Genetic characterization and population bottleneck in the Hucul horse based on microsatellite and mitochondrial data

The aim of this work was to gather information about the origin and genetic characterization of the Central European Hucul horse based on 71 horses using 17 microsatellites and the D‐loop region of mtDNA. Their genetic relationship to the Polish Konik (N = 7), German (N = 4) and Hungarian wild Przewalski horses (N = 4) and 200 horse sequences from GenBank was also analysed. Both microsatellite and mtDNA analysis showed a high genetic variation in the Hucul. A total of 130 alleles were detected, the mean number of observed alleles per microsatellite was 7.647, and the number of effective alleles was 4.401. The average observed and expected heterozygosity were 0.706 and 0.747, respectively. The high heterozygosity values and Wright's fixation index (F_IS) (?0.128) indicated a low level of inbreeding, low or no selection pressure, and large number of alleles. mtDNA analysis revealed 18 haplotypes for the Hucul population with a total of 23 variable sites. Haplotype and nucleotide diversities were 0.935 ± 0.011 and 0.022 ± 0.012, respectively. Neutrality tests (Tajima's D and Fu's Fs) were non‐significant, and mismatch distribution was ragged, indicating that the Hucul population is in genetic equilibrium. The most frequent mtDNA D‐loop region belonged to haplogroup A (48%), which was also present in Przewalski Wild horse samples, while Polish Konik samples belonged to three haplotypes and C, F, and G haplogroups. Large and significant pairwise Φ_ST values along with a small number of common haplotypes indicated a low level of gene flow and lack of genetic structure among the three studied breeds (Hucul, Konik, and Przewalski Wild horse). The present work contributes to our knowledge of the genetic diversity of the Hucul horse and helps to define its genetic conservation. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 54–65.     

Oviposition behaviour of the soil mite Pergamasus brevicornis (Acari: Parasitidae)

We observed the oviposition behaviour of the soil mite Pergamasus brevicornis Berlese (Acari: Parasitidae) using continuous video-monitoring. Oviposition consisted of six sequential phases. The first phase (I) involved inspection of the substrate. In the second phase (II) there were rhythmic movements of the first pair of legs and slight reciprocating movements of the body. The third (III) was a resting phase. In the fourth phase (IV) the gnathosoma was lowered and the body was raised. In the next phase (V) there were two sub-phases. During the first (Va), the female held the egg below the gnathosoma. In the second sub-phase (Vb), the gnathosoma moved up holding the egg, which was then placed on the substrate. The last phase (VI) involved intense ‘cleaning’ movements of the chelicerae and palps. During Va a protective external eggshell structure is gradually formed, involving a phase where the egg shell is sticky. After moving the egg to the substrate, the female freed her palps and chelicerae from the sticky egg shell and cleaned her gnathosomal appendages. Phases II–V took on average 207 ± 69 s.     

Interpretation of the invertebrate-based BMWP-PL index in a gravel-bed river: insight from the Polish Carpathians

Like its British prototype (Biological Monitoring Working Party score system), the Polish benthic invertebrate-based BMWP-PL index is commonly regarded as an indicator of river water quality. This interpretation of the index has been verified in a study of the gravel-bed Bia?a River. Benthic macroinvertebrates were sampled at 10 sites and compared in one channelized and one unmanaged cross-section per site. The resulting taxa richness and BMWP-PL index scores were compared with water quality and physical habitat characteristics in the cross-sections. Channelized and unmanaged cross-sections clearly differed in their physical habitat conditions, and water quality characteristics mostly varied in the downstream direction. Particular cross-sections hosted between 3 and 26 invertebrate taxa, with the respective BMWP-PL scores indicating the water in the surveyed cross-sections varied between high and poor quality. However, the BMWP-PL scores were unrelated to physicochemical characteristics of the river water, which consistently pointed to high water quality. Instead, the scores were significantly related to several physical habitat variables, with the number of low-flow channels in a cross-section explaining the largest proportion of the variance in the index values. The relationship of the scores with the complexity of flow pattern in the river and a lack of their dependence on physicochemical water characteristics show that the BMWP-PL index should not be regarded as an indicator of water quality but rather as an indicator of the ecological status of rivers, dependent both on their hydromorphological and water-quality characteristics.     

Redox signals as a language of interorganellar communication in plant cells

Plants are redox systems and redox-active compounds control and regulate all aspects of their life. Recent studies have shown that changes in reactive oxygen species (ROS) concentration mediated by enzymatic and non-enzymatic antioxidants are transferred into redox signals used by plants to activate various physiological responses. An overview of the main antioxidants and redox signaling in plant cells is presented. In this review, the biological effects of ROS and related redox signals are discussed in the context of acclimation to changing environmental conditions. Special attention is paid to the role of thiol/disulfide exchange via thioredoxins (Trxs), glutaredoxins (Grxs) and peroxiredoxins (Prxs) in the redox regulatory network. In plants, chloroplasts and mitochondria occupying a chloroplasts and mitochondria play key roles in cellular metabolism as well as in redox regulation and signaling. The integrated redox functions of these organelles are discussed with emphasis on the importance of the chloroplast and mitochondrion to the nucleus retrograde signaling in acclimatory and stress response.     

Ultrafast Plasmonic Electron Emission from Ag Nanolayers with Different Roughness

We demonstrate ultrafast plasmonic electron emission and acceleration from Ag nanolayers having different roughness. We obtained the spectrum of the electrons and found that the surface roughness deeply influences the properties of the electron spectra. Numerical simulations on propagating surface plasmons coupled to localized plasmons on surface grains support the observations. Applications related to ultrafast electron sources and ultrafast photocathodes are envisaged.     

