Summary Background and aims: In the Atacama Desert certain plant species can be found in small and isolated areas, limited to regions with water availability. The degree of connectivity within and between these natural populations depends on their pollen and seed dispersal abilities, as well as on the barriers imposed by the landscape. Prosopis flexuosa is a species of high economic and ecological importance included in the algarrobo Conservation and Management program. The main objective of this work is to analyze the genetic variability and mating system of P. flexuosa in the Atacama Desert. M&M: Genetic diversity parameters as well as the mating system were evaluated in a natural population (Quillagua) based on microsatellite molecular markers. The hierarchical distribution of genetic variance and kinship coefficients were analyzed. Results: The results indicate high levels of genetic diversity (HE = 0.67-0.65; Ar = 3.83.7), high outcrossing rates (tm = 0.97, ts = 0.85), low biparental inbreeding (11.6%) and multiple paternity. The proportion of full sibs decreases when considering seeds from the same or different pods (89[PRESERVECIRC]16%). Only the variance between families is significant (p < 0.001) and mean kinships estimated show that progenies within families are not only constituted by half sibs. Conclusions: The results are discussed and related to the limited pollen and seed dispersal and their implication for the management of this resource. The study of the mating system parameters of this Chilean desert population suggests that the low population density and the environment fragmentation would not be influencing their mating capacity.

Resumen Introducción y Objetivos: En el desierto de Atacama ciertas plantas viven aisladas y acotadas a regiones con disponibilidad de agua. La conectividad dentro y entre poblaciones depende de las barreras impuestas por el paisaje y de su capacidad de dispersión. Prosopis flexuosa es una especie con alta importancia económica y ecológica incluida en el Programa de Conservación y Manejo del algarrobo. El objetivo de este trabajo es analizar la variabilidad genética y sistema de fecundación de P. flexuosa en el Desierto de Atacama. M&M: Se evaluó la diversidad genética y el sistema de fecundación sobre la base de marcadores moleculares microsatélites en una población natural (Quillagua). Se analizó la distribución jerárquica de la varianza genética y los niveles de las coancestrías. Resultados: Los resultados indican altos niveles de diversidad genética (HE = 0,67-0,65; Ar = 3,8-3,7), fecundación principalmente cruzada (tm = 0,97, ts = 0,85), baja endogamia biparental (11,6%) y paternidad múltiple. La proporción de hermanos completos disminuye cuando se consideran semillas del mismo o diferente fruto (89[PRESERVECIRC]16%). Solamente la varianza entre familias resulta significativa (p < 0,001) y las coancestrías promedio estimadas dan cuenta que las progenies familiares no están conformadas solamente por medios hermanos. Conclusiones: Los resultados son discutidos y relacionados con la dispersión limitada del polen y semillas y su implicancia para el manejo. El estudio del sistema de fecundación de esta población del desierto chileno sugiere que la baja densidad poblacional y la fragmentación del ambiente no influirían en su capacidad de apareamiento.

