Search results for "geneettinen monimuotoisuus"

Viability selection creates negative heterozygosity–fitness correlations in female Black Grouse Lyrurus tetrix

2017

There is widespread interest in the relationship between individual genetic diversity and fitness–related traits (heterozygosity–fitness correlations, HFC). Most studies found weak continuous increases of fitness with increasing heterozygosity while negative HFC have rarely been reported. Negative HFC are expected in cases of outbreeding depression and outbreeding is rare in natural populations; but negative HFC may also arise through viability selection acting on low heterozygosity individuals at an early stage producing a skew in the heterozygosity distribution leading to negative HFCs. We tested this idea using survival and clutch parameters (egg mass, egg volume, chick mass, clutch size…

Direct pathway cloning and expression of the radiosumin biosynthetic gene cluster

2023

Radiosumins are a structurally diverse family of low molecular weight natural products that are produced by cyanobacteria and exhibit potent serine protease inhibition. Members of this family are dipeptides characterized by the presence of two similar non-proteinogenic amino acids. Here we used a comparative bioinformatic analysis to identify radiosumin biosynthetic gene clusters from the genomes of 13 filamentous cyanobacteria. We used direct pathway cloning to capture and express the entire 16.8 kb radiosumin biosynthetic gene cluster from Dolichospermum planctonicum UHCC 0167 in Escherichia coli. Bioinformatic analysis demonstrates that radiosumins represent a new group of chorismate-der…

Mitochondrial DNA variation of Drosophila obscura (Diptera: Drosophilidae) across Europe

2022

Drosophila obscura is a common fruit fly that inhabits the temperate forests of Europe. While it is abundant in the north compared to other Drosophila, its density decreases southwards, where it is gradually replaced by other Drosophila species. This study describes variation in the mitochondrial Cyt b gene of D. obscura from several European populations. We observed a large number of haplotypes, together with the structuring of genetic variation. Genetic variation is higher in the west where O1 and related divergent haplotypes dominate. In the east, the O2 haplotype is most frequent, together with haplotypes that recently arose from it. In the central part of the species range, both O1 and…

Comparing RADseq and microsatellites for estimating genetic diversity and relatedness : Implications for brown trout conservation

2019

The conservation and management of endangered species requires information on their genetic diversity, relatedness and population structure. The main genetic markers applied for these questions are microsatellites and single nucleotide polymorphisms (SNPs), the latter of which remain the more resource demanding approach in most cases. Here, we compare the performance of two approaches, SNPs obtained by restriction-site-associated DNA sequencing (RADseq) and 16 DNA microsatellite loci, for estimating genetic diversity, relatedness and genetic differentiation of three, small, geographically close wild brown trout (Salmo trutta) populations and a regionally used hatchery strain. The genetic di…

Interactions and patterns between species diversity and genetic diversity

2015

Genetic diversity of a clonal earthworm : gene expression variation and impacts on decomposition in metal contaminated soil

2016

Biodiversity affects ecosystem functioning positively. Metal-contamination diminishes species diversity and ecosystem function depends on the remaining species, and the genotypes within them. I studied how the clonally reproducing earthworm Dendrobaena octaedra responds to soil metal contamination and how its genetic diversity affects decomposition. Expression of the gene for the metal tolerance protein metallothionein was compared between populations with or without metal exposure history: with exposure history expression was high and stable and without there was a slow response. Adaptation to metal contamination likely explains the differences. Clonality of D. octaedra was verified with m…

Species and genetic diversity relationships in benthic macroinvertebrate communities along a salinity gradient

2022

Background Species- and genetic diversity can change in parallel, resulting in a species-genetic diversity correlation (SGDC) and raising the question if the same drivers influence both biological levels of diversity. The SGDC can be either positive or negative, depending on whether the species diversity and the genetic diversity of the measured species respond in the same or opposite way to drivers. Using a traditional species diversity approach together with ultra-conserved elements and high throughput sequencing, we evaluated the SGDCs in benthic macrofauna communities in the Baltic Sea, a geologically young brackish water sea characterised by its steep salinity gradient and low species …

The relationship between genetic diversity of an annelid worm, Pygospio elegans, and local invertebrate species diversity

2016

Ympäristön monimuotoisuutta mitataan pääasiassa erilaisten biologisten yksiköiden lukumäärinä. Populaatiogenetiikassa ne ovat geenejä tai alleeleja yhden lajin sisällä, yhteisöekologiassa puolestaan lajeja eliöyhteisöjen sisällä. Molemmat näistä monimuotoisuuden tasoista – lajin sisäinen ja lajien välinen monimuotoisuus – muokkautuvat ekologisten ja evolutiivisten prosessien kautta, jotka puolestaan syntyvät ympäristön olosuhteista. Ympäristön ominaisuuksien ja niistä syntyvien prosessien tiedetään vaikuttavan molempiin monimuotoisuuden tasoihin samankaltaisesti: tämän teorian mukaan niiden välillä tulisi siten löytyä positiivinen korrelaatio. Tässä tutkimuksessa pyrin etsimään laajalti huo…

Maintenance of genetic diversity in cyclic populations - a longitudinal analysis in Myodes glareolus

2012

Conspicuous cyclic changes in population density characterize many populations of small northern rodents. The extreme crashes in individual number are expected to reduce the amount of genetic variation within a population during the crash phases of the population cycle. By long-term monitoring of a bank vole (Myodes glareolus) population we show that despite the substantial and repetitive crashes in the population size, high heterozygosity is maintained throughout the population cycle. The striking population density fluctuation in fact only slightly reduced the allelic richness of the population during the crash phases. Effective population sizes of vole populations remained also relativel…

Evolution of hermaphroditic mating systems in animals

2004

Miksi jotkin eläinlajit ovat kaksineuvoisia ja toisissa lajeissa koiras- ja naarasominaisuudet ovat eri yksilöissä? Kaksineuvoiset eläimet pystyvät lisääntymään itsesiitoksella ilman kumppania tai ristisiitoksella kumppanin kanssa. Kumpi lisääntymistapa on parempi? Muun muassa näitä kysymyksiä väitöskirjassaan pohtinut Mikael Puurtinen loi tutkimuksessaan teoriaa lisääntymistapojen evoluutiosta, sekä selvitti vedessä elävän isolimakotilon (Lymnaea stagnalis) lisääntymisbiologiaa. Suomen Akatemian nimittämässä evoluutioekologian huippuyksikössä tehty tutkimus toi arvokasta tietoa populaation geneettisen monimuotoisuuden vaikutuksista populaation elinkykyyn sekä kykyyn vastustaa loistauteja. …