Chromosome-Wide Mapping of Recombinational Activity

我们的目标是生成第一张哺乳动物重组活动的高分辨率地图 染色体作为整个基因组的代表，包括热点位置的变异和 物种内和物种间的活动，以及这种活动在F1动物和正反交之间的不同之处 雌雄减数分裂。为此，我们将从6个基因中的每一个定位在3000个减数分裂中产生的重组子 低于50-KB分辨率的交叉，使我们能够区分各个热点并检测低至 0.03厘米/热点。这些数据将有助于我们理解哺乳动物的重组作为一种生物 重组过程以及重组参数与染色体其他方面的关系 动力学。 瞄准5a。我们将绘制出在6个遗传杂交中出现的8号染色体上每个交叉的位置，3000 每个后代总共有18,000个减数分裂，分辨率低于50kb。其中四名交叉者将是女性F1 以菊花链设计(C57BL/6J x PWD/PhJ x WSB/EIJ x CAST/EIJ x C57BL/6J)创建的混血儿，然后 回交至C57BL/6J。C57BL/6J×PWD/PhJ和WSB/EIJ×CAST/EIJ杂交F1雄性杂交种 也将回交到C57BL/6J。只要有可能，将从F1衍生出相同数量的减数分裂 由原始亲本(AxB和BXA)的正反交所创造的动物。这种设计最适合于 收集关于这些杂交的遗传变异性、性别特异性和可能的印记效应的数据。 目标5b。使用目标5a的数据，我们将分析该位置的应变、性别和横向特异性， 重组热点在8号染色体上的分布和活性 在进化过程中，我们还将提供亚种间8号染色体热点的共识图谱。 目标5c。我们将向科学界提供18,000个回交DNA样本 和将在8号染色体上新开发的3000个SNP分析将发布在我们的 网站，并提供给其他人用于QTL和基因图谱研究。

Our goal is to generate the first high-resolution maps of mammalian recombination activity for an entire chromosome as a representative of the genome as a whole, including the variation in hotspot location and activity within and between species, and how this differs in F1 animals from reciprocal crosses and between male and female meiosis. For this we will map recombinants arising in 3000 meioses from each of six genetic crosses at under 50-Kb resolution, enabling us to distinguish individual hotspots and detect activities as low as 0.03 cM/hotspot. These data will go far in helping us understand mammalian recombination as a biological process as well as relationships between parameters of recombination and other aspects of chromosome dynamics. Aim 5a. we will map the location of every crossover on Chromosome 8 arising in six genetic crosses, 3000 offspring each for a total of 18,000 meioses, at under 50 kb resolution. Four of the crosses will be female F1 hybrids created in a daisy-chain design (C57BL/6J x PWD/PhJ x WSB/EiJ x CAST/EiJ x C57BL/6J) and then backcrossed to C57BL/6J. F1 male hybrids from crosses of C57BL/6J x PWD/PhJ and WSB/EiJ x CAST/EiJ will also be backcrossed to C57BL/6J. Whenever possible, equal numbers of meioses will be derived from F1 animals created by reciprocal crosses of the original parents (AxB and BXA). This design is optimal for gathering data on genetic variability, sex specificity, and possible imprinting effects in these crosses. Aim 5b. using the data of aim 5a, we will analyze the strain, sex and cross direction specificity of the location, distribution and activity of the recombination hotspots along the length of Chromosome 8. For understanding evolutionary processes, we will also provide a consensus map of Chromosome 8 hotspots across subspecies. Aim 5c. we will make the 18,000 backcross DMA samples available to the scientific community via a repository, and the 3000 SNP assays that will be newly developed on Chromosome 8 will be posted on our web site and made available to others for QTL and gene mapping studies.