ABSTRACT The hairy-tailed bolo mouse, Necromys lasiurus (Lund, 1841), which is typical of the Cerrado (CE), has been recorded in some open areas within the Atlantic Forest (AF) domain of the Brazilian state of Rio de Janeiro (RJ). In the CE, N. lasiurus is a known reservoir of zoonotic agents, and is the reservoir of an orthohantavirus genotype, Araraquara virus (ARAV), the etiological agent of Hantavirus Pulmonary Syndrome (HPS). Given this, the presence of N. lasiurus has potentially negative implications for public health in the state, and therefore it is important to elucidate the origin of its populations in RJ and their connections with populations outside the AF known to carry the ARAV. In the present study we combined phylogenetic and phylogeographic approaches to elucidate the evolutionary history of N. lasiurus populations in RJ, and to test if their dispersal into the AF domain is recent or ancient. These analyses were based on sequences of the mitochondrial Cytochrome b gene, obtained from N. lasiurus specimens from the Atlantic Forest of Rio de Janeiro (AF-RJ), together with all the sequences of this gene available for N. lasiurus in GenBank. In addition to the phylogenetic and phylogeographic analyses, the sequences were used to test among five hypothetical demographic scenarios, proposed to explain the evolutionary history of the hairy-tailed bolo mouse in the state of RJ. The results of all the analyses indicated that populations from AF and the Arid Diagonal (AD) of South America, which includes the CE, diverged in the Late Pleistocene but reconnected in the Holocene. The RJ population (AF-RJ) resulted from this recent genetic admixture among diverging populations from AF and AD. Despite the recent reconnection, no evidence has been found that the AF-RJ N. lasiurus population acts as a reservoir of ARAV, although the continued genetic connectivity with those from AD highlight the need to reinforce the public health monitoring of orthohantavirus in this rodent, especially given the potential spillover of other genotypes. Overall, then, the results of the present study provide important new insights into the evolutionary history of N. lasiurus, which should contribute to the surveillance of orthohantaviruses, and the development of more effective measures for the prevention and control of this zoonosis. hairytailed hairy tailed Lund, Lund (Lund 1841, 1841 , 1841) CE (CE) (AF . (RJ) N agents genotype ARAV (ARAV) HPS. HPS (HPS) ancient AFRJ, AFRJ GenBank scenarios (AD America Holocene (AF-RJ reconnection rodent genotypes Overall then orthohantaviruses zoonosis 184 (CE (RJ (ARAV (HPS 18 1

ABSTRACT The Northeastern Pacific (NEP) population of white sharks (Carcharodon carcharias) is genetically distinct from the rest of the world. This uniqueness results from adult fidelity to central California and Guadalupe Island aggregations sites. The strong mitochondrial genetic structure between the white sharks of central California and Guadalupe Island is also present, which indicates female philopatry. To date, few studies using nuclear DNA have found evidence of genetic patterns in the NEP white shark population, which could indicate that these sharks exhibit sex-biased dispersal. In this study, we evaluated the genetic structure, connectivity, and genetic diversity of NEP white sharks using samples from the southern California Bight (SCB), Baja California (including Sebastian Vizcaino Bay), the Gulf of California, and Guadalupe Island (GI) using nDNA (i.e. microsatellite loci). A total of five loci were successfully genotyped in 54 individuals. The patterns found in this study indicated low levels of genetic diversity among all localities (observed heterozygosity: Ho = 0.47), likely due to a founder effect. A slight genetic structure was present for NEP localities in this study (FST = 0.045, P = 0.0001), mainly identified between the SCB and GI locations. A sibship assignment analysis indicated low and moderate probabilities of full- and half-siblings between white shark juveniles from coastal areas, suggesting a high degree of connectivity between nursery areas in the NEP. Our results suggest that juveniles can mask the genetic structure in coastal zones.

Abstract The spotted rose snapper, Lutjanus guttatus, is an important fishery species with high potential for aquaculture. Genetic characterization of its natural populations is necessary to avoid stock collapse and loss of genetic diversity. Previous studies carried out in the Tropical Eastern Pacific (TEP), however, have shown contrasting results in the genetic structure of fish populations, particularly in species of Lutjanidae. Therefore, to understand the genetic structure of spotted rose snapper in the TEP, twelve microsatellite loci were used to assess the genetic diversity and explore the hypothesis of population genetic structure in samples of the species collected throughout the TEP. Fin clips from 186 sampled individuals (27 to 49 per site) were analyzed from five sites in the three regional biogeographic provinces, delimited by shoreline reef habitat breaks: La Paz (Cortez province), Colima and Oaxaca (Mexican province), Chiriqui and Port of Panama (Panamic province). Results of global Analysis of Molecular Variance (AMOVA), population pairwise FST, hierarchical AMOVA, and a discriminant analysis of principal components (DAPC) reflected a panmictic population involving the entire set of sampled sites. The role of larval dispersal, post-recruitment migration, and marine current dynamics as drivers of genetic connectivity in this species is discussed. guttatus aquaculture TEP , (TEP) however Lutjanidae Therefore 18 27 (2 4 site provinces breaks Cortez province, province province) Mexican Panamic province. . AMOVA (AMOVA) FST DAPC (DAPC dispersal postrecruitment post recruitment migration discussed (TEP 1 2 ( (AMOVA

