Multiple endosymbionts in populations of the ant Formica cinerea

<p>Abstract</p> <p>Background</p> <p>Many insects, including ants, are infected by maternally inherited <it>Wolbachia </it>endosymbiotic bacteria though other secondary endosymbionts have not been reported in ants. It has been suggested that the ability of <it>Wolbachia </it>to invade and remain in an ant population depends on the number of coexisting queens in a colony. We study the genetic and social structure of populations in the ant <it>Formica cinerea </it>which is known to have populations with either monogynous or polygynous colonies. We screen populations for several endosymbiotic bacteria to evaluate the presence of different endosymbionts, possible association between their prevalence and the social structure, and the association between endosymbiont prevalence and genetic differentiation of ant populations.</p> <p>Results</p> <p>We found three endosymbiotic bacteria; 19% of the nests were infected by <it>Wolbachia</it>, 3.8% by <it>Cardinium </it>and 33% by <it>Serratia</it>. There was significant variation among the populations regarding the proportion of nests infected by <it>Serratia</it>, <it>Wolbachia </it>and the pooled set of all the endosymbionts. Some individuals and colonies carried two of the bacteria, the frequency of double infections agreeing with the random expectation. The proportion of infected ants (individuals or colonies) did not correlate significantly with the population level relatedness values. The difference in the prevalence of <it>Wolbachia </it>between population pairs correlated significantly with the genetic distance (microsatellites) of the populations.</p> <p>Conclusions</p> <p>The discovery of several endosymbionts and co-infections by <it>Wolbachia </it>and <it>Cardinium </it>demonstrate the importance of screening several endosymbionts when evaluating their possible effects on social life and queen-worker conflicts over sex allocation. The low prevalence of <it>Wolbachia </it>in <it>F. cinerea </it>departs from the pattern observed in many other <it>Formica </it>ants in which all workers have been infected. It is likely that the strain of <it>Wolbachia </it>in <it>F. cinerea </it>differs from those in other <it>Formica </it>species. The correlation between the difference in <it>Wolbachia </it>prevalence and the pair-wise genetic distance of populations suggests that spreading of the bacteria is restricted by the isolation of the host populations.</p

Wolbachia transmission dynamics in Formica wood ants

Background: The role of Wolbachia endosymbionts in shaping the mitochondrial diversity of their arthropod host depends on the effects they have on host reproduction and on the mode of transmission of the bacteria. We have compared the sequence diversity of wsp ( Wolbachia surface protein gene) and the host mtDNA in a group of Formica ant species that have diverged approximately 0.5 million years ago ( MYA). The aim was to study the relationship of Wolbachia and its ant hosts in terms of vertical and horizontal transmission of the bacteria.Results: All studied ant species were doubly infected with two Wolbachia strains ( wFexl and wFex4) all over their geographical distribution area in Eurasia. The most common haplotypes of these strains were identical with strains previously described from a more distantly related Formica ant, with an estimated divergence time of 3.5 - 4 MYA. Some strain haplotypes were associated to the same or closely related mtDNA haplotypes as expected under vertical transmission. However, in several cases the wsp haplotypes coexisted with distant mtDNA haplotypes, a pattern which is more compatible with horizontal transmission of the bacteria.Conclusion: Two lines of evidence suggest that the sharing of Wolbachia strains by all F. rufa species is rather due to horizontal than vertical transmission. First, the fact that endosymbiont strains identical to those of F. rufa ants have been found in another species that diverged 3.5 - 4 MYA strongly suggests that horizontal transfer can and does occur between Formica ants. Second, the frequent sharing of identical Wolbachia strains by distant mitochondrial lineages within the F. rufa group further shows that horizontal transmission has occurred repeatedly. Nevertheless, our dataset also provides some evidence for longer- term persistence of infection, indicating that Wolbachia infection within this host clade has been shaped by both horizontal and vertical transmission of symbionts. The fact that all the ants were infected irrespective of the family structure of their societies gives no support to the proposed hypotheses that the spreading of Wolbachia in ants might be associated to the types of their societies

Pheromonal and enzyme genetic characteristics of the Bombus lucorum species complex in northern Europe

Spatial and temporal distribution of the species in the Bombus lucorum species complex, B. lucorum (L.), B. cryptarum (Fabricius) and B. magnus Vogt, were studied in Finland. Morphological distinction between the species is not as clear as in Central Europe, but B. lucorum can be distinguished from the other two with the help of enzyme genetic markers. B. lucorum is the most common of the three species in most of Finland, and B. cryptarum is abundant in the southwestern coastal area and in northern Lapland. B. magnus was only rarely found among the spring queens in southwestern Finland, and its range possibly restricts to southern and central parts of Finland. A comparison of the chemical composition of the male labial glands and enzyme genotypes shows that males produce species-specific marking pheromones

A high recombination rate in eusocial Hymenoptera: evidence from the common wasp Vespula vulgaris

Peer reviewe

Phylogenetic relationships of Palaearctic Formica species (Hymenoptera, Formicidae) based on mitochondrial cytochrome b sequences

