Genetic Variation and De Novo Mutations in the Parthenogenetic Caucasian Rock Lizard Darevskia unisexualis

Unisexual all-female lizards of the genus Darevskia that are well adapted to various habitats are known to reproduce normally by true parthenogenesis. Although they consist of unisexual lineages and lack effective genetic recombination, they are characterized by some level of genetic polymorphism. To reveal the mutational contribution to overall genetic variability, the most straightforward and conclusive way is the direct detection of mutation events in pedigree genotyping. Earlier we selected from genomic library of D. unisexualis two polymorphic microsatellite containg loci Du281 and Du215. In this study, these two loci were analyzed to detect possible de novo mutations in 168 parthenogenetic offspring of 49 D. unisexualis mothers and in 147 offspring of 50 D. armeniaca mothers . No mutant alleles were detected in D. armeniaca offspring at both loci, and in D. unisexualis offspring at the Du215 locus. There were a total of seven mutational events in the germ lines of four of the 49 D. unisexualis mothers at the Du281 locus, yielding the mutation rate of 0.1428 events per germ line tissue. Sequencing of the mutant alleles has shown that most mutations occur via deletion or insertion of single microsatellite repeat being identical in all offspring of the family. This indicates that such mutations emerge at the early stages of embryogenesis. In this study we characterized single highly unstable (GATA)n containing locus in parthenogenetic lizard species D. unisexualis. Besides, we characterized various types of mutant alleles of this locus found in the D. unisexualis offspring of the first generation. Our data has shown that microsatellite mutations at highly unstable loci can make a significant contribution to population variability of parthenogenetic lizards

Pattern and distribution of ergot alkaloids in cereals and cereal products from European countries

This paper reports on the occurrence of ergot alkaloids in cereals and cereal products in Europe. It includes occurrence data our group previously submitted to the European Food Safety Authority and new data we gathered afterwards. A total of 1,065 samples of cereals and cereal products intended for human consumption and animal feeding were analysed by liquid chromatography-tandem mass spectrometry for the presence of ergot alkaloids. The sample set included rye-, wheat- and multigrain-based food as well as rye-, wheat- and triticale-based feed. The study revealed that 59% of the analysed food and feed samples were contaminated with ergot alkaloids to some extent. In 55% of the samples, the levels of the -ine isomers were above the limit of quantification (LOQ), while contamination with the -inine isomers was found in 51% of the samples. The median values for the main ergot alkaloids (-ine forms) and the epimers (-inine forms) were 1 and 2 mu g/kg, respectively. Ergot alkaloids were present in 84% of rye food, 67% of wheat food, 48% of multigrain food, 52% of rye feed, 27% of wheat feed, and 44% of triticale feed at total alkaloid levels ranging from (LOQ) to 12,340 mu g/kg. Though the highest frequencies of contamination were observed for food samples, the feed samples, in particular Swiss rye feed, accounted for the highest levels of ergot alkaloids. The frequencies and levels of contamination were significantly lower in organic samples compared to conventional samples. Maximum levels of individual ergot alkaloids up to 3,270 mu g/kg (for ergotamine) were observed. Overall, ergosine, ergokryptine and ergocristine were the frequently occurring ergot alkaloids. The co-occurrence of all six ergot alkaloids was noted in 35% of the positive samples. Occurrence of a single ergot alkaloid was mainly observed for ergometrine

Rapid and sensitive LC-MS/MS determination of ergot alkaloids in buffered solutions: application to in vitro testing of a clay-based mycotoxin binder

A rapid liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of ergot alkaloids in buffered solutions from in vitro studies. The method implied a liquid-liquid extraction of the analytes under alkaline conditions prior to LC-MS/MS analysis and resulted in good recovery (91-123%) of the six ergot alkaloids defined by the European Food Safety Authority as most important, namely ergometrine, ergosine, ergotamine, ergocornine, ergokryptine and ergocristine, as well as their corresponding epimers. The method also proved to be sensitive, repeatable, linear, accurate and robust. Furthermore, the method was applied to evaluate the in vitro binding efficacy of a clay-based mycotoxin binder towards ergometrine, ergosine and ergocornine, through a design encompassing pH 3.0 and 6.8 to mimic the digestive tract. The binder demonstrated binding efficacy of 24, 93 and 97%, respectively, for these ergot alkaloids

ZNF555 protein binds to transcriptional activator site of 4qA allele and ANT1: potential implication in Facioscapulohumeral dystrophy

International audienceFacioscapulohumeral dystrophy (FSHD) is an epi/genetic satellite disease associated with at least two satellite sequences in 4q35: (i) D4Z4 macrosatellite and (ii) β-satellite repeats (BSR), a prevalent part of the 4qA allele. Most of the recent FSHD studies have been focused on a DUX4 transcript inside D4Z4 and its tandem contraction in FSHD patients. However, the D4Z4-contraction alone is not pathological, which would also require the 4qA allele. Since little is known about BSR, we investigated the 4qA BSR functional role in the transcriptional control of the FSHD region 4q35. We have shown that an individual BSR possesses enhancer activity leading to activation of the Adenine Nucleotide Translocator 1 gene (ANT1), a major FSHD candidate gene. We have identified ZNF555, a previously uncharacterized protein, as a putative transcriptional factor highly expressed in human primary myoblasts that interacts with the BSR enhancer site and impacts the ANT1 promoter activity in FSHD myoblasts. The discovery of the functional role of the 4qA allele and ZNF555 in the transcriptional control of ANT1 advances our understanding of FSHD pathogenesis and provides potential therapeutic targets

Examples of families where where no intrafamily variation of PCR products was revealed.

<p>a – Du281 locus, <i>D. armeniaca</i> family; b – 215 locus, <i>D. armeniaca</i> family; c – 215 locus, <i>D. unisexualis</i> family. Maternal DNAs are marked by M, offspring DNAs are shown by arrows and numbered in each family.</p

Allelic variants of microsatellite clusters of <i>Du281</i> locus in parthenogenetic lizard families <i>D. unisexualis</i>.

<p>Variations in microsatellite clusters are denoted by bold letters. T-A-T and C-G-C are haplotypes specific for allelic variants of <i>D. unisexualis</i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002730#pone.0002730-Korchagin1" target="_blank">[24]</a>. In Family 2 the observed changes were the same in all offspring (1–5). In family 3 the observed changes were the same in all offspring(1, 2). In Family 4 the observed changes are the same in three offspring (1, 3 and 4).</p

The Roles of Mosquitoes in the Circulation of Monoxenous Trypanosomatids in Temperate Climates

Monoxenous (insect-restricted) trypanosomatids are highly diverse and abundant in nature. While many papers focus on the taxonomy and distribution of these parasites, studies on their biology are still scarce. In particular, this concerns trypanosomatids inhabiting the ubiquitous mosquitoes. To shed light on the circulation of monoxenous trypanosomatids with the participation of mosquitoes, we performed a multifaceted study combining the examination of naturally- and experimentally-infected insects using light and electron microscopy and molecular identification of parasites. Our examination of overwintering mosquitoes (genera Culex and Culiseta) revealed that their guts contained living trypanosomatids, which can be spread during the next season. Experimental infections with Crithidia spp. demonstrated that imagines represent permissive hosts, while larvae are resistant to these parasites. We argue that for the parasites with wide specificity, mosquitoes act as facultative hosts. Other trypanosomatids may have specific adaptations for vertical transmission in these insects at the expense of their potential to infect a wider range of hosts and, consequently, abundance in nature