Resumen El pargo lunarejo, Lutjanus guttatus, es una importante especie pesquera, con alto potencial para la acuicultura. La caracterización genética de sus poblaciones naturales es necesaria para evitar el colapso del stock y la pérdida de diversidad genética. Sin embargo, estudios previos realizados en el Pacífico Oriental Tropical (TEP), han mostrado resultados contrastantes en la estructura genética de poblaciones de peces, particularmente en especies de Lutjanidae. Por lo tanto, para entender la estructura genética del pargo lunarejo en el TEP, se usaron 12 loci microsatélites para evaluar la diversidad genética y explorar la hipótesis de estructura genética poblacional en muestras de la especie colectada a lo largo del TEP. Se analizaron fragmentos de aletas de 186 individuos (27 a 49 por sitio) de cinco localidades en las tres provincias biogeográficas regionales, delimitadas por las discontinuidades de hábitat de arrecife costero: La Paz (Provincia de Cortés), Colima y Oaxaca (Provincia Mexicana), Chiriquí y Puerto de Panamá (Provincia Panámica). Los resultados del Análisis de Varianza Molecular (AMOVA) global, FST de poblaciones pareadas, AMOVA jerárquico y un análisis discriminante de componentes principales (DAPC) reflejaron una población panmíctica que involucraba todo el conjunto de sitios muestreados. Se discute el papel de la dispersión larvaria, migración post-reclutamiento y la dinámica de las corrientes marinas como propulsores de la conectividad genética en esta especie. guttatus pesquera acuicultura embargo TEP , (TEP) peces Lutjanidae tanto 1 18 27 (2 4 sitio regionales costero Provincia Cortés, Cortés Cortés) Mexicana, Mexicana Mexicana) Panámica. Panámica . Panámica) (AMOVA global pareadas DAPC (DAPC muestreados larvaria postreclutamiento post reclutamiento (TEP 2 (

Electroconvulsive therapy (ECT) has multiple uses in psychiatry, but its mechanisms of action (MA) in patients with schizophrenia (PS) are poorly understood. We synthesize and discuss the available evidence in this regard. We conducted a search for primary human studies and systematic reviews searching MA of ECT in PS published in PubMed/Medline, SciELO, PsycInfo, and the Cochrane Library, including 24 articles. Genetic findings are scarce and inconsistent. At the molecular level, the dopaminergic and GABAergic role stands out. The increase in brain derived neurotrophic factor (BDNF) after ECT, is a predictor of positive clinical outcomes, while the change in N-acetyl aspartate levels would demonstrate a neuroprotective role for ECT. This intervention would improve inflammatory and oxidative parameters, thereby resulting in a symptomatic improvement. ECT is associated with an increase in functional connectivity in the thalamus, right putamen, prefrontal cortex and left precuneus, structures that play a role in the neural default mode network. A decrease in connectivity between the thalamus and the sensory cortex and an enhanced functional connectivity of the right thalamus to right putamen along with a clinical improvement have been reported after ECT. Moreover a volumetric increase in hippocampus and insula has been reported after ECT. These changes could be associated with the biochemical pathophysiology of schizophrenia. Most of the included studies are observational or quasi-experimental, with small sample sizes. However, they show simultaneous changes at different neurobiological levels, with a pathophysiological and clinical correlation. We propose that the research on ECT should be carried out from neurobiological dimensions, but with a clinical perspective.

Abstract The Cerrado encompasses a complex network of hydrographic basins, which is responsible for the formation and maintenance of the riparian and gallery forests. Alterations in the vegetation resulting from the paleoclimatic changes that occurred during the Pleistocene influenced the current distribution of these humid forests. To understand of the evolutionary dynamics of this landscape on the population structure of the associated organisms, we studied the population genetics of the Antilophia galeata (Pipridae), a bird endemic to the gallery forests of the Cerrado. For this, we evaluated the variability of the mitochondrial control region of 71 A. galeata specimens from 18 localities distributed throughout the Cerrado. The results indicated the existence of significant substructure among the populations located in the peripheral areas of the Cerrado, in comparison with the populations found in the central portion, reflecting historical changes in the environment. We also found high levels of diversity in all the populations, while the analysis of the demographic history revealed a scenario of stability. Overall, then, these findings indicate that the historical modifications of the gallery forest distribution may have been most accentuated in the peripheral zones, with a greater stability and connectivity persisting in the central portion of the biome.

