Quina Ana Sofia, Tavanez João Paulo, Mathias Maria da Luz
CESAM - Centro de Estudos do Ambiente e do Mar, Departamento de Biologia, Universidade de Aveiro, Aveiro, Portugal.
CESAM - Centro de Estudos do Ambiente e do Mar, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal.
Integr Zool. 2022 Nov;17(6):1179-1192. doi: 10.1111/1749-4877.12607. Epub 2021 Dec 3.
The Lusitanian (Microtus lusitanicus) and the Mediterranean (Microtus duodecimcostatus) pine voles are recently diverged sister species endemic of the Iberian Peninsula that can be identified with ecological and morphological characters, but in areas where the 2 species co-occur, species designation may be difficult. Genetic discrimination between M. lusitanicus and M. duodecimcostatus has not been achieved yet possibly because of their estimated recent split and an evolutionary history that includes inter-species gene flow. Following our previous observations on exons 5-7 of the p53 gene, here we analyze the potential use of the p53 genomic region as a discrimination marker of these species by extending our analyses to several kb upstream and downstream of the p53 gene and characterizing the degree of genetic differentiation in 7 markers within this region. Additionally, we fully sequenced the P53 protein of both species. We observed: (i) generally high differentiation in this region; (ii) M. duodecimcostatus showed in general higher values of nucleotide and haplotype diversities; (iii) the concatenated phylogenetic tree separates the 2 species; (iv) the 2 P53 proteins only differ in 1 amino acid; (v) 4 of the markers, 2 in p53, one in Atp1b2, and another in Wrap53, contain species-specific genetic variation thus allowing a reliable discrimination between specimens from both species, irrespective of sampling location or introgression status. We provide additional data on the putative role of p53 in the evolution of these species and present researchers with a fast and cost-effective resource for M. lusitanicus and M. duodecimcostatus identification.
卢西塔尼亚松田鼠（Microtus lusitanicus）和地中海松田鼠（Microtus duodecimcostatus）是伊比利亚半岛特有的两个新近分化的姐妹物种，可通过生态和形态特征进行识别，但在这两个物种共存的地区，物种鉴定可能会很困难。卢西塔尼亚松田鼠和地中海松田鼠之间的基因鉴别尚未实现，这可能是因为据估计它们是近期才分化的，且其进化史包括种间基因流动。基于我们之前对p53基因第5至7外显子的观察，在此我们通过将分析扩展至p53基因上下游数千碱基对，并对该区域内7个标记的遗传分化程度进行表征，来分析p53基因组区域作为这两个物种鉴别标记的潜在用途。此外，我们还对这两个物种的P53蛋白进行了全序列测定。我们观察到：（i）该区域总体上具有高度分化；（ii）地中海松田鼠的核苷酸多样性和单倍型多样性总体上更高；（iii）串联系统发育树将这两个物种区分开来；（iv）两种P53蛋白仅在1个氨基酸上存在差异；（v）其中4个标记，p53基因中有2个，Atp1b2基因中有1个，Wrap53基因中有另1个，包含物种特异性遗传变异，因此无论采样地点或渐渗状态如何，都能可靠地区分两个物种的样本。我们提供了关于p53在这些物种进化中假定作用的更多数据，并为研究人员提供了一种快速且经济高效的资源，用于卢西塔尼亚松田鼠和地中海松田鼠的鉴定。
