Climate change is an environmental emergency threatening species and ecosystems globally. Oceans have absorbed about 90% of anthropogenic heat and 20%-30% of the carbon emissions, resulting in ocean warming, acidification, deoxygenation, changes in ocean stratification and nutrient availability, and more severe extreme events. Given predictions of further changes, there is a critical need to understand how marine species will be affected. Here, we used an integrated risk assessment framework to evaluate the vulnerability of 132 chondrichthyans in the Eastern Tropical Pacific (ETP) to the impacts of climate change. Taking a precautionary view, we found that almost a quarter (23%) of the ETP chondrichthyan species evaluated were highly vulnerable to climate change, and much of the rest (76%) were moderately vulnerable. Most of the highly vulnerable species are batoids (77%), and a large proportion (90%) are coastal or pelagic species that use coastal habitats as nurseries. Six species of batoids were highly vulnerable in all three components of the assessment (exposure, sensitivity and adaptive capacity). This assessment indicates that coastal species, particularly those relying on inshore nursery areas are the most vulnerable to climate change. Ocean warming, in combination with acidification and potential deoxygenation, will likely have widespread effects on ETP chondrichthyan species, but coastal species may also contend with changes in freshwater inputs, salinity, and sea level rise. This climate-related vulnerability is compounded by other anthropogenic factors, such as overfishing and habitat degradation already occurring in the region. Mitigating the impacts of climate change on ETP chondrichthyans involves a range of approaches that include addressing habitat degradation, sustainability of exploitation, and species-specific actions may be required for species at higher risk. The assessment also highlighted the need to further understand climate change\'s impacts on key ETP habitats and processes and identified knowledge gaps on ETP chondrichthyan species.
El cambio climático es una emergencia medioambiental que amenaza a especies y ecosistemas en todo el mundo. Los océanos han absorbido alrededor del 90% del calor antropogénico y entre el 20% y el 30% de las emisiones de carbono, lo que ha provocado su calentamiento, acidificación, desoxigenación, cambios en la estratificación de los océanos y en la disponibilidad de nutrientes, así como fenómenos extremos más pronunciados. Dadas las predicciones de cambios, hay una importante necesidad de entender cómo las especies marinas se verán afectadas. En este estudio utilizamos una Evaluación Integrada de Riesgos para evaluar la vulnerabilidad de 132 condrictios del Pacífico Tropical Oriental (PTO) a los impactos del cambio climático. Adoptando un enfoque preventivo, estimamos que la vulnerabilidad general al cambio climático es Alta para casi una cuarta parte (23%) de las especies de condrictios del PTO evaluadas y Moderada para gran parte del resto (76%). La mayoría de las especies altamente vulnerables son batoideos (77%), y una gran proporción de éstas (90%) son especies costeras o especies pelágicas que utilizan los hábitats costeros como áreas de crianza. Seis especies de batoideos tuvieron una vulnerabilidad Alta en los tres componentes de la evaluación. Esta evaluación indica que las especies costeras, en particular las que dependen de áreas de crianza costeras, son las más vulnerables al cambio climático. Es probable que el calentamiento de los océanos, junto con la acidificación y la posible desoxigenación, tenga efectos generalizados sobre las especies de condrictios del PTO, pero las especies costeras se verán también afectadas por los cambios en los aportes de agua dulce, la salinidad y el aumento del nivel del mar. Esta vulnerabilidad relacionada con el clima se ve agravada por otros factores antropogénicos que ya se están produciendo en la región, como la sobrepesca y la degradación del hábitat. La mitigación de los impactos del cambio climático sobre los condrictios del PTO implica medidas que incluyan abordar la degradación del hábitat y la sostenibilidad de la explotación pesquera, y acciones para las especies de mayor riesgo son necesarias. Esta evaluación también destaca la necesidad de comprender mejor los impactos del cambio climático en los hábitats y procesos clave del PTO y las lagunas de conocimiento identificadas en relación con las especies de condrictios del PTO.

The preimplantation mammalian (including mouse and human) embryo holds remarkable regulatory abilities, which have found their application, for example, in the preimplantation genetic diagnosis of human embryos. Another manifestation of this developmental plasticity is the possibility of obtaining chimaeras by combining either two embryos or embryos and pluripotent stem cells, which enables the verification of the cell pluripotency and generation of genetically modified animals used to elucidate gene function. Using mouse chimaeric embryos (constructed by injection of embryonic stem cells into the eight-cell embryos) as a tool, we aimed to explore the mechanisms underlying the regulatory nature of the preimplantation mouse embryo. We comprehensively demonstrated the functioning of a multi-level regulatory mechanism involving FGF4/MAPK signalling as a leading player in the communication between both components of the chimaera. This pathway, coupled with apoptosis, the cleavage division pattern and cell cycle duration controlling the size of the embryonic stem cell component and giving it a competitive advantage over host embryo blastomeres, provides a cellular and molecular basis for regulative development, ensuring the generation of the embryo characterised by proper cellular composition.

