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ABSTRACT The fungal pathogenCandida albicansmust acquire phosphate to colonize, infect, and proliferate in the human host.C. albicanshas four inorganic phosphate (P_i) transporters, Pho84 being the major high-affinity transporter; its cells can also use glycerophosphocholine (GPC) as their sole phosphate source. GPC is a lipid metabolite derived from deacylation of the lipid phosphatidylcholine. GPC is found in multiple human tissues, including the renal medulla, where it acts as an osmolyte.C. albicansimports GPC into the cell via the Git3 and Git4 transporters. Internalized GPC can be hydrolyzed to release P_i. To determine if GPC import and subsequent metabolism affect phosphate homeostasis upon P_ilimitation, we monitored growth and phenotypic outputs in cells provided with either P_ior GPC. Inpho84∆/∆ mutant cells that exhibit phenotypes associated with P_ilimitation, GPC provision rescued sensitivity to osmotic and cell wall stresses. The glycerophosphodiesterase Gde1 was required for phenotypic rescue of osmotic stress by GPC provision. GPC provision, like P_iprovision, resulted in repression of the PHO regulon and activation of TORC1 signaling. P_iuptake was similar to GPC uptake when phosphate availability was low (200 µM). While available at lower concentrations than P_iin the human host, GPC is an advantageous P_isource for the fungus because it simultaneously serves as a choline source. In summary, we find GPC is capable of substituting for P_iinC. albicansby many though not all criteria and may contribute to phosphate availability for the fungus in the human host. IMPORTANCECandida albicansis the most commonly isolated species from patients suffering from invasive fungal disease.C. albicansis most commonly a commensal organism colonizing a variety of niches in the human host. The fungus must compete for resources with the host flora to acquire essential nutrients such as phosphate. Phosphate acquisition and homeostasis have been shown to play a key role inC. albicansvirulence, with several genes involved in these processes being required for normal virulence and several being upregulated during infection. In addition to inorganic phosphate (P_i),C. albicanscan utilize the lipid-derived metabolite glycerophosphocholine (GPC) as a phosphate source. As GPC is available within the human host, we examined the role of GPC in phosphate homeostasis inC. albicans. We find that GPC can substitute for P_iby many though not all criteria and is likely a relevant physiological phosphate source forC. albicans. 

The Pallas’s cat (Otocolobus manul) is one of the most understudied taxa in the Felidae family. The species is currently assessed as being of “Least Concern” in the IUCN Red List, but this assessment is based on incomplete data. Additional ecological and genetic information is necessary for the long-term in situ and ex situ conservation of this species. We identified 29 microsatellite loci with sufficient diversity to enable studies into the individual identification, population structure, and phylogeography of Pallas’s cats. These microsatellites were genotyped on six wild Pallas’s cats from the Tibet Autonomous Region and Mongolia and ten cats from a United States zoo-managed population that originated in Russia and Mongolia. Additionally, we examined diversity in a 91 bp segment of the mitochondrial 12S ribosomal RNA (MT-RNR1) locus and a hypoxia-related gene, endothelial PAS domain protein 1 (EPAS1). Based on the microsatellite and MT-RNR1 loci, we established that the Pallas’s cat displays moderate genetic diversity. Intriguingly, we found that the Pallas’s cats had one unique nonsynonymous substitution in EPAS1 not present in snow leopards (Panthera uncia) or domestic cats (Felis catus). The analysis of the zoo-managed population indicated reduced genetic diversity compared to wild individuals. The genetic information from this study is a valuable resource for future research into and the conservation of the Pallas’s cat.