Biology subjects

Martin, E. A.

Publications and source records attributed to Martin, E. A..

At least 19 recordsLinked to original sources

bioRxiv2026

Bovine-derived H5N1 influenza virus efficiently infects lactating swine via the mammary gland

Since 2024, highly pathogenic influenza A(H5N1) viruses have spread extensively among U.S. dairy cattle, where they replicate efficiently in the mammary gland and are shed at high titers in milk. To directly assess susceptibility of commercial swine populations to bovine-derived H5N1 virus, lactating sows with prior influenza virus vaccination histories representative of U.S. commercial swine production systems were inoculated via the intramammary route and co-housed with their 1-week-old piglets to evaluate disease outcomes, viral replication, and potential for vertical transmission. Intramammary inoculation of lactating sows resulted in sustained viral RNA shedding in milk, while piglets exhibited sporadic oral viral RNA positivity that mirrored viral kinetics in milk. Lesions in mammary tissue and viral antigen staining, as well as development of neutralizing antibody responses and changes in milk color and consistency, further confirmed infection in the sows. Despite these molecular findings, none of the animals developed overt clinical disease, and respiratory involvement was not noted during the study period. Collectively, we demonstrate that intramammary exposure results in productive influenza A(H5N1) virus infection in lactating sows despite their vaccination histories, indicating the potential threat of viral spillover into commercial swine populations. The clinically inapparent nature of infection presents a risk of subclinical spread and underscores the importance of expanding viral surveillance to swine.

microbiology↗

bioRxiv2026

Top-down and bottom-up landscape processes influence the formation of microbial partnerships in herbivorous insects

Many insects form intimate associations with microbial partners, spanning a continuum from obligate mutualisms to transient associations. These microbial partners confer a range of functional benefits, including protection from natural enemies, detoxification of plant secondary metabolites, and improved fitness. The prevalence and abundance of microbial symbionts can vary between insect populations, indicating that the insect-microbe relationship is influenced by external factors. However, little is known on the factors that determine the assembly, structure, and composition of the microbiome of herbivorous insects. We posit that the factors influencing the insect-microbe relationship occur at the landscape-scale, acting through a combination of bottom-up, top-down, and indirect effects between plants, herbivores, and their natural enemies. We test this in two agro-ecosystems by sampling individual insects from three sap-feeding and one leaf-chewing species. Our results explicitly show for the first time that habitat configurational complexity and the proportion of host-plant crop in the landscape, combined with natural enemy abundance, can act as direct and indirect drivers of microbial symbiosis in herbivorous insects. This highlights the wider implications landscape habitat and ecosystem structure has on species interactions across managed agricultural landscapes.

ecology↗

bioRxiv2026

Natural H5N1 immunity in dairy cows is durable and cross-protective but non-sterilizing

Ongoing transmission of influenza A virus (H5N1) in U.S. dairy cattle threatens both animal and human health, underscoring the need to understand the durability of host immunity against reinfection with evolving genotypes. We challenged naive and convalescent cows, infected one year prior with H5N1 genotype B3.13, with either homologous B3.13 or heterologous D1.1 genotype virus. Homologous rechallenge resulted in complete clinical protection with no infectious viral shedding. Conversely, heterologous rechallenge led to transient clinical disease and limited infectious viral shedding. Convalescent cows experienced significantly milder disease than naive cows, which developed severe illness with high viral shedding and required early euthanasia, regardless of the strain. These findings indicate that naturally acquired immunity offers strong protection against severe illness but may allow silent transmission of divergent strains. Therefore, natural herd immunity alone is unlikely to eliminate the virus; controlling H5N1 in cattle will likely require vaccination strategies that address viral evolution.

immunology↗

bioRxiv2025

A neurorecording toolkit for longitudinal assessments of transplanted human cortical organoids in vivo

Human cortical organoids (hCOs) are three-dimensional neural cell aggregates that recapitulate certain structural and functional aspects of the developing human cortex. Xenotransplantation of hCOs into the rodent brain enables human-centric modeling of neurodevelopmental processes in a physiologically relevant environment. Here, we present a neurorecording toolkit for longitudinal structural and functional assessment of hCO xenografts as they mature in vivo. Single hCOs were implanted into the retrosplenial cortex of adult immunodeficient mice and monitored for up to 8 months. Optical coherence tomography was used for label-free imaging of xenograft vascularization and structure, enabling quantitative assessments of capillary density and graft volume. To probe neuronal activity, human neurons were labeled with a calcium sensor before implantation using either adeno-associated or lentivirus for sparse or dense neuronal labeling, respectively. Fluorescent imaging was conducted using two-photon, widefield, and swept confocally-aligned planar excitation microscopy for single cell, whole-graft, and volumetric calcium imaging, respectively. Results from these modalities indicate an increase in neuronal activity and synchronicity over time during in vivo graft maturation. Further, we chronically implanted surface graphene microelectrode arrays (gMEAs) and performed recordings of xenograft and host local field potential signals simultaneously with 2P calcium imaging, confirming the spatial localization and human origin of electrical signals recorded at the xenograft surface.

