Chromosomal regions associated with segregation distortion in maize
Chromosomal regions associated with segregation distortion in maize
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DOI：
10.1007/s00122-002-0970-9
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发表时间：
2002-09-01
影响因子：
5.4
通讯作者：
Bernardo, R
中科院分区：
文献类型：
--
作者：
Lu, H;Romero-Severson, J;Bernardo, R
分离扭曲使基因型频率偏离孟德尔期望。我们在这项研究中的目的是评估玉米中分离扭曲发生的频率，识别与分离扭曲一致相关的染色体区域，并检查配子体因素对连锁图谱的影响。我们为 LH200/LH216 F(2)Syn3（即随机交配 3 次）群体构建了一个简单序列重复 (SSR) 连锁图，并将该图中的分离失真与三个已发表的连锁图中的分离失真进行了比较。在四个作图群体的 1,820 个共显性标记中，301 个 (17%) 显示分离扭曲 (P < 0.05)。显示分离扭曲的标记频率范围为 Tx303/CO159 作图群体中的 19% 到 B73/Mo17 作图群体中的 36%。研究发现减数分裂的数量与群体中检测到的分离扭曲的频率之间存在正相关关系。在给定的染色体上，几乎所有显示分离扭曲的标记都倾向于来自同一亲本的等位基因。 10 条玉米染色体上总共 18 个染色体区域与分离扭曲相关。这些染色体区域在四个群体中的一致位置表明存在分离扭曲区域（SDR）。三个已知的配子体因素可能是这些 SDR 的遗传原因。如之前的研究所示，当 SDR 中仅存在一个配子体因子时，分离失真不会影响图谱距离的估计。
Segregation distortion skews the genotypic frequencies from their Mendelian expectations. Our objectives in this study were to assess the frequency of occurrence of segregation distortion in maize, identify chromosomal regions consistently associated with segregation distortion, and examine the effects of gametophytic factors on linkage mapping. We constructed a simple sequence repeat (SSR) linkage map for a LH200/LH216 F(2)Syn3 (i.e., random-mated three times) population, and compared the segregation distortion in this map with the segregation distortion in three published linkage maps. Among 1,820 codominant markers across the four mapping populations, 301 (17%) showed segregation distortion (P < 0.05). The frequency of markers showing segregation distortion ranged from 19% in the Tx303/CO159 mapping population to 36% in the B73/Mo17 mapping population. A positive relationship was found between the number of meioses and the frequency of segregation distortion detected in a population. On a given chromosome, nearly all of the markers showing segregation distortion favored the allele from the same parent. A total of 18 chromosomal regions on the ten maize chromosomes were associated with segregation distortion. The consistent location of these chromosomal regions in four populations suggested the presence of segregation distortion regions (SDRs). Three known gametophytic factors are possible genetic causes of these SDRs. As shown in previous research, segregation distortion does not affect the estimate of map distance when only one gametophytic factor is present in an SDR.