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In this bibliographic essay I first give some of the reasons that, in my opinion, had led to the lack of knowledge about the Chicago School as regards the Literary Criticism. Afterwards I have prepared a basic bibliography on Neo-Aristotelians, which up to the present time, has been little known due to its dispersion and lack of organization in a general project. The primary sources show an intellectual activity which has been both long and huge, regarding time and its interests respectively; whereas the secondary sources embody a fair view of the response that the Chicago School has been given throughout the years. This bibliography is meant to be neither exhaustive nor critic, but a first serious approach to the theoretical and critical activity of a group of scholars with common interests who are a very important milestone in the 20th-century American literary criticism.

The genus Urotrygon comprises small‐ to medium‐sized endemic round rays on the American continent and has undergone several synonymization processes. Here, we used an integrative taxonomic approach, including meristic, morphometric, and mtDNA analyses, to resolve the particularly intricate relationship among Urotrygon munda Gill, 1863, Urotrygon chilensis (Günther, 1872), and Urotrygon asterias (Jordan & Gilbert, 1883). The latter species is currently a synonym of U. munda but is also considered the U. chilensis "northern morphotype." These taxonomic entities have historically been confounded, mainly due to their phenotypical resemblance along their geographic distribution in the eastern Pacific. We assessed 78 specimens (43 "northern" and 30 "southern morphotypes" of U. chilensis, as well as 5 U. munda) using 19 external variables for taxonomic and morphometric analysis. Distinct meristic patterns, including pectoral and pelvic ceratotrichia, vertebrae number, and thorn distribution along the dorsal midline, were observed in the series‐type specimens of the three taxonomic entities. Our multivariate morphometric analyses consistently differentiated the three groups as distinct taxonomic entities, with an overall classification accuracy of 66.7%. The meristic results also provided reliable information distinguishing the three entities. Based on the nicotinamide adenine dinucleotide (NADH2) and cytochrome oxidase subunit I (COI) genes, our phylogenetic analysis were consistent with the morphometric and meristic data, supporting these three entities as distinct species having their own evolutionary lineages. Our comprehensive approach confidently demonstrated that the northern U. chilensis morphotype matched and corresponded to the description of the Starry round ray, U. asterias, confirming its taxonomic resurrection as a valid species distinct from U. chilensis and U. munda. The geographic distribution of U. asterias spans from the tropical west coast of Mexico (including the Gulf of California) to Costa Rica, revealing that microevolutionary processes have well‐defined population clades within this range. Furthermore, U. chilensis is unequivocally established as the sole Urotrygon species occurring south of the Guayaquil marine ecoregion. In addition, the public COI and NADH2 sequences available for Urotrygon hosted in the ad hoc online databases were found to be misidentified, emphasizing the need for rigorous taxonomic scrutiny in this group. Finally, our research underscores the significance of an integrative approach that combines morphometric, meristic, and molecular techniques with historical data to disentangle the complexities of closely related taxa. [ABSTRACT FROM AUTHOR]

The taxonomic status of butterfly rays within the genus Gymnura remains a subject of ongoing debate among researchers. Some authors recognize up to five valid species for the Americas, while others considered several to be synonyms, which has posed a persistent challenge. We aimed to shed light on this complexity by employing molecular operational taxonomic units (MOTUs) based on the mitochondrial gene cytochrome oxidase I (COI). Genetic sequences were obtained from fresh muscle tissue collected in the marine ecoregions corresponding to the type locality from all the nominal butterfly ray species distributed along the Eastern Tropical Pacific (ETP). Our results unveiled compelling findings; all the species delimitation models used consistently identified seven MOTUs for the American continent and an extra G. altavela MOTU restricted to Africa. In addition, our results and models exceeded the worldwide accepted interspecific threshold of 2.0%. Remarkably, our results support the taxonomic reinstatement of Gymnura afuerae (Hildebrand, 1946) as a valid species, with a range expanding into the ETP in the Southern Hemisphere. Similarly, our data support the recent suggestion of resurrecting Gymnura valenciennii (Duméril, 1865) as a valid species in the western Atlantic. These findings urge a reassessment of the conservation status and a comprehensive taxonomic revision of American butterfly rays. [ABSTRACT FROM AUTHOR]