neuroscience↗

bioRxiv2025

O-GlcNAc modifications regulate lamin A tail processing

Lamin A processing is highly regulated, and necessary for proper assembly of the nuclear lamina facilitating its role in nuclear structure and chromatin organization. Pre-lamin A is first farnesylated, and then a short C-terminal peptide is cleaved to produce mature lamin A. O-GlcNAc Transferase (OGT), a glucose sensitive post-translational modification enzyme, is a potential regulator for lamin A processing. To explore the role of OGT in lamin A biogenesis, we examined the effects of OGT levels and OGT inhibition. Variation in OGT dose or inhibition of its activity did not alter endogenous lamin A abundance or distribution. To more directly test the regulatory effects of O-GlcNAcylation on lamin A, we adapted a tail cleavage assay. Mutation of an OGT binding motif and O-GlcNAc modification sites reduced tail cleavage efficiency, suggesting that O-GlcNAcylation promotes lamin A processing. Our findings add to the understanding of the regulation of lamin A cleavage and identify a potential link between glucose metabolism and lamina biogenesis.

cell biology↗

bioRxiv2024

Electrical synapse molecular diversity revealed by proximity-based proteomic discovery

Neuronal circuits are composed of synapses that are either chemical, where signals are transmitted via neurotransmitter release and reception, or electrical, where signals pass directly through interneuronal gap junction channels. While the molecular complexity that controls chemical synapse structure and function is well appreciated, the proteins of electrical synapses beyond the gap-junction-forming Connexins are not well defined. Yet, electrical synapses are expected to be molecularly complex beyond the gap junctions. Connexins are integral membrane proteins requiring vesicular transport and membrane insertion/retrieval to achieve function, homeostasis, and plasticity. Additionally, electron microscopy of neuronal gap junctions reveals neighboring electron dense regions termed the electrical synapse density (ESD). To reveal the molecular complexity of the electrical synapse proteome, we used proximity-dependent biotinylation (TurboID) linked to neural Connexins in zebrafish. Proteomic analysis of developing and mature nervous systems identifies hundreds of Connexin-associated proteins, with overlapping and distinct representation during development and adulthood. The identified protein classes span cell adhesion molecules, cytoplasmic scaffolds, vesicular trafficking, and proteins usually associated with the post synaptic density (PSD) of chemical synapses. Using circuits with stereotyped electrical and chemical synapses, we define molecular sub-synaptic compartments of ESD localizing proteins, we find molecular heterogeneity amongst electrical synapse populations, and we examine the synaptic intermingling of electrical and chemical synapse proteins. Taken together, these results reveal a new complexity of electrical synapse molecular diversity and highlight a novel overlap between chemical and electrical synapse proteomes. Moreover, human homologs of the electrical synapse proteins are associated with autism, epilepsy, and other neurological disorders, providing a novel framework towards understanding neuro-atypical states.

neuroscience↗

bioRxiv2024

Neurovascular Impulse Response Function (IRF) during spontaneous activity differentially reflects intrinsic neuromodulation across cortical regions

