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Amphibians represent a diverse group of tetrapods, marked by deep divergence times between their three systematic orders and families. Studying amphibian biology through the genomics lens increases our understanding of the features of this animal class and that of other terrestrial vertebrates. The need for amphibian genomics resources is more urgent than ever due to the increasing threats to this group. Amphibians are one of the most imperiled taxonomic groups, with approximately 41% of species threatened with extinction due to habitat loss, changes in land use patterns, disease, climate change, and their synergistic effects. Amphibian genomics resources have provided a better understanding of ontogenetic diversity, tissue regeneration, diverse life history and reproductive modes, antipredator strategies, and resilience and adaptive responses. They also serve as critical models for understanding widespread genomic characteristics, including evolutionary genome expansions and contractions given they have the largest range in genome sizes of any animal taxon and multiple mechanisms of genetic sex determination. Despite these features, genome sequencing of amphibians has significantly lagged behind that of other vertebrates, primarily due to the challenges of assembling their large, repeat-rich genomes and the relative lack of societal support. The advent of long-read sequencing technologies, along with computational techniques that enhance scaffolding capabilities and streamline computational workload is now enabling the ability to overcome some of these challenges. To promote and accelerate the production and use of amphibian genomics research through international coordination and collaboration, we launched the Amphibian Genomics Consortium (AGC) in early 2023. This burgeoning community already has more than 282 members from 41 countries (6 in Africa, 131 in the Americas, 27 in Asia, 29 in Australasia, and 89 in Europe). The AGC aims to leverage the diverse capabilities of its members to advance genomic resources for amphibians and bridge the implementation gap between biologists, bioinformaticians, and conservation practitioners. Here we evaluate the state of the field of amphibian genomics, highlight previous studies, present challenges to overcome, and outline how the AGC can enable amphibian genomics research to "leap" to the next level.

Total Knee Arthroplasty (TKA) is one of the most successful procedures in Orthopaedic Surgery, with good clinical results and high survival rate in more than 90% of the cases at long-term follow-up. Since the increase of population's mean age, worsening of articular degenerative alterations, and articular sequelae related to previous fractures, there is a persistent growing of the number of knee arthroplasties in every country each year, with expected increase of complications rates. Painful TKA is considered an unusual complication, but several reports focus on this challenging clinical issue.Common causes of painful TKA may be divided as early or late, and in referred, periarticular or intra-articular. Among the early, we recall implant instability (related to surgical and technical mistakes) and problems of extensor mechanism (patella not resurfaced, malalignment of femoral, tibial, or patellar component, tendons failure or degeneration). Late causes of painful TKA are almost related to aseptic loosening and infection, but also, even if unusual, reflex sympathetic dystrophy, synovitis, and hypersensitivity to metal implants are represented.Hypersensitivity to metal is a clinical issue with significative increase, but to date without a specific characterization. The Authors report about incidence, clinical features, and diagnostic pathways of hypersensitivity to metal implants, focusing on the prevention of this challenging problem.

We studied the expression of several homeobox genes of the HOX family in the adult human intestinal mucosa. HOX genes are regulatory genes homologous to the homeotic genes controlling the body plan of the fruit fly Drosophila melanogaster. The HOX genes are distributed in four homologous HOX loci termed HOX-A, B, C and D, located on four different chromosomes. They have been found to be expressed in many embryonic tissues and axial structures like the central nervous system, the spine and in selected adult cells. The expression of 39 HOX genes belonging to HOX-A, B, C and D was studied by in situ hybridization on specimens of mucosa from normal adult colon. All the genes studied were shown to be expressed in these tissues, but the genes belonging to the four loci showed different localization within the colonic mucosa: HOX-A genes are expressed in undifferentiated proliferating cells at the base of the crypts, HOX-C genes in differentiated cells at the apex of the crypts and HOX-B and HOX-D genes are weakly expressed along the entire crypt length. Expression of some of these genes was also studied in differentiating CaCo-2 cells and tumoral tissues. In particular, in colonic adenocarcinomatous cells, some HOX-A genes appear to be abundantly expressed confirming the presence of these gene products in normal.

The goal of this study was to provide a comprehensive view of the compositional characteristics of fish genomes. We therefore expanded the number of fish species that we had explored so far in their DNAs by analytical ultracentrifugation in CsCl density gradient from 122 to 201. This study included representatives from three out of nine orders of Elasmobranchs (sharks and rays), both orders of dipnoan lungfishes, and both orders of chondrosteans (sturgeons and bichirs). We also studied 19 out of 38 teleostean orders, which represent all but four (minor) superorders of the subdivision Teleostei, a group comprising about 23,600 species (96% of all extant fishes). This leaves for further studies two subclasses, Holocephali (chimaeras), and Coelacanthimorpha (gombessas). In spite of this substantial increase in the number of species and orders analysed, all average properties (the modal buoyant density, rho(0), the average buoyant density, , the CsCl profile asymmetry, A, and the compositional heterogeneity, H), and all their ranges were unchanged compared to a previous study [J. Mol. Evol. 31 (1990) 265]. This suggests that, in all likelihood, the properties reported in the present paper can be considered as generally valid for all fish genomes.

An analysis by CsCl density gradient centrifugation has shown that, at a fragment size of about 100 kb, the DNA of a urochordate, Ciona intestinalis, is remarkably homogeneous in base composition. Localization of 16 coding sequences from C. intestinalis, chosen so as to cover the distribution range of all available coding sequences for this organism, showed a nearly symmetrical distribution almost coinciding with the DNA distribution. Both distributions are remarkably different from those found in vertebrates, which are skewed towards high GC levels (to a greater extent in warm-blooded vertebrates). In order to account for this change in genome organization, we propose a working hypothesis that can be tested. Basically, we suggest that the genome duplication that occurred between urochordates and fishes was accompanied by a preferential integration of transposons in one compartment of the genome, which was made gene-poor (by lowering gene density) compared to the rest. Since the gene-poor compartment (the 'empty quarter') is characterized by a lower level of gene expression compared to the gene-rich compartment (the 'genome core') in the vertebrate genome, we further suggest, as a working hypothesis, that a compartmentalization according to gene expression already existed in urochordates.

Population disjunctions have been proposed to play an important role in speciation processes. In this study, we have examined the possible role of the Pacific Ocean-Sea of Cortez disjunction as a contributing factor to cryptic speciation in a reef fish, the opaleye, Girella nigricans. Mitochondrial control region (D-loop) sequences (380 bp) of 117 individuals completely separated opaleye populations from the Pacific Ocean and the Sea of Cortez. Although opaleye exhibit pelagic larval stages that remain in the water column for several months, gene flow between the Pacific Ocean and the Sea of Cortez was found to be extremely limited (FST = 0.84, Nm = 0.10). Whereas limited gene flow and reciprocal monophyly suggest that the observed physical and genetic disjunction are potentially contributing to the incipient speciation of Pacific and Sea of Cortez opaleye, moderate levels of D-loop sequence divergence (3.3%) and the absence of fixed allozyme markers challenge this idea. Pacific Coast populations also exhibited restricted gene flow levels (FST = 0.25, Nm = 1.49) across Punta Eugenia, a recognized oceanographic boundary along the Baja California coast. Thus, opaleye individuals grouped into three clades: one clade in the Sea of Cortez, one Pacific clade south of Punta Eugenia, and one Pacific clade north of Punta Eugenia. Future work in this region will determine if our results can be generalized to other disjunct populations.