Body morphology is a valuable feature for distinguishing teleostean fishes. However, the utility of character variation in separate body regions has yet to be tested. The taxonomy of the Gerreidae family is controversial due to character overlapping among its fish species. This work aims to analyze and compare the body shape variation in three regions, cephalic, trunk, and caudal peduncle, using landmark data and geometric morphometric methods in 17 species and five genera of the family Gerreidae. The pattern of shape variation for the cephalic region consisted of well‐defined character states exclusive of each species analyzed. Shape variation in the trunk and caudal peduncle regions does not distinguish all species in this study. This study showed that the dorsal cephalic profile is highly variable among the species, therefore, shape variation in this region is useful for distinguishing Gerreidae species. In contrast, some species within the same genus share similar shape states in the trunk and caudal peduncle regions, with the most shape variation in the dorsal profile and anal fin for the trunk and in the middle of the caudal peduncle. [ABSTRACT FROM AUTHOR]

Twenty-three species and four subspecies of odontocete belonging to five families (Delphinidae, Physeteridae, Kogiidae, Phocoenidae, and Ziphiidae) are distributed along the Pacific coast of northern Mexico. The morphological variability of these species has been studied extensively and a number of taxonomic studies have focused on cranial characteristics. The goal of this study was to describe the periotics of the odontocetes of the Pacific coast of northern Mexico and develop a taxonomic tool using descriptions of each species. We used a geometric morphometric analysis of 186 periotics housed in local and national osteological collections. Our results show the taxonomic value of periotics and a significant phylogenetic signal associated with this structure. Based on these results we present a descriptive catalog that can be used for identification purposes. En la costa noroeste del Pacífico mexicano, se distribuyen 23 especies y cuatro subespecies de odontocetos pertenecientes a cinco familias (Delphinidae, Physeteridae, Kogiidae, Phocoenidae y Ziphiidae). La alta variabilidad morfológica de estas especies ha sido objeto de diversas investigaciones, varias de las cuales se han centrado en aspectos taxonómicos basados en características craneales. El objetivo de este estudio fue describir los perióticos de los odontocetos de la costa noroeste del Pacífico mexicano y elaborar una herramienta taxonómica a través de la descripción de cada especie. Se realizó un análisis de morfometría geométrica empleando 186 perióticos depositados en colecciones osteológicas locales y nacionales. Nuestros resultados enfocados en 17 especies, indicaron que los perióticos son estructuras que presentan valor taxonómico y señal filogenética. Con base en los resultados morfométricos y las observaciones directas, preparamos un catálogo que describe los perióticos de cada especie, el cual se podrá emplear como una herramienta útil para fines de identificación. [ABSTRACT FROM AUTHOR]

2-deoxyglucose is a glucose analog that impacts many aspects of cellular physiology. After its uptake and its phosphorylation into 2-deoxyglucose-6-phosphate (2DG6P), it interferes with several metabolic pathways including glycolysis and protein N-glycosylation. Despite this systemic effect, resistance can arise through strategies that are only partially understood. In yeast, 2DG resistance is often associated with mutations causing increased activity of the yeast 5'-AMP activated protein kinase (AMPK), Snf1. Here we focus on the contribution of a Snf1 substrate in 2DG resistance, namely the alpha-arrestin Rod1 involved in nutrient transporter endocytosis. We report that 2DG triggers the endocytosis of many plasma membrane proteins, mostly in a Rod1-dependent manner. Rod1 participates in 2DG-induced endocytosis because 2DG, following its phosphorylation by hexokinase Hxk2, triggers changes in Rod1 post-translational modifications and promotes its function in endocytosis. Mechanistically, this is explained by a transient, 2DG-induced inactivation of Snf1/AMPK by protein phosphatase 1 (PP1). We show that 2DG-induced endocytosis is detrimental to cells, and the lack of Rod1 counteracts this process by stabilizing glucose transporters at the plasma membrane. This facilitates glucose uptake, which may help override the metabolic blockade caused by 2DG, and 2DG export—thus terminating the process of 2DG detoxification. Altogether, these results shed a new light on the regulation of AMPK signaling in yeast and highlight a remarkable strategy to bypass 2DG toxicity involving glucose transporter regulation. Author summary: In this article, we study the resistance to a drug named 2-deoxyglucose (2DG). 2DG is an efficient inhibitor of several metabolic pathways, particularly glycolysis which is of prime importance for tumor cell proliferation. Cancer cells but also cells from other organisms can develop various resistance strategies that only being unraveled. Here, using baker's yeast as a model organism, we document the resistance mechanism of a mutant lacking the arrestin gene ROD1, known to regulate nutrient transporter endocytosis. First, we show that 2DG triggers the endocytosis of many nutrient transporters. Mechanistically, 2DG leads to a transient inhibition of the AMPK signaling pathway, which in turn promotes the activation of Rod1, a pre-requisite for 2DG-induced endocytosis. Consequently, cells lacking Rod1 maintain various proteins at the plasma membrane including hexose transporters, the latter being essential for 2DG resistance. Hexose transporter stabilization at the cell surface may sustain glucose import and help cells cope with the 2DG-induced metabolic blockade, while also allowing 2DG detoxication. [ABSTRACT FROM AUTHOR]