Ascending neuromodulatory projections from deep brain nuclei generate internal brain states that differentially engage specific neuronal cell types. Because neurovascular coupling is cell-type specific and neuromodulatory transmitters have vasoactive properties, we hypothesized that the impulse response function (IRF) linking spontaneous neuronal activity with hemodynamics would depend on neuromodulation. To test this hypothesis, we used optical imaging to measure (1) release of neuromodulatory transmitters norepinephrine (NE) or acetylcholine (ACh), (2) Ca2+ activity of local cortical neurons, and (3) changes in hemoglobin concentration and oxygenation across the dorsal surface of cerebral cortex during spontaneous neuronal activity in awake mice. A canonical convolution model with a global, stationary IRF (i.e., the convolution kernel) describing evolution of total hemoglobin (HbT, reflective of dilation dynamics) with respect to Ca2+, resulted in a poor fit to the data. However, the HbT time-course was well predicted, pixel-by-pixel, by a weighted sum of Ca2+ and NE time-courses. Consistent with this result, modeling HbT as a weighted sum of stationary Ca2+ - and NE-specific IRFs (IRFCa2+ and IRFNE) convolved with the respective time-courses dramatically improved the fit compared to the global IRF. IRFCa2+ and IRFNE, estimated from the data, were positive and negative, respectively. In contrast to NE, ACh was largely redundant with Ca2+ and therefore did not improve HbT estimation. Because NE covaried with arousal, we observed instances of the diminished hemodynamic coherence between cortical regions during high arousal despite coherent behavior of the underlying neuronal Ca2+ activity. We conclude that while neurovascular coupling with respect to neuronal Ca2+ is a dynamic and seemingly complex phenomenon, hemodynamic fluctuations can be captured by a simple linear model with stationary IRFs with respect to the underlying dilatory and constrictive forces. In the current study, these forces were captured by the positive IRFCa2+ (dilation) and negative IRFNE (constriction). Without accounting for NE neuromodulation and the associated vasoconstriction, diminished hemodynamic coherence, commonly referred to as "functional (dys)connectivity" in BOLD fMRI studies, can be falsely interpreted as neuronal desynchronizations.

neuroscience↗

bioRxiv2023

Widefield in vivo imaging system with two fluorescence and two reflectance channels, a single sCMOS detector, and shielded illumination

SignificanceWidefield microscopy of the entire dorsal part of mouse cerebral cortex enables large-scale ("mesoscopic") imaging of different aspects of neuronal activity with spectrally compatible fluorescent indicators as well as hemodynamics via oxy- and deoxyhemoglobin absorption. Versatile and cost-effective imaging systems are needed for large-scale, color-multiplexed imaging of multiple fluorescent and intrinsic contrasts. AimDevelop a system for mesoscopic imaging of two fluorescent and two reflectance channels. ApproachExcitation of red and green fluorescence is achieved through epi-illumination. Hemoglobin absorption imaging is achieved using 525- and 625-nm LEDs positioned around the objective lens. An aluminum hemisphere placed between objective and cranial window provides diffuse illumination of the brain. Signals are recorded sequentially by a single sCMOS detector. ResultsWe demonstrate performance of our imaging system by recording large-scale spontaneous and stimulus-evoked neuronal, cholinergic, and hemodynamic activity in awake head-fixed mice with a curved "crystal skull" window expressing the red calcium indicator jRGECO1a and the green acetylcholine sensor GRABACh3.0. Shielding of illumination light through the aluminum hemisphere enables concurrent recording of pupil diameter changes. ConclusionsOur widefield microscope design with single camera can be used to acquire multiple aspects of brain physiology and is compatible with behavioral readouts of pupil diameter.

neuroscience↗

bioRxiv2023

Global meta-analysis reveals overall benefits of silvopastoral systems for biodiversity

Domestic livestock grazing accounts for roughly one quarter of the worlds terrestrial surface and is a leading driver of biodiversity loss. Yet, it also provides a critical livelihood for nearly one billion smallholder farmers, creating a paradox that highlights the need for conservation strategies to balance human and ecological needs. Silvopastoral systems (SPS) integrate trees with livestock pastures, offering a promising solution to boost livestock productivity while safeguarding natural areas and biodiversity. However, evidence for the biodiversity benefits provided by SPS is limited to studies focusing on specific geographic regions or taxa. Through a global meta-analysis of 45 studies spanning 15 countries, four biogeographic regions, and seven taxa, we provide the first quantitative synthesis evaluating how SPS affect biodiversity and community stability relative to treeless pastures and natural forests. Overall, we show that SPS harbor higher levels of biodiversity (i.e., richness, abundance, and diversity) and stability than treeless pastures, and perform comparably to nearby forests. However, variations exist across regions and taxa, with the strongest positive responses in tropical dry regions and for low-mobility taxa like invertebrates and plants. Mammals, birds, and soil microorganisms, on the other hand, showed no significant biodiversity differences between treeless pastures and SPS. Thus, integrating SPS and protected areas as complementary components of a multifunctional landscape will be key to halting multi-taxa biodiversity loss and building sustainable livestock systems. Our findings support the conservation potential of SPS, while underscoring the need for strategic implementation to maximize benefits for biodiversity conservation.

