Diagnosis and surgical management of cholecystolithiasis in two adult inland beardeddragons (pogona vitticeps)

Two male inland bearded dragons (Pogona vitticeps) of 5 and 6 yr of age were presented for anorexia with and without lethargy, respectively. In both cases, a firm, spherical, and mobile mass, measuring 2 cm in diameter, was palpated in the cranio-medial coelom. Radiographs were unremarkable. Ultrasonographic evaluation was highly suggestive of cholecystolithiasis. Coeliotomy confirmed the presence of a markedly enlarged gallbladder containing a cholecystolith in both cases, and cholecystectomies were performed. Both dragons resumed eating after 1–7 days and were doing well 3–6 months postoperatively. The gallbladder wall was unremarkable on histology, and the choleliths were composed of protein and calcium carbonate crystals. Cholecystolithiasis in bearded dragons has been the subject of very few case reports, probably due to its low occurrence. The lack of available data on the diagnosis and management may have led to this condition being underdiagnosed in this species. Ultrasonography was essential to the clinical diagnosis of cholecystolithiasis in our two cases and should be recommended as part of the diagnostic approach of bearded dragons with cranio-medial coelomic masses

Rab8 Regulates the Actin-based Movement of Melanosomes

Rab GTPases have been implicated in the regulation of specific microtubule- and actin-based motor proteins. We devised an in vitro motility assay reconstituting the movement of melanosomes on actin bundles in the presence of ATP to investigate the role of Rab proteins in the actin-dependent movement of melanosomes. Using this assay, we confirmed that Rab27 is required for the actin-dependent movement of melanosomes, and we showed that a second Rab protein, Rab8, also regulates this movement. Rab8 was partially associated with mature melanosomes. Expression of Rab8Q67L perturbed the cellular distribution and increased the frequency of microtubule-independent movement of melanosomes in vivo. Furthermore, anti-Rab8 antibodies decreased the number of melanosomes moving in vitro on actin bundles, whereas melanosomes isolated from cells expressing Rab8Q67L exhibited 70% more movements than wild-type melanosomes. Together, our observations suggest that Rab8 is involved in regulating the actin-dependent movement of melanosomes