Twenty-three species and four subspecies of odontocete belonging to five families (Delphinidae, Physeteridae, Kogiidae, Phocoenidae, and Ziphiidae) are distributed along the Pacific coast of northern Mexico. The morphological variability of these species has been studied extensively and a number of taxonomic studies have focused on cranial characteristics. The goal of this study was to describe the periotics of the odontocetes of the Pacific coast of northern Mexico and develop a taxonomic tool using descriptions of each species. We used a geometric morphometric analysis of 186 periotics housed in local and national osteological collections. Our results show the taxonomic value of periotics and a significant phylogenetic signal associated with this structure. Based on these results we present a descriptive catalog that can be used for identification purposes. [ABSTRACT FROM AUTHOR]

Although morphological abnormalities in several rays and skate species around the American continents have frequently mentioned, their numbers are unknown. The present work record morphological abnormalities in four Urotrygonidae species. Two anophthalmic specimens were detected (Urotrygon microphthalmum and Urobatis halleri). Two individuals lacked caudal fins (Urobatis maculatus and Urotrygon chilensis). Two round rays showed incomplete fusion of the pectoral fin to the head (U. microphthalmum and U. chilensis). Vertebral compression and fusion were found in a 6‐year‐old female Urotrygon rogersi. In addition, 118 abnormal batomorph specimens were gathered from the available bibliography, spanning the last six decades (1959–2021). Amblyraja doellojuradoi was the species with the highest number of abnormalities (18). The most common anomaly was an incomplete fusion of the pectoral fin with the head. Since 2010, at least 30 anomalous batomorphs have been recorded every 5 years. Sixty‐nine abnormal specimens occurred in the Northern Hemisphere (1.00–60.00 N). The Cortezian (Pacific) and Southeastern Brazil (Atlantic) marine ecoregions stood out with the highest number of these specimens. Mexico recorded 58 anomalous specimens, followed by Brazil (n = 36). Biological, abiotic and anthropogenic factors are probably the leading causes. However, additional studies are necessary to elucidate these speculations. [ABSTRACT FROM AUTHOR]

Loliginid squids from the northeastern Pacific are partially sympatric, and their identification is difficult as their diagnostic characters often overlap. Statoliths are hard structures that may vary with respect to phylogeny and thus have potential use in taxonomy. This, however, has to be investigated using robust methods. Here, we employ geometric morphometrics to evaluate the taxonomic utility of statolith shape in loliginids caught in Mexican waters and to acquire knowledge on statolith evolution through comparative phylogenetic methods. The loliginid species we examined showed specific statolith morphology that facilitates species identification. Our results also show that statolith shape has a strong phylogenetic signal and is a powerful character for species recognition. The ancestral statolith morphologies are not very different from extant forms, probably reflecting the relatively recent origin of the two genera evaluated and their low evolutionary rate. In addition, the evolution of statolith shape in species of the genus Lolliguncula seems to have been faster than that in the genus Doryteuthis , especially in L. panamensis , which could be related to habitat differentiation in the neritic coastal environment inhabited by loliginid squids. Our analysis of statolith shape demonstrates the potential for combining neontology and paleontology in understanding the diversification of loliginid squids. [ABSTRACT FROM AUTHOR]

