Glyphosate (Gly) is a broad-spectrum herbicide widely used thanks to its high efficiency and low toxicity. However, evidence exists of its toxic effects on non-target organisms. Among these, the animals inhabiting agricultural fields are particularly threatened.
View Article and Find Full Text PDFThe expansion of agriculture produces a steady increase in habitat fragmentation and degradation due to the increased use of pesticides and herbicides. Habitat loss and alteration associated with crop production play an important role in reptile decline, among which lizards are particularly endangered. In this study, we evaluated testicular structure, steroidogenesis, and estrogen receptor expression/localization after three weeks of oral exposure to glyphosate at 0.
View Article and Find Full Text PDFThe Heat Shock Proteins (HSPs) are a superfamily of molecular chaperones that maintain cellular homeostasis under stress. HSP70 represents the major stress-inducible family member, often activated in response to changes in thermal ranges of organisms, and therefore playing an important role enhancing thermal tolerance limits in ectothermic animals. The present study aimed to investigate the presence and the localization of HSP70 through the development of Podarcis siculus, an oviparous lizard inhabiting temperate Mediterranean regions, showing a limited potential to tolerate thermal changes during embryogenesis.
View Article and Find Full Text PDFThe potential toxicity of glyphosate, a widely used broad-spectrum herbicide, is currently a great matter of debate. As vertebrate insectivores, lizards protect plants from herbivorous insects increasing plant biomass via the trophic cascade and represent an important link between invertebrates and higher predators. A negative effect of glyphosate on lizards' survival could have major impacts at the ecological levels.
View Article and Find Full Text PDFThe terrestrial lizard Podarcis siculus is the most abundant reptile in Italy, where is considered a ubiquitous species. This lizard is widely distributed from the islands to the Apennines, from cultivated fields to anthropized areas such as gardens and city parks. For this reason, these animals are exposed to extensive physical and chemical stresses, as well as to the possibility of coming into contact with industrial pollutants and substances used in agricultural practices.
View Article and Find Full Text PDFObesity and overweight are frequently associated with male subfertility. To address new findings on the players involved in the obesity-induced impairment of spermatogenesis, we used a high-fat diet-induced overweight-rat model. Following four weeks of high-fat diet, the organization of seminiferous epithelium was affected, and tubules lumen showed immature/degenerated cells, typical signs of hormonal imbalance and testicular damage.
View Article and Find Full Text PDFEstrogen receptors alpha (ERα) and beta (ERβ) are transcription factors known to be involved in the regulation of many complex physiological processes in mammals. They are expressed primarily in the reproductive tract of all vertebrates females, thus indicating important and conserved functions in female reproductive success. ERs are also present in physiological different tissues as bone, brain, liver, skin and adipose tissues, in both females and males.
View Article and Find Full Text PDFSpermatogenesis is a fascinating biological process aiming to generate haploid spermatozoa from diploid spermatogonia through a specific hormonal network between gonadotropins and steroids. Increasing evidence suggests that the primary female sex hormone estrogen plays an active role in this process. This research points out on the role of estrogen during lizard spermatogenesis by using three experimental approaches: (1) exposure to an analogue of nonsteroidal estrogen as Clomiphene citrate that acts both as estrogen agonist and antagonist; (2) exposure to the gonadotropin FSH; and (3) exposures to FSH followed by Clomiphene.
View Article and Find Full Text PDFThe "sex-hormone" estrogen-17β promotes several cognitive functions and is a master regulator of brain bioenergetics via the estrogen receptors α and β (ERα and ERβ). In this work, by using Real-Time PCR analysis, we evaluated the effect of aging and high fat diet (HFD) on ERα and ERβ expression in rat hippocampus and cortex. In young rats, ERβ is abundant in cortex and ERα in hippocampus.
View Article and Find Full Text PDFMetallothioneins (MTs) are an evolutionary conserved multigene family of proteins whose role was initially identified in binding essential metals. The physiological role of MT, however, has been revealed to be more complex than expected, since not only are MTs able to bind to toxic heavy metals, but many isoforms have shown specialized and alternative functions. Within this uncertainty, the information available on MTs in non-mammalian vertebrates, particularly in neglected tetrapods such as the reptiles, is even more scant.
View Article and Find Full Text PDFMetallothionein (MT) is the main protein involved in the homeostasis of metallic micronutrients and in cellular defence against heavy metals and reactive oxygen species. Found in almost all vertebrate tissues, MT presence and localization in the testis has been controversial. In the present study, by using in situ hybridization and immunohistochemical analysis we assessed the localization of both MT transcript and protein in Podarcis sicula testes during two different phases of the reproductive cycle: the autumnal resumption and the spring-early summer mating period.
