Transmission ratio distortion (TRD) is defined as the observed deviation from the expected Mendelian inheritance of alleles from heterozygous parents. This phenomenon is attributed to various biological mechanisms acting on germ cells, embryos or fetuses, or even in early postnatal life. Current statistical approaches typically use two independent parametrizations assuming that TRD relies on allele‐ or genotype‐related mechanisms, although they have never been tested and compared. This study compared allele‐ and genotype‐related TRD models on simulated datasets with 1000 genotyped offspring and real data from 168 sire–dam–offspring beef cattle trios. The analysis of simulated datasets favored the true model of analysis in most cases (>93%), and a low percentage of missidentification occurred under (almost) null dominance (genotype‐related model) or similar and moderate‐to‐low sire‐ and dam‐specific TRD parameters (allele‐related model). Moreover, the correlation between simulated and predicted distortion parameters was high (>0.97) under the true model. The comparison of allele‐ and genotype‐related TRD models is an appealing tool to infer the biological source of TRD (i.e. haploid vs. diploid cells) when screening the whole genome. The analysis of beef cattle data corroborated a TRD region previously reported in chromosome 4, although discarding allele‐related mechanisms and favoring the genotype‐related model as the more reliable one. The results of this study highlight the relevance of implementing and comparing different parametrizations to capture all kinds of TRD, and to compare them using appropriate statistical methods.

中文翻译：

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区分等位基因和特定基因型的传输比率失真

传输比畸变（TRD）定义为与杂合亲本等位基因的预期孟德尔遗传的观察偏差。这种现象归因于作用于生殖细胞，胚胎或胎儿，甚至在出生后早期的各种生物学机制。假设TRD依赖于等位基因或基因型相关的机制，当前的统计方法通常使用两个独立的参数设置，尽管它们从未经过测试和比较。这项研究在模拟数据集上比较了与等位基因和基因型相关的TRD模型，该数据集包含1000个基因型后代和168个父-母-后代肉牛三重奏的真实数据。在大多数情况下（> 93％），对模拟数据集的分析倾向于使用真正的分析模型，在（几乎）无效优势（与基因型相关的模型）或相似且中等至较低的父系和大坝特定的TRD参数（等位基因相关的模型）下发生的误判率低。此外，在真实模型下，模拟和预测的变形参数之间的相关性很高（> 0.97）。等位基因和基因型相关TRD模型的比较是一个引人注目的工具，可以在筛选整个基因组时推断出TRD的生物学来源（即单倍体细胞与二倍体细胞）。对肉牛数据的分析证实了先前在第4号染色体中报告的TRD区域，尽管它放弃了等位基因相关的机制，并支持基因型相关的模型作为更可靠的模型。这项研究的结果突显了实施和比较不同参数来捕获各种TRD的相关性，