Urotrygon chilensis (Günther, 1872) was described based on a single specimen acquired by the British Museum of Natural History, London, from the Johan Cesar Godeffroy Museum in Hamburg. This medium-sized, benthic stingray is found along the eastern Pacific shelf (distance ranging almost 7000 km). During the last century, it has been frequently mentioned in the taxonomy and biogeography of Chile's marine fishes. However, since the original description in 1872, no other record of this species has been reported from Chilean waters. In this study, the historical presence of U. chilensis in Chile was confirmed based on three mature male specimens held at the Zoological Museum of the University of Hamburg (ZMH) collected in Taltal Harbour (Chile) in July 1894. According to the International Code of Zoological Nomenclature guidelines, we propose Taltal Harbour as the type locality of U. chilensis. Additionally, we conduct a historical review to determine how Albert Günther might have obtained the holotype. The discovery of these specimens catalogued in the fish collection at the ZMH is a demonstration of the important role that natural history museums play in documenting biodiversity patterns. The geographical distribution of U. chilensis is extended to the Central Chile marine ecoregion, approximately 1,500 km southward, from records in available databases. However, 126 years after its last recorded capture off Chile's coast, the historical presence of U. chilensis at such southern latitudes seems to reflect vagrancy in response to weather conditions. [ABSTRACT FROM AUTHOR]

Octopus hubbsorum is the most commonly captured species of octopus on the western coast of Mexico. Despite the commercial importance of this species, management information remains scarce. We determined the genetic diversity and population genetic structure of O. hubbsorum by using mtDNA sequences (COI and ND5). The population structure was not supported byAMOVAor a spatial clustering model. Furthermore, an isolation by distance model did not explain our data. Three haplogroups were detected using a Bayesian assignment; however, the distribution of these haplogroups did not differ among the sampling sites. Our results indicated historical processes of a sudden population expansion, as has been reported for other species in the study region as consequence of climatic changes. However, this expansion did not affect the distribution of the mitochondrial lineages analysed in the study. The weak population genetic structure in O. hubbsorum associated with the life history of the species can explain our results. We suggest that to expand knowledge regarding the genetic structure and population dynamics of O. hubbsorum throughout its range, markers such as microsatellites or single-nucleotide polymorphisms (SNPs) are needed. Thus, on the basis of the information available, the studied population should be assumed to have a weak genetic structure. [ABSTRACT FROM AUTHOR]

Sweet bell peppers are a Solanaceous fruit belonging to the Capsicum annuum L. species whose consumption is popular in world gastronomy due to its wide variety of colors (ranging green, yellow, orange, red, and purple), shapes, and sizes and the absence of spicy flavor. In addition, these fruits have a characteristic flavor and nutritional attributes that include ascorbic acid, polyphenols, and carotenoids. A quality criterion for the harvest of this fruit is maturity; this attribute is visually determined by the consumer when verifying the color of the fruit's pericarp. The present work proposes an artificial vision system that automatically describes ripeness levels of the bell pepper and compares the Fuzzy logic (FL) and Neuronal Networks for the classification stage. In this investigation, maturity stages of bell peppers were referenced by measuring total soluble solids (TSS), ° Brix, using refractometry. The proposed method was integrated in four stages. The first one consists in the image acquisition of five views using the Raspberry Pi 5 Megapixel camera. The second one is the segmentation of acquired image samples, where background and noise are removed from each image. The third phase is the segmentation of the regions of interest (green, yellow, orange and red) using the connect components algorithm to select areas. The last phase is the classification, which outputs the maturity stage. The classificatory was designed using Matlab's Fuzzy Logic Toolbox and Deep Learning Toolbox. Its implementation was carried out onto Raspberry Pi platform. It tested the maturity classifier models using neural networks (RBF-ANN) and fuzzy logic models (ANFIS) with an accuracy of 100% and 88%, respectively. Finally, it was constructed with a content of ° Brix prediction model with small improvements regarding the state of art. [ABSTRACT FROM AUTHOR]

In the present study, the population genetic structure of the Pacific thread herring (Opisthonema libertate) was analyzed through mitochondrial DNA (mtDNA) control region sequences. Organisms were collected from June 2015 to July 2015 from four commercial landing sites (Bahia Magdalena, Guaymas and Mazatlan, Mexico, and Puntarenas, Costa Rica) and one artisanal sampling site (Puerto La Libertad, El Salvador). A total of 125 sequences were analyzed. High levels of haplotype (h = 0.990) and nucleotide (π = 0.030) diversity were found. Pairwise Φst comparisons indicated differences attributed mainly to the organisms from El Salvador. However, Bayesian inferences did not support the existence of different populations. The haplotype distribution between locations did not show a clear phylogeographic pattern. Mismatched distribution showed a unimodal pattern for the five sampled areas, indicative of sudden demographic expansion. These results were supported by Bayesian skyline plot. Our results do not support the hypothesis that the Pacific thread herring presents a population genetic structure. Future genetic comparisons should include a larger number of samples as well as more polymorphic molecular markers to further support our results. [ABSTRACT FROM AUTHOR]

