South Parks Road, Oxford OX1 3TG, UK.
2 Wellcome Trust Centre for Human Genetics, Oxford University, Roosevelt Drive, Oxford OX3 7BN, UK.
3 Department of Comparative Genetics and Refinement, Biomedical Primate Research Center, Lange Kleiweg 139 2288 GJ, Rijswijk, Netherlands.
4 Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