ABSTRACT Background: The objective of this study was the genetic characterization of remaining populations of the species Paratecoma peroba occurring in fragments of the Atlantic Forest, by estimating parameters of diversity and genetic structure. The study was carried out in two forest fragments, the Atlantic Forest Environmental Education Pole (area 1) and the Pacotuba National Forest (area 2), where 93 adult trees were identified. Results: Ten Inter Simple Sequence Repeats (ISSR) primers were used in genotyping, obtaining 112 amplified bands with 87.5% polymorphism. The genetic diversity estimated for the populations from the Nei (H*) and Shannon (I*) indices was higher for area 1. For the joint data, moderate genetic diversity was observed, referring to the average values of 0.26 and 0.40, obtained for the H* and I* indices, respectively. Molecular variance analysis resulted in moderate differentiation between populations (Φ ST = 0.143), while gene flow analysis (N m = 6.69) revealed the occurrence of similar alleles between them. However, the predominance of a single genetic group in area 2, revealed from Bayesian approach, indicates that its genetic structure, possibly generated by the current scenario of fragmentation of the Atlantic Forest and the distancing of populations, affecting the contemporary gene flow. Conclusion: Despite the moderate genetic diversity of the species for the area 2 population, actions toward inclusion of seedlings obtained from seeds from neighboring fragments, including area 1, and the increase in the connectivity of forest fragments through ecological corridors, could assist in augmenting its genetic variation.

Resumen: Antecedentes y Objetivos: Los individuos de Balmea stormiae (Rubiaceae) son árboles o arbustos hemiepífitos que habitan malpaíses con bosques de pino-encino en poblaciones disyuntas en Centroamérica y México. La especie se considera en peligro de extinción y particularmente se ha documentado que las poblaciones de Michoacán han estado expuestas a fuertes presiones antropogénicas. Por tal motivo, en este estudio se estimó la diversidad genética en cuatro poblaciones de Michoacán, contrastando esta información con la obtenida en una población de Jalisco, ambas regiones ubicadas en el centro-occidente de México. Métodos: Las muestras vegetales fueron recolectadas en cinco poblaciones de la región occidente del Cinturón Volcánico Transmexicano. Para evaluar la diversidad genética, se utilizó el intrón rps16 del ADN de cloroplasto, el espaciador transcrito externo (ETS) del ADN ribosomal nuclear y marcadores dominantes ISSR de ADN nuclear (Inter Secuencias Simples Repetidas por sus siglas en inglés). Resultados clave: Los marcadores moleculares revelaron alta diferenciación genética entre las poblaciones de Jalisco y Michoacán, la cual se atribuye a la baja conectividad entre estas. Posiblemente se deba a la baja capacidad de dispersión a larga distancia de las semillas y el polen. Se detectó flujo genético moderado y expansión demográfica reciente en las poblaciones de Michoacán. Los niveles de variación genética en las poblaciones de Michoacán concuerdan con la edad de los flujos de lava, siendo Arocutín y Zacapu las poblaciones más diversas sobre los flujos de lava más antiguos. Conclusiones: Los resultados podrían explicarse por el origen relativamente reciente, producto de la actividad volcánica del Holoceno, de los ambientes en los que habita esta especie, sumado a la perturbación recurrente relacionada con grandes asentamientos prehispánicos de Michoacán.

