Sex, amitosis, and evolvability in the ciliate Tetrahymena thermophila
Sex, amitosis, and evolvability in the ciliate Tetrahymena thermophila
复制标题
纤毛虫嗜热四膜虫的性别、无丝分裂和进化性
DOI：
10.1093/evolut/qpac031
复制
发表时间：
2022
期刊：
影响因子：
3.3
通讯作者：
Zufall, Rebecca A.
中科院分区：
文献类型：
--
作者：
Tarkington, Jason;Zhang, Hao;Azevedo, Ricardo B. R.;Zufall, Rebecca A.
了解产生遗传变异的机制，从而有助于适应过程，是进化生物学的一个主要目标。突变和遗传交换作为产生遗传变异的机制已经得到了很好的研究。然而，还有其他因素，如基因组结构，也可能影响某些种群的遗传变异量，这些变异产生机制本身在多大程度上受到自然选择的影响仍然是一个悬而未决的问题。为了测试基因组结构对遗传变异产生的影响，从而进化，我们研究了四膜虫嗜热，一种纤毛虫，具有不寻常的基因组结构和核分裂机制，称为无丝分裂，同源染色体随机分布到子细胞。无丝分裂导致新产生的有性后代的无性后代之间的遗传变异，因为不同的后代细胞将包含不同的亲本等位基因组合。我们假设，无丝分裂，从而增加了新产生的有性后代相对于他们的未交配的父母和物种进行有丝分裂的进化。为了验证这一假设，我们使用实验进化和模拟来比较由单一有性后代建立的嗜热嗜热菌种群与多代没有有性行为的亲本种群的适应率。在实验室种群和模拟种群中，有性后代建立的种群比亲本种群适应得更快。这表明，杂合子的无丝分裂产生的额外的遗传变异可以增加性别后的适应率，并可能有助于解释更普遍的四膜虫和纤毛虫的不寻常的遗传结构的进化成功。
Understanding the mechanisms that generate genetic variation, and thus contribute to the process of adaptation, is a major goal of evolutionary biology. Mutation and genetic exchange have been well studied as mechanisms to generate genetic variation. However, there are additional factors, such as genome architecture, that may also impact the amount of genetic variation in some populations, and the extent to which these variation generating mechanisms are themselves shaped by natural selection is still an open question. To test the effect of genome architecture on the generation of genetic variation, and hence evolvability, we studiedTetrahymena thermophila, a ciliate with an unusual genome structure and mechanism of nuclear division, called amitosis, whereby homologous chromosomes are randomly distributed to daughter cells. Amitosis leads to genetic variation among the asexual descendants of a newly produced sexual progeny because different progeny cells will contain different combinations of parental alleles. We hypothesize that amitosis thus increases the evolvability of newly produced sexual progeny relative to their unmated parents and species that undergo mitosis. To test this hypothesis, we used experimental evolution and simulations to compare the rate of adaptation inT. thermophilapopulations founded by a single sexual progeny to parental populations that had not had sex in many generations. The populations founded by a sexual progeny adapted more quickly than parental populations in both laboratory populations and simulated populations. This suggests that the additional genetic variation generated by amitosis of a heterozygote can increase the rate of adaptation following sex and may help explain the evolutionary success of the unusual genetic architecture ofTetrahymenaand ciliates more generally.
登录
查看更多内容
影响因子：
3.3
作者：
J. Woodard;E. Kaneshiro;M. Gorovsky
通讯作者：
J. Woodard;E. Kaneshiro;M. Gorovsky
嗜热四膜虫大核发育过程中的高频基因内重组恢复了野生型 SerH1 基因。
影响因子：
3.3
作者：
J. Deák;F. P. Doerder
通讯作者：
F. P. Doerder
色素四膜虫交配型系统的遗传不稳定性。
影响因子：
3.3
作者：
E. M. Simon;E. Orias
通讯作者：
E. Orias
影响因子：
64.8
作者：
Colegrave, N
通讯作者：
Colegrave, N
DOI：
10.1111/j.0014-3820.2002.tb00845.x
发表时间：
2002
期刊：
Nematologica
影响因子：
--
作者：
N. Colegrave;O. Kaltz;G. Bell
通讯作者：
G. Bell