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Lactase persistence (LP), the continued expression of lactase into adulthood, is the most strongly selected single gene trait over the last 10,000 years in multiple human populations. It has been posited that the primary allele causing LP among Eurasians, rs4988235-A [1], only rose to appreciable frequencies during the Bronze and Iron Ages [2, 3], long after humans started consuming milk from domesticated animals. This rapid rise has been attributed to an influx of people from the Pontic-Caspian steppe that began around 5,000 years ago [4, 5]. We investigate the spatiotemporal spread of LP through an analysis of 14 warriors from the Tollense Bronze Age battlefield in northern Germany (∼3,200 before present, BP), the oldest large-scale conflict site north of the Alps. Genetic data indicate that these individuals represent a single unstructured Central/Northern European population. We complemented these data with genotypes of 18 individuals from the Bronze Age site Mokrin in Serbia (∼4,100 to ∼3,700 BP) and 37 individuals from Eastern Europe and the Pontic-Caspian Steppe region, predating both Bronze Age sites (∼5,980 to ∼3,980 BP). We infer low LP in all three regions, i.e., in northern Germany and South-eastern and Eastern Europe, suggesting that the surge of rs4988235 in Central and Northern Europe was unlikely caused by Steppe expansions. We estimate a selection coefficient of 0.06 and conclude that the selection was ongoing in various parts of Europe over the last 3,000 years.Naked mole-rats are highly vocal, eusocial, subterranean rodents with, counterintuitively, poor hearing. The causes underlying their altered hearing are unknown. Moreover, whether altered hearing is degenerate or adaptive to their unique lifestyles is controversial. We used various methods to identify the factors contributing to altered hearing in naked and the related Damaraland mole-rats and to examine whether these alterations result from relaxed or adaptive selection. Remarkably, we found that cochlear amplification was absent from both species despite normal prestin function in outer hair cells isolated from naked mole-rats. Instead, loss of cochlear amplification appears to result from abnormal hair bundle morphologies observed in both species. By exploiting a well-curated deafness phenotype-genotype database, we identified amino acid substitutions consistent with abnormal hair bundle morphology and reduced hearing sensitivity. Amino acid substitutions were found in unique groups of six hair bundle link proteins. Molecular evolutionary analyses revealed shifts in selection pressure at both the gene and the codon level for five of these six hair bundle link proteins. Substitutions in three of these proteins are associated exclusively with altered hearing. Altogether, our findings identify the likely mechanism of altered hearing in African mole-rats, making them the only identified mammals naturally lacking cochlear amplification. Moreover, our findings suggest that altered hearing in African mole-rats is adaptive, perhaps tailoring hearing to eusocial and subterranean lifestyles. Finally, our work reveals multiple, unique evolutionary trajectories in African mole-rat hearing and establishes species members as naturally occurring disease models to investigate human hearing loss.Accurate chromosome segregation during cell division critically depends on error correction of chromosome-spindle interactions and the spindle assembly checkpoint (SAC) [1-3]. The kinase MPS1 is an essential regulator of both processes, ensuring full chromosome biorientation before anaphase onset [3, 4]. To understand when and where MPS1 activation occurs and how MPS1 signaling is modulated during mitosis, we developed MPS1sen, a sensitive and specific FRET-based biosensor for MPS1 activity. By placing MPS1sen at different subcellular locations, we show that MPS1 activity initiates in the nucleus ∼9-12 min prior to nuclear envelope breakdown (NEB) in a kinetochore-dependent manner and reaches the cytoplasm at the start of NEB. MAPK inhibitor Soon after initiation, MPS1 activity increases with switch-like kinetics, peaking at completion of NEB. We further show that timing and extent of pre-NEB MPS1 activity is regulated by Aurora B and PP2A-B56. MPS1sen phosphorylation declines in prometaphase as a result of formation of kinetochore-microtubule attachments, reaching low but still detectable levels at metaphase. Finally, leveraging the sensitivity and dynamic range of MPS1sen, we show deregulated MPS1 signaling dynamics in colorectal cancer cell lines and tumor organoids with diverse genomic instability phenotypes.Experimental sleep-wake disruption in rodents and humans causally modulates β-amyloid (Aβ) dynamics (e.g., [1-3]). This leads to the hypothesis that, beyond cross-sectional associations, impaired sleep structure and physiology could represent prospective biomarkers of the speed with which Aβ accumulates over time. Here, we test the hypothesis that initial baseline measures of non-rapid eye movement (NREM) sleep slow-wave activity (SWA) and sleep quality (efficiency) provide future forecasting sensitivity to the rate of Aβ accumulation over subsequent years. A cohort of clinically normal older adults was assessed using objective sleep polysomnography in combination with longitudinal tracking of Aβ accumulation with [11C]PiB positron emission tomography (PET) imaging. Both the proportion of NREM SWA below 1 Hz and the measure of sleep efficiency predicted the speed (slope) of subsequent Aβ deposition over time, and these associations remained robust when taking into account additional cofactors of interest (e.g., age, sex, sleep apnea). link2 Moreover, these measures were specific, such that no other macro- and microphysiological architecture metrics of sleep demonstrated such sensitivity. Our data support the proposal that objective sleep markers could be part of a set of biomarkers that statistically forecast the longitudinal trajectory of cortical Aβ deposition in the human brain. Sleep may therefore represent a potentially affordable, scalable, repeatable, and non-invasive tool for quantifying of Aβ pathological progression, prior to cognitive symptoms of Alzheimer's disease (AD).Human speech shares a 3-8-Hz theta rhythm across all languages [1-3]. According to the frame/content theory of speech evolution, this rhythm corresponds to syllabic rates derived from natural mandibular-associated oscillations [4]. The underlying pattern originates from oscillatory movements of articulatory muscles [4, 5] tightly linked to periodic vocal fold vibrations [4, 6, 7]. link3 Such phono-articulatory rhythms have been proposed as one of the crucial preadaptations for human speech evolution [3, 8, 9]. However, the evolutionary link in phono-articulatory rhythmicity between vertebrate vocalization and human speech remains unclear. From the phonatory perspective, theta oscillations might be phylogenetically preserved throughout all vertebrate clades [10-12]. From the articulatory perspective, theta oscillations are present in non-vocal lip smacking [1, 13, 14], teeth chattering [15], vocal lip smacking [16], and clicks and faux-speech [17] in non-human primates, potential evolutionary precursors for speech rhythmicity [1, 13]. Notably, a universal phono-articulatory rhythmicity similar to that in human speech is considered to be absent in non-human primate vocalizations, typically produced with sound modulations lacking concomitant articulatory movements [1, 9, 18]. Here, we challenge this view by investigating the coupling of phonatory and articulatory systems in marmoset vocalizations. Using quantitative measures of acoustic call structure, e.g., amplitude envelope, and call-associated articulatory movements, i.e., inter-lip distance, we show that marmosets display speech-like bi-motor rhythmicity. These oscillations are synchronized and phase locked at theta rhythms. Our findings suggest that oscillatory rhythms underlying speech production evolved early in the primate lineage, identifying marmosets as a suitable animal model to decipher the evolutionary and neural basis of coupled phono-articulatory movements.The fluent production of a signed language requires exquisite coordination of sensory, motor, and cognitive processes. Similar to speech production, language produced with the hands by fluent signers appears effortless but reflects the precise coordination of both large-scale and local cortical networks. The organization and representational structure of sensorimotor features underlying sign language phonology in these networks remains unknown. Here, we present a unique case study of high-density electrocorticography (ECoG) recordings from the cortical surface of profoundly deaf signer during awake craniotomy. While neural activity was recorded from sensorimotor cortex, the participant produced a large variety of movements in linguistic and transitional movement contexts. We found that at both single electrode and neural population levels, high-gamma activity reflected tuning for particular hand, arm, and face movements, which were organized along dimensions that are relevant for phonology in sign language. Decoding of manual articulatory features revealed a clear functional organization and population dynamics for these highly practiced movements. Furthermore, neural activity clearly differentiated linguistic and transitional movements, demonstrating encoding of language-relevant articulatory features. These results provide a novel and unique view of the fine-scale dynamics of complex and meaningful sensorimotor actions.Social experiences greatly define subsequent social behavior. Lack of such experiences, especially during critical phases of development, can severely impede the ability to behave adequately in social contexts. To date, it is not well characterized how early-life social isolation leads to social deficits and impacts development. In many model species, it is challenging to fully control social experiences, because they depend on parental care. Moreover, complex social behaviors involve multiple sensory modalities, contexts, and actions. Hence, when studying social isolation effects, it is important to parse apart social deficits from general developmental effects, such as abnormal motor learning. Here, we characterized how social experiences during early development of zebrafish larvae modulate their social behavior at 1 week of age, when social avoidance reactions can be measured as discrete swim events. We show that raising larvae in social isolation leads to enhanced social avoidance, in terms of the distance at which larvae react to one another and the strength of swim movement they use. Specifically, larvae raised in isolation use a high-acceleration escape swim, the short latency C-start, more frequently during social interactions. These behavioral differences are absent in non-social contexts. By ablating the lateral line and presenting the fish with local water vibrations, we show that lateral line inputs are both necessary and sufficient to drive enhanced social avoidance reactions. Taken together, our results show that social experience during development is a critical factor in shaping mechanosensory avoidance reactions in larval zebrafish.
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