Säga (Silurus glanis L.) loodusliku populatsiooni ja Eestisse imporditud kasvanduste karjade geneetiline iseloomustamine
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Kuupäev
2018
Kättesaadavus
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Säga on Eestis haruldane liik, kuuludes II kaitsekategooriasse ning Eesti Punase
Raamatu eriti ohustatud liikide nimistusse. Tema geneetiliste iseärasuste
väljaselgitamine on väga oluline geneetilise mitmekesisuse säilitamiseks või
taastamiseks nii looduslikes populatsioonides kui kasvanduse karjades. Magistritöö
eesmärkideks oli välja selgitada säga loodusliku Peipsi populatsiooni ja Eestisse
imporditud kasvanduste karjade geneetilised iseärasused ja hinnata kasvanduse karjade
sobivust loodusliku populatsiooni täiendamiseks. Geneetiliste markeritena kasutati
mitokondriaalse DNA (mtDNA) kahe piirkonna (ND5/6 ja CytB/D-ling)
restriktsioonifragmentide pikkuspolümorfismi (RFLP), mtDNA D-lingu nukleotiidset
järjestust ja rakutuuma DNA lühikesi tandeemseid korduvjärjestusi ehk mikrosatelliite.
Uurimistöö tulemusena leidis kinnitust hüpotees, et Peipsi looduslik sägapopulatsioon
ja Lätist ning Leedust pärinevad Eesti kalakasvanduste sägakarjad on emaliinide
poolest üksteisega geneetiliselt sarnased ja erinevad teiste Euroopa piirkondade varem
uuritud populatsioonidest. Samuti leidis osaliselt kinnitust teine hüpotees, mille
kohaselt võiks Läti ja Leedu päritolu sägakarjad sobida Peipsi loodusliku
sägapopulatsiooni täiendamiseks. Geneetiliste markerite analüüsi tulemustest selgus, et
geneetiliselt kõige varieeruvam on Lapavira kasvanduse Leedu päritolu sägakari, mis
mikrosatelliitide analüüsi põhjal on ka kõige sarnasem Peipsi populatsioonile. Seetõttu
võiks just Lapavira sägakari olla kõige sobivam Peipsi järve populatsiooni
täiendamiseks, võimaldades suurendada selle geneetilist variatsiooni ja likvideerida
inbriidingut.
Wels catfish (Silurus glanis L.) is an endangered species in Estonia who is protected by Nature Conservation Act and also belongs to Red Data Book. Genetic characterization of wels catfish populations is important for species restoration programmes and aquaculture. The aim of this thesis was to characterise genetically wels catfish (Silurus glanis L.) native population and imported farmed stocks in Estonia by using mitochondrial (mtDNA) and nuclear DNA (nDNA) variations. MtDNA variations were studied using PCR-RFLP analysis of ND5/6 and CytB/Dloop regions, and by sequencing of the D-loop, while nDNA variations were characterised using 20 microsatellite loci. The results of this study confirmed our first hypothesis that the native Peipsi population and the farmed stocks which were imported to Estonia from Latvia and Lithuania are genetically similar by maternal lines and differ from previously studied wels catfish populations in other parts of Europe. Also we were partially able to confirm our second hypothesis which stated that the imported farmed wels catfish stocks which originated from Latvia and Lithuania could be genetically suitable for enhancing the native lake Peipsi population in Estonia. Analysis of genetic markers showed that the Lapavira stock which originated from Lithuania was genetically the most variable among studied stocks and it was also the most similar to Peipsi native population. Therefore, it would be the most suitable for enhancing the native lake Peipsi population, allowing to increase its genetic variation and to liquidate the accumulated inbreeding.
Wels catfish (Silurus glanis L.) is an endangered species in Estonia who is protected by Nature Conservation Act and also belongs to Red Data Book. Genetic characterization of wels catfish populations is important for species restoration programmes and aquaculture. The aim of this thesis was to characterise genetically wels catfish (Silurus glanis L.) native population and imported farmed stocks in Estonia by using mitochondrial (mtDNA) and nuclear DNA (nDNA) variations. MtDNA variations were studied using PCR-RFLP analysis of ND5/6 and CytB/Dloop regions, and by sequencing of the D-loop, while nDNA variations were characterised using 20 microsatellite loci. The results of this study confirmed our first hypothesis that the native Peipsi population and the farmed stocks which were imported to Estonia from Latvia and Lithuania are genetically similar by maternal lines and differ from previously studied wels catfish populations in other parts of Europe. Also we were partially able to confirm our second hypothesis which stated that the imported farmed wels catfish stocks which originated from Latvia and Lithuania could be genetically suitable for enhancing the native lake Peipsi population in Estonia. Analysis of genetic markers showed that the Lapavira stock which originated from Lithuania was genetically the most variable among studied stocks and it was also the most similar to Peipsi native population. Therefore, it would be the most suitable for enhancing the native lake Peipsi population, allowing to increase its genetic variation and to liquidate the accumulated inbreeding.
Kirjeldus
Magistritöö
Vee ja maismaa ökosüsteemide rakendusbioloogia õppekaval
Märksõnad
magistritööd, säga, rakutuuma DNA, mitokondriaalne DNA, populatsioonid (biol.)