Dubreuil-Tranchant Christine, Guyot Romain, Guellim Amira, Duret Caroline, de la Mare Marion, Razafinarivo Norosoa, Poncet Valérie, Hamon Serge, Hamon Perla, de Kochko Alexandre
IRD, UMR DIADE, Centre IRD de Montpellier, BP 64501, 34394 Montpellier Cedex 5, France.
Int J Evol Biol. 2011;2011:358412. doi: 10.4061/2011/358412. Epub 2011 Sep 27.
Miniature Inverted-repeat Transposable Elements (MITEs) are small nonautonomous class-II transposable elements distributed throughout eukaryotic genomes. We identified a novel family of MITEs (named Alex) in the Coffea canephora genome often associated with expressed sequences. The Alex-1 element is inserted in an intron of a gene at the CcEIN4 locus. Its mobility was demonstrated by sequencing the insertion site in C. canephora accessions and Coffea species. Analysis of the insertion polymorphism of Alex-1 at this locus in Coffea species and in C. canephora showed that there was no relationship between the geographical distribution of the species, their phylogenetic relationships, and insertion polymorphism. The intraspecific distribution of C. canephora revealed an original situation within the E diversity group. These results suggest possibly greater gene flow between species than previously thought. This MITE family will enable the study of the C. canephora genome evolution, phylogenetic relationships, and possible gene flows within the Coffea genus.
微型反向重复转座元件（MITEs）是分布于整个真核生物基因组中的小型非自主II类转座元件。我们在咖啡（Coffea canephora）基因组中鉴定出一个新的MITE家族（命名为Alex），其常与表达序列相关联。Alex-1元件插入到CcEIN4基因座处一个基因的内含子中。通过对咖啡种内不同个体以及咖啡属其他物种中该插入位点进行测序，证实了其可移动性。对Alex-1在咖啡属物种以及咖啡种内该基因座插入多态性的分析表明，物种的地理分布、系统发育关系与插入多态性之间不存在关联。咖啡种内分布揭示了E多样性组内的一种原始情况。这些结果表明物种间的基因流可能比之前认为的更多。这个MITE家族将有助于研究咖啡的基因组进化、系统发育关系以及咖啡属内可能的基因流。
