Japanese macaques (Macaca fuscata) social development: Sex differences in Juvenile behavior

We have quantitatively documented the development of sex differences in the behavior of juvenile Japanese macaques (1 to 2 years of age). Mothers treated their offspring differently by sex, i.e., mothers of males broke contact with them more frequently than did mothers of females. Juvenile males played more, and mounted other macaques more frequently; juvenile females groomed their mothers more and were also punished by other group members more frequently than were males. Males showed a pattern of decreasing interactions with their mothers, but females increased the frequency of their maternal interactions. These patterns appear to presage the life histories of the sexes. However, comparisons with other species of nonhuman primates indicate that although sex differences in behavior are common, the variability among species severely limits cross-specific generalizations.     

Incidence of novel and potentially archaeal nitrogenase genes in the deep Northeast Pacific Ocean

Archaea have been detected throughout the oceanic water column and are quantitatively important members of picoplankton in the deep ocean. Two common groups, group I Crenarchaeota and group II Euryarchaeota, are consistently detected in warm hydrothermal fluid and are assumed to have been drawn into the subseafloor, mixed with hydrothermal fluid and then expelled. However, because they remain resistant to cultivation, very little is known about their physiology. Here we show that cold deep-seawater from the axial valley of Endeavour Segment on the Juan de Fuca Ridge contains not only groups I and II archaea as expected, but also unique potentially archaeal nitrogenase (nifH) genes, which are required for nitrogen fixation. These nifH genes are phylogenetically distinct and have dissimilar G+C content compared with those of hydrothermal vent archaea, suggesting that they belong to non-thermophilic deep-sea archaea. Furthermore, this sample did not contain mcrA genes, which are present in methanogens, the only known archaeal nitrogen fixers. These nifH genes were not detected in upper water column samples, or in a deep-seawater sample 100 km away from the spreading axis of the Juan de Fuca Ridge. We propose that these unique nifH genes may be localized to archaea that circulate through the nitrogen-poor subseafloor at the mid-ocean ridge as part of their life cycle.     

Developmentally regulated thyroid hormone distributor proteins in marsupials, a reptile, and fish

Thyroid hormones are essential for vertebrate development. There is a characteristic rise in thyroid hormone levels in blood during critical periods of thyroid hormone-regulated development. Thyroid hormones are lipophilic compounds, which readily partition from an aqueous environment into a lipid environment. Thyroid hormone distributor proteins are required to ensure adequate distribution of thyroid hormones, throughout the aqueous environment of the blood, and to counteract the avid partitioning of thyroid hormones into the lipid environment of cell membranes. In human blood, these proteins are albumin, transthyretin and thyroxine-binding globulin. We analyzed the developmental profile of thyroid hormone distributor proteins in serum from a representative of each order of marsupials (M. eugenii; S.crassicaudata), a reptile (C. porosus), in two species of salmonoid fishes (S. salar; O. tshawytsch), and throughout a calendar year for sea bream (S. aurata). We demonstrated that during development, these animals have a thyroid hormone distributor protein present in their blood which is not present in the adult blood. At least in mammals, this additional protein has higher affinity for thyroid hormones than the thyroid hormone distributor proteins in the blood of the adult. In fish, reptile and polyprotodont marsupial, this protein was transthyretin. In a diprotodont marsupial, it was thyroxine-binding globulin. We propose an hypothesis that an augmented thyroid hormone distributor protein network contributes to the rise in total thyroid hormone levels in the blood during development.     

RNA Mimicry by the Fap7 Adenylate Kinase in Ribosome Biogenesis

During biogenesis of the 40S and 60S ribosomal subunits, the pre-40S particles are exported to the cytoplasm prior to final cleavage of the 20S pre-rRNA to mature 18S rRNA. Amongst the factors involved in this maturation step, Fap7 is unusual, as it both interacts with ribosomal protein Rps14 and harbors adenylate kinase activity, a function not usually associated with ribonucleoprotein assembly. Human hFap7 also regulates Cajal body assembly and cell cycle progression via the p53–MDM2 pathway. This work presents the functional and structural characterization of the Fap7–Rps14 complex. We report that Fap7 association blocks the RNA binding surface of Rps14 and, conversely, Rps14 binding inhibits adenylate kinase activity of Fap7. In addition, the affinity of Fap7 for Rps14 is higher with bound ADP, whereas ATP hydrolysis dissociates the complex. These results suggest that Fap7 chaperones Rps14 assembly into pre-40S particles via RNA mimicry in an ATP-dependent manner. Incorporation of Rps14 by Fap7 leads to a structural rearrangement of the platform domain necessary for the pre-rRNA to acquire a cleavage competent conformation.     

Towards new sources of resistance to the currant-lettuce aphid (<Emphasis Type="Italic">Nasonovia ribisnigri</Emphasis>)

Domesticated lettuce varieties encompass much morphological variation across a range of crop type groups, with large collections of cultivars and landrace accessions maintained in genebanks. Additional variation not captured during domestication, present in ancestral wild relatives, represents a potentially rich source of alleles that can deliver to sustainable crop production. However, these large collections are difficult and costly to screen for many agronomically important traits. In this paper, we describe the generation of a diversity collection of 96 lettuce and wild species accessions that are amenable to routine phenotypic analysis and their genotypic characterization with a panel of 682 newly developed expressed sequence tag (EST)-linked KASP? single nucleotide polymorphism (SNP) markers that are anchored to the draft Lactuca sativa genome assembly. To exemplify the utility of these resources, we screened the collection for putative sources of resistance to currant-lettuce aphid (Nasonovia ribisnigri) and carried out association analyses to look for potential SNPs linked to resistance.     

