Romero Miguel, Cerritos R, Ximenez Cecilia
Faculty of Experimental Medicine, Experimental Immunology Laboratory, National Autonomous University of Mexico, Dr. Balmis 148, Colonia Doctores, 06720 Mexico City, Mexico.
J Parasitol Res. 2016;2016:3241027. doi: 10.1155/2016/3241027. Epub 2016 Apr 27.
Horizontal gene transfer has proved to be relevant in eukaryotic evolution, as it has been found more often than expected and related to adaptation to certain niches. A relatively large list of laterally transferred genes has been proposed and evaluated for the parasite Entamoeba histolytica. The goals of this work were to elucidate the importance of lateral gene transfer along the evolutionary history of some members of the genus Entamoeba, through identifying donor groups and estimating the divergence time of some of these events. In order to estimate the divergence time of some of the horizontal gene transfer events, the dating of some Entamoeba species was necessary, following an indirect dating strategy based on the fossil record of plausible hosts. The divergence between E. histolytica and E. nuttallii probably occurred 5.93 million years ago (Mya); this lineage diverged from E. dispar 9.97 Mya, while the ancestor of the latter separated from E. invadens 68.18 Mya. We estimated times for 22 transferences; the most recent occurred 31.45 Mya and the oldest 253.59 Mya. Indeed, the acquisition of genes through lateral transfer may have triggered a period of adaptive radiation, thus playing a major role in the evolution of the Entamoeba genus.
水平基因转移已被证明与真核生物的进化相关，因为它的发现频率高于预期，且与适应某些生态位有关。对于寄生虫溶组织内阿米巴，已经提出并评估了一份相对较长的横向转移基因清单。这项工作的目标是，通过识别供体群体并估计其中一些事件的分歧时间，来阐明水平基因转移在溶组织内阿米巴属某些成员进化历史中的重要性。为了估计一些水平基因转移事件的分歧时间，需要对一些溶组织内阿米巴物种进行定年，这要遵循基于合理宿主化石记录的间接定年策略。溶组织内阿米巴和纳氏内阿米巴之间的分歧可能发生在593万年前；这个谱系在997万年前与迪斯帕内阿米巴分化，而后者的祖先在6818万年前与侵袭内阿米巴分离。我们估计了22次转移的时间；最近一次发生在3145万年前，最古老的一次发生在25359万年前。事实上，通过横向转移获得基因可能引发了一个适应性辐射期，从而在溶组织内阿米巴属的进化中发挥了重要作用。