ecology↗

bioRxiv2022

ZO1 scaffold isoforms differentially contribute to electrical synapse formation

Electrical synapses are neuronal gap junction (GJ) channels associated with a macromolecular complex called the electrical synapse density (ESD), which regulates development and dynamically modifies electrical transmission. However, the proteomic makeup and molecular mechanisms utilized by the ESD that direct electrical synapse formation are not well understood. Using the Mauthner cell of zebrafish as a model, we previously found that the intracellular scaffolding protein ZO1b is a member of the ESD, localizing postsynaptically, where it is required for GJ channel localization, electrical communication, neural network function, and behavior. Here, we show that the complexity of the ESD is further diversified by the genomic structure of the ZO1b gene locus. The ZO1b gene is alternatively initiated at three transcriptional start sites resulting in isoforms with unique N-termini that we call ZO1b-Alpha, -Beta, and - Gamma. We demonstrate that ZO1b-Beta and ZO1b-Gamma are broadly expressed throughout the nervous system and localize to electrical synapses. By contrast, ZO1b-Alpha is expressed mainly non-neuronally and is not found at synapses. We generate mutants in all individual isoforms, as well as double mutant combinations in cis on individual chromosomes, and find that ZO1b-Beta is necessary and sufficient for robust GJ channel localization. ZO1b-Gamma, despite its localization to the synapse, plays an auxiliary role in channel localization. This study expands the notion of molecular complexity at the ESD, revealing that an individual genomic locus can contribute distinct isoforms to the macromolecular complex at electrical synapses. Further, independent scaffold isoforms have differential contributions to developmental assembly of the interneuronal GJ channels. We propose that ESD molecular complexity arises both from the diversity of unique genes and from distinct isoforms encoded by single genes. Overall, ESD proteomic diversity is expected to have critical impacts on the development, structure, function, and plasticity of electrical transmission.

neuroscience↗

bioRxiv2022

Common facultative endosymbionts do not influence sensitivity of cereal aphids to pyrethroids

O_LICereal aphids, including the bird cherry-oat aphid, Rhopalosiphum padi, and the grain aphid, Sitobion avenae, can transmit viruses that significantly reduce crop yields. To mitigate against yield losses, insecticides are routinely used to manage aphid populations. C_LIO_LIAphids can form relationships with endosymbionts that confer fitness benefits or consequences to the aphid. Recent artificial inoculation experiments indicate that endosymbionts could increase aphid susceptibility to insecticides, but this has not been explored using aphid populations naturally infected with endosymbionts. C_LIO_LIHere, we sampled aphids from an important cereal production region in Lower Saxony, Germany. We characterised the endosymbiont profile of these aphid populations and conducted pyrethroid dose-response assays to test the hypothesis that facultative endosymbionts increase aphid susceptibility to insecticides. C_LIO_LIWe find that the level of insecticide susceptibility is highly variable in S. avenae and we identify populations that are sensitive and tolerant to pyrethroids, including populations collected from the same field. For R. padi, we find evidence for decreased sensitivity to pyrethroids, representing the first report of reduced sensitivity to pyrethroids in R. padi sampled from Central Europe. C_LIO_LIWe detected high endosymbiont infection frequencies in the aphid populations. 84% of aphids carry one facultative endosymbiont and 9% of aphids carry two facultative endosymbionts. We detected associations with Regiella insecticola, Fukatsia symbiotica, and Hamiltonella defensa. However, we do not identify a link between endosymbiont infection and insecticide susceptibility, indicating that other factors may govern the development of insecticide resistance and the need for alternative management strategies. C_LI

zoology↗

bioRxiv2022

Neurobeachin controls the asymmetric subcellular distribution of electrical synapse proteins

The subcellular positioning of synapses and their specialized molecular compositions form the fundamental basis of neural circuits. Like chemical synapses, electrical synapses are constructed from an assortment of adhesion, scaffolding, and regulatory molecules, yet little is known about how these molecules localize at specified subcellular neuronal compartments. Here we investigated the relationship between the autism- and epilepsy-associated gene Neurobeachin, neuronal gap junction channelforming Connexins, and the scaffold ZO1. Using the zebrafish Mauthner circuit we found Neurobeachin localizes to the electrical synapse independent of ZO1 and Connexins. By contrast, we show Neurobeachin is required postsynaptically for the robust localization of ZO1 and Connexins. We demonstrate Neurobeachin binds ZO1 but not Connexins. Finally, we find Neurobeachin is required to restrict postsynaptic electrical synapse proteins to dendrites. These findings reveal a mechanism for the asymmetric synaptic localization of electrical synapse components providing a basis for the subcellular specialization of neuronal gap junctions.

