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Variación morfológica de las hormigas Myrmecocystus de las dunas costeras de Baja California, México

Morphological variation of Myrmecocystus ants from the coastal dunes of Baja California, Mexico

Samuel Antonio Hernández Jiménez (2023, [Tesis de maestría])

La península de Baja California cuenta con dunas costeras aisladas sobre las cuales se distribuyen hormigas del género Myrmecocystus Snelling, 1976, cuya distribución se restringe en estos hábitats; la artropofauna de estas dunas es poco conocida. Se evaluaron las diferencias morfológicas de Myrmecocystus de seis poblaciones recolectadas a lo largo de la península de Baja California correspondientes a seis dunas. Para medir las diferencias morfológicas de las poblaciones, se analizaron 109 individuos, 20 por cada duna, a excepción de una duna en donde sólo se recolectaron nueve individuos. Para evaluar los cambios de forma intra e interpoblacionales, se analizaron dos estructuras morfológico-funcionales: 1) cabeza, incluyendo el clípeo relacionada con la competencia y alimentación y 2) tórax, incluyendo el propodeo, que muestra la diferencia de casta entre obreras. Con una cámara fija montada en un microscopio estereoscópico se tomaron 198 microfotografías digitales, para evaluar cambios de forma mediante un análisis de morfometría geométrica. Se detectaron diferencias asociadas al aislamiento geográfico. La variación observada en la cabeza puede ayudar a diferenciar las poblaciones del norte de la península (Santa Rosaliíta, Punta Mazo, Guerrero Negro y Punta Abreojos) y las del sur (Las Barrancas y Bahía Magdalena), la variación morfológica del tórax no mostró diferencias significativas. Existen variaciones intraespecíficas que podrían ser consecuencia de las condiciones ambientales (fenotípicas) o por procesos aleatorios como la deriva génica. El presente estudio arroja datos de la variación morfológica de seis poblaciones que representan dos especies de Myrmecocystus aun no descritas para la península de Baja California. Estos resultados repercutirán en la descripción y un aumento documentado de la biodiversidad de la artropofauna bajacaliforniana.

The Baja California peninsula has isolated coastal dunes on which ants of the genus Myrmecocystus Snelling, 1976 are distributed, whose distribution is restricted in these habitats; The arthropofauna of these dunes is poorly understood. The morphological differences of Myrmecocystus were evaluated from six populations collected along the Baja California peninsula corresponding to six dunes. To measure the morphological differences of the populations, 109 individuals were analyzed, 20 for each dune, except for one dune where only nine individuals were collected. To evaluate intra- and interpopulation shape changes, two morphological-functional structures were analyzed: 1) head, including the clypeus related to competition and feeding, and 2) thorax, including the propodeum, which shows the caste difference between workers. With a fixed camera mounted on a stereoscopic microscope, 198 digital microphotographs were taken to evaluate shape changes through a geometric morphometry analysis. Differences associated with geographic isolation were detected. The variation observed in the head can help to differentiate the populations of the north of the peninsula (Santa Rosaliíta, Punta Mazo, Guerrero Negro, and Punta Abreojos) and those of the south (Las Barrancas and Magdalena Bay), the morphological variation of the thorax did not show significant differences. There are intraspecific variations that could be a consequence of environmental conditions (phenotypic) or random processes such as gene drift. The present study yields data on the morphological variation of six populations representing two species of Myrmecocystus not yet described for the Baja California peninsula. These results will have an impact on the description and a documented increase in the biodiversity of the Baja Californian arthropofauna.

