Parental origin of the two additional haploid sets of chromosomes in an embryo with tetraploidy

We report on the molecular investigations performed on an embryo with tetraploidy, karyotype 92,XXXY. The embryo was spontaneously aborted after eight weeks of gestation. Molecular analyses were performed in order to determine the parental origin and mode of formation of the two additional haploid sets of chromosomes. Microsatellite markers mapping to pericentromeric chromosome regions were used. Our results show a maternal origin of one additional set of chromosomes most likely due to the incorporation of the polar body of meiosis I and a paternal origin of the second additional set of chromosomes most likely due to dispermy. The karyotype 92,XXXY is rather unusual, indeed the vast majority of cases with tetraploidy have the karyotypes 92,XXXX or 92,XXYY. To the best of our knowledge this is the first case with 92,XXXY for which molecular investigations have been performed

Unexpectedly diverse forest dung beetle communities in degraded rain forest landscapes in Madagascar

Tropical forests, which harbor high levels of biodiversity, are being lost at an alarming speed. Madagascar, a biodiversity hotspot, has lost more than half of its original forest cover. Most of the remaining forests are small fragments of primary and secondary forest with differing degrees of human impact. These forests, as well as coffee and fruit plantations, may be important in supporting the forest-dependent biodiversity in Madagascar but this has been little studied. In Madagascar, dung beetles, which offer important ecosystem services, are largely restricted to forests. We examined the ability of fragmented and degraded forests to support dung beetle diversity, compared to the large areas of primary forest in eastern Madagascar. We found a general trend of a reduction of species with a loss of forest connectivity. In contrast, a higher level of forest disturbance was associated with higher species diversity. In several sites of low-quality forest as many or more species were found as in less disturbed and primary forests. The average size of dung beetles was smaller in the lower quality localities than in the primary forests. These findings suggest that many forest dung beetles in Madagascar are better adapted to forest disturbance than earlier expected, although they require some level of connectivity to surrounding forest. in Malagasy is available with online material.Peer reviewe

Mixed metal oxide nanoparticles inhibit growth of Mycobacterium tuberculosis into THP-1 cells

Objective/background: Humans have been in a constant battle with tuberculosis (TB). Currently, overuse of antibiotics has resulted in the spread of multidrug-resistant Mycobacterium tuberculosis (MDR), leading to antibiotic ineffectiveness at controlling the spread of TB infection in host cells and especially macrophages. Additionally, the Mycobacterium tuberculosis (Mtb) has developed methods to evade the immune system and survive. With the discovery of nanoparticle (NP)-based drugs, it is necessary to research their anti-mycobacterial properties and bactericidal mechanisms. In this study, we synthesized mixed metal oxide NPs and tested their ability to inhibit Mtb growth into macrophages and investigated the cytotoxic effects of NPs in THP-1 cells. Methods: Silver (Ag) NPs and zinc oxide (ZnO) NPs were synthesized by chemical reduction and chemical deposition in aqueous solution, and the diffraction light scattering, scanning electron microscopy, transmission electron microscopy, and ultraviolet–visible light-absorption spectra were used to identify NP properties. Ag and ZnO NPs were mixed together at a ratio of 8ZnO/2Ag and diluted into Löwenstein–Jensen medium followed by the addition of bacteria and incubation for 28 days at 37°C. The toxicity of NPs to THP-1 cells was assessed by MTT test, and macrophages were infected with Mtb for 4 h at 37°C under 5% CO2. Results: Nano-sized particles were estimated at ˜30–80nm, and the initial concentration of Ag NPs and ZnO NPs were estimated at ˜20 ppm and ˜60 ppm. The minimal inhibitory concentration ratio of 8ZnO/2Ag NPs against Mtb was detected at ˜1/32 of the initial concentration. Ag NPs in the range of concentrations exhibited no anti-Mtb effects, whereas ZnO NPs showed potent antibacterial activity at ˜1/128 of the initial concentration. ZnO NPs at all concentrations showed cytotoxic activity, whereas 100% of THP-1 cells remained viable in the presence of Ag NPs at ˜1/32 and ˜1/64 of the initial concentrations. However, at ratios of 8ZnO/2Ag, ˜39.94% of the cells at ˜1/16 of the initial concentration remained viable, with 100% of THP-1 cells at ˜1/32 of the initial concentration remaining viable. Conclusion: Although Ag NPs exhibited low cytotoxicity, they were unable to inhibit Mtb growth in vitro. ZnO NPs exhibited strong anti-Mtb activity and inhibited bacterial growth, but exhibited high cytotoxicity to human macrophage cells. By mixing Ag and ZnO NPs at a ratio of 8ZnO/2Ag, we acquired a mixture that exhibited potent antibacterial activity against Mtb and no cytotoxic effects on THP-1 cells, resulting in inhibition of both in vitro and ex vivo Mtb growth [Figure 1],[Figure 2],[Figure 3], [Table 1],[Table 2],[Table 3].{Figure 1}{Figure 2}{Figure 3} {Table 1}{Table 2}{Table 3