Low frequency of mouse t haplotypes in wild populations is not explained by modifiers of meiotic drive.
Low frequency of mouse t haplotypes in wild populations is not explained by modifiers of meiotic drive.
复制标题
野生群体中小鼠 t 单倍型的低频率不能用减数分裂驱动的修饰因子来解释。
DOI：
10.1093/genetics/144.4.1787
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发表时间：
1996
期刊：
影响因子：
3.3
通讯作者：
Silver,LM
中科院分区：
文献类型：
--
作者：
Ardlie,KG;Silver,LM
这三种倍型是小鼠17号染色体的自然存在形式，显示出杂合+/t雄性的非孟德尔遗传。在实验室研究中，通常观察到≥0.90或更高的传输率。根据这一水平的传播率，理论分析预测野生种群中有很高的倍型频率(∼75%)。相比之下，经验频率通常只有15%-25%。这导致了一种说法，即驱动的修饰语可能在降低频率方面起到了作用。为了验证这一假说，我们测量了野生+/t小鼠的传输率失真(TRD)水平。在野外捕获的怀孕雌性幼虫和实验室饲养的野生幼崽中，TRD都很高(平均为0.9)。与其他研究的结果相反，我们发现在半致死型和利特型之间，以及在受孕于周期或产后发情的小鼠之间，TRD水平没有差异。我们发现了三窝具有异常低的TRD的后代，它们都是混血繁殖的，尽管这可能在自然种群中发挥的作用尚不清楚。这些发现表明，在自然种群中普遍缺乏DRIVE修饰物，并表明其他因素导致观察到的野生二倍型频率较低。
thaplotypes are naturally occurring forms of mouse chromosome17that show non-Mendelian transmission from heterozygous +/tmales. In laboratory studies, transmission ratios of ≥0.90 or higher are typically observed. With transmission ratios of this level, theoretical analyses predict high frequencies ofthaplotypes (∼75%) in wild populations. In contrast, empirical frequencies of only 15–25% are typically found. This has led to the suggestion that modifiers of drive may play a role in reducingtfrequencies. We have measured transmission ratio distortion (TRD) levels in wild +/tmice to examine this hypothesis. TRD was very high in both litters collected from wild-caught pregnant females, and in wild litters bred in the laboratory (mean = 0.9). Contrary to the results of other studies, we found no difference in TRD levels between semilethal and lethalthaplotypes nor between litters conceived from cycling or postpartum estrus. We found three litters with aberrantly low TRDs that were all multiply sired, although the role this might play in natural populations is unknown. These findings show a general absence of modifiers of drive in natural populations and suggest that other factors are responsible for the low observed frequencies of wildthaplotypes.