Alometría, Especiación, Morfometría Geométrica, Forma, Especies no descritas Allotometry, Speciation, Geometric Morphometry, Shape, Undescribed Species BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA DE INSECTOS (ENTOMOLOGÍA) MORFOLOGÍA DE LOS INSECTOS MORFOLOGÍA DE LOS INSECTOS

Comparative live-cell imaging analyses of SPA-2, BUD-6 and BNI-1 in Neurospora crassa reveal novel features of the filamentous fungal polarisome

Alexander Lichius (2012, [Artículo])

A key multiprotein complex involved in regulating the actin cytoskeleton and secretory machinery required for polarized growth in fungi, is the polarisome. Recognized core constituents in budding yeast are the proteins Spa2, Pea2, Aip3/Bud6, and the key effector Bni1. Multicellular fungi display a more complex polarized morphogenesis than yeasts, suggesting that the filamentous fungal polarisome might fulfill additional functions. In this study, we compared the subcellular organization and dynamics of the putative polarisome components BUD-6 and BNI-1 with those of the bona fide polarisome marker SPA-2 at various developmental stages of Neurospora crassa. All three proteins exhibited a yeast-like polarisome configuration during polarized germ tube growth, cell fusion, septal pore plugging and tip repolarization. However, the localization patterns of all three proteins showed spatiotemporally distinct characteristics during the establishment of new polar axes, septum formation and cytokinesis, and maintained hyphal tip growth. Most notably, in vegetative hyphal tips BUD-6 accumulated as a subapical cloud excluded from the Spitzenkörper (Spk), whereas BNI-1 and SPA-2 partially colocalized with the Spk and the tip apex. Novel roles during septal plugging and cytokinesis, connected to the reinitiation of tip growth upon physical injury and conidial maturation, were identified for BUD-6 and BNI-1, respectively. Phenotypic analyses of gene deletion mutants revealed additional functions for BUD-6 and BNI-1 in cell fusion regulation, and the maintenance of Spk integrity. Considered together, our findings reveal novel polarisome-independent functions of BUD-6 and BNI-1 in Neurospora, but also suggest that all three proteins cooperate at plugged septal pores, and their complex arrangement within the apical dome of mature hypha might represent a novel aspect of filamentous fungal polarisome architecture. © 2012 Lichius et al.

fungal protein, protein BNI 1, protein BUD 6, protein SPA 2, protein Spk, unclassified drug, actin binding protein, cytoskeleton protein, fungal protein, article, cell fusion, cellular distribution, comparative study, conidium, controlled study, cyto BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA MICROBIOLOGÍA MICROBIOLOGÍA

Cell carbon content and biomass assessments of dinoflagellates and diatoms in the oceanic ecosystem of the Southern Gulf of Mexico

LORENA PATRICIA LINACRE ROJAS (2021, [Objeto de congreso])

This study assessed the cell carbon content and biomass for genera of dinoflagellates and diatoms in the oceanic ecosystem of the Southern Gulf of Mexico. Carbon content estimates were based on biovolume calculations derived from linear dimension measurements of individual cells and the approximate geometric body shape of each genus. Then, biomass assessments were performed for both groups in two gulf regions (Perdido and Coatzacoalcos) using these carbon content factors and cell abundances. After four seasonal cruises, 11,817 cells of dinoflagellates and 3,412 cells of diatoms were analyzed. Diverse body shapes and cell sizes were observed among 46 dinoflagellate genera and 37 diatom genera. Nano-cells of dinoflagellates (68% <20 μm) and micro-cells of diatoms (77% 20–200 μm, mostly 50–75 μm) were predominant. According to this cell-size structure, on average, diatoms contained 40% more carbon per cell than dinoflagellates. Contrasting carbon content estimates were observed within the genera of both microalgae. Large carbon averages (>10,000 pg C cell-1) were attributed to Gonyaulacal and some occasional genera of dinoflagellates (e.g., Pyrocystis and Noctiluca) and centric diatoms. In contrast, values up to 3 orders of magnitude lower were found for Peridinial and Gymnodinial dinoflagellates and pennate diatoms. Based on these carbon content estimates, which can be considered representative for most of this oceanic ecosystem, seasonal and regional differences were found in the biomass assessments conducted for these functional groups. Overall, dinoflagellates (mostly low-carbon Gymnodinales) had larger depth-integrated biomass than diatoms (mainly rich-carbon centric forms) within the euphotic zone. An exception to it was the late-summer cruise at the Coatzacoalcos region when a surface bloom of centric diatoms was observed in stations influenced by river runoff. This work contributes useful reference information for future ecological studies and models for understanding the biogeochemical functioning of this open-ocean ecosystem. © 2021 Linacre et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Carbon, biomass, Oceanic ecosystem, Southern Gulf of Mexico, Mexico CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA

Shopping for Ecological Indices? On the Use of Incidence-Based Species Compositional Similarity Measures

IAN MACGREGOR FORS FEDERICO ESCOBAR SARRIA JUAN FERNANDO ESCOBAR IBAÑEZ NATALIA MESA SIERRA FREDY ALEXANDER ALVARADO ROBERTO Rafael Rueda Hernández CLAUDIA ELIZABETH MORENO ORTEGA Ina Falfán ERICK JOAQUIN CORRO MENDEZ Eduardo Octavio Pineda Arredondo Amandine Bourg JOSE LUIS AGUILAR LOPEZ (2022, [Artículo])

"β-diversity has been under continuous debate, with a current need to better understand the way in which a new wave of measures work. We assessed the results of 12 incidence-based β-diversity indices. Our results of gradual species composition overlap between paired assemblages considering progressive differences in species richness show the following: (i) four indices (β-2, β-3, β-3.s, and βr) should be used cautiously given that results with no shared species retrieve results that could be misinterpreted; (ii) all measures conceived specifically as partitioned components of species compositional dissimilarities ought to be used as such and not as independent measures per se; (iii) the non-linear response of some indices to gradual species composition overlap should be interpreted carefully, and further analysis using their results as dependent variables should be performed cautiously; and (iv) two metrics (βsim and βsor) behave predictably and linearly to gradual species composition overlap. We encourage ecologists using measures of β-diversity to fully understand their mathematical nature and type of results under the scenario to be used in order to avoid inappropriate and misleading inferences."

Beta diversity Nestedness Replacement Richness difference Species turnover BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) ECOLOGÍA VEGETAL ECOLOGÍA VEGETAL

The Pacific harbor seal gut microbiota in Mexico: Its relationship with diet and functional inferences

ARLETTE MARIMAR PACHECO SANDOVAL (2019, [Artículo])

Diet is a primary driver of the composition of gut microbiota and is considered one of the main routes of microbial colonization. Prey identification is fundamental for correlating the diet with the presence of particular microbial groups. The present study examined how diet influenced the composition and function of the gut microbiota of the Pacific harbor seal (Phoca vitulina richardii) in order to better understand the role of prey consumption in shaping its microbiota. This species is a good indicator of the quality of the local environment due to both its foraging and haul-out site fidelity. DNA was extracted from 20 fecal samples collected from five harbor seal colonies located in Baja California, Mexico. The V4 region of 16S rRNA gene was amplified and sequenced using the Illumina technology. Results showed that the gut microbiota of the harbor seals was dominated by the phyla Firmicutes (37%), Bacteroidetes (26%) and Fusobacteria (26%) and revealed significant differences in its composition among the colonies. Funtional analysis using the PICRUSt software suggests a high number of pathways involved in the basal metabolism, such as those for carbohydrates (22%) and amino acids (20%), and those related to the degradation of persistent environmental pollutants. In addition, a DNA metabarcoding analysis of the same samples, via the amplification and sequencing of the mtRNA 16S and rRNA 18S genes, was used to identify the prey consumed by harbor seals revealing the consumption of prey with mainly demersal habits. Functional redundancy in the seal gut microbiota was observed, irrespective of diet or location. Our results indicate that the frequency of occurrence of specific prey in the harbor seal diet plays an important role in shaping the composition of the gut microbiota of harbor seals by influencing the relative abundance of specific groups of gut microorganisms. A significant relationship was found among diet, gut microbiota composition and OTUs assigned to a particular metabolic pathway. © 2019 Pacheco-Sandoval et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

RNA 16S, RNA 18S, amino acid analysis, animal food, Article, bacterium colony, Bacteroidetes, basal metabolic rate, biodegradation, controlled study, DNA barcoding, feces analysis, Firmicutes, Fusobacteria, intestine flora, metabolism, Mexico, microb BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA ANIMAL (ZOOLOGÍA) BIOLOGÍA ANIMAL (ZOOLOGÍA)

