Male mouse recombination maps for each autosome identified by chromosome painting

Linkage maps constructed from genetic analysis of gene order and crossover frequency provide few clues to the basis of the genomewide distribution of meiotic recombination, such as chromosome structure, that influences meiotic recombination. To bridge this gap, we have generated the first cytological recombination map that identifies individual autosomes in the male mouse. We prepared meiotic chromosome (synaptonemal complex [SC]) spreads from 110 mouse spermatocytes, identified each autosome by multicolor fluorescence in situ hybridization of chromosome- specific DNA libraries, and mapped 12,000 sites of recombination along individual autosomes, using immunolocalization of MLH1, a mismatch repair protein that marks crossover sites. We show that SC length is strongly correlated with crossover frequency and distribution. Although the length of most SCs corresponds to that predicted from their mitotic chromosome length rank, several SCs are longer or shorter than expected, with correspond..., SC Spreads and Immunostaining Three juvenile (20–21 d old) C57BL/6J mice (the same line analyzed by the Mouse Genome Sequencing Project) were used to prepare and immunolabel the SC spreads, as described elsewhere (Anderson et al. 1999). Complete sets of SCs in which the SCs were well separated but not obviously stretched or broken and that had ≥ 19 MLH1 foci were selected for analysis. Three fluorescent images (4, 6-diamino-2-phyenylindole [DAPI], SCP3, and MLH1) were captured for each SC set. mFISH After image acquisition of the immunofluorescence signals, the spermatocyte preparations were subjected to two or three rounds of denaturation and FISH. To identify each autosome, chromosome-specific painting probes (Rabbitts et al. 1995) were combinatorially labeled with fluorescein isothiocyanate (FITC)–2-deoxyuridine 5-tri phosphate (dUTP), Cy5-dUTP (both from Amersham), or 6-carboxytetramethylrhodamine (TAMRA)-dUTP (Applied Biosystems) and were combined to form two different probe pools ..., , # Male mouse recombination maps for each autosome identified by chromosome painting ## Description of the data and file structure The data are presented in an Excel spreadsheet with 22 sheets. Sheet 1 (karyotype-absolute positi calc) defines the average length of each mouse SC, after identification using chromosome-specific DNA probes. Sheet 2 (Notes) contains definitions of the headings used for Sheet 3 (raw data sorted by SC) and Sheets 4 through 22 (\"SC1 abs\" through \"SC19 abs\"). Sheet 2 also contains explanations for how the karyotype was derived, and two references in which this data was used for publication are also presented. Sheet 3 contains the positions of all MLH1 foci observed on all of the SCs with each MLH1 focus position expressed as a fraction of SC length from the centromere. Sheets 4 – 22 (labeled as \"SC1 abs\", \"SC2 abs\", \"SC3 abs\", \"SC4 abs\", SC5 abs, \"SC6 abs\", \"SC7 abs\", \"SC8 abs\", \"SC9 abs\", \"SC10 abs\", \"SC11 abs\", \"SC12 abs\", \"SC13 abs\", \"SC14 abs\", \"SC15 ...基于基因顺序与交换频率的遗传分析构建的连锁图谱，对影响减数分裂重组的全基因组重组分布基础（如染色体结构）的阐释极为有限。为填补这一研究空白，我们构建了首份可识别雄性小鼠单条常染色体的细胞学重组图谱。我们从110个小鼠精母细胞中制备了减数分裂染色体（联会复合体[synaptonemal complex, SC]）铺片，通过染色体特异性DNA文库的多色荧光原位杂交识别每条常染色体，并利用标记交换位点的错配修复蛋白MLH1（MutL同源物1）的免疫定位技术，在单条常染色体上定位了12000个重组位点。研究表明，SC长度与交换频率及分布具有显著相关性。尽管多数SC的长度与其有丝分裂染色体长度等级的预测值相符，但仍有部分SC的长度超出或低于预期……联会复合体铺片与免疫染色：我们选取3只幼年（20~21日龄）C57BL/6J小鼠——即小鼠基因组测序项目（Mouse Genome Sequencing Project）所分析的同一品系小鼠——按照已发表方案（Anderson等，1999）制备SC铺片并开展免疫标记。筛选出联会复合体分离完好、未出现明显拉伸或断裂，且包含≥19个MLH1焦点的完整SC组用于后续分析。为每个SC组采集3幅荧光图像：4',6-二脒基-2-苯基吲哚（4',6-diamidino-2-phenylindole, DAPI）、联会复合体蛋白3（SCP3）及MLH1通道的图像。多色荧光原位杂交（multicolor fluorescence in situ hybridization, mFISH）：完成免疫荧光信号的图像采集后，对精母细胞制片进行2~3轮变性与荧光原位杂交（fluorescence in situ hybridization, FISH）。为识别每条常染色体，我们将染色体特异性绘画探针（Rabbitts等，1995）采用异硫氰酸荧光素（fluorescein isothiocyanate, FITC）标记的2'-脱氧尿苷5'-三磷酸（2'-deoxyuridine 5'-triphosphate, dUTP）、Cy5-dUTP（均购自Amersham公司）或6-羧基四甲基罗丹明（6-carboxytetramethylrhodamine, TAMRA）-dUTP（Applied Biosystems公司）进行组合标记，并混合为两组不同的探针池……# 基于染色体绘画识别的雄性小鼠各常染色体重组图谱 数据与文件结构说明：本数据集以Excel电子表格形式存储，共包含22个工作表。工作表1（karyotype-absolute positi calc）记录了通过染色体特异性DNA探针识别后的小鼠各SC的平均长度。工作表2（Notes，注释表）包含了工作表3（按SC排序的原始数据表）以及工作表4至22（命名为"SC1 abs"至"SC19 abs"）所用表头的定义；该工作表同时阐释了核型的推导方法，并列出了两篇使用本数据集发表成果的参考文献。工作表3收录了所有SC上观测到的全部MLH1焦点的位置信息，每个MLH1焦点的位置以其相对于着丝粒的SC长度占比表示。工作表4至22分别命名为"SC1 abs"、"SC2 abs"、"SC3 abs"、"SC4 abs"、"SC5 abs"、"SC6 abs"、"SC7 abs"、"SC8 abs"、"SC9 abs"、"SC10 abs"、"SC11 abs"、"SC12 abs"、"SC13 abs"、"SC14 abs"、"SC15 abs"……