Comparative cytogenetic analysis of the “Sylvaemus” group of Apodemus (Rodentia, Muridae): A. sylvaticus from Sicily and A. flavicollis from the central Apennines

Chromosome mapping of three common markers, ie major and 5S rRNA genes (rDNA) and telomeric repeats, and conventional chromosome bandings were applied to two sibling species, Apodemus sylvaticus Linnaeus, 1758 and A. flavicollis Melchior, 1834, to further investigate intra- and interspecific karyological differentiation in the genus Apodemus. A slight variation of the rDNA-patterns was detected between the two Apodemus species. In both of them, the major NORs were located on autosome pairs 8, 11, 12 and 22, while the two other rDNA sites detected on chromosomes 7 and 21 were variable in, respectively, A. sylvaticus and A. flavicollis. Several tiny rDNA sites were present on the sex chromosomes in both species, but their incidence was lower in A. flavicollis. Single 5S rDNA chromosomal sites were conserved on chromosome pair 20. No interstitial sites of telomeric repeats were present in either species. In the Sicilian population of A. sylvaticus, the constitutive heterochromatin pattern corresponded to the “sylvaticus-E1” cytotype, while A. flavicollis had a species-specific pattern restricted to centromeres of all chromosomes. The results are discussed in relation to cytogenetic data available for the genus, with emphasis on the Sylvaemus group/subgenus.     

Annual fishes of the genus Nothobranchius as a model system for aging research

Aging research in vertebrates is hampered by the lack of short-lived models. Annual fishes of the genus Nothobranchius live in East African seasonal ponds. Their life expectancy in the wild is limited by the duration of the wet season and their lifespan in captivity is also short. Nothobranchius are popular aquarium fishes and many different species are kept as captive strains, providing rich material for comparative studies. The present paper aims at reviving the interest in these fishes by reporting that: (1) Nothobranchius can be cultured, and their eggs stored dry at room temperature for months or years, offering inexpensive methods of embryo storage; (2) Nothobranchius show accelerated growth and expression of aging biomarkers at the level of histology and behaviour; (3) the species Nothobranchius furzeri has a maximum lifespan of only 3 months and offers the possibility to perform investigations thus far unthinkable in a vertebrate, such as drug screening with life-long pharmacological treatments and experimental evolution; (4) when the lifespan of different species is compared, a general correlation is found between wet season duration in their natural habitat and longevity in captivity; and (5) vertebrate aging-related genes, such as p66Shc and MTP, can be easily isolated in Nothobranchius by homology cloning. These fishes can become excellent models for aging studies. They can be employed to test the effects of experimental manipulation on aging at a pace comparable with that of Drosophila and to probe the effects of natural selection on the evolution of aging-related genes.     

Carbocysteine lysine salt monohydrate (SCMC-LYS) is a selective scavenger of reactive oxygen intermediates (ROIs)

Carbocysteine lysine salt monohydrate (SCMC-Lys) is a well-known mucoactive drug whose therapeutic efficacy is commonly related to the ability of SCMC-Lys to replace fucomucins by sialomucins. The aim of this study was to determine if SCMC-Lys could exert an anti-oxidant action by scavenging reactive oxygen intermediates (ROIs). Our results show that SCMC-Lys proved effective as a selective scavenger of hypochlorous acid (HOCl) and hydroxyl radical (OH.), this effect being related to the reactivity of the SCMC tioether group. The scavenger activity of SCMC-Lys was observed in free cellular system as well as in activated human polymorphonuclear neutrophils (PMNs). SCMC-Lys scavenger activity on HOCl was paralleled by a powerful protection from HOCl-mediated inactivation of alpha1-antitripsin (alpha1-AT) inhibitor, the main serum protease inhibitor. Production of interleukin-(IL-)8, a major mediator of PMN recruitment in inflammatory diseases, is known to be mediated by intracellular OH. SCMC-Lys significantly reduced IL-8 production on stimulated human peripheral blood mononuclear cells (PBMCs) in the same range of concentrations affecting OH. activity. It is concluded that SCMC-Lys could exert, in addition to its mucoactive capacity, an anti-oxidant action, thus contributing to the therapeutic efficacy of SCMC-Lys.     

