👤 G Mantovani

Beef cattle breeds from Central and Southern Italy, such as Marchigiana, Chianina, Romagnola, Maremmana, and Podolica, represent a unique genetic resource shaped by centuries of natural and artificial selection. Their origin, partly linked to the Podolian group, remains debated, while their adaptation to diverse environments and close association with regional economies enhance their zootechnical and cultural value. Despite their importance, comprehensive assessments of their genomic diversity are still limited, especially in an international context where preserving local breeds is crucial to maintain global biodiversity and resilience in livestock systems. This study investigates population structure, inbreeding, selection signatures, and effective population size using medium-density single-nucleotide polymorphism genotypes. Multivariate and clustering approaches confirmed clear genetic differentiation among breeds, with Chianina and Romagnola being the most divergent, in line with their intensive selection history. In contrast, Maremmana and Podolica displayed shared ancestral components, reflecting their adaptation to extensive and marginal environments. Pairwise F Show less

Regulation of cortisol secretion by aberrant hormone receptors may play a role in the pathogenesis of ACTH-independent Cushing's syndrome. In this study, the topic was evaluated by combining in vivo and in vitro approaches. Cortisol responses to various stimuli (standard meal, GnRH + TRH, cisapride, vasopressin, glucagon) were assessed in 6 patients with clinical or subclinical adrenal Cushing's syndrome, and non-functioning adrenal adenoma in two cases. Abnormal responses were observed in three patients with Cushing's syndrome; one patient showed a gastric inhibitory polypeptide (GIP)-dependent cortisol rise after meal, together with responses after GnRH and cisapride; the second patient showed an LH-dependent cortisol response to GnRH, and in the third cortisol rose after cisapride. The pattern of receptor expression performed by RT-PCR showed that while GIP-R was only expressed in tumor from the responsive patient, 5-hydroxytryptamine type 4 receptor and LH-R were also present in normal adrenal tissues and tissues from non-responsive patients. Interestingly, an activating mutation of Gsalpha gene was identified in one of these tumors. Therefore, cortisol responses to agents operating via Gs protein coupled receptors (in one case associated with Gsalpha mutation) were found in Cushing's patients, while these responses were absent in the others. The finding of receptor expression in normal and non-responsive tumors suggests that different mechanisms are probably involved in inducing in vivo cortisol responses. Show less