Abstract: Background and Aims: Individuals of Balmea stormiae (Rubiaceae) are trees or hemiepiphytic shrubs that inhabit pine-oak forests on rock outcrops in disjunct populations of Central America and Mexico. The species is considered endangered and especially the populations of Michoacán have been reported as exposed to strong anthropogenic pressures. For this reason, in this study the genetic diversity of four populations of Michoacán was estimated, contrasting this information with that obtained from one population of Jalisco, both regions located in west-central Mexico. Methods: Samples were collected in five populations in the western region of the Trans-Mexican Volcanic Belt. The chloroplast rps16 intron, the external transcribed spacer of ribosomal DNA (ETS) and seven Inter-Simple Sequence Repeats of nuclear DNA (ISSR) were used to assess genetic diversity. Key results: Molecular markers revealed high genetic differentiation between the populations from Jalisco and Michoacán, attributed to the low connectivity amongst them, probably due to the low long distance dispersal capacity of seeds and pollen. Moderate genetic flow and demographic expansion were detected for populations in Michoacán. The degree of genetic diversity in Michoacán populations are consistent with the age of lava flows, whereby Arocutín and Zacapu are the most diverse populations located on the oldest lava flows. Conclusions: Results could be explained by the relatively recent origin, resulting from Holocene volcanic activity, of the environments in which the species inhabits, coupled with the recurring disturbance related to large pre-Hispanic settlements.

Resumen Aplicamos un enfoque de dominios ambientales para identificar las características ambientalmente heterogéneas que definen una matriz del paisaje. Construimos capas ambientales a 3 escalas, nacional, regional y local, para considerar las diferentes escalas que pueden tener distintos estudios. Utilizamos una clasificación numérica jerárquica para datos espaciales y una clasificación multivariada. Con base en los dominios obtenidos, construimos mapas de heterogeneidad ambiental y determinamos las variables asociadas para cada escala. Probamos específicamente la idoneidad de nuestro enfoque para definir estrategias de muestreo para estudios de genética del paisaje, usando como especie focal al roedor Heteromys pictus. Así, de los dominios obtenidos en la escala local seleccionamos sitios de muestreo que incluyeran la más amplia heterogeneidad del hábitat, los cuales corroboramos en campo. La matriz del paisaje que generamos fue utilizada con datos genéticos previamente obtenidos para H. pictus. Nuestro protocolo nos permitió identificar variables significativamente asociadas con la dispersión (flujo génico) de los individuos en su hábitat natural. Demostramos así su pertinencia para definir eficientemente localidades de muestreo (matriz del paisaje) que abarquen la mayor heterogeneidad ambiental, en paisajes explorados e inexplorados, e identificar de forma rápida localidades y sus características ambientales en sitios con poca información previa.

Abstract We apply an environmental domains approach to identify environmentally heterogeneous characteristics defining a landscape matrix. We built environmental layers for national, regional, and local scales, considering the different scales studies can have. We used a numerical classification of explicit spatial layers and performed a multivariate classification. Based on the domains obtained, we mapped the landscape’s climatic heterogeneity and identified a comprehensive set of environmental variables that defined the landscape matrix at each scale. We specifically tested our approach for its suitability to define a sampling strategy for a landscape genetics study, using as focal species the rodent Heteromys pictus. Namely, from the domains obtained at the local scale, we selected sampling localities that comprised the broadest habitat heterogeneity, which we corroborated in the field. The landscape matrix thus generated was used with genetic data previously obtained for H. pictus. Our approach allowed identification of environmental variables significantly associated with dispersal (gene flow) of H. pictus individuals in their natural habitat. We demonstrate its adequacy to efficiently determine sampling localities -or landscape sites- that encompass the highest environmental heterogeneity, in explored and unexplored landscapes, enabling rapid identification of localities and their environmental characteristics where in situ information is scarce.

ABSTRACT Gene flow allows connectivity of geographically isolated populations and which genetic diversity is reduced. Understanding how gene flow occurs is essential to conservation and selection of priority populations for intervention. In this study, the rates of migration and selfing of Copaifera langsdorffii Desf. sampled in Cerrado fragments in the State of São Paulo, Brazil, were estimated through computer simulations. Different selfing and migration rates were tested and the combination that showed values of observed and expected heterozygosity closest to those previously obtained with microsatellite markers was selected. According to the simulations, selfing and migration were low. Due to the high geographical distances among the fragments, gene flow was limited and may have led to low genetic diversity in the fragments. It is recommend enriching the area with high genetic diversity germplasm and reducing disturbance to promote the occurrence of pollinators, in order to increase the genetic diversity.

