Honkatukia Mervi, Tuiskula-Haavisto Maria, de Koning Dirk-Jan, Virta Anneli, Mäki-Tanila Asko, Vilkki Johanna
Animal Production Research, MTT Agrifood Research Finland, 31600 Jokioinen, Finland.
Genet Sel Evol. 2005 Sep-Oct;37(5):563-77. doi: 10.1186/1297-9686-37-6-563.
We describe the results from genetic dissection of a QTL region on chicken chromosome 2, shown to affect egg weight and quality in an earlier genome scan of an F2 intercross between two divergent egg layer lines. As the 90% confidence intervals for the detected QTL covered tens of centiMorgans, new analyses were needed. The datasets were re-analysed with denser marker intervals to characterise the QTL region. Analysis of a candidate gene from the original QTL region, vimentin, did not support its role in controlling egg white thinning. Even after reanalysis with additional seven markers in the QTL area, the 90% confidence intervals remained large or even increased, suggesting the presence of multiple linked QTL for the traits. A grid search fitting two QTL on chromosome 2 for each trait suggested that there are two distinct QTL areas affecting egg white thinning in both production periods and egg weight in the late production period. The results indicate possible pleiotropic effects of some of the QTL on egg quality and egg weight. However, it was not possible to make a distinction between close linkage versus pleiotropic effects.
我们描述了对鸡2号染色体上一个QTL区域进行基因剖析的结果，在先前对两个不同蛋鸡品系间F2代杂交群体的基因组扫描中，该区域已显示出会影响蛋重和蛋品质。由于检测到的QTL的90%置信区间覆盖了数十个厘摩，因此需要进行新的分析。利用更密集的标记间隔对数据集重新进行分析，以表征该QTL区域。对原始QTL区域中的一个候选基因波形蛋白进行分析，并不支持其在控制蛋清变稀方面发挥作用。即使在QTL区域用另外七个标记重新分析后，90%置信区间仍然很大甚至增大了，这表明这些性状存在多个连锁QTL。对每个性状在2号染色体上拟合两个QTL的网格搜索表明，有两个不同的QTL区域影响两个生产阶段的蛋清变稀以及后期生产阶段的蛋重。结果表明，一些QTL对蛋品质和蛋重可能存在多效性影响。然而，无法区分紧密连锁与多效性影响。
