First Report of Eratyrus cuspidatus (Hemiptera: Reduviidae) Infected with Trypanosoma cruzi in Peridomestic Environment in Chiapas, Mexico.

Background: Triatomine bugs are natural vectors of Trypanosoma cruzi, which causes Chagas disease or American trypanosomiasis. The role of sylvatic triatomine species as vectors of T. cruzi in Mexico remains to be fully understood. Our research on the epidemiology of Chagas disease in Southeastern Mexico involved sampling triatomines in rural settings. Materials and Methods: A triatomine was collected in a peridomestic environment of a rural dwelling in the state of Chiapas. The triatomine was identified morphologically as an adult female Eratyrus cuspidatus Stal. Results: Microscopic analysis revealed flagellate forms of T. cruzi in the feces of the E. cuspidatus collected. This was confirmed by quantitative polymerase chain reaction. Amplification of the mini-exon gene showed that the T. cruzi infecting E. cuspidatus corresponded to lineage I. Conclusions: This is the first report from Mexico of E. cuspidatus found infected in a human dwelling, which represents an important adaptation process to inhabit human environments.

What Do You Need to Know before Studying Chagas Disease? A Beginner's Guide.

Chagas disease is one of the most important tropical infections in the world and mainly affects poor people. The causative agent is the hemoflagellate protozoan Trypanosoma cruzi, which circulates among insect vectors and mammals throughout the Americas. A large body of research on Chagas disease has shown the complexity of this zoonosis, and controlling it remains a challenge for public health systems. Although knowledge of Chagas disease has advanced greatly, there are still many gaps, and it is necessary to continue generating basic and applied research to create more effective control strategies. The aim of this review is to provide up-to-date information on the components of Chagas disease and highlight current trends in research. We hope that this review will be a starting point for beginners and facilitate the search for more specific information.

Mini-exon gene reveals circulation of TcI Trypanosomacruzi (Chagas, 1909) (Kinetoplastida, Trypanosomatidae) in bats and small mammals in an ecological reserve in southeastern Mexico.

A wide variety of mammals are involved in the sylvatic cycle of Trypanosomacruzi, the causative agent of Chagas disease. In many areas in Latin America where T.cruzi is endemic, this cycle is poorly known, and its main reservoirs have not been identified. In this study we analyzed T.cruzi infection in bats and other small mammals from an Ecological Reserve in southeastern Mexico. From January through March 2021, we captured wild individuals to extract cardiac and peripheral blood, and infection was detected by PCR of the mini-exon gene. In bats, the prevalence of infection was 16.36%, while in small mammals the prevalence was 28.57%. All of the samples that were positive for T.cruzi were identified as the TCI genotype. Our findings suggest that this zone, situated at the periphery of urban zones might have epidemiological relevance in the sylvatic cycle of T.cruzi and needs to be monitored. The infection of bats in this area is particularly concerning since the flight pattern of this populations overlaps with human settlements. Despite being subject to conservation protections, there continue to be anthropogenic actions that disturb the study area, which could exacerbate risks to public health.

The use of highly diverse clades as a surrogate for habitat integrity analysis: Argia damselflies as a practical tool for rapid assessments.

Human activities have impacted many environments on earth, and thus several species are facing an increased risk of extinction. The environmental crisis requires rapid tools to assess the ecosystem health accurately. Studies have been conducted with visual indices that quantify habitat integrity by predicting species richness and diversity. However, whether a diverse clade can predict habitat integrity has not been used. The genus Argia (Rambur, 1842) is one of the most locally diverse groups in southeastern Mexico. In this context, we hypothesized that the occurrence, species richness, and diversity of adults Argia spp. could be a better predictor of the Visual-Based Habitat Assessment Score (VBHAS) than the other taxonomic levels or less diverse clades. We found that the richness and diversity of Argia spp. are positively correlated with VBHA scores, as same as taxonomic ratios. Simultaneously, VBHA scores increase to 23.51 times when Argia spp. diversity increases. We discuss the possible use of a diverse Odonata clade, as Argia spp. could surrogate habitat integrity for local long-term biomonitoring programs. This approach requires testing with other indices and verifying a reliable and consistent relationship between diverse clades and environmental assessment scores.

Effect of climate change on the potential distribution of Helodermaalvarezi (Squamata, Helodermatidae).

Climate change represents a real threat to biodiversity conservation worldwide. Although the effects on several species of conservation priority are known, comprehensive information about the impact of climate change on reptile populations is lacking. In the present study, we analyze outcomes on the potential distribution of the black beaded lizard (Helodermaalvarezi Bogert & Martin del Campo, 1956) under global warming scenarios. Its potential distribution, at present and in projections for the years 2050 and 2070, under both optimistic and pessimistic climate change forecasts, were computed using current data records and seven bioclimatic variables. General results predict a shift in the future potential distribution of H.alvarezi due to temperature increase. The optimistic scenario (4.5 W/m2) for 2070 suggests an enlargement in the species' distribution as a response to the availability of new areas of suitable habitat. On the contrary, the worst-case scenario (7 W/m2) shows a distribution decrease by 65%. Moreover, the range distribution of H.alvarezi is directly related to the human footprint, which consequently could magnify negative outcomes for this species. Our research elucidates the importance of conservation strategies to prevent the extinction of the black beaded lizard, especially considering that this species is highly threatened by aversive hunting.

