Ancient DNA sheds light on the ancestry of pre-hispanic Canarian pigs

Background

Canarian Black (CB) pigs belong to an autochthonous and endangered breed, which is spread throughout the Canarian archipelago. It is commonly accepted that they represent a relic of the pig populations that were bred by the Berbers in North Africa over millennia. It is important to note that the geographic isolation of the Canary Islands has preserved this genetic legacy intact from foreign introgressions until the Spanish conquest of the archipelago in the 15^th century. Ten years ago, it was demonstrated that, in CB pigs, the frequency of the Asian A2 cytochrome-b haplogroup reached 73%. The current work aimed at investigating whether this observation is explained by either a recent or an ancient introgression of CB pigs with Far Eastern pigs.

Results

Genetic analyses of 23 ancient samples from pre-hispanic Canarian pigs (420 to 2500 years before present) showed that Near Eastern and Far Eastern genetic signatures were totally absent in the primitive Canarian pre-hispanic pigs. Indeed, the haplotypes detected in these pigs were closely related to those of North African and European wild boars.

Conclusions

Our results demonstrate that the high frequency of the Far Eastern mitochondrial cytochrome B A2 haplotype in modern Canarian Black pigs probably corresponds to a relatively recent introgression with British breeds.

Electronic supplementary material

The online version of this article (doi:10.1186/s12711-015-0115-7) contains supplementary material, which is available to authorized users.     

7th SOSORT consensus paper: conservative treatment of idiopathic & Scheuermann's kyphosis

Abstract

Thoracic hyperkyphosis is a frequent problem and can impact greatly on patient's quality of life during adolescence. This condition can be idiopathic or secondary to Scheuermann disease, a disease disturbing vertebral growth. To date, there is no sound scientific data available on the management of this condition. Some studies discuss the effects of bracing, however no guidelines, protocols or indication's of treatment for this condition were found. The aim of this paper was to develop and verify the consensus on managing thoracic hyperkyphosis patients treated with braces and/or physiotherapy.

Methods

The Delphi process was utilised in four steps gradually modified according to the results of a set of recommendations: we involved the SOSORT Board twice, then all SOSORT members twice, with a Pre-Meeting Questionnaire (PMQ), and during a Consensus Session at the SOSORT Lyon Meeting with a Meeting Questionnaire (MQ).

Results

There was an unanimous agreement on the general efficacy of bracing and physiotherapy for this condition. Most experts suggested the use of 4-5 point bracing systems, however there was some controversy with regards to physiotherapeutic aims and modalities.

Conclusion

The SOSORT panel of experts suggest the use of rigid braces and physiotherapy to correct thoracic hyperkyphosis during adolescence. The evaluation of specific braces and physiotherapy techniques has been recommended.     

Structure and organization of the bovine beta-globin genes

Genomic clones spanning the entire cow beta-globin gene locus have been isolated and characterized. These clones demonstrate that the linkage of embryonic-like (epsilon) genes and pseudogenes (psi) to the previously described fetal (gamma) and adult (beta) genes is as follows: 5'-epsilon 3-epsilon 4-psi 3-beta-epsilon 1-epsilon 2-psi 1- psi 2-gamma-3'. Present data indicate that, like that of the goat, the fetal and adult genes arose via block duplication of an ancestral four- gene set: epsilon-epsilon-psi-beta. This duplication event preceded the divergence of cows and goats, which occurred greater than or equal to 18-20 Myr ago. However, cows do not have the additional four-gene block containing a preadult/stress globin gene (beta C). Furthermore, the cow fetal cluster contains an extra beta-like pseudogene, which apparently arose by a small-scale duplication. The fixation of this duplication may indicate a possible evolutionary role for pseudogenes.      

Experimental evaluation of the relationship between lethal or non-lethal virulence and transmission success in malaria parasite infections

Background  

Evolutionary theory suggests that the selection pressure on parasites to maximize their transmission determines their optimal host exploitation strategies and thus their virulence. Establishing the adaptive basis to parasite life history traits has important consequences for predicting parasite responses to public health interventions. In this study we examine the extent to which malaria parasites conform to the predicted adaptive trade-off between transmission and virulence, as defined by mortality. The majority of natural infections, however, result in sub-lethal virulent effects (e.g. anaemia) and are often composed of many strains. Both sub-lethal effects and pathogen population structure have been theoretically shown to have important consequences for virulence evolution. Thus, we additionally examine the relationship between anaemia and transmission in single and mixed clone infections.     

Perforin oligomers form arcs in cellular membranes: a locus for intracellular delivery of granzymes