1H and15N resonance assignments and secondary structure of the human thioredoxin C62A,C69A,C73A mutant

Summary The complete assignment of¹H and¹⁵N backbone resonances and near-complete¹H side-chain resonance assignments have been obtained for the reduced form of a mutant of human thioredoxin (105 residues) in which the three non-active site cysteines have been substituted by alanines: C62A, C69A, C73A. The assignments were made primarily on the basis of three-dimensional.¹⁵N-separated nuclear Overhauser and Hartmann-Hahn spectroscopy, in conjunction with two-dimensional homonuclear and heteronuclear correlation experiments. Based on comparisons of short-range and interstrand nuclear Overhauser effects, patterns of amide exchange, and chemical-shift differences, the structure appears essentially unchanged from that of the previously determined solution structure of the native protein [Forman-Kay. J.D. et al. (1991)Biochemistry, 30, 2685–2698). An assay for thioredoxin shows that the C62A, C69A, C73A mutant retains activity. The assignment of the spectrum for this mutant of human thioredoxin constitutes the basis for future studies aimed at comparing the details of the active-site conformation in the reduced and oxidized forms of the protein.     

Barnebya,A new genus of Malpighiaceae from Brazil

The new genusBarnebya is described and illustrated and its systematic position in the Malpighiaceae is discussed, especially its similarity in some respects to the primitive subfamily Byrsonimoideae and in other respects to the Old World genusAcridocarpus. Two species are recognized,B. dispar comb. nov. andB. harleyi sp. nov.; these are described and illustrated and a key is provided for their distinction.     

MEPE-Derived ASARM Peptide Inhibits Odontogenic Differentiation of Dental Pulp Stem Cells and Impairs Mineralization in Tooth Models of X-Linked Hypophosphatemia

Mutations in PHEX (phosphate-regulating gene with homologies to endopeptidases on the X-chromosome) cause X-linked familial hypophosphatemic rickets (XLH), a disorder having severe bone and tooth dentin mineralization defects. The absence of functional PHEX leads to abnormal accumulation of ASARM (acidic serine- and aspartate-rich motif) peptide − a substrate for PHEX and a strong inhibitor of mineralization − derived from MEPE (matrix extracellular phosphoglycoprotein) and other matrix proteins. MEPE-derived ASARM peptide accumulates in tooth dentin of XLH patients where it may impair dentinogenesis. Here, we investigated the effects of ASARM peptides in vitro and in vivo on odontoblast differentiation and matrix mineralization. Dental pulp stem cells from human exfoliated deciduous teeth (SHEDs) were seeded into a 3D collagen scaffold, and induced towards odontogenic differentiation. Cultures were treated with synthetic ASARM peptides (phosphorylated and nonphosphorylated) derived from the human MEPE sequence. Phosphorylated ASARM peptide inhibited SHED differentiation in vitro, with no mineralized nodule formation, decreased odontoblast marker expression, and upregulated MEPE expression. Phosphorylated ASARM peptide implanted in a rat molar pulp injury model impaired reparative dentin formation and mineralization, with increased MEPE immunohistochemical staining. In conclusion, using complementary models to study tooth dentin defects observed in XLH, we demonstrate that the MEPE-derived ASARM peptide inhibits both odontogenic differentiation and matrix mineralization, while increasing MEPE expression. These results contribute to a partial mechanistic explanation of XLH pathogenesis: direct inhibition of mineralization by ASARM peptide leads to the mineralization defects in XLH teeth. This process appears to be positively reinforced by the increased MEPE expression induced by ASARM. The MEPE-ASARM system can therefore be considered as a potential therapeutic target.     

Interaction of hepatitis B virus X protein with damaged DNA-binding protein p127: Structural analysis and identification of antagonists

The hepatitis B virus X protein is a multifunctional protein that is essential for natural infection and has also been implicated in liver cancer development. Previous studies have identified the DDB1 subunit of the damaged-DNA binding complex as a critical partner of X protein in the infection process, X-mediated cytotoxicity and stability of the viral protein. Here, we investigated the structural and functional constraints of X-DDB1 interaction using various mutational analyses. Our data show that the interaction interface of X with DDB1 is confined to a 15-residue epitope. All substitutions responsible for loss of binding mapped to this core-binding domain. In contrast, a marked increase in affinity for DDB1 resulted from substitutions at clustered positions lying close to the DDB1-binding epitope and correlated with loss of apoptotic potential. Selection of mutations in DDB1 that partially rescue the binding defect of an X mutant gave further insight into the contacts established between the two proteins. Importantly, both the core-binding domain of X and the gain-of-affinity X mutants inhibited DDB1-mediated stabilization of wild-type X protein. These X protein derivatives thus provide the basis for the development of therapeutic agents that antagonize X function through competitive inhibition of X-DDB1 interaction.