Genetic analysis of olm (Proteus anguinus) populations in the overlapping area of the Adriatic and Danube drainage basins

Rod Proteus ima trenutno kot edinega predstavnika vrsto Proteus anguinus, ki jo naprej delimo na dve podvrsti: P. a. anguinus in P. a. parkelj. Že okoli četrt stoletja je znano, da ta delitev na podlagi morfoloških znakov ne odseva dejanskih taksonomskih razmer. Na podlagi alocimov, mitohondrijske DNA, jedrne DNA in tudi ponovnega podrobnejšega pregleda zunanje morfologije so se pokazale genetske razlike med posameznimi izoliranimi populacijami. V tem delu smo pod drobnogled vzeli evolucijsko linijo jugozahodne Slovenije, kjer živi samo svetla podvrsta P. a. anguinus. Dosedanje raziskave so jugozahodno linijo vrednotile kot od drugih globoko ločeno linijo, z dokazi za še nadaljnje cepitve znotraj linije. Glavni razlog za pestro genetsko strukturo na območju bi lahko pripisali razvodnici med jadranskim in donavskim povodjem. Za ugotavljanje pripadnosti populaciji posameznih vzorcev smo uporabili mitohondrijsko DNA in kratka ponavljajoča se zaporedja jedrne DNA. Glavne populacijsko genetske analize so bile opravljene z Bayesovim pristopom gručenja z uporabo algoritma markovske verige Monte Carlo. Pripadnost posameznim populacijam smo vrednotili tudi z genotipizacijo z restrikcijsko analizo kontrolne regije mitohondrijske DNA. Rezultati so pokazali, da je v jugozahodni Sloveniji v okolice Sežane zaradi zapletenega podzemnega pretakanja in redkega hidrološkega dogodka v reki Reki prišlo do stikanja dveh liniji proteusa: Kraške PSV in populacije zahodne kraške Ljubljanice. Med osebki prihaja do križanja na ozkem območju v Jami Sežanske Reke.The genus Proteus currently only encompasses two subspecies: P. a. anguinus and P. a. parkelj. It has been known for more than a quarter of a century that this division of the species on the basis of morphological signs is no longer good enough. On the basis of alloenzymes, mitochondrial DNA, core DNA and also a more detailed overview of external morphology, genetic differences between isolated populations have been demonstrated. In this work we take a more detailed look at the southwestern region of Slovenia, where only the white subspecies of P. a. anguinus is present. Current research has evaluated the southwest population as a deeply separated from others, with evidence for further differentiation within the population. The main reason for the diverse genetic structure in the area could be attributed to the geographic barrier represented by two different drainage basins: the Adriatic and Danube. In order to determine the affiliation to the population of individual samples, the mitochondrial DNA was used and short tandem repeats of nuclear DNA. The main population genetic analysis was carried out using the Bayesian approach using the MCMC algorithm. Affiliation to individual populations was also assessed by genotyping with restriction analysis of the control region of mitochondrial DNA. The results thus showed that in the southwestern region of Slovenia in the vicinity of Sežana, due to the complicated underground flows and rare hydrological events in the Reka river two distinct lines of proteus come into contact: Karst PSV and the eastern karst Ljubljanica population. Between these two populations there is a contact zone where hybridization occurs in a narrow area in the cave Jama Sežana River