Genetska pestrost drežniške pasme domače koze Capra aegagrus hircus in ugotavljanje introgresivne hibridizacije z alpskim kozorogom C. ibex : doktorska disertacija

Pogorevc, Neža (author), Horvat, Simon (mentor), Simčič, Mojca (comentor)

Karakterizacija genetskega ozadja in ocena sorodnosti med pasmami rejnih živali predstavljata pomemben korak pri oblikovanju rejskih programov, ki so predpogoj ohranjanja in reje populacije živali določene pasme. Ta proces je pri ogroženih lokalnih pasmah potrebno izvesti premišljeno. V tej študiji smo prvič ocenili parametre genetske pestrosti, strukturo populacije in morebitne primesi tujih pasem v slovenski avtohtoni pasmi drežniška koza. Več parametrov, na primer veliko število populacijsko specifičnih alelov, je dokazalo edinstven genetski podpis drežniške koze, kar je dodatno potrdila tudi samostojna veja na različnih prikazih filogenetskih dreves. Filogenetska analiza je drežniško kozo razporedila bližje avstrijskim in italijanskim pasmam koz, kar je v skladu z geografsko bližino pasem in zgodovinskimi povezavami na tem območju. Na gorskih pašnikih si drežniška koza, pasma domačih koz (Capra aegagrus hircus), deli habitat z alpskim kozorogom (C. ibex), kar lahko vodi do medvrstnega križanja. Med drežniškimi kozami in alpskimi kozorogi nismo odkrili sledi nedavne introgresivne hibridizacije v nobeni smeri, vendar se je ta verjetno zgodila v času prednikov obeh vrst. Potrdili smo identiteto medvrstnega križanca, ki je potomec prve generacije med samico drežniške koze in samcem alpskega kozoroga. Gre za plodnega križanca, saj smo v tropu drežniških koz odkrili tudi njegova potomca. Introgresivna hibridizacija lahko predstavlja potencialno nevarnost za izgubo genetskih značilnosti obeh ogroženih populacij, kar je dovolj prepričljiv razlog, da so potrebne nadaljnje aktivnosti v smeri nadzora obeh vrst. Z ustreznimi ukrepi lahko omogočimo sobivanje domačih koz in alpskih kozorogov na visokogorskih pašnikih. Naša raziskava je ocenila stanje populacij in predstavlja osnovo za razvoj genomskih orodij za spremljanje in upravljanje z obema populacijama v Sloveniji.

• Language: Slovenian
• Keywords: drežniška koza, genetska pestrost, struktura populacije, introgresivna hibridizacija, alpski kozorog, Capra
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: BF - Biotechnical Faculty
• Year: 2024
• PID: 20.500.12556/RUL-160520
• COBISS.SI-ID: 205885187
• Publication date in RUL: 30.08.2024

Secondary language

• Language: English
• Title: Genetic diversity of the Drežnica breed of the domestic goat Capra aegagrus hircus and assessing the introgressive hybridization with Alpine ibex C. ibex : doctoral dissertation

Abstract

Characterizing the genetic background and evaluating the relatedness between livestock breeds is an important step in designing the breeding programs that are essential for conservation and breeding of populations. This process must be carried out thoughtfully for endangered local breeds. In this study, we examined for the first time the parameters of genetic diversity, population structure and possible admixture with foreign breeds in the Slovenian autochthonous breed Drežnica goat. Several parameters, like large number of population-specific alleles, proved a unique genetic signature of the Drežnica goat, which was additionally confirmed by an independent branch on different phylogenetic trees. The phylogenetic analysis brought the Drežnica goat closer to the Austrian and Italian goat breeds, which is consistent with the geographical proximity of these breeds and the historical connections in this area. On the mountain pastures, the Drežnica goat, domestic goat breed (Capra aegagrus hircus), shares its habitat with the Alpine ibex (C. ibex), which can lead to interbreeding between the species. We did not find evidence of recent introgressive hybridization between Drežnica goats and Alpine ibex in either direction, but it probably took place at the time of the ancestors of both species. We have confirmed the identity of an interspecific hybrid, which is a first generation offspring between a female Drežnica goat and a male Alpine ibex. The hybrid is fertile, as we have also discovered its offspring in the flock of Drežnica goats. Introgressive hybridization could present a potential threat for a loss of unique genetic characteristics that define each endangered populations, which is a good reason for further efforts to control both species. With proper genetic monitoring, we could enable the coexistence of domestic goats and Alpine ibex on high mountain pastures. Our research assessed the genetic status of the populations and provides the basis for the development of genomic tools to monitor and manage both populations in Slovenia.

• Keywords: Drežnica goat, genetic diversity, population structure, introgressive hybridization, Alpine ibex, Capra