Fishman L, Kelly A J, Morgan E, Willis J H
Department of Biology, Duke University, Durham, North Carolina 27708, USA.
Genetics. 2001 Dec;159(4):1701-16. doi: 10.1093/genetics/159.4.1701.
As part of a study of the genetics of floral adaptation and speciation in the Mimulus guttatus species complex, we constructed a genetic linkage map of an interspecific cross between M. guttatus and M. nasutus. We genotyped an F(2) mapping population (N = 526) at 255 AFLP, microsatellite, and gene-based markers and derived a framework map through repeated rounds of ordering and marker elimination. The final framework map consists of 174 marker loci on 14 linkage groups with a total map length of 1780 cM Kosambi. Genome length estimates (2011-2096 cM) indicate that this map provides thorough coverage of the hybrid genome, an important consideration for QTL mapping. Nearly half of the markers in the full data set (49%) and on the framework map (48%) exhibited significant transmission ratio distortion (alpha = 0.05). We localized a minimum of 11 transmission ratio distorting loci (TRDLs) throughout the genome, 9 of which generate an excess of M. guttatus alleles and a deficit of M. nasutus alleles. This pattern indicates that the transmission ratio distortion results from particular interactions between the heterospecific genomes and suggests that substantial genetic divergence has occurred between these Mimulus species. We discuss possible causes of the unequal representation of parental genomes in the F(2) generation.
作为对沟酸浆属物种复合体中花适应性和物种形成遗传学研究的一部分，我们构建了沟酸浆（Mimulus guttatus）和鼻状沟酸浆（M. nasutus）种间杂交的遗传连锁图谱。我们对一个F2作图群体（N = 526）的255个AFLP、微卫星和基于基因的标记进行了基因分型，并通过反复的排序和标记剔除得出了一个框架图谱。最终的框架图谱由14个连锁群上的174个标记位点组成，总图谱长度为1780厘摩（Kosambi）。基因组长度估计值（2011 - 2096厘摩）表明该图谱全面覆盖了杂种基因组，这是进行QTL定位的一个重要考量因素。全数据集（49%）和框架图谱（48%）中近一半的标记表现出显著的传递率失真（α = 0.05）。我们在整个基因组中定位了至少11个传递率失真位点（TRDL），其中9个产生了过量的沟酸浆等位基因和不足的鼻状沟酸浆等位基因。这种模式表明传递率失真是由异源基因组之间的特定相互作用导致的，并表明这些沟酸浆属物种之间已经发生了显著的遗传分化。我们讨论了F2代中亲本基因组不均衡代表的可能原因。