Background. The Lacandon mojarra, Eugerres castroaguirrei González-Acosta et Rodiles-Hernández, 2013, was described from the Grijalva-Usumacinta River basin (Mexico). According to the diagnosis E. castroaguirrei differs from the only other freshwater Gerreidae, the Mexican mojarra, Eugerres mexicanus (Steindachner, 1863) by the combination of certain morphological characters. However, a comparison of materials obtained in the Usumacinta River, besides of type materials and other preserved specimens, yielded contradictory results. Therefore, the objective of this paper was to clearly determine if E. mexicanus and E. castroaguirrei are subjective synonyms applying morphological and molecular analyses. Materials and methods. A total of 44 specimens were included in this study including the specimens collected specifically for this study, the type and non-type materials of Eugerres castroaguirrei from Colección de Peces de El Colegio de la Frontera Sur, Unidad San Cristóbal, Chiapas, México, and the types of Eugerres mexicanus, belonging to the Museum of Natural History, Wien, Austria. The morphological comparison also included data from the 42 specimens of E. castroaguirrei reported in the new species description. Biometric data were analysed as body proportions. We used Friedman's test to compare our biological materials with those used in the new species description. Molecular genetics comparisons on both putative freshwater gerreid species were made based on three mitochondrial gene fragments: 12SrRNA, 16SrRNA, and Cytochrome Oxidase subunit I (COI), and the nuclear gene: Recombination-Activating protein 1 (RAG1). Results. Neither the non-parametric Friedman's test nor the Nemenyi's procedure showed differences among individuals for both putative species in multiple pair-wise comparisons of body proportions. Moreover, the genetic divergence from all genes indicated that all individuals exhibited almost identical sequences, with inter-specific pair-wise genetic distances that ranged from 0.00% to 0.100% in all of the fragments. Conclusion. Our morphological and molecular genetics analyses demonstrated that E. mexicanus and E. castroaguirrei are subjective synonyms, therefore, Eugerres mexicanus (Steindachner, 1863) must be considered a valid species name, and Eugerres castroaguirrei González-Acosta et Rodiles-Hernández, 2013 a junior synonym. [ABSTRACT FROM AUTHOR]

Background: In taxonomic studies of fish, the use of preserved samples has been a common practice. Under the framework of morphometrics, the effect of the preservation techniques on body shape is rarely taken into account. Changes during preservation can cause errors in the results, which may eventually lead to wrong conclusions. To explore the effect of a traditional preservation procedure, we quantified the changes in body shape and size of the golden mojarra, Diapterus aureolus (Jordan et Gilbert, 1882), using geometric morphometrics. Materials and methods: Fish fresh samples were photographed and frozen for at least seven months. Then, they were set in 10% formaldehyde, and passed through a wash of tap water and submerged in 70% ethanol. After five months the samples were photographed again. The differences between the mean shapes of two data groups (fresh fish and fixed specimens) were calculated by using the Procrustes distance. Effects associated with preservation were visualized by comparing the mean shape from each group, using a thin plate spline. A canonical variate analysis was carried out to detect the degree of intra- and inter-specific variation with D. brevirostris as an outgroup. Also, matrices of correct classification, based on Mahalanobis distances, were obtained. Results: Procrustes distance between the two data sets was statistically significant (P < 0.001), suggesting that the fixation process produces changes in body shape. Canonical Variate Analysis verified that there were significant differences among three groups (fresh D. aureolus, fixed D. aureolus, and D. brevirostris; P < 0.001 for both CV1 and CV2), which were correctly classified (98.9%). In spite of the significant differences detected between the fresh and fixed data sets, these were less than those found in the outgroup. The pooled data of all specimens belonging to D. aureolus (fresh and fixed) produced a definitive correct classification (100%) between D. aureolus and D. brevirostris, indicating that the differences caused by the preservation method is not enough to confound species and, consequently, taxonomic integrity was totally acceptable. Conclusion: Our results show a change in size and shape that are consistent with changes obtained with this and other methods applied to other species: generally shapes change and sizes tend to shrink with preservation of specimens. This is probably caused by dehydration from freezing and thawing, exposure to ethanol, and dissolution of skeletal structures caused by formaldehyde. While this effect was clear, it was not enough to confuse species. Caution is advised when working with groups with a close relation (populations or not clearly-defined species). We recommend a similar exercise with a case study with these levels of divergence. [ABSTRACT FROM AUTHOR]

