Lachapelle Marc Y, Drouin Guy
Département de biologie et Centre de recherche avancée en génomique environnementale, Université d'Ottawa, 30 Marie Curie, Ottawa, Ontario, Canada.
Genetica. 2011 Feb;139(2):199-207. doi: 10.1007/s10709-010-9537-x. Epub 2010 Dec 8.
The capacity to biosynthesize ascorbic acid has been lost in a number of species including primates, guinea pigs, teleost fishes, bats, and birds. This inability results from mutations in the GLO gene coding for L-gulono-γ-lactone oxidase, the enzyme responsible for catalyzing the last step in the vitamin C biosynthetic pathway. We analyzed available primate and rodent GLO gene sequences to determine their evolutionary history. We used a method based on sequence comparisons of lineages with and without functional GLO genes to calculate inactivation dates of 61 and 14 MYA for the primate and guinea pig genes, respectively. These estimates are consistent with previous phylogeny-based estimates. An analysis of transposable element distribution in the primate and rodent GLO sequences did not reveal conclusive evidence that illegitimate recombination between repeats has contributed to the loss of exons in the primate and guinea pig genes.
包括灵长类动物、豚鼠、硬骨鱼、蝙蝠和鸟类在内的许多物种已经丧失了生物合成抗坏血酸的能力。这种无能力是由编码L-古洛糖酸-γ-内酯氧化酶的GLO基因突变导致的，该酶负责催化维生素C生物合成途径中的最后一步。我们分析了现有的灵长类动物和啮齿动物的GLO基因序列，以确定它们的进化历史。我们使用了一种基于有功能和无功能GLO基因谱系序列比较的方法，分别计算出灵长类动物和豚鼠基因的失活日期为6100万年前和1400万年前。这些估计与之前基于系统发育的估计一致。对灵长类动物和啮齿动物GLO序列中转座元件分布的分析没有揭示出确凿证据表明重复序列之间的非法重组导致了灵长类动物和豚鼠基因中外显子的丢失。