neuroscience↗

bioRxiv2022

Types of cis- and trans-gene regulation of expression quantitative trait loci across human tissues

Expression quantitative trait loci (eQTLs) have been identified for most genes in the human genome across tissues and cell types. While most of the eQTLs are near the associated genes, some can be far away or on different chromosomes, with the regulatory mechanisms largely unknown. Here, we study cis- and trans-regulation by eQTLs on protein-coding genes and long noncoding RNAs (lncRNAs) across nearly 50 tissues and cell types. Specifically, we constructed trios consisting of an eQTL, its cis-gene and trans-gene and inferred the regulatory relationships with causal network inference. We identify multiple types of regulatory networks for trios: across all the tissues, more than half of the trios are inferred to be conditionally independent, where the two genes are conditionally independent given the genotype of the eQTL (gene 1 [<-] eQTL [->] gene 2). Around 1.5% of the trios are inferred to be mediation (eQTL [->] mediator [->] target), around 1.3% fully connected among the three nodes, and just a handful v-structures (eQTL [->] gene 1 [<-] gene 2). Unexpectedly, across the tissues, on average more than half of the mediation trios have the trans-gene as the mediator. Most of the mediators (cis and trans) are tissue specific, and cis-gene mediators are significantly enriched for protein-coding genes, whereas trans-gene mediators have a similar distribution of protein-coding genes and lncRNAs to the whole genome.

genomics↗

bioRxiv2021

A dose-sensitive OGT-TET3 complex is necessary for normal Xist RNA distribution and function

Female (XX) mouse embryonic stem cells (mESCs) differ from their male (XY) counterparts because they have lower levels of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC). This difference in DNA modifications is a result of having two X chromosomes (Xs), both of which are active at this developmental stage. We identified an X-linked gene, Ogt, that controls levels of 5mC and 5hmC in mESCs. OGT is a post-translational modification enzyme and we identified the 5-methylcytosine dioxygenase TET3 as an OGT target that is differentially modified in XX and XY mESCs. In addition to influencing 5mC and 5hmC abundance, OGT dose also controls TET3 and OGT distribution. OGT and TET3 are predominantly nuclear in XX mESCs and cytoplasmic in XY mESCs. Furthermore, these proteins are present in different complexes in XX and XY mESCs. Mutational analysis revealed that TET3 determines the XX-specific abundance of 5mC and 5hmC in mESCs. While TET3 null XX mESCs exhibited modest changes in gene expression, there were substantial alterations upon differentiation into epiblast-like cells (mEpiLCs). In addition, these TET3 null XX mESCs did not undergo X-chromosome inactivation (XCI) when differentiated. These data suggest that an X-dose sensitive complex containing OGT and TET3 regulates cytosine modifications and XCI.

genetics↗

bioRxiv2020

Electrical synaptic transmission requires a postsynaptic scaffolding protein

Electrical synaptic transmission relies on neuronal gap junctions containing channels constructed by Connexins. While at chemical synapses neurotransmitter-gated ion channels are critically supported by scaffolding proteins, it is unknown if channels at electrical synapses require similar scaffold support. Here we investigated the functional relationship between neuronal Connexins and Zonula Occludens 1 (ZO1), an intracellular scaffolding protein localized to electrical synapses. Using model electrical synapses in zebrafish Mauthner cells, we demonstrated that ZO1 is required for robust synaptic Connexin localization, but Connexins are dispensable for ZO1 localization. Disrupting this hierarchical ZO1/Connexin relationship abolishes electrical transmission and disrupts Mauthner-cell-initiated escape responses. We found that ZO1 is asymmetrically localized exclusively postsynaptically at neuronal contacts where it functions to assemble intercellular channels. Thus, forming functional neuronal gap junctions requires a postsynaptic scaffolding protein. The critical function of a scaffolding molecule reveals an unanticipated complexity of molecular and functional organization at electrical synapses.

neuroscience↗

bioRxiv2020

Reducing ecological complexity using the archetype approach - an application to natural pest control

