Background/Aim: Biotin affects the genetic expression of several glucose metabolism enzymes, besides being a cofactor of carboxylases. To explore how extensively biotin affects the expression of carbon metabolism genes, we studied the effects of biotin starvation and replenishment in 3 distantly related eukaryotes: yeast Saccharomyces cerevisiae, nematode Caenorhabditis elegans and rat Rattus norvegicus. Methods: Biotin starvation was produced in Wistar rats, in C. elegans N2 and S. cerevisiae W303A fed with abundant glucose. High-density oligonucleotide microarrays were used to find gene expression changes. Glucose consumption, lactate and ethanol were measured by conventional tests. Results: In spite of abundant glucose provision, the expression of fatty oxidation and gluconeogenic genes was augmented, and the transcripts for glucose utilization and lipogenesis were diminished in biotin starvation. These results were associated with diminished glucose consumption and glycolysis products (lactate and ethanol in yeast), which was consistent across 3 very different eukaryotes. Conclusion: The results point toward a strongly selected role of biotin in the control of carbon metabolism, and in adaptations to variable availability of carbon, conceivably mediated by signal transduction including soluble guanylate cyclase, cGMP and a cGMP-dependent protein kinase (PKG) and/or biotin-dependent processes.

Sporotrichosis is a subcutaneous mycosis caused by Sporothrix schenckii complex. The disease has been reported worldwide. However, the incidence of the etiological agent varies in its geographic distribution. We studied 39 clinical isolates of Sporothrix schenckii from diverse regions in Mexico, collected from 1998 to 2016. Molecular identification was performed by sequence analysis of the partial calmodulin gene. In vitro antifungal susceptibility to amphotericin B (AMB), itraconazole (ITC), voriconazole (VRC), posaconazole (PSC), fluconazole (FLC), terbinafine (TRB), caspofungin (CSF), anidulafungin (ANF), and micafungin (MCF) was evaluated. Thirty-eight isolates of S. schenckii complex were divided into five supported clades in a phylogenetic tree. The predominant clinical form was lymphocutaneous (92.3%), fixed cutaneous (5.1%), and disseminated (2.5%). Terbinafine exhibited the best in vitro antifungal activity, while fluconazole was ineffective against Sporothrix schenckii complex. Our results showed diverse geographic distribution of clinical isolates in eight states; definitive identification was done by CAL gen PCR-sequencing. In Mexico, S. schenckii is considered to be an etiological agent of human sporotrichosis cases, and lymphocutaneous is the most prevalent form of the disease. This study revealed four clades of S. schenckiisensu stricto by phylogenetic analysis. Furthermore, we report one case of S. globosa isolated from human origin from the North of Mexico.

Chemerin, encoded by the retinoic acid receptor responder 2 (RARRES2) gene is an adipocytesecreted protein with autocrine/paracrine functions in adipose tissue, metabolism and inflammation with a recently described function in vascular tone regulation, liver, steatosis, etc. This molecule is believed to represent a critical endocrine signal linking obesity to diabetes. There are no data available regarding evolution of RARRES2 in non-human primates and great apes. Expression profile and orthology in RARRES2 genes are unknown aspects in the biology of this multigene family in primates. Thus; we attempt to describe expression profile and phylogenetic relationship as complementary knowledge in the function of this gene in primates. To do that, we performed A RT-PCR from different tissues obtained during necropsies. Also we tested the hypotheses of positive evolution, purifying selection, and neutrality. And finally a phylogenetic analysis was made between primates RARRES2 protein. RARRES2 transcripts were present in liver, lung, adipose tissue, ovary, pancreas, heart, hypothalamus and pituitary tissues. Expression in kidney and leukocytes were not detectable in either species. It was determined that the studied genes are orthologous. RARRES2 evolution fits the hypothesis of purifying selection. Expression profiles of the RARRES2 gene are similar in baboons and chimpanzees and are also phylogenetically related.