Abstract Hominin evolution is characterized by adaptive solutions often rooted in behavioral and cognitive changes. If balancing selection had an important and long-lasting impact on the evolution of these traits, it can be hypothesized that genes associated with them should carry an excess of shared polymorphisms (trans- SNPs) across recent Homo species. In this study, we investigate the role of balancing selection in human evolution using available exomes from modern (Homo sapiens) and archaic humans (H. neanderthalensis and Denisovan) for an excess of trans-SNP in two gene sets: one associated with the immune system (IMMS) and another one with behavioral system (BEHS). We identified a significant excess of trans-SNPs in IMMS (N=547), of which six of these located within genes previously associated with schizophrenia. No excess of trans-SNPs was found in BEHS, but five genes in this system harbor potential signals for balancing selection and are associated with psychiatric or neurodevelopmental disorders. Our approach evidenced recent Homo trans-SNPs that have been previously implicated in psychiatric diseases such as schizophrenia, suggesting that a genetic repertoire common to the immune and behavioral systems could have been maintained by balancing selection starting before the split between archaic and modern humans.
Abstract Domestication is of unquestionable importance to the technological revolution that has given rise to modern human societies. In this study, we analyzed the DNA and protein sequences of six genes of the oxytocin and arginine vasopressin systems (OXT-OXTR; AVP-AVPR1a, AVPR1b and AVPR2) in 40 placental mammals. These systems play an important role in the control of physiology and behavior. According to our analyses, neutrality does not explain the pattern of molecular evolution found in some of these genes. We observed specific sites under positive selection in AVPR1b (ω = 1.429, p = 0.001) and AVPR2 (ω= 1.49, p = 0.001), suggesting that they could be involved in behavior and physiological changes, including those related to the domestication process. Furthermore, AVPR1a, which plays a role in social behavior, is under relaxed selective constraint in domesticated species. These results provide new insights into the nature of the domestication process and its impact on the OXT-AVP system.
Abstract The FOXP subfamily is probably the most extensively characterized subfamily of the forkhead superfamily, playing important roles in development and homeostasis in vertebrates. Intrinsically disorder protein regions (IDRs) are protein segments that exhibit multiple physical interactions and play critical roles in various biological processes, including regulation and signaling. IDRs in proteins may play an important role in the evolvability of genetic systems. In this study, we analyzed 77 orthologous FOXP genes/proteins from Tetrapoda, regarding protein disorder content and evolutionary rate. We also predicted the number and type of short linear motifs (SLIMs) in the IDRs. Similar levels of protein disorder (approximately 70%) were found for FOXP1, FOXP2, and FOXP4. However, for FOXP3, which is shorter in length and has a more specific function, the disordered content was lower (30%). Mammals showed higher protein disorders for FOXP1 and FOXP4 than non-mammals. Specific analyses related to linear motifs in the four genes showed also a clear differentiation between FOXPs in mammals and non-mammals. We predicted for the first time the role of IDRs and SLIMs in the FOXP gene family associated with possible adaptive novelties within Tetrapoda. For instance, we found gain and loss of important phosphorylation sites in the Homo sapiens FOXP2 IDR regions, with possible implication for the evolution of human speech.
Abstract Oxytocin receptor (OXTR) and arginine vasopressin receptors (AVPR1a, AVPR1b, and AVPR2) are paralogous genes that emerged through duplication events; along the evolutionary timeline, owing to speciation, numerous orthologues emerged as well. In order to elucidate the evolutionary forces that shaped these four genes in placental mammals and to reveal specific aspects of their protein structures, 35 species were selected. Specifically, we investigated their molecular evolutionary history and intrinsic protein disorder content, and identified the presence of short linear interaction motifs. OXTR seems to be under evolutionary constraint in placental mammals, whereas AVPR1a, AVPR1b, and AVPR2 exhibit higher evolutionary rates, suggesting that they have been under relaxed or experienced positive selection. In addition, we describe here, for the first time, that the OXTR, AVPR1a, AVPR1b, and AVPR2 mammalian orthologues preserve their disorder content, while this condition varies among the paralogues. Finally, our results reveal the presence of short linear interaction motifs, indicating possible functional adaptations related to physiological and/or behavioral taxa-specific traits.