Re-establishment of the genus Pseudalbizzia (Leguminosae, Caesalpinioideae, mimosoid clade): the New World species formerly placed in Albizia

GABRIELA AVILES PERAZA Erik Koenen Ricarda Riina Colin Hughes Jens Ringelberg GERMAN CARNEVALI FERNANDEZ CONCHA Ivón Mercedes Ramírez Morillo Lilia Lorena Can Itza Iván Tamayo-Cen Jorge Humberto Ramírez Prado Xavier Cornejo Sawai Mattapha RODRIGO STEFANO DUNO (2022, [Artículo])

Following recent mimosoid phylogenetic and phylogenomic studies demonstrating the non-monophyly of the genus Albizia, we present a new molecular phylogeny focused on the neotropical species in the genus, with much denser taxon sampling than previous studies. Our aims were to test the monophyly of the neotropical section Arthrosamanea, resolve species relationships, and gain insights into the evolution of fruit morphology. We perform a Bayesian phylogenetic analysis of sequences of nuclear internal and external transcribed spacer regions and trace the evolution of fruit dehiscence and lomentiform pods. Our results find further support for the non-monophyly of the genus Albizia, and confirm the previously proposed segregation of

Hesperalbizia, Hydrochorea, Balizia and Pseudosamanea. All species that were sampled from section Arthrosamanea form a clade that is sister to a clade composed of Jupunba, Punjuba, Balizia and Hydrochorea. We find that lomentiform fruits are independently derived from indehiscent septate fruits in both Hydrochorea and section Arthrosamanea. Our results show that morphological adaptations to hydrochory, associated with shifts into seasonally flooded habitats, have occurred several times independently in different geographic areas and different lineages within the ingoid clade. This suggests that environmental conditions have likely played a key role in the evolution of fruit types in Albizia and related genera. We resurrect the name Pseudalbizzia to accommodate the species of section Arthrosamanea, except for two species that were not sampled here but have been shown in other studies to be more closely related to other ingoid genera and we restrict the name Albizia s.s. to the species from Africa, Madagascar, Asia, Australia, and the Pacific. Twenty-one new nomenclatural combinations in Pseudalbizzia are proposed, including 16 species and 5 infraspecific varietal names. In addition to the type species Pseudalbizzia berteroana, the genus has 17 species distributed across tropical regions of the Americas, including the Caribbean. Finally, a new infrageneric classification into five sections is proposed and a distribution map of the species of Pseudalbizzia is presented.

ARTHROSAMANEA HYDROCHORY MONOPHYLY NEOTROPICS PHYLOGENY TAXONOMY BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) TAXONOMÍA VEGETAL TAXONOMÍA VEGETAL

Revisiting the phylogeny and taxonomy of the Pithecellobium clade (Leguminosae, Caesalpinioideae) with new generic circumscriptions

Iván Tamayo-Cen Benjamin Torke JOSE ENRIQUE LOPEZ CONTRERAS GERMAN CARNEVALI FERNANDEZ CONCHA Ivón Mercedes Ramírez Morillo Lilia Lorena Can Itza RODRIGO STEFANO DUNO (2022, [Artículo])

We present the most complete molecular phylogeny to date of the Pithecellobium clade of subfamily Caesalpinioideae. This neotropical group was informally recognised (as the Pithecellobium alliance) at the end of the 20th century by Barneby and Grimes (1996) and includes five genera and 33 species distributed from the southern United States and Caribbean Islands to north-eastern South America. Our aims were to further test the monophyly of the group and its genera and to identify sister group relationships within and amongst the genera. A phylogenetic analysis of nuclear ribosomal DNA sequences (ITS and ETS) was performed. The results provide further support for the monophyly of the Pithecellobium clade. The genera Ebenopsis, Pithecellobium and Sphinga were strongly supported as monophyletic. Havardia and Painteria were found to be non-monophyletic, prompting their re-circumscriptions and the description of two new genera: Gretheria and Ricoa. New combinations are made for the three species transferred to the new genera. © Iván Tamayo-Cen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

