Consistent patterns of common species across tropical tree communities.

Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge.

Consistent diel activity patterns of forest mammals among tropical regions.

An animal's daily use of time (their "diel activity") reflects their adaptations, requirements, and interactions, yet we know little about the underlying processes governing diel activity within and among communities. Here we examine whether community-level activity patterns differ among biogeographic regions, and explore the roles of top-down versus bottom-up processes and thermoregulatory constraints. Using data from systematic camera-trap networks in 16 protected forests across the tropics, we examine the relationships of mammals' diel activity to body mass and trophic guild.

Erratum to: Born to sing! Song development in a singing primate.

[This corrects the article DOI: 10.1093/cz/zoab018.].

Born to sing! Song development in a singing primate.

In animal vocal communication, the development of adult-like vocalization is fundamental to interact appropriately with conspecifics. However, the factors that guide ontogenetic changes in the acoustic features remain poorly understood. In contrast with a historical view of nonhuman primate vocal production as substantially innate, recent research suggests that inheritance and physiological modification can only explain some of the developmental changes in call structure during growth.

Maternal influence on the development of nut-cracking skills in the chimpanzees of the Taï forest, Côte d'Ivoire (Pan troglodytes verus).

Chimpanzees' (Pan troglodytes) nut-cracking behavior represents one of the most complex forms of tool-use known among nonhuman animals. Given the close phylogenetic relationship between these apes and humans, investigating how such complex behavior develops in immatures can reveal the evolutionary roots of the cognitive processes that enabled the evolution of outstanding technological skills in our lineage. In this study, we investigated whether maternal behavior directly enhanced nut-cracking skills in immature individuals.

Extraction of honey from underground bee nests by central African chimpanzees (Pan troglodytes troglodytes) in Loango National Park, Gabon: Techniques and individual differences.

A detailed analysis of tool use behaviors can disclose the underlying cognitive traits of the users. We investigated the technique used by wild chimpanzees to extract the underground nests of stingless bees (Meliplebeia lendliana), which represent a hard-to-reach resource given their highly undetectable location. Using remote-sensor camera trap footage, we analyzed 151 visits to 50 different bee nests by 18 adult chimpanzees of both sexes.

The Indris Have Got Rhythm! Timing and Pitch Variation of a Primate Song Examined between Sexes and Age Classes.

A crucial, common feature of speech and music is that they show non-random structures over time. It is an open question which of the other species share rhythmic abilities with humans, but in most cases the lack of knowledge about their behavioral displays prevents further studies. Indris are the only lemurs who sing.

Detection of thyroid peroxidase mRNA and protein in orbital tissue.

Objective: We have previously reported that the absence of thyroid peroxidase antibodies (TPOAb) in Graves' disease (GD) was associated with an increased risk of Graves' ophthalmopathy (GO). This observation raised the possibility that TPOAb could act as a protective factor. However, the presence of thyroid peroxidase (TPO) in the orbit has not been previously reported.

An in vitro model based on cell monolayers grown on the underside of large- pore filters in bicameral chambers for studying thyrocyte-lymphocyte interactions.

In the processes underlying thyroid autoimmunity, thyrocytes probably act as antigen-presenting cells exposing T-cell epitopes to intrathyroid lymphocytes. To study the interactions between lymphocytes and thyrocytes, which are arranged in a tight, polarized monolayer, we developed a new in vitro model based on human thyrocytes grown on the underside of a filter placed in a bicameral chamber. Thyrocytes from Graves' disease glands were plated onto the upper face of a 8-mum-pore polyethylene terephthalate culture insert filter placed in the inverted position and grown for 24 h before the insert was returned to the normal position for a week in the cell culture plate wells.

Antigenicity and immunogenicity of the C-terminal peptide of human thyroglobulin.

Thyroglobulin (Tg) is cleaved into several peptides during thyroid hormone synthesis, an oxidative process. P40, an iodinated C-terminal peptide from human Tg, has a molecular weight of about 40 kDa and contains two hormonogenic sites. P40 is the smallest peptide that is still recognized by monoclonal antibodies from mice immunized with human Tg directed against its immunodominant region.

Directed mutagenesis in region 713-720 of human thyroperoxidase assigns 713KFPED717 residues as being involved in the B domain of the discontinuous immunodominant region recognized by human autoantibodies.

Autoantibodies (aAbs) to thyroid peroxidase (TPO), the hallmark of autoimmune thyroid disease (AITD), recognize conformational epitopes restricted to an immunodominant region (IDR), divided into two overlapping domains A and B. Despite numerous efforts aimed at localizing the IDR and identifying aAb-interacting residues on TPO, only two critical amino acids, Lys(713) and Tyr(772), have been characterized. Precise and complete delineation of the other residues involved in the IDR remains to be defined.

Complement activation by direct C4 binding to thyroperoxidase in Hashimoto's thyroiditis.

Biosynthesis of thyroid hormones is an oxidative process that generates reactive oxygen species (ROS) and involves thyroperoxidase (TPO) that is one of the main autoantigens involved in autoimmune thyroid diseases. The ectodomain of TPO consists of a large N-terminal myeloperoxidase-like module followed by a complement control protein (CCP)-like module and an epidermal growth factor-like module. The presence of these two additional gene modules suggests that they may play some crucial, hitherto unsuspected role associated with thyroid function.

Evidence that the complement control protein-epidermal growth factor-like domain of thyroid peroxidase lies on the fringe of the immunodominant region recognized by autoantibodies.