Eriodictyol is a hydroxylated flavonoid displaying multiple pharmaceutical activities, such as antitumoral, antiviral or neuroprotective. However, its industrial production is limited to extraction from plants due to its inherent limitations. Here, we present the generation of a Streptomyces albidoflavus bacterial factory edited at the genome level for an optimized de novo heterologous production of eriodictyol. For this purpose, an expansion of the Golden Standard toolkit (a Type IIS assembly method based on the Standard European Vector Architecture (SEVA)) has been created, encompassing a collection of synthetic biology modular vectors (adapted for their use in actinomycetes). These vectors have been designed for the assembly of transcriptional units and gene circuits in a plug-and-play manner, as well as for genome editing using CRISPR-Cas9-mediated genetic engineering. These vectors have been used for the optimization of the eriodictyol heterologous production levels in S. albidoflavus by enhancing the flavonoid-3\'-hydroxylase (F3\'H) activity (by means of a chimera design) and by replacing three native biosynthetic gene clusters in the bacterial chromosome with the plant genes matBC (involved in extracellular malonate uptake and its intracellular activation into malonyl-CoA), therefore allowing more malonyl-CoA to be devoted to the heterologous production of plant flavonoids in this bacterial factory. These experiments have allowed an increase in production of 1.8 times in the edited strain (where the three native biosynthetic gene clusters have been deleted) in comparison with the wild-type strain and a 13 times increase in eriodictyol overproduction in comparison with the non-chimaera version of the F3\'H enzyme.

Animal breeding drives genetic progress mainly through the male germline. This process is slow to respond to rapidly mounting environmental pressures that threaten sustainable food security from animal protein production. New approaches promise to accelerate breeding by producing chimaeras, which comprise sterile host and fertile donor genotypes, to exclusively transmit elite male germlines. Following gene editing to generate sterile host cells, the missing germline can be restored by transplanting either: (i) spermatogonial stem cells (SSCs) into the testis; or (ii) embryonic stem cells (ESCs) into early embryos. Here we compare these alternative germline complementation strategies and their impact on agribiotechnology and species conservation. We propose a novel breeding platform that integrates embryo-based complementation with genomic selection, multiplication, and gene modification.

An important challenge in ecology is to understand variation in species\' maximum intrinsic rate of population increase, r max , not least because r max underpins our understanding of the limits of fishing, recovery potential, and ultimately extinction risk. Across many vertebrate species, terrestrial and aquatic, body mass and environmental temperature are important correlates of r max . In sharks and rays, specifically, r max is known to be lower in larger species, but also in deep sea ones. We use an information-theoretic approach that accounts for phylogenetic relatedness to evaluate the relative importance of body mass, temperature, and depth on r max . We show that both temperature and depth have separate effects on shark and ray r max estimates, such that species living in deeper waters have lower r max . Furthermore, temperature also correlates with changes in the mass scaling coefficient, suggesting that as body size increases, decreases in r max are much steeper for species in warmer waters. These findings suggest that there are (as-yet understood) depth-related processes that limit the maximum rate at which populations can grow in deep-sea sharks and rays. While the deep ocean is associated with colder temperatures, other factors that are independent of temperature, such as food availability and physiological constraints, may influence the low r max observed in deep-sea sharks and rays. Our study lays the foundation for predicting the intrinsic limit of fishing, recovery potential, and extinction risk species based on easily accessible environmental information such as temperature and depth, particularly for data-poor species.

The taxon Elasmobranchii (sharks and rays) contains one of the long-established evolutionary lineages of vertebrates with a tantalizing collection of species occupying critical aquatic habitats. To overcome the current limitation in molecular resources, we launched the Squalomix Consortium in 2020 to promote a genome-wide array of molecular approaches, specifically targeting shark and ray species. Among the various bottlenecks in working with elasmobranchs are their elusiveness and low fecundity as well as the large and highly repetitive genomes. Their peculiar body fluid composition has also hindered the establishment of methods to perform routine cell culturing required for their karyotyping. In the Squalomix consortium, these obstacles are expected to be solved through a combination of in-house cytological techniques including karyotyping of cultured cells, chromatin preparation for Hi-C data acquisition, and high fidelity long-read sequencing. The resources and products obtained in this consortium, including genome and transcriptome sequences, a genome browser powered by JBrowse2 to visualize sequence alignments, and comprehensive matrices of gene expression profiles for selected species are accessible through https://github.com/Squalomix/info.