FABACEAE INGEAE INGOID CLADE MIMOSOID NEW WORLD PHYLOGENETIC SYSTEMATIC TAXONOMY BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) TAXONOMÍA VEGETAL TAXONOMÍA VEGETAL

Strong floristic distinctiveness across Neotropical successional forests

Catarina Jakovac Jorge Arturo Meave del Castillo Frans Bongers Susan Letcher JUAN MANUEL DUPUY RADA Daniel Piotto Danaë Rozendaal Marielos Peña-Claros Dylan Craven Braulio Santos Alexandre Siminski Alfredo Fantini Alice Cristina Rodrigues Alma Hernandez-Jaramillo Álvaro Idárraga-Piedrahita André Junqueira Angelica Almeyda Zambrano Bernardus de Jong Bruno X. Pinho Bryan Finegan Carolina Castellanos Castro Daisy Christiane Zambiazi Daisy Dent Daniel Hernán Garcia-Villalobos Deborah Kennard Diego Delgado Eben Broadbent Edgar Ortiz-Malavasi Eduardo A. Pérez-García Edwin Lebrija-Trejos Erika Berenguer Erika Marin-Spiotta Esteban Alvarez_Davila EVERARDO VALADARES DE SÁ SAMPAIO Felipe Melo Fernando Elias Filipe França Florian Oberleitner Francisco Mora Ardila G. Bruce Williamson Gabriel Colletta George Cabral Geraldine Derroire Geraldo Fernandes Hans van der Wal Heitor Mancini Teixeira Henricus F.M. Vester Hernando Garcia Ima Vieira Jaider Jiménez-Montoya Jarcilene Almeida Cortez Jefferson Hall Jerome Chave Jess Zimmerman Jhon Edison Nieto Vargas Joice Ferreira JORGE ENRIQUE RODRIGUEZ VELAZQUEZ Jorge Ruiz Jos Barlow Jose Aguilar Cano JOSE LUIS HERNANDEZ STEFANONI Julien Engel Justin Becknell Kátia Janaina Zanini Madelon Lohbeck Marcelo Tabarelli Marco Antonio Romero Romero Maria Uriarte Maria das Dores Magalhães Veloso Mário do Espírito Santo Masha van der Sande Michiel van Breugel Miguel Martínez-Ramos Naomi Schwartz Natalia Norden Nathalia Pérez-Cárdenas Noel Antonio González_Valdivia PASCAL PETRONELLI Patricia Balvanera Paulo Massoca Pedro Brancalion Pedro Manuel Villa Peter Hietz Rebecca Ostertag René López Camacho Ricardo Cesar Rita Mesquita Robin Chazdon Rodrigo Muñoz Saara DeWalt Sandra Müller Sandra M Duran Sebastião Martins Susana Ochoa-Gaona Susana Rodriguez-Buritica T. Mitchell Aide Tony Vizcarra Bentos Vanessa de Souza Moreno Laura Vanessa Granda William Thomas Whendee Silver YULE NUNES Lourens Poorter (2022, [Artículo])

Forests that regrow naturally on abandoned fields are important for restoring biodiversity and ecosystem services, but can they also preserve the distinct regional tree floras? Using the floristic composition of 1215 early successional forests (≤20 years) in 75 human-modified landscapes across the Neotropic realm, we identified 14 distinct floristic groups, with a between-group dissimilarity of 0.97. Floristic groups were associated with location, bioregions, soil pH, temperature seasonality, and water availability. Hence, there is large continental-scale variation in the species composition of early successional forests, which is mainly associated with biogeographic and environmental factors but not with human disturbance indicators. This floristic distinctiveness is partially driven by regionally restricted species belonging to widespread genera. Early secondary forests contribute therefore to restoring and conserving the distinctiveness of bioregions across the Neotropical realm, and forest restoration initiatives should use local species to assure that these distinct floras are maintained. Copyright © 2022 The Authors, some rights reserved.

CONSERVATION ECOSYSTEMS FORESTRY BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) ECOLOGÍA VEGETAL ECOLOGÍA VEGETAL