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Despite the growing interest in the evolutionary cytogenetics of squamates, chromosomal data are lacking for most taxa. We performed a preliminary molecular taxonomic analysis and a comparative cytogenetic study on Hemorrhois hippocrepis and Malpolon monspessulanus. We used a combination of standard karyotyping, Chromomycin A3/Methyl green staining, C-banding, Ag-NOR staining and NOR-FISH to provide the first karyotype description of H. hippocrepis and a re-description of the karyotype of M. monspessulanus, including chromosome markers, heterochromatin patterns and sex chromosome systems. Our results show that H. hippocrepis has 2 n = 36 chromosomes, with 16 macro- and 20 microchromosomes and NORs on the 6th pair. The 4th pair represents homomorphic (metacentric) ZW sex chromosomes, but the W chromosome is completely heterochromatic. Malpolon monspessulanus has 2 n = 44 chromosomes, with 20 macro- and 24 microchromosomes, NORs on the 6th telocentric pair. The 4th pair represents the sex chromosomes (ZZ/ZW), with a W chromosome smaller than the Z and completely heterochromatic. Comparing our cytogenetic data to those available from the literature, we note the occurrence and distribution of primitive and derived chromosomal characteristics and discuss the chromosome diversification in two snake clades belonging to Colubridae and Psammophiidae, respectively. We highlight that these two families followed different chromosome diversification pathways, characterised by a highly conserved karyotype structure in Colubridae and a higher chromosome variability in Psammophiidae, mostly driven by a progressive reduction of the chromosome number by means of chromosome fusions. We also provide cytotaxonomic insights supporting the distinction between M. monspessulanus and M. insignitus. [ABSTRACT FROM AUTHOR]

Due to its high toxicity and bioaccumulation tendency, tebuconazole (TBZ) is one of the ten substances posing the highest risk of harmful effects in aquatic ecosystems. The liver, a key compartment for xenobiotics detoxification, is also the organ in which TBZ mainly accumulates in fish. Herein, we investigated for the first time the morpho-functional changes induced in zebrafish (Danio rerio) liver after a short-term exposure (48, 96, and 192 hours) to a low, environmentally relevant concentration of TBZ (5 µg/L) to disclose the early effects under a realistic exposure scenario. We revealed that pathological alterations with varying degrees of severity could be detected in all the examined samples. The injuries become intense and irreversible with increased exposure time involving both hepatocytes and vascular components based on the degree of tissue changes. The main morphological alterations were: parenchyma dyschromia, macrophages infiltration, congestion of blood vessels, and sinusoids. TBZ exposure also resulted in a significant decrease in glycogen contents and hepatocyte dimensions, and the modulation of superoxide dismutase, an early indicator of oxidative stress. We demonstrated that even a very low dose of TBZ affects hepatic morphology and function, disrupting liver homeostasis and physiology. [ABSTRACT FROM AUTHOR]

The anatomical organization of the lung in Pelophylax kl. esculentus tadpoles has been described in early and middle-staged tadpoles (Gosner stages 32 and 39). The lung's ontogenic development has been studied using light microscopy and both scanning and transmission electron microscopy. In the early-staged tadpoles, the lung is well vascularized, but it is provided with only two internal septa types and devoid of ciliated epithelium and lamellar bodies. The complete differentiation process is putatively reached in the middle-staged tadpoles (GS 39), and numerous septa of first, second, and third-order deeply protruding into the lung lumen could be recognized. The histological and ultrastructural features at this stage correspond to that described in the adults' lungs, but mucous secreting goblet cells could not be detected. Pneumocytes, with numerous apical microvilli, surround the growing network of capillaries and show a cytoplasm rich in dense bodies and few mature lamellar bodies. On the epithelial surface, a thin layer of mucous covering the underlying epithelium could also be seen. Neuroepithelial bodies, supposed to be involved in chemoreception, are organized in clusters on the first order septa and surrounded by cytoplasmatic processes originating by neighboring cells. The lung arrangement of P. kl. esculentus is compared with that of other Anurans in order to further elucidate the putative role of the lung in gas exchanges. The present studies reduce the information gap existing in the literature regarding lung morphology and development in amphibian larval stages, also contributing to the discussion on the onset of airbreathing respiration in tadpoles. [ABSTRACT FROM AUTHOR]

We provide comparative and updated staging tables for the larvae of three syntopic newt species – Triturus carnifex, Lissotriton italicus and Ichthyosaura alpestris inexpectatus –living in Calabria. A detailed description, stage by stage, of the full larval period until completion of metamorphosis is furnished, accompanied by photographic tables of the most important stages. The appearance of the most prominent and easily identifiable morphological features (i.e. development of gills, balancers and limbs; and body pigmentation), and length, have been used as staging criteria. Ontogenic development in the three considered species is compared with that of other Caudata species. For the three newt species, we also performed a comparative analysis of the developmental larval phases, emphasising the shared and species-specific features. The present descriptive study adds comparative information on distinctive morphological traits that may be useful for the recognition of newts during larval ontogeny and, in some cases, when sampling in the field. [ABSTRACT FROM AUTHOR]