Autumn migratory orientation and displacement responses of two willow warbler subspecies (Phylloscopus trochilus trochilus and P. t. acredula) in South Sweden

Topography and historical range expansion has formed a so-called migratory divide between two subspecies of willow warbler (Phylloscopus trochilus) in central Scandinavia. The autumn migratory directions of individuals assigned molecularly to both subspecies and possible hybrids were recorded using orientation cage experiments in southwest and southeast Sweden. We found pronounced differences in willow warblers’ orientation in respect to genotype. The mean directions registered in the control experiments were in accordance with the ringing recoveries and analyses of stable isotopes for Scandinavian willow warblers. With the same individuals we performed displacement experiments between both sites. They resulted in non-significant orientation, which could be explained by the intermediate distance of the displacement or reactions to housing, transportation and location. On a separate set of birds we tested whether stress following transportation could explain the disorientation and found that orientation before and after transport was unchanged. Experimental studies of effects of intermediate displacements across longitudes and studies of orientation of hybrid individuals in the zones of migratory divides are crucial for understanding the mechanisms underlying orientation behaviour. Our work further stresses the importance of knowing the migration genotype of a particular bird under study, in order to correctly evaluate expected migration routes.     

Eukaryote-Conserved Methylarginine Is Absent in Diplomonads and Functionally Compensated in Giardia

Methylation is a common posttranslational modification of arginine and lysine in eukaryotic proteins. Methylproteomes are best characterized for higher eukaryotes, where they are functionally expanded and evolved complex regulation. However, this is not the case for protist species evolved from the earliest eukaryotic lineages. Here, we integrated bioinformatic, proteomic, and drug-screening data sets to comprehensively explore the methylproteome of Giardia duodenalis—a deeply branching parasitic protist. We demonstrate that Giardia and related diplomonads lack arginine-methyltransferases and have remodeled conserved RGG/RG motifs targeted by these enzymes. We also provide experimental evidence for methylarginine absence in proteomes of Giardia but readily detect methyllysine. We bioinformatically infer 11 lysine-methyltransferases in Giardia, including highly diverged Su(var)3-9, Enhancer-of-zeste and Trithorax proteins with reduced domain architectures, and novel annotations demonstrating conserved methyllysine regulation of eukaryotic elongation factor 1 alpha. Using mass spectrometry, we identify more than 200 methyllysine sites in Giardia, including in species-specific gene families involved in cytoskeletal regulation, enriched in coiled-coil features. Finally, we use known methylation inhibitors to show that methylation plays key roles in replication and cyst formation in this parasite. This study highlights reduced methylation enzymes, sites, and functions early in eukaryote evolution, including absent methylarginine networks in the Diplomonadida. These results challenge the view that arginine methylation is eukaryote conserved and demonstrate that functional compensation of methylarginine was possible preceding expansion and diversification of these key networks in higher eukaryotes.     

Change of the protein composition of the thyroid colloid during treatment with propylthiouracil and thyroxine A microgel electrophoretic study of single rat thyroid follicles

Propylthiouracil and thyroxine were given daily to rats for 4 weeks. Samples of colloid were collected in vivo from the superficial thyroid follicles during this period and their protein composition was analysed by gel electrophoresis.It was observed that the aggregates of thyroglobulin, i.e., the 27-S thyroid iodoprotein and the heavier fractions, were reduced to 50% after 1 week and were almost absent after 2 weeks.A faster migrating thyroglobulin fraction was observed in the samples of colloid and in the homogenate of the whole gland after 48 h of treatment. During the following period of treatment there was an increase in the relative amount of the faster migrating thyroglobulin fraction compared to 19-S thyroglobulin in the colloid, the former comprising approx. 75% of the globulins after 4 weeks, It can be concluded that propylthiouracil inhibits the formation of the 27-S iodoprotein and that a structurally altered and iodine-poor thyroglobulin fraction is accumulated in the follicle lumen.     

Green fluorescent protein as a reporter system in the transformation of barley cultivars

A cereal transformation vector, pN1473, containing the strong constitutive rice actin promoter Act-1 , a multiple cloning site, and the nos terminator, was constructed. Fusion of a plant-optimized gfp gene to Act-1 in pN1473 resulted in the vector pN1473GFP. To assess the suitability of pN1473, and GFP as a reporter system in barley transformation, two barley cultivars (Baronesse and Golden Promise) were transformed by microprojectile bombardment. Transient gfp expression in transformed embryogenic callus material was detectable by fluorescence microscopy less than 12 h after transformation. The presence of the gfp gene in callus and regenerated plantlets was confirmed by PCR amplification and DNA gel-blot analysis.     

Haemosporidian infections in skylarks (<Emphasis Type="Italic">Alauda arvensis</Emphasis>): a comparative PCR-based and microscopy study on the parasite diversity and prevalence in southern Italy and the Netherlands

Changes in agricultural management have been identified as the most probable cause for the decline of Skylark (Alauda arvensis) populations in Europe. However, parasitic infections have not been considered as a possible factor influencing this process. Four hundred and thirty-four Skylarks from the Southern Italy and the Netherlands were screened for haemosporidian parasites (Haemosporida) using the microscopy and polymerase chain reaction (PCR)-based methods. The overall prevalence of infection was 19.5%; it was 41.8% in Italian birds and 8.3% in Dutch birds. The prevalence of Plasmodium spp. was 34.1% and 6.5% in Skylarks from Italy and Netherlands, respectively. Approximately 15% of all recorded haemosporidian infections were simultaneous infections both in Italian and Dutch populations. Six different mitochondrial cytochrome b (cyt b) lineages of Plasmodium spp. and three lineages of Haemoproteus tartakovskyi were found. The lineage SGS1 of Plasmodium relictum was the most prevalent at both study sites; it was recorded in 24.7% of birds in Italy and 5.5% in the Netherlands. The lineages SYAT05 of Plasmodium vaughani and GRW11 of P. relictum were also identified with a prevalence of <2% at both study sites. Two Plasmodium spp. lineages (SW2 and DELURB4) and three H. tartakovskyi lineages have been found only in Skylarks from Italy. Mitochondrial cyt b lineages SYAT05 are suggested for molecular identification of P. vaughani, a cosmopolitan malaria parasite of birds. This study reports the greatest overall prevalence of malaria infection in Skylarks during the last 100 years and shows that both Plasmodium and Haemoproteus spp. haemosporidian infections are expanding in Skylarks so it might contribute to a decrease of these bird populations in Europe.