Antimicrobial peptides (AMPs) are gene encoded short peptides which play an important role in the innate immunity of almost all living organisms ranging from bacteria to mammals. Histones play a very important role in defense as precursors to bioactive peptides. The present study is an attempt to decipher the antimicrobial activity of a histone H2A derived peptide, Harriottin-1 from sicklefin chimaera, Neoharriotta pinnata. Analysis in silico predicted the molecule with potent antibacterial and anticancer property. The Harriottin-1 was recombinantly produced and the recombinant peptide rHar-1 demonstrated potent antibacterial activity at 25 μM besides anticancer activity. The study strongly suggests the importance of histone H2A derived peptides as a model for the design and synthesis of potent peptide drugs.

This study aimed to establish the distribution of As, Cd, Cu, Pb, and Zn, in the muscle and liver of the spotted ratfish Hydrolagus colliei from the northern Gulf of California to establish the bioaccumulation background data in this species. The individuals (n = 110) were obtained by bycatch from the Gulf of California hake fisheries, and the metals and metalloid were measured by atomic absorption spectrometry. The element with the highest concentration in the muscle (15.19 ± 5.40 mg kg-1) and the liver (20.98 ± 10.30 mg kg-1) was As, followed by essential elements (Zn > Cu), and the lowest were the non-essential Pb (0.029 ± 0.014 and 0.048 ± 0.038 mg kg-1, muscle and liver, respectively) and Cd (0.022 ± 0.014 and 0.796 ± 0.495 mg kg-1, muscle and liver, respectively). The liver showed higher bioaccumulation than the muscle in all the studied elements. The sex was not a factor that influenced the bioaccumulation. The concentrations of As in the muscle did not exceed the maximum permissible limits of Mexican legislation, and < 50% of the samples exceed Cd and Pb limits of the Mexican, European Union, and WHO/FAO regulations. The differences found between the elements and tissues could be related to the different diets of the species, their migratory patterns, and their life conditions. Studies in the deep-sea water H. colliei are limited, and further investigations are needed regarding the feeding habits of H. colliei as well as the interactions of potentially toxic elements within the deep-sea water habitat.

Some human preimplantation embryos are chromosomally mosaic. For technical reasons, estimates of the overall frequency vary widely from <15 to >90% and the true frequency remains unknown. Aneuploid/diploid and aneuploid/aneuploid mosaics typically arise during early cleavage stages before the embryonic genome is fully activated and when cell cycle checkpoints are not operating normally. Other mosaics include chaotic aneuploid mosaics and mixoploids, some of which arise by abnormal chromosome segregation at the first cleavage division. Chimaeras are similar to mosaics, in having two genetically distinct cell populations, but they arise from more than one zygote and occur less often. After implantation, the frequency of mosaic embryos declines to about 2% and most are trisomic/diploid mosaics, with trisomic cells confined to the placenta. Thus, few babies are born with chromosomal mosaicism. This review discusses the origin of different types of chromosomal mosaics and chimaeras; their fate and the relationship between preimplantation chromosomal mosaicism and confined placental mosaicism in human conceptuses and animal models. Abnormal cells in mosaic embryos may be depleted by cell death, other types of cell selection or cell correction but the most severely affected mosaic embryos probably die. Trisomic cells could become restricted to placental lineages if cell selection or correction is less effective in placental lineages and/or they are preferentially allocated to a placental lineage. However, the relationship between preimplantation mosaicism and confined placental mosaicism may be complex because the specific chromosome(s) involved will influence whether chromosomally abnormal cells survive predominately in the placental trophoblast and/or placental mesenchyme.
Human cells normally have 23 pairs of chromosomes, which carry the genes. During the first few days of development, some human embryos are chromosomal mosaics. These mosaic embryos have both normal cells and cells with an abnormal number of chromosomes, which arise from the same fertilised egg. (More rarely, the different cell populations arise from more than one fertilised egg and these embryos are called chimaeras.) If chromosomally abnormal cells survive to term, they could cause birth defects. However, few abnormal cells survive and those that do are usually confined to the placenta, where they are less likely to cause harm. It is not yet understood how this restriction occurs but the type of chromosomal abnormality influences which placental tissues are affected. This review discusses the origin of different types of chromosomally abnormal cells, their fate and how they might become confined to the placenta in humans and animal models.

Scuticociliatosis, caused by ciliated protozoa of the subclass Scuticociliatia, has been associated with high mortalities in marine fish. Environmental factors such as an increase in water temperature can enhance this disease. The aim of the present report is to describe the occurrence of a cluster of cases of scuticociliatosis in a multispecies marine cold-water system in a public aquarium. Philasterides dicentrarchi was identified by PCR in formalin-fixed tissues of some of the fish showing meningitis or meningoencephalitis, dermatitis and myositis with intralesional protozoa. An increase in water temperature of approximately 2°C was identified as a potential contributing factor for this cluster of infections. Higher temperature may have enhanced the propagation or pathogenicity of scuticociliates or increased host susceptibility of some species of fish, especially wolf-eel Anarrhichthys ocellatus and spotted ratfish Hydrolagus colliei. This report also highlights the complexity of dealing with mixed species systems housing fish from different natural ecozones.