Variation and genetic structure of the endangered Lepus flavigularis (Lagomorpha: Leporidae) / Variación y estructura genética de la liebre en peligro de extinción, Lepus flavigularis (Lagomorpha: Leporidae)

Abstract Lepus flavigularis, is an endemic and endangered species, with only four populations inhabiting Oaxaca, México: Montecillo Santa Cruz, Aguachil, San Francisco del Mar Viejo and Santa María del Mar. Nevertheless, human activities like poaching and land use changes, and the low genetic diversity detected with mitochondrial DNA and allozymes in previous studies, have supported the urgent need of management strategies for this species, and suggest the definition of management units. For this, it is necessary to study the genetic structure with nuclear genes, due to their inheritance and high polymorphism, therefore, the objective of this study was to examine the variation and genetic structure of L. flavigularis using nuclear microsatellites. We sampled four populations of L. flavigularis and a total of 67 jackrabbits were captured by night sampling during the period of 2001 to 2006. We obtained the genomic DNA by the phenol-chloroform-isoamyl alcohol method. To obtain the diversity and genetic structure, seven microsatellites were amplified using the Polymerase Chain Reaction (PCR); the amplifications were visualized through electrophoresis with 10 % polyacrylamide gels, dyed with ethidium bromide. Genetic diversity was determined using the software GenAlEx v. 6.4, and genetic structure was obtained with ARLEQUIN v. 3.1; null alleles were evaluated using the program Micro-Checker v.2.2.2. Additionally, a Bayesian analysis was performed with software STRUCTURE v. 2.2.3., and the isolation by distance (IBD) was studied using the program PASSAGE v.2.0.11.6. Our results showed that the genetic variation found was low ( HO = 0.30, HE = 0.24) when compared to other jackrabbit species. Fixed alleles and moderate levels of genetic differentiation (F ST = 0.18, P = 0.001) were detected among populations, indicating the effect of the genetic drift and limited gene flow. Bayesian clustering analysis revealed two groups: (1) jackrabbits from Montecillo Santa Cruz, and (2) individuals living in Aguachil, San Francisco del Mar Viejo and Santa María del Mar. No evidence was found of isolation by distance. It is possible that the geographic barriers present between populations (e.g. lagoons, human settlements), rather than the geographical distance between them, may explain the observed genetic structure. The inbreeding coefficient was negative ( FIS =-0.27, P = 0.03), indicating genetic sub-structure in populations. We suggest two management units based on the genetically closer populations, which will help define precise conservation actions in L. flavigularis. This research is the basis for defining translocation of individuals between populations, nevertheless, a more extensive future study, with specific molecular markers for L. flavigularis, is required. In addition, it is necessary to analyze the barriers that limit the gene flow, since it is urgent to reduce the genetic differentiation between populations and increase the genetic diversity of this species.

Resumen Lepus flavigularis es una especie endémica y en peligro, con solo cuatro poblaciones ubicadas en Oaxaca, México: Montecillo Santa Cruz, Aguachil, San Francisco del Mar Viejo y Santa María del Mar. Las actividades humanas (e.g. cacería, cambios de uso de suelo) y la baja diversidad genética detectada con ADN mitocondrial y aloenzimas muestran la urgencia de desarrollar estrategias de manejo para esta especie. Para definir unidades de manejo es necesario estudiar la estructura genética con genes nucleares debido a su herencia y alto polimorfismo, por lo tanto, el objetivo de este estudio fue examinar la variación y estructura genética de L. flavigularis con microsatélites nucleares. Se obtuvo el ADN genómico de 67 liebres de las cuatro poblaciones de L. flavigularis, capturadas mediante muestreo nocturno de 2001 a 2006, mediante el método fenol-cloroformo-alcohol isoamílico. Para obtener la diversidad y estructura genética se amplificaron siete microsatélites con la Reacción en Cadena de la Polimerasa (PCR). Las amplificaciones se visualizaron mediante electroforesis con geles de poliacrilamida al 10 %, teñidas con bromuro de etidio. La diversidad genética se determinó con el programa GenAlEx v.6.4, y la estructura genética se obtuvo con el ARLEQUIN v.3.1. Se evaluaron los alelos nulos con el programa Micro-Checker v.2.2.2. Adicionalmente, se realizó un análisis bayesiano con el software STRUCTURE v.2.2.3, y se estudió el aislamiento por distancia (IBD) mediante el programa PASSAGE v.2.0.11.6. La variación genética encontrada fue baja ( HO = 0.30, HE = 0.24) en comparación con otras especies de liebres. Se detectaron alelos fijos y diferenciación genética moderada (F ST = 0.18, P < 0.001) entre las poblaciones, lo que indica el efecto de la deriva genética y flujo genético limitado. El análisis Bayesiano reveló dos grupos: (1) liebres de Montecillo Santa Cruz, e (2) individuos de Aguachil, San Francisco del Mar Viejo y Santa María del Mar. No se detectó evidencia de aislamiento por distancia. Es posible que las barreras geográficas presentes entre las poblaciones (e.g. lagunas, asentamientos humanos), más que la distancia geográfica entre ellas, expliquen la estructura genética observada. El coeficiente de endogamia fue negativo ( FIS =-0.27, P = 0.03), indicando sub-estructura genética en las poblaciones. Sugerimos dos unidades de manejo con base en las poblaciones más cercanas genéticamente, lo que ayudará a definir acciones precisas de conservación en L. flavigularis. Esta investigación es la base para definir la translocación de individuos entre las poblaciones, sin embargo, se requiere un estudio futuro más amplio que incorpore marcadores moleculares específicos para L. flavigularis. Asimismo, es necesario analizar las barreras que limitan el flujo genético, ya que es urgente reducir la diferenciación genética entre poblaciones e incrementar la diversidad genética de esta especie.