Blood Metals Concentration in Type 1 and Type 2 Diabetics

Mechanisms for the onset of diabetes and the development of diabetic complications remain under extensive investigations. One of these mechanisms is abnormal homeostasis of metals, as either deficiency or excess of metals, can contribute to certain diabetic outcomes. Therefore, this paper will report the blood levels of chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), mercury (Hg), nickel (Ni), lead (Pb), selenium (Se), and zinc (Zn) in subjects with type 1 diabetes (n?=?192, mean age 48.8 years, mean disease duration 20.6 years), type 2 diabetes (n?=?68, mean age 68.4 years, mean disease duration 10.2 years), and in control subjects (n?=?59, mean age 57.2 years), and discuss the results indicating their possible role in diabetes. The metal concentrations were measured by sector field inductively coupled plasma mass spectrometry after microwave-induced acid digestion of blood samples. The accuracy was checked using a blood-based certified reference material, and recoveries of all elements were in the range of 92–101 % of certified values. Type 1 diabetes was found to be associated with Cr (p?=?0.02), Mn (p?<?0.001), Ni (p?<?0.001), Pb (p?=?0.02), and Zn (p?<?0.001) deficiency, and type 2 diabetes with Cr (p?=?0.014), Mn (p?<?0.001), and Ni (p?<?0.001) deficiency. These deficiencies were appreciated also subdividing the understudied patients for gender and age groups. Furthermore, in type 1 diabetes, there was a positive correlation between Pb and age (p?<?0.001, ρ?=?0.400) and Pb and BMI (p?<?0.001, ρ?=?0.309), while a negative correlation between Fe and age (p?=?0.002, ρ?=??0.218). In type 2 diabetes, there was a negative correlation between Fe and age (p?=?0.017, ρ?=??0.294) and Fe and BMI (p?=?0.026, ρ?=??0.301). Thus, these elements may play a role in both forms of diabetes and combined mineral supplementations could have beneficial effects.     

Matrix metalloproteinase (MMP)-2 gene polymorphisms affect circulating MMP-2 levels in patients with migraine with aura

Matrix metalloproteinases (MMP) are involved in the disruption of blood–brain barrier (BBB) during migraine attacks. In the present study, we hypothesized that two functional polymorphisms (C^− 1306T and C^− 735T) in MMP-2 gene and MMP-2 haplotypes are associated with migraine and modify MMP-2 and tissue inhibitor of MMP (TIMP)-2 levels in migraine. Genotypes for MMP-2 polymorphisms were determined by real time-PCR using Taqman allele discrimination assays. Haplotypes were inferred using the PHASE program. Plasma MMP-2 and TIMP-2 concentrations were measured by gelatin zymography and ELISA, respectively, in 148 healthy women without history of migraine and in 204 women with migraine (153 without aura; MWA, and 51 with aura; MA). Patients with MA had higher plasma MMP-2 concentrations and MMP-2/TIMP-2 ratios than patients with MWA and controls (P < 0.05). While MMP-2 genotype and haplotype distributions for the polymorphisms were similar among the groups (P > 0.05), we found that the CC genotype for C^− 735T polymorphism and the CC haplotype were associated with higher plasma MMP-2 concentrations in MA group (P < 0.05). Our findings may help to understand the role of MMP-2 and its genetic variants in the pathophysiology of migraine and to identify a particular group of migraine patients with increased MMP-2 levels that would benefit from the use of MMP inhibitors.     

