Cardiac physiology and metabolic gene expression during late organogenesis among F. heteroclitus embryo families from crosses between pollution-sensitive and -resistant parents

Background The teleost fish Fundulus heteroclitus inhabit estuaries heavily polluted with persistent and bioaccumulative chemicals. While embryos of parents from polluted sites are remarkably resistant to toxic sediment and develop normally, embryos of parents from relatively clean estuaries, when treated with polluted sediment extracts, are developmentally delayed, displaying deformities characteristic of pollution-induced embryotoxicity. To gain insight into parental effects on sensitive and resistant phenotypes during late organogenesis, we established sensitive, resistant, and crossed embryo families using five female and five male parents from relatively clean and predominantly PAH-polluted estuaries each, measured heart rates, and quantified individual embryo expression of 179 metabolic genes. Results Pollution-induced embryotoxicity manifested as morphological deformities, significant developmental delays, and altered cardiac physiology was evident among sensitive embryos resulting from crosses between females and males from relatively clean estuaries. Significantly different heart rates among several geographically unrelated populations of sensitive, resistant, and crossed embryo families during late organogenesis and pre-hatching suggest site-specific adaptive cardiac physiology phenotypes relative to pollution exposure. Metabolic gene expression patterns (32 genes, 17.9%, at p < 0.05; 11 genes, 6.1%, at p < 0.01) among the embryo families indicate maternal pollutant deposition in the eggs and parental effects on gene expression and metabolic alterations. Conclusion Heart rate differences among sensitive, resistant, and crossed embryos is a reliable phenotype for further explorations of adaptive mechanisms. While metabolic gene expression patterns among embryo families are suggestive of parental effects on several differentially expressed genes, a definitive adaptive signature and metabolic cost of resistant phenotypes is unclear and shows unexpected sensitive-resistant crossed embryo expression profiles. Our study highlights physiological and metabolic gene expression differences during a critical embryonic stage among pollution sensitive, resistant, and crossed embryo families, which may contribute to underlying resistance mechanisms observed in natural F. heteroclitus populations living in heavily contaminated estuaries.

A Novel Mistranslating tRNA Model in Drosophila melanogaster has Diverse, Sexually Dimorphic Effects

Transfer RNAs (tRNAs) are the adaptor molecules required for reading of the genetic code and the accurate production of proteins. tRNA variants can lead to genome-wide mistranslation, the misincorporation of amino acids not specified by the standard genetic code into nascent proteins. While genome sequencing has identified putative mistranslating tRNA variants in human populations, little is known regarding how mistranslation affects multicellular organisms. Here, we create a Drosophila melanogaster model for mistranslation by integrating a serine tRNA variant that mistranslates serine for proline (tRNASerUGG, G26A) into the fly genome. Using mass spectrometry, we find that tRNASerUGG, G26A misincorporates serine for proline at a frequency of ~ 0.6% per codon. We find that mistranslation extends development time and decreases the number of flies that reach adulthood. Adult flies containing tRNASerUGG, G26A present with more morphological deformities and worse climbing performance than flies expressing only wild type tRNA. Female flies with the serine tRNA variant have more deformities and experience a faster decline in climbing performance than males, suggesting sex-specific effects. This model will enable studies into the synergistic effects of mistranslating tRNA variants and disease-causing alleles.

Safety Profile of Caesalpinia spinosa Aqueous Extract Tested in Oreochromis niloticus Toward Its Application in Dermocosmetics

Herbal extracts have been widely used in dermocosmetics as a source of biomolecules and also as a natural claim. Fruits from Caesalpinia spinosa show great potential for their polyphenolic content, preservative, and film-forming features, as previously reported in specialized literature; however, the toxicity requires investigation. We explored Oreochromis niloticus (tilapia) in larval, alevins, and juvenile stages to evaluate the ex vivo and in vivo genotoxicity and in vivo acute and chronic toxicity of C. spinosa aqueous extract in different concentrations. Cytotoxicity, animal behavior, morphological deformities, and DNA damage were evaluated. Our results showed genotoxic effect in ex vivo tests, but no DNA damage in in vivo erythrocytes. We suggest a mechanism of cell permeability involved in the toxicity of C. spinosa aqueous extract. Internal validation showed the feasibility of O. niloticus applied for toxicity evaluation. Further studies could contribute for better understanding the uses and safety of C. spinosa in cosmetics and topical pharmaceutical products.