Peer reviewe

No difference in implant survival between 28-mm M2a RingLoc metal-on-metal and metal-on-polyethylene total hip arthroplasty : results from the Finnish Arthroplasty Register

Publisher Copyright: © 2022 The Author(s).Background and purpose — Long-term outcome of small head (28 mm) metal-on-metal (MoM) total hip arthroplasty (THA) is available mainly for Metasul devices (Sulzer Medica, Winterthur, Switzerland). Biomet MoM THA was frequently used in Finland. Therefore, we assessed long-term survivorship of the M2a 28-mm RingLoc MoM THA (Biomet, Warsaw, IN, USA) and compared it with the metal-on-polyethylene (MoP) RingLoc THA from the same manufacturer. Patients and methods — We conducted a register study based on THAs from the Finnish Arthroplasty Register performed between January 1, 2000 and December 31, 2007. 290 28-mm head M2a MoM THAs and 1,647 28-mm head MoP THAs (reference group) were included. The endpoint was revision for any reason, or revision for aseptic loosening, osteolysis, liner wear, or metallosis as one group. Kaplan– Meier survival estimates were calculated, and revision risks were assessed using a Cox multiple regression model, both with 95% confidence intervals (CI). Results — No difference was found in the 15-year Kaplan–Meier survivorship between the 28-mm head M2a RingLoc MoM THA and the reference group for any reason for revision (87.7% [82.9–92.1] and 83.3% [81.0–85.3], respectively). The adjusted hazard ratio (HR) for any reason for revision for the MoM THA group compared with the reference group was at least equal or better (0.70 [0.48–1.02]). Both groups presented similar survival for revision for aseptic loosening of the cup, osteolysis, liner wear, or metallosis, at 96.2% (92.7–98.0) and 95.4% (93.9–96.5), respectively. Interpretation — In the long-term survival there was no difference between the M2a 28-mm RingLoc MoM THA and 28-mm MoP THA. Further follow-up regimens for M2a 28-mm RingLoc THA patients may be unnecessary, but long-term metal ion and radiological data is needed before any formal suggestions.Peer reviewe

Implant survival of 2,723 vitamin E-infused highly crosslinked polyethylene liners in total hip arthroplasty: data from the Finnish Arthroplasty Register

Background and purpose - The use of crosslinked polyethylene in total hip arthroplasty (THA) has decreased wear remarkably. It has been suggested that the antioxidative effects of vitamin E may enhance the wear properties of polyethylene even further. This study evaluates revision rates between vitamin E-infused polyethylene liners (E1 and E-poly, ZimmerBiomet, Warsaw, IN, USA) versus moderately crosslinked polyethylene (ModXLPE) liners from the same manufacturer used in primary THA.Patients and methods - We conducted a study based on data from the Finnish Arthroplasty Register. The study group consisted of 2,723 THAs with a vitamin E-infused liner and a reference group of 2,707 THAs with a moderately crosslinked polyethylene liner. Survivorship, revision risk, and re-revision causes were compared between groups.Results - The 7-year survival of the vitamin E-infused polyethylene liner group and of the reference group with revision for any reason as the endpoint was comparable (94% [95% CI 92.9-94.9] and 93% [CI 91.9-93.9], respectively). The adjusted hazard ratio (HR) for any revision was similar between the groups (0.7 [CI 0.4-1.1]). When revision for aseptic loosening was studied as the endpoint, the survival for the study group was 99% (CI 98.6-99.4) and for the reference group 99% (CI 98.7-99.5), and the risk of revision was comparable between the study groups (HR 1.3 [CI 0.7-2.5]).Interpretation - After an observation period of 7 years vitamin E-infused liners shows results equal to results obtained with crosslinked polyethylene liners

Suomen tekonivelrekisteri 40 vuotta laadun tukena

Vertaisarvioitu. English summary.• Implanttirekisteri on maailman kolmanneksi vanhin edelleen toiminnassa oleva kliininen kansallinen laaturekisteri. • Implanttirekisteri on ortopedien ja THL:n yhteistyönä uudistettu vastaamaan 2020-luvun tarpeita. • Implanttirekisteriin perustuvia tutkimusraportteja julkaistiin 17 kappaletta pelkästään vuosina 2019–2020. Moni tieteellinen julkaisumme on merkittävästi muuttanut hoitokäytäntöjä.Peer reviewe

Suomen tekonivelrekisteri 40 vuotta laadun tukena

• Implanttirekisteri on maailman kolmanneksi vanhin edelleen toiminnassa oleva kliininen kansallinen laaturekisteri.• Implanttirekisteri on ortopedien ja THL:n yhteistyönä uudistettu vastaamaan 2020-luvun tarpeita.• Implanttirekisteriin perustuvia tutkimusraportteja julkaistiin 17 kappaletta pelkästään vuosina 2019–2020. Moni tieteellinen julkaisumme on merkittävästi muuttanut hoitokäytäntöjä.</p