Ancestral chromosomal signatures of Paenungulata (Afroteria) reveal the karyotype of Amazonian manatee (Trichechus inunguis, Sirenia: Trichechidae) as the oldest among American manatees.

BACKGROUND: Chromosomal painting in manatees has clarified questions about the rapid evolution of sirenians within the Paenungulata clade. Further cytogenetic studies in Afrotherian species may provide information about their evolutionary dynamics, revealing important insights into the ancestral karyotype in the clade representatives. The karyotype of Trichechus inunguis (TIN, Amazonian manatee) was investigated by chromosome painting, using probes from Trichechus manatus latirostris (TML, Florida manatee) to analyze the homeologies between these sirenians. RESULTS: A high similarity was found between these species, with 31 homologous segments in TIN, nineteen of which are whole autosomes, besides the X and Y sex chromosomes. Four chromosomes from TML (4, 6, 8, and 9) resulted in two hybridization signals, totaling eight acrocentrics in the TIN karyotype. This study confirmed in TIN the chromosomal associations of Homo sapiens (HSA) shared in Afrotheria, such as the 5/21 synteny, and in the Paenungulata clade with the syntenies HSA 2/3, 8/22, and 18/19, in addition to the absence of HSA 4/8 common in eutherian ancestral karyotype (EAK). CONCLUSIONS: TIN shares more conserved chromosomal signals with the Paenungulata Ancestral Karyotype (APK, 2n = 58) than Procavia capensis (Hyracoidea), Loxodonta africana (Proboscidea) and TML (Sirenia), where TML presents less conserved signals with APK, demonstrating that its karyotype is the most derived among the representatives of Paenungulata. The chromosomal changes that evolved from APK to the T. manatus and T. inunguis karyotypes (7 and 4 changes, respectively) are more substantial within the Trichechus genus compared to other paenungulates. Among these species, T. inunguis presents conserved traits of APK in the American manatee genus. Consequently, the karyotype of T. manatus is more derived than that of T. inunguis.

Karyotypes of Manatees: New Insights into Hybrid Formation (Trichechus inunguis × Trichechus m. manatus) in the Amazon Estuary.

Great efforts have been made to preserve manatees. Recently, a hybrid zone was described between Trichechus inunguis (TIN) and the Trichechus manatus manatus (TMM) in the Amazon estuary. Cytogenetic data on these sirenians are limited, despite being fundamental to understanding the hybridization/introgression dynamics and genomic organization in Trichechus. We analyzed the karyotype of TMM, TIN, and two hybrid specimens ("Poque" and "Vitor") by classical and molecular cytogenetics. G-band analysis revealed that TMM (2n = 48) and TIN (2n = 56) diverge by at least six Robertsonian translocations and a pericentric inversion. Hybrids had 2n = 50, however, with Autosomal Fundamental Number (FNA) = 88 in "Poque" and FNA = 74 in "Vitor", and chromosomal distinct pairs in heterozygous; additionally, "Vitor" exhibited heteromorphisms and chromosomes whose pairs could not be determined. The U2 snDNA and Histone H3 multi genes are distributed in small clusters along TIN and TMM chromosomes and have transposable Keno and Helitron elements (TEs) in their sequences. The different karyotypes observed among manatee hybrids may indicate that they represent different generations formed by crossing between fertile hybrids and TIN. On the other hand, it is also possible that all hybrids recorded represent F1 and the observed karyotype differences must result from mechanisms of elimination.

Novel insights on aquatic mammal MHC evolution: Evidence from manatee DQB diversity.

The low diversity in marine mammal major histocompatibility complex (MHC) appears to support the hypothesis of reduced pathogen selective pressure in aquatic systems compared to terrestrial environments. However, the lack of characterization of the aquatic and evolutionarily distant Sirenia precludes drawing more generalized conclusions. Therefore, we aimed to characterize the MHC DQB diversity of two manatee species and compare it with those reported for marine mammals. Our results identified 12 and 6 alleles in T. inunguis and T. manatus, respectively. Alleles show high rates of nonsynonymous substitutions, suggesting loci are evolving under positive selection. Among aquatic mammals, Pinnipeda DQB had smaller numbers of alleles, higher synonymous substitution rate, and a dN/dS ratio closer to 1, suggesting it may be evolving under more relaxed selection compared to fully aquatic mammals. This contradicts one of the predictions of the hypothesis that aquatic environments impose reduced pathogen pressure to mammalian immune system. These results suggest that the unique evolutionary trajectories of mammalian MHC may impose challenges in drawing ecoevolutionary conclusions from comparisons across distant vertebrate lineages.

TLR4 and TLR8 variability in Amazonian and West Indian manatee species from Brazil.