Resumen Introducción: La estimación de la conectividad en corales escleractinios, como P. verrucosa, dentro de una red de áreas marinas protegidas (MPA) preestablecidas es fundamental para garantizar la efectividad en su conservación e incrementar su resiliencia. Objetivo: Determinar la estructura genética y la conectividad entre los demes de P. verrucosa dentro del Golfo de California, y evaluar el papel y efectividad de la red preestablecida de áreas marinas protegidas. Métodos: Se evaluó la conectividad de P. verrucosa en cinco locaciones a lo largo del golfo incluyendo tres MPA usando seis marcadores microsatélites. Resultados: Se demostró que existe estructura poblacional adjudicada a la presencia local y heterogénea de individuos clones (F ST = 0.108***); pero al removerlos del análisis, los individuos de origen sexual conformaron una metapoblación en panmixia (F ST = 0.0007 NS). Así mismo, se identificaron 10 potenciales migrantes en la región con una dispersión promedio de 116.57 km (± 80.47 SE) y sin conexión entre localidades extremas. De relevancia, se identificó la importancia ecológica del área central o Bahía de La Paz y MPA Archipiélago Espíritu Santo, como fuente larvaria de corales a toda la región. Además, se determinó que el espacio inter-MPA fue mayor que la distancia de dispersión promedio larvaria mencionada, por lo que sería de importancia ecológica el establecimiento de MPAs intermedias que favorezcan la conectividad a distancias cortas. Conclusiones: Los resultados encontrados en el estudio son pertinentes y contribuyen como línea base para los tomadores de decisiones y autoridades, proporcionando la conectividad de la región para establecer las estrategias de protección apropiadas, sugiriendo aumentar la conservación de las subpoblaciones centrales, la cuales promueven la resiliencia metapoblacional de P. verrucosa ante factores ambientales y/o antropogénicos.

Abstract Introduction: Estimates of contemporary connectivity of the broadcast spawning coral Pocillopora verrucosa between multi-use marine protected areas (MUMPAs) are required to assess MUMPA effectiveness and their ability to enhance resilience against disturbances. Objective: To determine the genetic structure and connectivity patterns between P. verrucosa demes inside the Gulf of California and evaluate the role and effectiveness of established MUMPAS in their protection and resilience. Methods: We assessed P. verrucosa connectivity along its peninsular range (∼350 km), including five locations and three MUMPAs in the Gulf of California using six microsatellite genetic markers. Results: Population structure was significant (F ST = 0.108***) when demes included clonal replicates; however, when these clones were removed from the analysis, the sexual individuals comprised a metapopulation panmixia (F ST = 0.0007 NS). To further understand connectivity patterns, an assignment test was carried out which identified ten recent between-deme migrants with a mean dispersal distance of 116.6 km (± 80.5 SE). No long-distance dispersal was detected. These results highlight the ecological importance of the Bahía de La Paz region, including Archipiélago de Espíritu Santo MUMPA. This region, located at the center of the species peninsular range, exports larva to downstream sink demes such as the Loreto (northwardly) and Cabo Pulmo (southwardly) MUMPAs. Of importance, inter-MUMPA spacing was larger than the mean larval dispersal by ~56 km, suggesting thar the designation of intermediate ‘no-take’ zones would enhance short-distance connectivity. Conclusion: This study contributes as a baseline for policymakers and authorities to provide robust strategies for coral ecosystem protection and suggest that protection efforts must be increased towards peninsular intermediate reefs to promote metapopulation resilience from natural and anthropogenic factors.

Abstract This manuscript reviews the mechanisms that contribute to the production of the autism spectrum disorder (ASD), especially the genetic and immunological components. Knowing the participating elements and mechanisms are essential to establish preventive measures and look for early markers. The ASD can have subtle or devastating manifestations, and exerting immunomodulatory actions could be useful in the management of these patients. There seems to be different environmental insults that may act as triggers in genetically predisposed subjects; these insults can promote an inflammatory response in which interleukin-6 could participate actively at the level of neural stem cells and progenitors. The degree of involvement in neurogenesis and astrogenesis, and therefore, the observed clinical spectrum will depend on two facts that alter the neural circuits, including the brain region that loses proper input or output connectivity due to abnormal migration of a group of neurons, and the astrocytic survival.

