Nichols Krista M, Broman Karl W, Sundin Kyle, Young Jennifer M, Wheeler Paul A, Thorgaard Gary H
School of Biological Sciences and Center for Reproductive Biology, Washington State University, Pullman, Washington 99164-4236, USA.
Genetics. 2007 Jan;175(1):335-47. doi: 10.1534/genetics.106.064311. Epub 2006 Oct 22.
Effects of maternal cytoplasmic environment (MCE) on development rate in rainbow trout were evaluated within a quantitative trait loci (QTL) analysis framework. Previous research had identified QTL for development rate in doubled haploid (DH) progeny produced from a cross between the Oregon State University (OSU) and the Swanson (SW) River rainbow trout clonal lines. In this study, progeny for QTL mapping were produced from a cross between the OSU and Clearwater (CW) River clonal lines. Doubled haploids were produced from the OSU x CW F1 by androgenesis using eggs from different females (or MCEs); with androgenesis, the maternal nuclear genome was destroyed by irradiation and diploidy was restored by blocking the first embryonic cleavage by heat shock. All embryos were incubated at the same temperature and development rate quantified as time to hatch. Using a linkage map constructed primarily with AFLP markers, QTL mapping was performed, including MCE covariates and QTL x MCE effects in models for testing. The major QTL for development rate in the OSU x SW cross overlaps with the major QTL found in this OSU x CW cross; effects at this locus were the same across MCEs. Both MCE and QTL x MCE effects contribute to variability in development rate, but QTL x MCE were minor and detected only at small-effect QTL.
在数量性状基因座（QTL）分析框架内，评估了母体细胞质环境（MCE）对虹鳟鱼发育速率的影响。先前的研究已经在俄勒冈州立大学（OSU）和斯旺森（SW）河虹鳟鱼克隆系杂交产生的双单倍体（DH）后代中确定了发育速率的QTL。在本研究中，用于QTL定位的后代是由OSU和清水河（CW）克隆系杂交产生的。通过使用来自不同雌性（或MCE）的卵子进行雄核发育，从OSU×CW F1中产生双单倍体；在雄核发育过程中，母体核基因组通过辐射被破坏，二倍体通过热休克阻断第一次胚胎卵裂得以恢复。所有胚胎都在相同温度下孵化，发育速率以孵化时间来量化。使用主要由AFLP标记构建的连锁图谱进行QTL定位，在测试模型中包括MCE协变量和QTL×MCE效应。OSU×SW杂交中发育速率的主要QTL与本研究中OSU×CW杂交中发现的主要QTL重叠；该位点的效应在不同MCE中是相同的。MCE和QTL×MCE效应都对发育速率的变异性有贡献，但QTL×MCE效应较小，仅在小效应QTL中检测到。