There is no consensus regarding the location of the immunodominant region (IDR) on thyroid peroxidase (TPO) recognized by the majority of autoantibodies. Strong evidence indicates that it lies upstream of amino acid 741. However, an epitope has been localized to downstream residues 742-848 encompassing a disulfide-rich complement control protein (CCP)-like and epidermal growth factor (EGF)-like domain.

Human thyroperoxidase folds in one complex B-cell immunodominant region.

Human thyroperoxidase (TPO) ectodomain is successively made of myeloperoxidase-, complement control protein repeat-, and epidermal growth factor-like gene modules. However, the TPO immunodominant region targeted by autoantibodies from patients with an autoimmune thyroid disease has not been mapped on the molecule. Here, we used two purified recombinant TPO peptides produced in eukaryotic cells, which correspond to the major first and the further two gene modules of TPO.

Androgen-dependent expression of FcgammaRIIB2 by thyrocytes from patients with autoimmune Graves' disease: a possible molecular clue for sex dependence of autoimmune disease.

Thyrocyte expression of HLA class I and class II antigens and related accessory molecules would convert these epithelial cells into functional antigen-presenting cells. Here we show that whereas normal thyrocytes express FcRn, Graves' disease thyrocytes also express FcgammaRIIB2. We further find that expression of FcgammaRIIB2, but not FcRn, is repressed by dihydrotestosterone.

Hydrogen peroxide-induced production of a 40 kDa immunoreactive thyroglobulin fragment in human thyroid cells: the onset of thyroid autoimmunity?

We recently reported that, during in vitro thyroid-hormone synthesis, H(2)O(2) stress cleaved thyroglobulin (Tg) into C-terminal peptides. These peptides were found to contain the immunodominant region of Tg recognized by Tg autoantibodies from patients with an autoimmune thyroid disease. To test the hypothesis that Tg fragmentation is an early upstream initiating event involved in Tg autoimmune response and the consequence of oxidative injuries, we studied the effect of H(2)O(2) stress on human thyroid cells.

Production of immunoreactive thyroglobulin C-terminal fragments during thyroid hormone synthesis.

Here, we studied the fragmentation of the prothyroid hormone, thyroglobulin (Tg), which occurs during thyroid hormone synthesis, a process which involves iodide, thyroperoxidase, and the H2O2-generating system, consisting of glucose and glucose oxidase. Various peptides were found to be immunoreactive to autoantibodies to Tg from patients and monoclonal antibodies directed against the immunodominant region of Tg. The smallest peptide (40 kDa) bore thyroid hormones and was identified at the C-terminal end of the Tg molecule, which shows homologies with acetylcholinesterase.

Multicenter study on TGPO autoantibody prevalence in various thyroid and non-thyroid diseases; relationships with thyroglobulin and thyroperoxidase autoantibody parameters.

Objective: TGPO autoantibodies (aAbs) that bind simultaneously to thyroglobulin (Tg) and thyroperoxidase (TPO) are present in the serum of patients with autoimmune thyroid diseases (AITD) and have been found to differ from monospecific Tg and TPO aAbs. To obtain further insights on the prevalence defined as the rate of occurrence and significance of TGPO aAbs in a large population, we carried out a collaborative study involving 15 European teams.

Methods: Serum samples from 3122 patients with various thyroid and non-thyroid diseases and normal subjects were assayed using a novel TGPO aAb detection kit.

Molecular model, calcium sensitivity, and disease specificity of a conformational thyroperoxidase B-cell epitope.

While studying the humoral mechanisms involved in thyroid autoimmunity, we located a B-cell autoepitope in the extracellular C-terminal region of human thyroperoxidase. Structural modeling showed that this region encompasses both a Sushi-like and an epidermal growth factor-like domain, the flexible arrangement of which was putatively stabilized by calcium. The recombinant peptide was found to contain the previously identified conformational thyroperoxidase autoepitope.

Thyroglobulin monoclonal antibody cross-reacting with thyroperoxidase induces in syngeneic mice anti-idiotypic monoclonal antibodies with dual autoantigen binding properties. The intertope hypothesis.

Autoimmune thyroid diseases are characterized by antibodies (Ab) directed to thyroglobulin (Tg) and thyroperoxidase (TPO). Some of them, TGPO Ab, are Tg Ab with an interspecies idiotype (Id) reacting with TPO. Taking advantage of a carefully studied TGPO monoclonal antibody (mAb), we examined the basis of the hypothesis that TPO Ab would ultimately derive from TGPO Ab through idiotypic induction.

Comparative mapping of cloned human and murine antithyroglobulin antibodies: recognition by human antibodies of an immunodominant region.

Antibodies (Ab) to thyroglobulin (Tg) are common in patients with autoimmune thyroid diseases, but it is currently unclear how Tg Ab are involved in the pathology of autoimmune thyroid disease. We have previously reported the isolation of immunoglobulin G (IgG)kappa and IgGlambda Fab from phage display combinatorial libraries from the cervical lymph node of a single Hashimoto's thyroiditis patient with a high anti-Tg titer. Sequence analysis of these Fab indicated a restricted heavy chain usage with a nonrestricted light chain usage, with Fab inhibiting the binding of patient Tg Ab by between 39% and 79%.

A conformational B-cell epitope on the C-terminal end of the extracellular part of human thyroid peroxidase.

To investigate the B-cell autoimmune epitopes on human thyroid peroxidase (TPO), we generated proteolytic peptides by enzymatic hydrolysis of TPO in nondenaturing and nonreducing conditions. The hydrolysate was chromatographed on a reverse phase column. We eluted a material immunoreactive with both a TPO monoclonal antibody recognizing a linear epitope (mAb47, amino acid 713-721) and TPO autoantibodies (aAb) from patients.