Bmp7 Functions via a Polarity Mechanism to Promote Cloacal Septation

During normal development in human and other placental mammals, the embryonic cloacal cavity separates along the axial longitudinal plane to give rise to the urethral system, ventrally, and the rectum, dorsally. Defects in cloacal development are very common and present clinically as a rectourethral fistula in about 1 in 5,000 live human births. Yet, the cellular mechanisms of cloacal septation remain poorly understood.We previously detected Bone morphogenetic protein 7 (Bmp7) expression in the urorectal mesenchyme (URM), and have shown that loss of Bmp7 function results in the arrest of cloacal septation. Here, we present evidence that cloacal partitioning is driven by Bmp7 signaling in the cloacal endoderm. We performed TUNEL and immunofluorescent analysis on cloacal sections from Bmp7 null and control littermate embryos. We found that loss of Bmp7 results in a dramatic decrease in the endoderm survival and a delay in differentiation. We used immunological methods to show that Bmp7 functions by activating the c-Jun N-terminal kinase (JNK) pathway. We carried out confocal and 3D imaging analysis of mitotic chromosome bundles to show that during normal septation cells in the cloacal endoderm divide predominantly in the apical-basal direction. Loss of Bmp7/JNK signaling results in randomization of mitotic angles in the cloacal endoderm. We also conducted immunohistochemical analysis of human fetal sections to show that BMP/phospho-SMAD and JNK pathways function in the human cloacal region similar as in the mouse.Our results strongly indicate that Bmp7/JNK signaling regulates remodeling of the cloacal endoderm resulting in a topological separation of the urinary and digestive systems. Our study points to the importance of Bmp and JNK signaling in cloacal development and rectourethral malformations

Cryoconite – from minerals and organic matter to bioengineeredsediments on glacier's surfaces

Cryoconite is a mixture of mineral and organic material covering glacial ice, playing important roles in biogeochemical cycles and lowering the albedo of a glacier surface. Understanding the differences in structure of cryoconite across the globe can be important in recognizing past and future changes in supraglacial environments and ice-organisms-minerals interactions. Despite the worldwide distribution and over a century of studies, the basic characteristics of cryoconite, including its forms and geochemistry, remain poorly studied. The major purpose of our study is the presentation and description of morphological diversity, chemical and photoautotrophs composition, and organic matter content of cryoconite sampled from 33 polar and mountain glaciers around the globe. Observations revealed that cryoconite is represented by various morphologies including loose and granular forms. Granular cryoconite includes smooth, rounded, or irregularly shaped forms; with some having their surfaces covered by cyanobacteria filaments. The occurrence of granules increased with the organic matter content in cryoconite.Moreover, amajor driver of cryoconite colouringwas the concentration of organicmatter and its interplay with minerals. The structure of cyanobacteria and algae communities in cryoconite differs between glaciers, but representatives of cyanobacteria families Pseudanabaenaceae and Phormidiaceae, and algae families Mesotaeniaceae and Ulotrichaceaewere themost common. Themost of detected cyanobacterial taxa are known to produce polymeric substances (EPS) that may cement granules. Organic matter content in cryoconite varied between glaciers, ranging from 1% to 38%. The geochemistry of all the investigated samples reflected local sediment sources, except of highly concentrated Pb andHg in cryoconite collected fromEuropean glaciers near industrialized regions, corroborating cryoconite as element-specific collector and potential environmental indicator of anthropogenic activity. Our work supports a notion that cryoconite may bemore than just simple sediment and instead exhibits complex structure with relevance for biodiversity and the functioning of glacial ecosystem

Importance of nest boxes for breeding birds in forest areas - the Wielkopolski National Park case study