Background. Although the species of the family Gerreidae have been subjected to many studies, their taxonomy at specific- and sometimes generic levels is still confusing. To contribute to the clarification of the taxonomy of the Mexican Pacific mojarras, the morphology of sagittal otoliths among six species of mojarras (Diapterus brevirostris, Eugerres lineatus, Eucinostomus dowii, E entomelas, E. currani, and Gerres cinereus) was compared using size and shape descriptors. Otolith shape has long been known to be species-specific but this has not been tested in species of the family Gerreidae. Therefore, our goal was to explore the effectiveness of otolith descriptors for identifying gerreid fish at species level. Materials and methods. Gerreid fish were captured between January 2009 and January 2010, off the Pacific coast of Mexico. The right- and left sagittae of 160 individuals were extracted for analysis. Size and shape descriptors considered in the presently reported analysis were: surface area, perimeter, length, width, rectangularity, ellipticity, roundness, circularity, aspect ratio, form-factor, Feret length, Feret width, Feret maximum, Feret minimum, diameter maximum, diameter minimum, diameter mean, ratio maximum, and ratio minimum. Other measurements were made in the otolith region of sulcus acusticus, such as: cauda length, ostium length, ostium width, sulcus length, and rostrum width. Canonical discriminant analysis on otoliths morphology was used to identify differences between species. Results. Rectangularity, roundness, otolith length, and Feret length were the main otolith descriptors that explain the inter-specific variability. Significant differences (Wilks' lambdas (λ), P < 0.001), high canonical correlation coefficients, and also a high classification success (overall mean >90%) allowed the separation of the species by using discriminant functions. Results from both G-test and Cohen's kappa procedure confirmed the high rates of classification success obtained by the discriminant analysis. Conclusion. These results suggest the usefulness of otolith morphology for differentiation of Gerreidae species from Mexican Pacific waters, thereby demonstrating that otolith shape is species-specific. Otolith morphology descriptions provided in this study is presented for the first time for the species included. [ABSTRACT FROM AUTHOR]

The shortbill spearfish Tetrapturus angustirostris Tanaka, 1915 is a widespread tropical and temperate species but is relatively rare, with very few published or cataloged records in museums and fish collections. We reported for the first time a specimen of T. angustirostris from the Pacific coast of Mexico, including meristic, morphometric and molecular data, which was caught in the vicinity of Los Cabos, Baja California Sur, Mexico, in November 2015. [ABSTRACT FROM AUTHOR]

Legionella pneumophila is the causative agent of Legionnaires' disease, a severe pneumonia. L. pneumophila injects via a type-IV-secretion-system (T4SS) more than 300 bacterial proteins into macrophages, its main host cell in humans. Certain of these bacterial effectors target organelles in the infected cell and hijack multiple processes to facilitate all steps of the intracellular life cycle of this pathogen. In this review, we discuss the interplay between L. pneumophila, an intracellular bacterium fully armed with virulence tools, and mitochondria, the extraordinary eukaryotic organelles playing prominent roles in cellular bioenergetics, cell-autonomous immunity and cell death. We present and discuss key findings concerning the multiple interactions of L. pneumophila with mitochondria during infection and the mechanisms employed by T4SS effectors that target mitochondrial functions to subvert infected cells., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Historically, the taxonomic identification of the two snook species, Centropomus viridis and C. nigrescens, has been challenging due to their morphological similarity and the inconsistency of the characters used for diagnosis. Therefore, this study aimed to evaluate the usefulness of the morphologic, meristic, and morphometric characters currently being used to identify C. viridis and C. nigrescens, based on molecular data. The results showed that the gas-bladder shape (i.e., C. viridis with diverticula and C. nigrescens without diverticula) was the only morphological character univocally related to genetic identification. Likewise, geometric morphometrics separated two groups; each corresponds to only one of two genetically (and gas bladder shape) identified species. Of all the meristic characters examined, only the second dorsal fin ray count (nine for C. viridis and ten for C. nigrescens) was related to the gas bladder shape and genetic identity; therefore, it is the only external character with a diagnostic utility to separate each species.