Resumen Este manuscrito revisa los mecanismos que contribuyen a la producción del trastorno del espectro autista (TEA), especialmente los componentes genéticos e inmunológicos. Conocer los elementos y mecanismos participantes es fundamental para establecer medidas preventivas y buscar marcadores tempranos. El TEA puede tener manifestaciones sutiles o devastadoras, y ejercer acciones inmunomoduladoras podría ser útil en el manejo de estos pacientes. Parece haber diferentes agresiones ambientales que pueden actuar como desencadenantes en sujetos genéticamente predispuestos; Estas agresiones pueden promover una respuesta inflamatoria en la que la interleucina-6 podría participar actuando activamente a nivel de células madre neurales y progenitores. El grado de implicación en la neurogénesis y la astrogénesis, y por tanto, el espectro clínico observado, dependerá de dos hechos que alteran los circuitos neuronales, incluida la región del cerebro que pierde la conectividad de entrada o salida adecuada debido a la migración anormal de un grupo de neuronas, y la supervivencia astrocítica.

Abstract Background: Sporadic flowering contributes significantly to genetic diversity and connectivity among populations. Woody bamboos present sporadic or gregarious flowering patterns with long flowering cycles. In this study, we analyze the genetic diversity of three Guadua species distributed along the Gulf of Mexico slope that have different patterns of flowering. Questions: (1) Are the three Guadua species genetically differentiated? (2) Does the vulnerable species G. inermis have low levels of genetic diversity? (3) What is the relative contribution of geographic and environmental factors to the genetic structure of G. inermis? Species studied: G. amplexifolia, Guadua inermis and G. tuxtlensis. Study site and dates: During 2014 and 2015, we collected samples of G. inermis in Puebla and southeastern Mexico, G. amplexifolia in Veracruz and Oaxaca, and G. tuxtlensis in southern Veracruz. Methods: We successfully amplified five of nine SSR markers, and genotyped a total of 155 samples. Results: The three Guadua species were genetically differentiated. For G. inermis, we found high levels of population genetic diversity, which are relatively higher than those of other monocot species. Genetic differentiation was high and three groups were detected: north, central and south. We found a significant association between genetic distances and the maximum temperature of the warmest month, but not with geographic distance. Conclusions: Our study is the first to analyze levels of genetic diversity in Mexican bamboos and confirms their taxonomic identity. G. inermis has a strong genetic structure, even when populations are geographically close.

Resumen Antecedentes: La floración esporádica puede influenciar la estructura genética de las poblaciones. Los bambúes presentan patrones de floración esporádica o gregaria. En este estudio analizamos la diversidad genética de tres especies de Guadua con diferentes patrones de floración distribuidos en la Vertiente del Golfo de México. Preguntas: 1) ¿Están las tres especies de Guadua (G. inermis, G. amplexifolia y G. tuxtlensis) genéticamente diferenciadas? 2) ¿Presenta G. inermis bajos niveles de diversidad genética? 3) ¿Cuál es la contribución relativa de los factores geográficos y ambientales en la estructura genética de G. inermis? Especies de estudio: G. amplexifolia, Guadua inermis y G. tuxtlensis. Sitio y años de estudio: En 2014 y 2015, colectamos muestras de G. inermis en Puebla y sureste de México; G. amplexifolia en Veracruz y Oaxaca, y G. tuxtlensis en el sureste de Veracruz. Métodos: Amplificamos exitosamente cinco marcadores SSR de un total de nueve y genotipificamos 155 muestras. Resultados: Las tres especies analizadas están genéticamente diferenciadas. G. inermis presentó altos niveles de diversidad genética, y superiores a otras especies de monocotiledóneas. Los niveles de diferenciación genética fueron altos y se detectaron tres grupos: norte, sur y centro. Encontramos una asociación significativa entre las distancias genéticas con la temperatura máxima del mes más caliente, pero no con la distancia geográfica. Conclusiones: Nuestro trabajo es el primer estudio que evalúa los niveles de diversidad genética en bambúes mexicanos y confirma su identidad taxonómica. G. inermis tiene una estructura genética alta, incluso cuando las poblaciones están cerca geográficamente.