Mycobacterium tuberculosis UvrB forms dimers in solution and interacts with UvrA in the absence of ligands

During its life cycle Mycobacterium tuberculosis (MTB) must face a variety of environmental and endogenous physical and chemical stresses that could produce genotoxic damage. However, MTB possesses efficient systems to counteract the harmful effects of DNA‐damaging assaults. The nucleotide excision repair (NER) is a highly conserved multi‐enzymatic cascade that is initiated by the concerted action of three core proteins, that is UvrA, UvrB, and UvrC. Although the functional roles of these enzymes are well characterized, the intra‐pathway coordination of the NER components and the dynamics of their association is still a matter of debate. In the presented study, we analyzed the hydrodynamic properties and the oligomeric state of the MTB UvrB protein (MtUvrB) that we expressed and purified to homogeneity in a tag‐free form. Our results show that, differently to what has been previously observed for the His‐tagged version of the protein, MtUvrB forms dimers in solution, which are characterized by an elongated shape, as determined by small‐angle X‐ray scattering analysis. Moreover, to gain insights into the mycobacterial UvrA/UvrB lesion sensing/tracking complex we adopted a size‐exclusion chromatography‐based approach, revealing that the two proteins interact in the absence of ligands, leading to the assembling of A₂B₂ hetero‐tetramers in solution. Surface plasmon resonance analysis showed that the dissociation constant of the MtUvrA/MtUvrB complex falls in the low micromolar range that could represent the basis for a fine modulation of the complex architecture accompanying the multi‐step DNA repair activity of mycobacterial NER.     

Familial adenomatous polyposis-associated desmoids display significantly more genetic changes than sporadic desmoids

Desmoid tumours (also called deep or aggressive fibromatoses) are potentially life-threatening fibromatous lesions. Hereditary desmoid tumours arise in individuals affected by either familial adenomatous polyposis (FAP) or hereditary desmoid disease (HDD) carrying germline mutations in APC. Most sporadic desmoids carry somatic mutations in CTNNB1. Previous studies identified losses on 5q and 6q, and gains on 8q and 20q as recurrent genetic changes in desmoids. However, virtually all genetic changes were derived from sporadic tumours. To investigate the somatic alterations in FAP-associated desmoids and to compare them with changes occurring in sporadic tumours, we analysed 17 FAP-associated and 38 sporadic desmoids by array comparative genomic hybridisation and multiple ligation-dependent probe amplification. Overall, the desmoids displayed only a limited number of genetic changes, occurring in 44% of cases. Recurrent gains at 8q (7%) and 20q (5%) were almost exclusively found in sporadic tumours. Recurrent losses were observed for a 700 kb region at 5q22.2, comprising the APC gene (11%), a 2 Mb region at 6p21.2-p21.1 (15%), and a relatively large region at 6q15-q23.3 (20%). The FAP-associated desmoids displayed a significantly higher frequency of copy number abnormalities (59%) than the sporadic tumours (37%). As predicted by the APC germline mutations among these patients, a high percentage (29%) of FAP-associated desmoids showed loss of the APC region at 5q22.2, which was infrequently (3%) seen among sporadic tumours. Our data suggest that loss of region 6q15-q16.2 is an important event in FAP-associated as well as sporadic desmoids, most likely of relevance for desmoid tumour progression.     

Genetic and physical characterisation of the locus controlling columnar habit in apple (Malus × domestica Borkh.)

A better understanding of the genetic control of tree architecture would potentially allow improved tailoring of newly bred apple cultivars in terms of field management aspects, such as planting density, pruning, pest control and disease protection. It would also have an indirect impact on yield and fruit quality. The Columnar (Co) locus strongly suppresses lateral branch elongation and is the most important genetic locus influencing tree architecture in apple. Co has previously been mapped on apple linkage group (LG) 10. In order to obtain fine mapping of Co, both genetically and physically, we have phenotypically analysed and screened three adult segregating experimental populations, with a total of 301 F₁ plants, and one substantial 3-year old population of 1,250 F₁ plants with newly developed simple sequence repeat (SSR) markers, based on the ‘Golden delicious’ apple genome sequence now available. Co was found to co-segregate with SSR marker Co04R12 and was confined in a region of 0.56 cM between SSR markers Co04R11 and Co04R13, corresponding to 393 kb on the ‘Golden delicious’ genome sequence. In this region, 36 genes were predicted, including at least seven sequences potentially belonging to genes that could be considered candidates for involvement in control of shoot development. Our results provide highly reliable, virtually co-segregating markers that will facilitate apple breeding aimed at modifications of the tree habit and lay the foundations for the cloning of Co.