Amazonian (Trichechus inunguis) and West Indian (Trichechus manatus) manatees are aquatic mammals vulnerable to extinction found in the Amazon basin and the coastal western Atlantic. Toll-like receptors (TLR) play a key role in recognizing pathogen-associated molecular patterns using leucine-rich repeats (LRRs). We described the diversity of TLR4 and TLR8 genes in these two species of manatee. Amazonian manatee showed seven SNPs in TLR4 and the eight in TLR8, while West Indian manatee shared four and six of those SNPs, respectively. In our analysis, TLR4 showed one non-conservative amino acid replacement substitution in LRR7 and LRR8, on the other hand, TLR8 was less variable and showed only conserved amino acid substitutions. Selection analysis showed that only one TLR4 site was subjected to positive selection and none in TLR8. TLR4 in manatees did not show any evidence of convergent evolution compared to species of the cetacean lineage. Differences in TLR4 and TLR8 polymorphism may be related to distinct selection by pathogens, population reduction of West Indian manatees, or an expected consequence of population expansion in Amazonian manatees. Future studies combining pathogen association and TLR polymorphism may clarify possible roles of these genes and be used for conservation purposes of manatee species.

Morphometric and morphological characterization of Trypanosoma sp. (Kinetoplastea: Trypanosomatidae) hemoparasite of Crested Eagle, Morphnus guianensis in the Brazilian Amazon.

Morphnus guianensis is a species belonging to the Accipitridae family classified as almost threatened by the International Union for Conservation of Nature (IUCN). Trypanosomes are flagellated protozoa that carry out their life cycle in the circulatory system of vertebrate hosts and within the digestive tract of invertebrate hosts. This study recorded Trypanosoma sp. parasitizing M. guianensis in the Brazilian Amazon, providing data related to the morphology and morphometry of the trypomastigote forms of peripheral blood of this bird. The mean values of the measured morphological regions were used to compare morphometric similarity with morphotypes described for Trypanosoma sp. through the Bray-Curtis method and, after statistical analysis, the dendrogram was generated from the morphological similarities with a similarity greater than 95% with T. paddae described for different hosts in different geographical regions.

Tick fauna of wild animals received and attended at the Santarém Zoological Park, western Pará State, Brazil / Ixodofauna de animais silvestres resgatados e atendidos no Jardim Zoológico de Santarém, oeste do estado do Pará, Brasil

ABSTRACT: Ticks are known worldwide for parasitizing a number of wild hosts. However, few studies have been conducted on ticks in zoos in Brazil. The objective of the present study was to collect, identify, and report the parasitic tick fauna found on wild Amazon animals received and attended at the Santarém Zoological Park from September 2004 to September 2013. In all, 56 animals, including 26 mammals and 30 reptiles, were sampled, from which 1172 ticks were collected and identified, comprising 862 adults, 284 nymphs, and 26 larvae. Nymphs of Amblyomma geayi on three-toed sloth (Bradypus tridactylus), adults of Amblyomma longirostre on black dwarf porcupine (Coendou nycthemera), and nymphs of Amblyomma naponense on southern tamandua (Tamandua tetradactyla) were identified for the first time in the country in the present study. Although, the North region is the largest among the five Brazilian regions, this is the first study conducted with ticks and animals attended in a zoo in the Brazilian Amazon.

RESUMO: Carrapatos são conhecidos mundialmente por parasitar uma série de hospedeiros silvestres. No entanto, poucos são os estudos realizados com carrapatos em Jardins Zoológicos no Brasil. O presente estudo objetivou coletar, identificar e relatar a fauna parasitária de carrapatos de animais silvestres Amazônicos resgatados e atendidos no Zoológico de Santarém, durante o período de setembro de 2004 a setembro de 2013. Ao todo foram amostrados 56 animais incluindo 26 mamíferos e 30 répteis, no qual foram coletados e identificados 1172 carrapatos distribuídos em 862 adultos, 284 ninfas e 26 larvas. Foram identificados de forma inédita no presente estudo ninfas de Amblyomma geayi em preguiça-de-três-dedos (Bradypus tridactylus), adultos de Amblyomma longirostre em ouriço-cacheiro (Coendou nycthemera), além de ninfas de Amblyomma naponense em tamanduá-mirim (Tamandua tetradactyla) no país. Apesar da região Norte ser a maior entre as cinco regiões brasileiras, este é o primeiro trabalho realizado com animais atendidos em Zoológico utilizando os carrapatos como alvo de estudo na Amazônia nacional.