ABSTRACT In the Alvarado Lagoon System (ALS) in south-central Veracruz on Mexico's gulf coast, the blue land crab, Cardisoma guanhumi, a semi-terrestrial crustacean species, represents an important fishery resource, but one that is subject to overexploitation and habitat destruction. Identifying genetic diversity and the genetic unit are required to establish efficient conservation strategies. The present study's goal was to assess the genetic structure and degree of genetic diversity of C. guanhumi populations along the ALS. A fragment of the D-loop region of the mtDNA (750 bp) and a partial sequence of the COI gene (580 pb) was sequenced for 120 specimens collected at four sites in the ALS. Genetic diversity indices were estimated for each marker. The study sites’ gene flow was estimated, as was the effective population size and the mutational rate for each locality. A haplotype network was built to estimate the gene genealogies of the populations. A Tajima's neutrality test, Fu tests, and mismatch analysis were performed to detect demographic expansion. Results show that this C. guanhumi population has high genetic diversity with a large gene flow among the localities studied and expanded during the recent evolutionary past. All haplotypes from both markers are novel for the species, according to the NCBI GenBank. The high genetic diversity and genetic connectivity among sites suggests that the size of blue crab populations in the ALS has not been drastically affected by past exploitation. Finally, management strategies are proposed to protect the species.

Resumen Introducción: Existen problemas y acertijos en la comprensión de la reproducción, el crecimiento y la mortalidad en los ciclos de vida de los equinodermos. Objetivo: Explorar los problemas y acertijos en los ciclos de vida que son importantes y desafiantes. Métodos: La literatura es usada para dilucidar los problemas asociados con todas las etapas de vida. Resultados: Las fuentes de larvas que se asientan en un sitio se exploran usando modelos oceanográficos y métodos genéticos. Existen pocos estudios que han estimado la mortalidad larval del plancton bajo condiciones de campo y los resultados difieren de los resultados experimentales o los patrones de asentamiento. En un número pequeño de estudios, la tasa de mortalidad de las larvas recién asentadas parece cambiar rápidamente a medida que los organismos crecen. Existen problemas para medir tamaños y el sesgo de medición interfiere con el uso de muchos métodos de marcado para estimar el crecimiento. También hay problemas con el uso de las líneas de crecimiento natural y con los programas comúnmente usados para estimar tanto el crecimiento como la mortalidad a partir de datos de frecuencia de tamaño. Un acertijo interesante es que los equinodermos pueden mostrar senescencia negativa con una tasa de mortalidad que disminuye con el tamaño. Existe un problema con el éxito de la fertilización basado en la densidad, por lo que no debería haber especies raras cuando los sexos están separados y existe un desove libre de gametos, sin embargo, parece haber equinodermos raros. Conclusiones: Todas las partes de los ciclos de vida de los equinodermos proveen problemas y acertijos que son importantes y desafiantes.

Abstract Introduction: There are problems and puzzles in understanding reproduction, growth and mortality in echinoderm life cycles. Objective: Explore problems and puzzles in life cycles that are important and challenging. Methods: The literature is used to elucidate problems associated with all life stages. Results: Sources of larvae that settle at a site are explored using oceanographic modelling and genetic methods. There are few studies that have estimated larval mortality in the plankton under field conditions and results differ from experimental results or patterns of settlement. In a small number of studies, mortality rate of newly settled larvae appears to change rapidly as individuals grow. There are problems measuring size, and measurement bias that interferes with many tagging methods used to estimate growth. There also are problems with the use of natural growth lines and commonly used software to estimate both growth and mortality from size-frequency data. An interesting puzzle is that echinoderms may show negative senescence with mortality rate decreasing with size. There is a problem in fertilization success based on density so there should not be rare species where sexes are separate with free spawning of gametes yet there seem to be rare echinoderms. Conclusions: All parts of echinoderm life cycles provide problems and puzzles that are important and challenging.