The study embraced 159 nest boxes placed in three different study plots in the Wielkopolski National Park in western Poland. In the first season, 64% of nest boxes were occupied by four species: great tit Parus major, blue tit Cyanistes caeruleus, Eurasian nuthatch Sitta europaea and European pied flycatcher Ficedula hypoleuca. The dominant species were great and blue tits. Over 80% of broods of great tits and blue tits were reared successfully. Birds preferred nest boxes located in plots with domination of oaks and Scots pine and with rich underbrush. Woodpeckers damaged entrances of 70% of the nest boxes, but did not cause any brood losses. In 13% of the boxes nests of hornets, bumblebees and wasps were found. Bumblebees chose boxes with a bird nest material, whereas wasps and hornets avoided sites occupied by the birds. In general, the insects had a small impact on breeding success of birds and caused failure of only 3% of all broods. Obtained results show that nest boxes in forests may increase density of the most common cavity nesters and secure their high breeding success

Zastosowanie biosurfaktantów do wytwarzania nowoczesnych żeli pod prysznic o podwyższonym bezpieczeństwie stosowania

In the paper the influence of the type of surfactant in shaping safety of shower gels was presented. For this purpose, two types of washing cosmetics different in terms of surface active compound were used. In regard of increasing environmental awareness of consumers and on the basis of „green chemistry”, a mild surfactant – Inulin Lauryl Carbamate (lNCI) has been used in the former preparation. The ingredient in the second washing cosmetics was Sodium Laureth Sulfate (SLES) – a widely used anion surfactant. The irritation potential on the basis of the zein value as well as the skin dryness level were assessed in these preparations.W pracy przedstawiono wpływ rodzaju surfaktantu na kształtowanie bezpieczeństwa stosowania żeli pod prysznic. W tym celu opracowano dwa prototypy kosmetyków myjących, różniących się zastosowanym związkiem powierzchniowo czynnym. W związku ze stale wzrastającą świadomością środowiskową konsumentów oraz na podstawie zasad „zielonej chemii” w pierwszym z preparatów zastosowano delikatny biosurfaktant – Inulin Lauryl Carbamate (laurylokarbaminian inuliny). W składzie drugiego prototypu kosmetyku myjącego znalazł się powszechnie stosowany anionowy surfaktant – oksyetylenowany laurylosiarczan sodu (SLES). Dla preparatów dokonano oceny potencjału drażniącego na podstawie liczby zeinowej oraz stopnia wysuszenia skóry

Crystal and Solution Structure Analysis of FhuD2 from <i>Staphylococcus aureus</i> in Multiple Unliganded Conformations and Bound to Ferrioxamine‑B

Iron acquisition is a central process for virtually all organisms. In <i>Staphylococcus aureus</i>, FhuD2 is a lipoprotein that is a high-affinity receptor for iron-bound hydroxamate siderophores. In this study, FhuD2 was crystallized bound to ferrioxamine-B (FXB), and also in its ligand-free state; the latter structures are the first for hydroxamate-binding receptors within this protein family. The structure of the FhuD2–FXB conformation shows that residues W197 and R199 from the C-terminal domain donate hydrogen bonds to the hydroxamate oxygens, and a ring of aromatic residues cradles the aliphatic arms connecting the hydroxamate moieties of the siderophore. The available ligand-bound structures of FhuD from <i>Escherichia coli</i> and YfiY from <i>Bacillus cereus</i> show that, despite a high degree of structural conservation, three protein families have evolved with critical siderophore binding residues on either the C-terminal domain (<i>S. aureus</i>), the N-terminal domain (<i>E. coli</i>), or both (<i>B. cereus</i>). Unliganded FhuD2 was crystallized in five conformations related by rigid body movements of the N- and C-terminal domains. Small-angle X-ray scattering (SAXS) indicates that the solution conformation of unliganded FhuD2 is more compact than the conformations observed in crystals. The ligand-induced conformational changes for FhuD2 in solution are relatively modest and depend on the identity of the siderophore. The crystallographic and SAXS results are used to discuss roles for the liganded and unliganded forms of FhuD2 in the siderophore transport mechanism