Perforin-mediated cytotoxicity is an essential host defense, in which defects contribute to tumor development and pathogenic disorders including autoimmunity and autoinflammation. How perforin (PFN) facilitates intracellular delivery of pro-apoptotic and inflammatory granzymes across the bilayer of targets remains unresolved. Here we show that cellular susceptibility to granzyme B (GzmB) correlates with rapid PFN-induced phosphatidylserine externalization, suggesting that pores are formed at a protein-lipid interface by incomplete membrane oligomers (or arcs). Supporting a role for these oligomers in protease delivery, an anti-PFN antibody (pf-80) suppresses necrosis but increases phosphatidylserine flip-flop and GzmB-induced apoptosis. As shown by atomic force microscopy on planar bilayers and deep-etch electron microscopy on mammalian cells, pf-80 increases the proportion of arcs which correlates with the presence of smaller electrical conductances, while large cylindrical pores decline. PFN appears to form arc structures on target membranes that serve as minimally disrupting conduits for GzmB translocation. The role of these arcs in PFN-mediated pathology warrants evaluation where they may serve as novel therapeutic targets.The cytotoxic cell granule-secretory pathway depends on perforin (PFN) to deliver granzyme (Gzm) proteases to the cytosol of target cells where they induce apoptosis and other biological effects, such as inflammation.¹ Ring-shaped transmembrane PFN pores hereafter called ‘cylindrical pores'', are presumed to act as the gateway for cytosolic entry, either at the plasma membrane or after endocytosis.^{2, 3, 4} In either case the highly cationic Gzms are thought to diffuse through these cylindrical pores formed by poly-PFN. Nevertheless, a mechanistic understanding of the phenomenon (how the cationic globular protein exchanges from its carrier proteoglycan, serglycin, to the pore and crosses the plasma and/or vesicular membranes) has been lacking due to limitations in imaging technology and in our detailed understanding of the molecular forms that PFN may adopt following interaction with a target cell plasma membrane.Here we show under conditions where cylindrical pore formation is minimal,⁵ that granzyme B (GzmB) translocation readily occurs. We previously demonstrated that a prelude to granzyme translocation is PFN-mediated, Ca-independent phosphatidylserine (PS) externalization (flip-flop) measured by annexin-V and lactadherin binding.⁶ This rapid PS flip-flop also occurs when mouse CD8 cells contact antigen-pulsed target cells. Inasmuch as the proteinaceous cylinders offer a formidable barrier to lipid flow, we have speculated that the observed movement of anionic phospholipids to the external leaflet is due to the formation of proteo-lipidic structures, which consists of oligomerized PFN monomers bearing an arc morphology and plasma membrane lipids.^{6, 7, 8}In the work reported here, the topology of PFN embedded into homogeneous planar bilayers and tumor cell plasma membranes was imaged by atomic force microscopy (AFM) and deep etch electron microscopy (DEEM), respectively. Further, the influence of an anti-human PFN mAb (pf-80) that rescues target cells from necrosis,⁹ was examined. The AFM data show that PFN forms arcs as well as rings in planar bilayers, while conductance measurements across equivalent membranes in parallel experiments measured functional pore sizes consistent with these varied structures. The pf-80 mAb increased the frequency of arc formation and reduced conductance values. Interestingly, PS flip-flop and granzyme delivery were both increased in target cells after PFN oligomerization was interrupted by the pf-80 mAb. A similar effect was seen in T24 bladder carcinoma cells imaged by DEEM. Treatment with PFN leads to deposition of rings (barrel stave pores) and arcs and the pf-80 mAb increased the ratio of arcs to rings on the surface of these cells. We suggest that the observed protein arcs function as toroidal pores in whole cells, explaining PS flip-flop, and act as focal points for granzyme translocation across lipid bilayer.     

Microsatellite allele frequencies in humans and chimpanzees, with implications for constraints on allele size

The distributions of allele sizes at eight simple-sequence repeat (SSR) or microsatellite loci in chimpanzees are found and compared with the distributions previously obtained from several human populations. At several loci, the differences in average allele size between chimpanzees and humans are sufficiently small that there might be a constraint on the evolution of average allele size. Furthermore, a model that allows for a bias in the mutation process shows that for some loci a weak bias can account for the observations. Several alleles at one of the loci (Mfd 59) were sequenced. Differences between alleles of different lengths were found to be more complex than previously assumed. An 8-base-pair deletion was present in the nonvariable region of the chimpanzee locus. This locus contains a previously unrecognized repeated region, which is imperfect in humans and perfect in chimpanzees. The apparently greater opportunity for mutation conferred by the two perfect repeat regions in chimpanzees is reflected in the higher variance in repeat number at Mfd 59 in chimpanzees than in humans. These data indicate that interspecific differences in allele length are not always attributable to simple changes in the number of repeats.      

Biometric variations and oxidative stress responses in juvenile Clarias gariepinus exposed to Termex®

The current study investigated the effects of termite insecticide, Termex® (imidacloprid 35.50% SC), on biometric variations and oxidative stress biomarkers in Clarias gariepinus. Fish were exposed to 4.00 and 6.00 µg l^–1 sublethal Termex® concentrations in 2017. The gill and liver tissues were sampled on days 7, 14, 21 and 28 and the results indicated that hepatosomatic index (HSI) decreased significantly when compared with the control on days 14, 21 and 28. The condition factor (CF) and viscera-somatic index (VSI) also decreased during the study period. The decrease was greater at 6.00 µg l^–1 Termex® concentration on days 21 and 28 for CF and days 14 to 28 for VSI, respectively. The lipid peroxidation (LPO) in both tissues was highest in the 6.00 µg l^?1 Termex® and increased with the duration. There was significant decrease (p < 0.05) in superoxide dismutase and glutathione peroxidase values, but significant increase in catalase activity in both tissues. The values of glutathione reductase in both tissues were comparable to the control, except on days 21 and 28 in the liver. There was negative correlation between the LPO in tissues and the HSI, CF and VSI values. The use of Termex® in the environment should be monitored to safeguard the health of aquatic organisms.