Methylmercury and Total Mercury in Eels, <Emphasis Type="Italic">Anguilla anguilla</Emphasis>, from Lakes in Northeastern Poland: Health Risk Assessment

In the aquatic environment, mercury is readily methylated into its most toxic form of methylmercury. In this form, it enters the aquatic food chain and its concentrations increase in subsequent links, which decreases the quality of fish meat and poses risks to consumer health. Concentrations of methylmercury (MeHg) and total mercury (THg) were determined in the muscle tissues of 64 eel specimens measuring from 59 to 95 cm in length as functions of specimen size and weight. Risks posed to consumers by eel from different length classes were also assessed. The mean concentration of THg in all of the eel examined was 0.179 mg kg^?1, but the range was from 0.028 to 0.487 mg kg^?1. The mean concentration of MeHg was 0.147 mg kg^?1, and the range was also wide from 0.023 to 0.454 mg kg^?1. Accumulated MeHg and THg increased with eel body length. The percentage share of MeHg in THg also changed with specimen length, and there was a positive correlation between the concentrations of MeHg and THg. Risk assessment was performed based on the doses of THg and MeHg ingested with fish for several specimen length classes. Consuming the meat of eel measuring 80 cm in length increased the estimated weekly intake (EWI) of THg and MeHg twofold in comparison to that from specimens 60 cm in length and fourfold in specimens exceeding 90 cm in length. The percentage shares of the EWI in the tolerable weekly intake and the target hazard quotient coefficient also increased proportionally. Generally, concentrations of MeHg and THg in eel are below current limits and pose no risk to consumer health as long as the consumption of larger specimens is avoided.     

Risk Factors for Normal and High-Tension Glaucoma in Poland in Connection with Polymorphisms of the Endothelial Nitric Oxide Synthase Gene

Aim

The purpose of this study was to evaluate the influence of polymorphisms of the eNOS gene on the clinical status of patients with normal and high tension glaucoma.

Methods

266 Polish Caucasian patients with primary open angle glaucoma were studied. Of the 266, 156 had normal tension glaucoma (NTG) and 110 high tension glaucoma (HTG). DNA material was isolated from peripheral venous blood using commercial kits. Real-time PCR reaction was used to amplify the promoter site of the endothelial nitric oxide synthase (eNOS) gene, including the single nucleotide polymorphism (SNP) site T-786C and part of the 7^th exon of eNOS, including G894T SNP. Genotypes were determined with TaqMan SNP Genotyping Assays.

Results

There were no significant differences in frequencies of the allelic variants of both polymorphisms. In G894T SNP, however, the wild GG form was more common in the HTG group. The SNP of the eNOS gene did not significantly influence the progression rate in either of the groups studied. There were no differences in variants of the eNOS gene regarding the necessity for and success of surgery and the progression of the disease. In the NTG group, no statistical correlation was observed between G894T, T786C polymorphism variants, and risk factors such as optic disc haemorrhages, optic disc notches, and peripapillary atrophy. Mean diastolic and systolic pressure during the day and night were lowest in NTG patients with the CC variant of the T786C polymorphism. No statistical correlation was observed between the G894T and T786C polymorphisms and capillaroscopic examination results.

Conclusions

Genotype frequencies are similar for both the eNOS G894T and T-786C polymorphisms in NTG and HTG patients. These polymorphisms do not correlate with risk factors and do not influence the state of the capillary system in NTG patients. Systolic blood pressure is lower in NTG patients with mutated alleles of both polymorphisms.     

Adhesion of the genome-sequenced <Emphasis Type="Italic">Lactococcus lactis</Emphasis> subsp. <Emphasis Type="Italic">cremoris</Emphasis> IBB477 strain is mediated by specific molecular determinants

Understanding the nature of mucus-microbe interactions will provide important information that can help to elucidate the mechanisms underlying probiotic adhesion. This study focused on the adhesive properties of the Lactococcus lactis subsp. cremoris IBB477 strain, previously shown to persist in the gastrointestinal tract of germ-free rats. The shear flow-induced detachment of L. lactis cells was investigated under laminar flow conditions. Such a dynamic approach demonstrated increased adhesion to bare and mucin-coated polystyrene for IBB477, compared to that observed for the MG1820 control strain. To identify potential genetic determinants giving adhesive properties to IBB477, the improved high-quality draft genome sequence comprising chromosome and five plasmids was obtained and analysed. The number of putative adhesion proteins was determined on the basis of surface/extracellular localisation and/or the presence of adhesion domains. To identify proteins essential for the IBB477 specific adhesion property, nine deletion mutants in chromosomal genes have been constructed and analysed using adhesion tests on bare polystyrene as well as mucin-, fibronectin- or collagen IV-coated polystyrene plates in comparison to the wild-type strain. These experiments demonstrated that gene AJ89_07570 encoding a protein containing DUF285, MucBP and four Big_3 domains is involved in adhesion to bare and mucin-coated polystyrene. To summarise, in the present work, we characterised the adhesion of IBB477 under laminar flow conditions; identified the putative adherence factors present in IBB477, which is the first L. lactis strain exhibiting adhesive and mucoadhesive properties to be sequenced and demonstrated that one of the proteins containing adhesion domains contributes to adhesion.