View Article and Find Full Text PDFIn the last years, the hormonal balance is threatened by the interferences of substances with hormone-like action (endocrine disruptor chemicals, EDCs) that may harm animal reproduction. Most EDCs are resistant to environmental degradation and are considered ubiquitous contaminants. EDCs may have synthetic or natural origins.
View Article and Find Full Text PDFNeurodegeneration is one of the main physiological consequences of aging on brain. Metallothioneins (MTs), low molecular weight, cysteine-rich proteins that bind heavy-metal ions and oxygen-free radicals, are commonly expressed in various tissues of mammals. MTs are involved in the regulation of cell proliferation and protection, and may be engaged in aging.
View Article and Find Full Text PDFIn the last years, worldwide organic farming has grown exponentially; as a consequence, the use of animal manure as a soil fertility source has become the principal agricultural choice. However, the use of manure as fertilizer can increase the amount of steroid hormone metabolites in the soil. In southern Italy, lacertidae lizards are the most abundant vertebrate group in agroecosystems and have been identified as potential model species for ecotoxicological studies.
View Article and Find Full Text PDFNonylphenol (NP) is classified among the endocrine disruptor chemicals with estrogen-like properties. It is widely used in many industries and to dilute pesticides in agriculture, and is known to affect the reproductive system of many aquatic and semi-aquatic organisms. This study aimed to verify how NP, administered via food and water, may interfere with the reproductive cycle of a terrestrial vertebrate.
View Article and Find Full Text PDFThe aim of this study is to assess, by RT-PCR, in situ hybridization, electron microscopy, and immunohistochemistry, the site/s of vitellogenin (VTG) synthesis in the mussel Mytilus galloprovincialis. Our investigations demonstrate that, among the analyzed tissues, the synthesis of VTG occurs only in the female gonad, that is, within the oocyte and follicle and connective cells. Such a synthesis is just evident in early vitellogenic oocytes, whose cytoplasm is characterized by numerous RER cisternae and an extended Golgi complex surrounded by nascent yolk platelets.
View Article and Find Full Text PDFThe epididymis in the male reproductive tract allows the survival, viability, and storage of spermatozoa from the testis. In the lizard Podarcis sicula, the epididymis can be regionalized to an initial segment called the caput that comprises the efferent ductules, followed by the middle and terminal segments, respectively termed the corpus and cauda. By means of in situ hybridization and immunocytochemistry, we analyzed the expression of the estrogen receptors of the alpha and beta type (ERα and ERβ) in Podarcis to test the responsiveness of the epididymal regions to estrogen in the annual reproductive cycle of this seasonal breeder.
View Article and Find Full Text PDFThe aim of this investigation was to identify the encoding sequence of vitellogenin receptor gene (vtgr), and its expression during the oogenesis in the spotted ray, Torpedo marmorata, in different phases of reproductive cycle. From an ovarian cDNA of vitellogenic female, we obtained a fragment of 581 bp, which corresponds to a partial sequence encoding the vitellogenin receptor (VTGR) in Torpedo (accession number: gi/193244760). This sequence shows a high identity with the VTGR of other vertebrates, particularly Leucoraja erinacea (89% identity) and Squalus acanthias (84% identity).
View Article and Find Full Text PDFIn vertebrates, the liver was long thought to be the only site of vitellogenin (Vtg) production, but recent studies demonstrated that Vtg is also expressed in extrahepatic districts. The aim of this paper is to assess, by in situ hybridization and immunohistochemistry, the expression of Vtg in the testis and kidney of Torpedo marmorata exposed to 17β-estradiol (E(2)). In treated samples vtg mRNA and Vtg were detected contemporaneously only in the testis; differently the kidney cells were positive to Vtg antibody, but negative to vtg mRNA.
View Article and Find Full Text PDFEndocrine Disruptor Chemicals (EDCs) with estrogen-like properties i.e nonylphenol (NP) induce vitellogenin (VTG) synthesis in males of aquatic and semi-aquatic species. In the oviparous species VTG is a female-specific oestrogen dependent protein.
View Article and Find Full Text PDFIn non-mammalian vertebrates yolk deposition in the oocytes is a hormone-dependent, gender-specific process. Produced by the ovary under gonadotropin stimulation, Estradiol 17-beta (E(2)) plays a key role in the liver synthesis of vitellogenin (VTG) which in turn is taken up by vitellogenic oocytes in the ovary. In many species a negative role in liver synthesis of VTG in females is also played by progesterone.
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