Species of the genus Octopus from the northeastern Pacific are ecologically and economically important; however, their taxonomy is confusing and has not been comprehensively assessed. In this study, we performed a taxonomic evaluation of these species considering the morphological characteristics of the original descriptions, a molecular analysis of partial COI-gene sequences, and a traditional morphometry analysis of nine body measurements. Several interesting findings were obtained with our results: for instance, we updated the diagnoses of some species by including characters such as the number of lamellae per demibranch and the presence of chromatophores in the visceral sac; we deposited partial COI-gene sequences of species that had not been incorporated into the GenBank repository; and according to the morphometric analysis, we confirmed that the lengths of arms I-IV are relevant to discriminate the species under study. The taxa evaluated were morphologically, molecularly and morphometrically well-delimited; however, features such as funnel organ shape and arm length proportions in regard to dorsal mantle length are either not included in the diagnosis of the genus Octopus or overlap with other genera. Hence, this information, combined with the results obtained from the molecular analysis, supports the generic re-assignation of two of the species evaluated., Competing Interests: The authors declare that they have no competing interests., (© 2019 Díaz-Santana-Iturrios et al.)

Cisplatin and derivatives are commonly used as chemotherapeutic agents. Although the cytotoxic action of cisplatin on cancer cells is very efficient, clinical oncologists need to deal with two major difficulties, namely the onset of resistance to the drug and the cytotoxic effect in patients. Here, we used Caenorhabditis elegans to investigate factors influencing the response to cisplatin in multicellular organisms. In this hermaphroditic model organism, we observed that sperm failure is a major cause of cisplatin-induced infertility. RNA sequencing data indicate that cisplatin triggers a systemic stress response, in which DAF-16/FOXO and SKN-1/NRF2, two conserved transcription factors, are key regulators. We determined that inhibition of the DNA damage-induced apoptotic pathway does not confer cisplatin protection to the animal. However, mutants for the pro-apoptotic BH3-only gene ced-13 are sensitive to cisplatin, suggesting a protective role of the intrinsic apoptotic pathway. Finally, we demonstrated that our system can also be used to identify mutations providing resistance to cisplatin and therefore potential biomarkers of innate cisplatin-refractory patients. We show that mutants for the redox regulator trxr-1 , ortholog of the mammalian thioredoxin reductase 1 TRXR1 , display cisplatin resistance. By CRISPR/Cas9, we determined that such resistance relies on the presence of the single selenocysteine residue in TRXR-1.This article has an associated First Person interview with the first author of the paper., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2018. Published by The Company of Biologists Ltd.)

Genes coding for members of the Sm-like (LSm) protein family are conserved through evolution from prokaryotes to humans. These proteins have been described as forming homo- or heterocomplexes implicated in a broad range of RNA-related functions. To date, the nuclear LSm2-8 and the cytoplasmic LSm1-7 heteroheptamers are the best characterized complexes in eukaryotes. Through a comprehensive functional study of the LSm family members, we found that lsm-1 and lsm-3 are not essential for C. elegans viability, but their perturbation, by RNAi or mutations, produces defects in development, reproduction, and motility. We further investigated the function of lsm-1, which encodes the distinctive protein of the cytoplasmic complex. RNA-seq analysis of lsm-1 mutants suggests that they have impaired Insulin/IGF-1 signaling (IIS), which is conserved in metazoans and involved in the response to various types of stress through the action of the FOXO transcription factor DAF-16. Further analysis using a DAF-16::GFP reporter indicated that heat stress-induced translocation of DAF-16 to the nuclei is dependent on lsm-1. Consistent with this, we observed that lsm-1 mutants display heightened sensitivity to thermal stress and starvation, while overexpression of lsm-1 has the opposite effect. We also observed that under stress, cytoplasmic LSm proteins aggregate into granules in an LSM-1-dependent manner. Moreover, we found that lsm-1 and lsm-3 are required for other processes regulated by the IIS pathway, such as aging and pathogen resistance., (© 2015 Cornes et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.)