Natural control of crop pests has the potential to complement or replace intensive agricultural practices, but its mainstream application requires reliable predictions in diverse socioecological settings. In lack of a widely accepted model of natural pest control, we review existing modelling approaches and critically examine their potential to provide understanding and predictions across agricultural landscapes. Models that explicitly represent the underlying mechanisms are better positioned to represent the diversity and context sensitivity of natural pest control than correlative models. Such mechanistic models have used diverse techniques to represent crop-pest-enemy combinations at various spatiotemporal scales. However, certain regions of the world and socioeconomic aspects of natural pest control are underrepresented, while modelling approaches are restricted by a fundamental trade-off between generality and realism. We propose that modelling natural pest control across agroecosystems requires a framework of context-specific generalizations, based on empirical evidence and theoretical expectations. Reviewed models of natural pest control indicate potential attributes of such a general predictive framework.

ecology↗

bioRxiv2019

Kirrel3-mediated synapse formation is attenuated by disease-associated missense variants

Missense variants in Kirrel3 are repeatedly identified as risk factors for autism spectrum disorder and intellectual disability but it has not been reported if or how these variants disrupt Kirrel3 function. Previously, we studied Kirrel3 loss-of-function using knockout mice and showed that Kirrel3 is a synaptic adhesion molecule necessary to form one specific type of hippocampal synapse in vivo. Here, we developed a new gain-of-function assay for Kirrel3 and find that wild-type Kirrel3 induces synapse formation selectively between Kirrel3-expressing cells via homophilic, trans-cellular binding. We tested six disease-associated Kirrel3 missense variants and find that five attenuate this synaptogenic function. All variants tested traffic to the cell surface and localize to synapses similar to wild-type Kirrel3. Two tested variants lack homophilic trans-cellular binding, which likely accounts for their reduced synaptogenic function. Interestingly, we also identified variants that bind in trans but cannot induce synapses, indicating Kirrel3 trans-cellular binding is necessary but not sufficient for its synaptogenic function. Collectively, these results suggest Kirrel3 functions as a synaptogenic, cell-recognition molecule, and this function is attenuated by missense variants associated with autism spectrum disorder and intellectual disability. Thus, we provide critical insight to Kirrel3 function in typical brain development and the consequences of missense variants associated with autism spectrum disorder and intellectual disability. SIGNIFICANCE STATEMENTHere, we advance our understanding of mechanisms mediating target-specific synapse formation by providing evidence that Kirrel3 trans-cellular interactions mediate contact recognition and signaling to promote synapse development. Moreover, this is the first study to test the effects of disease-associated Kirrel3 missense variants on synapse formation, and thereby, provides a framework to understand the etiology of complex neurodevelopmental disorders arising from rare missense variants in synaptic genes.

neuroscience↗

bioRxiv2019

WHO child growth standards for Pygmies: one size fits all?

BackgroundAfrican Pygmies exhibit a unique, genetically determined child growth dynamics and adult stature but the impact on assessing undernutrition remains unknown. Baka Pygmy health is highly compromised compared to sympatric populations. Evaluating child undernutrition is an important step to address this health quandry. We estimate stunting and wasting in Cameroons Baka children and investigate the applicability of the standards for Pygmy people.\n\nMethodsAnthropometric and health data from 685 2-to12 year old children were collected at 25 health centres in southern Cameroon. Growth was analysed using both, WHO Child Growth Standards and the population itself as reference to define frequencies of stunting, wasting and obesity.\n\nFindingsBaka children revealed with 68.4% the highest recorded level globally of stunting relative to the WHO child growth standard in 2-to-4 year olds. Wasting was at 8.2% in the upper third range in Sub-Saharan Africa. Obesity was with 6.5% similar to wasting, but no comparable data have been published for Sub-Saharan Africa. When referenced to the Baka population itself, values for stunting were dramatically lower at 1.0% and 2.9% for 2-to-4 and 5-to-12 year olds, respectively. Wasting was also lower at 2.8% and 1.8% and was exceeded by obesity at 3.4% and 3.5%, respectively. Brachial perimeters and oedemas indicated rare severe malnutrition (< 2%) whilst moderate and severe anaemia were frequent (26.6% and 3.3%, respectively).\n\nInterpretationWHO child growth standards for stunting are clearly not applicable to Pygmies thus contradicting the widespread emphasis of their ethnicity-independent applicability. The inferred values for wasting and obesity are also difficult to interpret and are likely overestimated by the WHO criteria. To achieve UN Sustainable Development Goals and to fulfil our humanitarian responsibility for fellow man, we recommend that Pygmy specific growth standards are developed for the genetically differing Pygmy tribes.

scientific communication and education↗