Variáveis hematológicas e bioquímicas de peixe-boi da Amazônia (Trichechus inungui) jovens / Hematological and biochemical variables of young Amazonian manatee (Trichechus inungui)

Peixes-boi da Amazônia (Trichechus inungui) jovens são frequentemente encontrados e resgatados de rios, no entanto para avaliar e monitorar o estado de saúde desses animais é necessário conhecer os valores de referência das variáveis hematológicas e bioquímicas nessa faixa etária. O trabalho objetivou determinar os valores hematológicos e bioquímicos de peixes-boi da amazônia jovens e saudáveis, mantidos em cativeiros. Foram coletadas 20 amostras sanguíneas de peixes-boi para a realização do hemograma e bioquímica. Os valores médios e desvio padrão das variáveis hematológicas foram: volume globular, 37±4%; eritrócitos, 4,4±0,35x106/µL; hemoglobina, 12,5±1,6g/dL; volume corpuscular médio (VCM), 85,33±4,28fL; hemoglobina corpuscular media (HCM), 28,29±1,39pg; e concentração de hemoglobina corpuscular media (CHCM), 33,13±0,20%, leucócitos totais, 9.080±1.868x103/µL; segmentados, 5.078±1.044,24x103/µL; linfócitos 3.556±1,063x103/µL; eosinófilos, 288± 215,51x103/µL; e monócitos, 165± 114,11x103/µL. A média e o intervalo (mínimo e máximo) das variáveis bioquímicas foram: creatinina quinase (CK), 112,53 (50,10-295,80) U/L; aspartato aminotransferase (AST), 6,02 (2,80-10,20) U/L; gama glutamiltransferase (GGT), 25,24 (10,80-45,30) U/L; fosfatase alcalina (FA), 98,73 (14,66-198,30) U/L; proteína total, 6,12 (5,38-7,10) g/dL; albumina, 4,23 (3,50-5,00) g/dL; colesterol, 310,13 (144-518) mg/dL; triglicerídeos, 127,98 (57,50-213,50) mg/dL; glicose, 43,63 (24,50-73,80) mg/dL; ureia, 30,21 (14,30-54,25); creatinina, 1,34 (0,93-1,76) mg/dL; cálcio, 10,08 (9,25-11,10) mg/dL; e fósforo inorgânico; 6,50 (4,10-8,80) mg/dL. No presente trabalho foi possível determinar valores hematológicos e bioquímicos de peixes-boi da Amazônia (Trichechus inungui) jovens, mantidos em cativeiro, os quais podem ser utilizados como referência para animais em cativeiro e de vida livre, mantidos em condições ambientais, e de manejo, semelhantes.(AU)

Amazonian manatee (Trichechus inunguis) young are often found and rescued from rivers, however to assess and monitor the health status of the animals is necessary to know the reference values of hematological and biochemical variables in this age group. The study aimed to determine hematological and biochemical values of healthy young manatee amazonian, kept in captivity. Were collected 20 blood samples of manatees in captivity for the hematological and biochemical evaluation. Means and standard deviations of hematological variables were: pack cell volume, 37±4%; red blood cell, 4.4±0.35x106/µL; hemoglobin, 12.5±1.6g/dL; mean corpuscular volume (VCM), 85.33±4.28fL; mean corpuscular hemoglobin (HCM), 28.29±1.39pg; and mean corpuscular hemoglobin concentration (CHCM), 33.13±0.20%. White blood cell, 9,080±1,868x103/µL; neutrofil, 5,078±1,044.24x103/µL; lymphocytes 3,556±1,063x103/µL; eosinophil, 288±215.51x103/µL; and monocyte, 1.65±114.11x103/µL. Means and ranges (minimum and maximum) of values for the analytes were: creatine kinase (CK), 112.53 (50.10-295.80) U/L; aspartate aminotransferase (AST), 6.02 (2.80-10.20) U/L; γ-glutamyltransferase (GGT), 25.24 (10.80-45.30) U/L; alkaline phosphatase (FA), 98.73 (14.66-198.30) U/L; total protein, 6.12 (5.38-7.10) g/dL; albumin, 4.23 (3.50-5.00) g/dL; cholesterol, 310.13 (144-518) mg/dL; triglycerides, 127.98 (57.50-213.50) mg/dL; glucose, 43.63 (24.50-73.80) mg/dL; urea, 30.21 (14.30-54.25); creatinine, 1.34 (0.93-1,76) mg/dL; calcium, 10.08 (9.25-11.10) mg/dL; and inorganic phosphorum, 6.50 (4.10-8.80) mg/dL. In the present study we determined hematological and biochemical values of manatees Amazonian (Trichechus inunguis) young held in captivity, which can be used as a reference for animals in bondage and free life, kept under similar ambient conditions, and management similar.(AU)