Etiology and management of disorders of temporomandibular joint: A literarure review

Temporomandibular disorders usually represented as a group of painful as well as altered conditions involving the muscles of mastication and the muscles around the temporomandibular joint. Usually the patient are un aware of the condition. Temporomandibular joint disorders affects twenty five percent of the population. Temporomandibular disorders represent with musculoskeletal degenerative conditions of the joint which results in functional as well as morphological deformities of the temporomandibular joint. As temporomandibular disorders cases are complex with unique nature with respect to each case, so the diagnosis and treatment modality is quite different for each type of case.

Monsters in the city: multiple deformities increase in terrestrial-breeding urban salamanders

Amphibians are subjected to an assortment of environmental stressors responsible for their population declines and malformations. Deciphering the underlying causes of amphibian deformities is challenging due to the complex nature and interplay among factors. We evaluated morphological deformities in 9 urban and 9 woodland populations of terrestrial-breeding fire salamanders. We report several types of malformations and higher incidences among urban populations. This model system allowed us to tease apart some of the common factors responsible for amphibian deformations, suggesting airborne/terrestrial pollutants, predation, and/or inbreeding as potential environmental stressors. Yet, the putative underlying factors of fire salamander deformities need to be properly addressed in thorough studies linking habitat quality and the prevalence of morphological abnormalities, as well as predator-prey interactions. Reporting deformation rates among amphibians is key to identify warning signals of population declines and preventing local extinctions.

Teratogenic and developmental toxic effects of etridiazole on zebrafish (Danio rerio) embryos

Etridiazole (EDZ), a thiadiazole-containing toxic chemical, is widely used as a fungicide. Regular usage of EDZ may reach and contaminate water bodies, but its adverse effects on aquatic vertebrates have not been well studied. Therefore, the present study aimed to evaluate the harmful effects of EDZ using zebrafish (ZF) (Danio rerio) embryos. ZF embryos were treated with 3.75, 7.5, 15, 30, and 60 mg/L of EDZ. Subsequently, mortality and developmental toxicities were quantified at 24, 48, 72, and 96 h post fertilization (hpf). The results showed that embryo mortality was concentration- and time-dependent. The median lethal concentration (LC50) of EDZ at 96-h was 25.58 ± 1.49 mg/L. Besides, EDZ induced a series of morphological deformities, including abnormal somite formation, abnormal eye pigmentation, abnormal tail morphology, tail kinks, skeletal malformations (lordosis, kyphosis, and scoliosis), and yolk sac edema in a concentration-dependent manner. Among the deformities, the most significant were reduced heartbeat and increased incidence of pericardial edema. The median effective concentration (EC50) of EDZ at 96-h was 17.93 ± 2.22 mg/L and the 96-h teratogenic index (TI) value was 1.52. Taken together, these results indicate that EDZ is a teratogen, and primarily affects the cardiovascular system of ZF.

Effects of Sub-Lethal Atrazine Concentrations on Embryogenesis, Larval Survival and Growth of African Catfish, Clarias gariepinus (Burchell, 1822)

The toxicity of environmentally relevant concentrations of atrazine on exposed fertilized eggs of Clarias gariepinus was evaluated in a 96hour static non-renewal bioassay. After exposure to atrazine concentrations of 0 (control), 4, 8, 12, and 16 μgL1 in water, first mitotic cleavage in the control occurred at 40 minutes after fertilization. The first cleavage did not occur in the 8 μgL-1 treatment group until 60 minutes after fertilization. Similar dose depended delayed cleavage was observed across atrazine exposed eggs. The first larvae emerged 22 hours from the time of fertilization at 27.00C in both control and atrazine treatment groups. However, hatching rates significantly differed between the control and atrazine exposed eggs (P<0.05) with 73.3% hatching rate in the control and 3.3% among the exposed eggs treated with 16μgL-1 of atrazine. Among the morphological deformities observed in the larvae of atrazine exposed eggs, kyphosis occurred more frequently with 60% of emerged larvae in the 16 μgL-1 atrazine treated group exhibiting the deformity. Morphometry showed significantly reduced head length, body length, body weight, and yolk diameter in 16 μgL-1 atrazine exposed eggs compared to the control. These results indicate that atrazine disrupted embryonic process and delayed hatching with severe larvae deformities.