Abstract Tracheobronchial wash (TBW) is a method to recover cell samples from the airways. The cytology of TBW fluid is an important technique for the diagnosis of pulmonary diseases in horses. Excessive mucus in TBW may cause cell damage and morphological changes that hinder cell type recognition, resulting in a misdiagnosis. The aim of this study was to compare the results of differential cell count in a tracheobronchial wash of filtered and non-filtered samples. Endoscopy and TBW procedures were performed in thirty horses. Each TBW sample was split into two aliquots. Two groups were formed: non-filtrated aliquots (NF) and filtrated aliquots (F). The filtration was performed using a hydrophilic gauze pad. After centrifugation, the differential cell count was performed considering 300 nucleated cells. The filtrated aliquots results presented a significant increase of macrophages count and a significant decrease in neutrophils count comparing to the results of non-filtrated aliquots. These findings were consistent with results of filtered bronchoalveolar wash published studies. Therefore, the filtration of TBW is not an efficient method.
Resumo O lavado traqueobrônquico (LTB) é um método usado para recuperar uma amostra de células das vias respiratórias. A citologia do LTB é descrita como uma importante ferramenta no diagnóstico de doença pulmonar em equinos. O excesso de muco geralmente presente no LTB pode alterar a morfologia, dificultando a identificação dos tipos celulares e, por consequência, prejudicando a contagem diferencial de células e a interpretação diagnóstica. O objetivo deste trabalho foi verificar o efeito da filtração do LTB de equinos sobre a contagem diferencial de células na avaliação citológica do lavado traqueobrônquico. Foram utilizados 30 equinos que foram submetidos a coletas de amostras de LTB via endoscópio. De cada amostra obtida foi separada uma primeira alíquota não filtrada (NF). Uma segunda alíquota (F) foi obtida filtrando-se o LTB, utilizando-se uma compressa de gaze hidrófila. As alíquotas F e NF foram submetidas à citocentrifugação para contagem diferencial de 300 células nucleadas. Verificou-se um aumento significativo no percentual de macrófagos e redução significativa de neutrófilos nas amostras filtradas. As alterações observadas foram condizentes com achados de estudos prévios realizados em lavado broncoalveolar. Conclui-se que a filtração do LTB não é uma metodologia aconselhável, pois acarreta em alterações de contagem significativas nas proporções de importantes marcadores celulares de inflamação, podendo gerar possíveis erros de diagnóstico.
The use of determining the enzymatic activities in the posterior respiratory tract as a diagnostic tool has already been demonstrated in several species. In this context, this paper aims to determine the activity of alkaline phosphatase (ALP) in the bronchoalveolar lavage (BAL) of horses from the Military Police of the State of Rio de Janeiro, comparing healthy animals with asymptomatic carriers of an inflammatory airway disease (IAD). Twenty-eight adult male animals with no history of respiratory diseases in the last two months prior to the study were studied. Physical exam and blood laboratory test results (ALP, hematocrit, leukogram, total protein and plasma fibrinogen) were within physiological parameters. The equines were separated into two groups according to the results of the bronchoalveolar cytology. The determination of ALP was done by spectrophotometry with aliquots of the supernatant of the BAL preserved in liquid nitrogen. To estimate pulmonary epithelial lining fluid and ALP activity, correction of the dilution caused by the lavage was done. The horses with a cell type differential count compatible with IAD presented a lower ALP activity in BAL when compared to healthy animals, therefore this dosage can be used as a complement in the diagnosis of IAD.
A utilidade da determinação das atividades enzimáticas no trato respiratório posterior como ferramenta diagnóstica já foi demonstrada em várias espécies. Nesse contexto, este trabalho teve por objetivo determinar a atividade da Fosfatase Alcalina (FAL) no lavado broncoalveolar (LBA) de equinos da Polícia Militar do Estado do Rio de Janeiro, comparando animais sadios com portadores assintomáticos de doença inflamatória das vias aéreas (DIVA). Para tal, foram avaliados 28 animais adultos, machos, sem histórico de doença respiratória nos dois meses anteriores ao estudo, com os resultados dos exames físicos e laboratoriais (FAL sanguínea, hematócrito, leucograma, proteína total e fibrinogênio plasmáticos) dentro dos parâmetros fisiológicos. Os equinos foram divididos em dois grupos de acordo com o resultado da citologia broncoalveolar. A determinação da atividade da FAL foi realizada por meio de espectrofotometria a partir de alíquotas do sobrenadante do LBA preservadas em nitrogênio líquido. Para a estimativa do fluido epitelial pulmonar e da atividade da FAL neste, foi realizada a correção da diluição provocada pelo lavado. Os equinos com contagem diferencial de tipos celulares compatível com DIVA apresentaram atividade de FAL no LBA menor, quando comparados aos animais sadios, podendo essa dosagem ser utilizada como complementação do diagnóstico da DIVA.
