Browsing by Issue Date, starting with "2023-01-13"
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- Current and potential future distribution of Endemic Salvia ceratophylloides Ard. (Lamiaceae)Publication . Laface, Valentina Lucia Astrid; Musarella, Carmelo Maria; Tavilla, Gianmarco; Sorgonà, Agostino; Cano-Ortiz, Ana; Quinto Canas, Ricardo; Spampinato, GiovanniHuman activities and climate change are the main factors causing habitat loss, jeopardising the survival of many species, especially those with limited range, such as endemic species. Recently, species distribution models (SDMs) have been used in conservation biology to assess their extinction risk, environmental dynamics, and potential distribution. This study analyses the potential, current and future distribution range of Salvia ceratophylloides Ard., an endemic perennial species of the Lamiaceae family that occurs exclusively in a limited suburban area of the city of Reggio Calabria (southern Italy). The MaxEnt model was employed to configure the current potential range of the species using bioclimatic and edaphic variables, and to predict the potential suitability of the habitat in relation to two future scenarios (SSP245 and SSP585) for the periods 2021–2040 and 2041–2060. The field survey, which spanned 5 years (2017–2021), involved 17 occurrence points. According to the results of the MaxEnt model, the current potential distribution is 237.321 km2 , which considering the preferred substrates of the species and land-use constraints is re-estimated to 41.392 km2 . The model obtained from the SSP245 future scenario shows a decrease in the area suitable for the species of 35% in the 2021–2040 period and 28% in the 2041–2060 period. The SSP585 scenario shows an increase in the range suitable for hosting the species of 167% in the 2021–2040 period and 171% in the 2041–2060 period. Assessing variation in the species distribution related to the impacts of climate change makes it possible to define priority areas for reintroduction and in situ conservation. Identifying areas presumably at risk or, on the contrary, suitable for hosting the species is of paramount importance for management and conservation plans for Salvia ceratophylloides.
- Study of Matrix Gla Protein (MGP) deficiency in the zebrafish and its interaction with elastin: contribution to the study of Keutel syndromePublication . Nascimento, Pedro Manuel Fortes; Santos, João; Gavaia, PauloThe Keutel Syndrome (KS) is a rare autosomal recessive disorder that manifests in humans due to loss-of-function mutations in the MATRIX GLA PROTEIN (MGP) gene, which is correlated with ectopic calcification within cartilaginous and vascular tissues. The mechanisms by which MGP inhibits calcium deposition are still poorly understood, thus contributing to a major limitation in the comprehension of the disease pathophysiology and therefore the development of effective therapies. The Mgp-deficient mice model has been very used to favor the understanding of the disease. However, the symptomatology in Mgp-deficient mice is far more severe from what is observed in KS patients, which generates interest in the development of new animal models that can mimic the disease. The objectives of this work were to contribute to the establishment for the first time of a zebrafish model to study KS pathophysiology and to investigate whether MGP is a crucial inhibitor of vascular and cartilage calcification in the zebrafish model. For that, we identified and characterized an mgp zebrafish through RT-PCR and sequencing, and found an 18-nucleotide deletion at exon 4. Next, we performed a morphometric analysis at the larval and adult stages of development, where we found that the homozygous mgp mutant larvae are smaller than their wild-type siblings. To investigate the impact of the mutation in the process of ectopic mineralization, the zebrafish mutants were treated with warfarin, a potent inhibitor of the vitamin K cycle that induces ectopic calcification, and we found that the homozygous mutants die more. To determine the pathological accumulation of calcium, we performed Alizarin red S and von Kossa stainings, and we found that the mgp homozygous mutants have an extensive accumulation of calcium in the abdominal intervertebral space, caudal fin ray area, heart and parasphenoidal carotid artery. To confirm that these effects were due to the loss of expression of Mgp, we performed an immunohistochemistry analysis with an anti-BGP lab produced antibody and found a reduction in the expression of Mgp in the mgp mutants. In conclusion, we characterized a zebrafish mutant for mgp and found that they have a reduced size and extensive accumulation of calcium in bone and soft tissues. The mgp zebrafish mutant mimics the conditions observed in human KS patients suggesting that it might be a good model to study the pathophysiology of the KS.