Pulmonary inflammatory diseases have been observed in equine since their domestication. Non-infectious disease processes of the lower airways are amongst the most important diseases of the equine respiratory tract. This study aims to determine the cytology profile and effect of age on the evaluation of equine bronchoalveolar lavage (BAL) obtained from healthy animals and from horses with asymptomatic inflammatory airway disease (IAD). Thirty two horses, including 20 males and 12 females, without clinical signs of pulmonary disease and with age varying from 4 to 21 years, were assigned to two groups: 15 animals in the control group and 17 in the asymptomatic group. Groups were divided according to physical examination and mucous accumulation observed during tracheal endoscopy. The BAL results from healthy and asymptomatic horses were, respectively: 56.9% and 48.0% macrophages, 37.2% and 40.0% lymphocytes, 3.3% and 7.1% neutrophils, 1.7% and 1.4% mast cells, 0.3% and 0.7% eosinophils; 0,5% and 0.4% epithelial cells. When horses in the two groups were analyzed according to their age range, no differences were found. In conclusion, IAD in the asymptomatic group was significantly different from the control group. The asymptomatic horses presented a discrete infiltrate of neutrophils, which does not influence cytological evaluation of BAL.
Doenças inflamatórias pulmonares são observadas na espécie equina desde sua domesticação. Dentre as enfermidades de maior importância do trato respiratório equino, estão os distúrbios não infecciosos de vias aéreas posteriores. Este trabalho teve por objetivo determinar o perfil citológico e o efeito da idade na avaliação do lavado broncoalveolar (LBA) de equinos sadios e com Doença Inflamatória das Vias Aéreas (DIVA) assintomática. Foram utilizados 32 equinos adultos, aparentemente sadios, de ambos os sexos (20 machos e 12 fêmeas), com faixa etária média semelhante, sendo 15 animais do grupo controle e 17 animais do grupo doente assintomático. Os grupos foram estabelecidos segundo os critérios de GERBER et al. (2004) para acúmulo de muco traqueal após a realização de exames físicos diretos e endoscopia traqueal. Foi realizado o LBA e o percentual dos valores médios obtidos na análise citológica dos cavalos sadios e com DIVA assintomática foram, respectivamente: 56,9% e 48,0% de macrófagos, 37,2% e 40,0% de linfócitos, 3,3% e 7,1% de neutrófilos, 1,7% e 1,4% de mastócitos, 0,3% e 0,7% de eosinófilos; e 0,5% e 0,4% de células epiteliais. Concluiu-se que a DIVA nos animais integrantes do grupo doente assintomático caracterizou- se por um discreto infiltrado de neutrófilos e que a idade não influencia na avaliação citológica do LBA.
After a brief review of the most recent findings in the study of human evolution, an extensive comparison of the complete genomes of our nearest relative, the chimpanzee (Pan troglodytes), of extant Homo sapiens, archaic Homo neanderthalensis and the Denisova specimen were made. The focus was on non-synonymous mutations, which consequently had an impact on protein levels and these changes were classified according to degree of effect. A total of 10,447 non-synonymous substitutions were found in which the derived allele is fixed or nearly fixed in humans as compared to chimpanzee. Their most frequent location was on chromosome 21. Their presence was then searched in the two archaic genomes. Mutations in 381 genes would imply radical amino acid changes, with a fraction of these related to olfaction and other important physiological processes. Eight new alleles were identified in the Neanderthal and/or Denisova genetic pools. Four others, possibly affecting cognition, occured both in the sapiens and two other archaic genomes. The selective sweep that gave rise to Homo sapiens could, therefore, have initiated before the modern/archaic human divergence.