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Villalta, J.

Publications and source records attributed to Villalta, J..

2 recordsLinked to original sources

Geographic distribution of genetic diversity of Heterocephalus glaber analyzed using whole genome sequencing and a chromosome-scale genome assembly

Naked mole-rats (Heterocephalus glaber) are a species of rodent endemic to the Horn of Africa, notable among mammals for their long lifespans, resistances to a variety of stresses, and eusocial mating behavior. Though their natural range extends across large portions of Kenya, Ethiopia, Somalia, and Djibouti, the large majority of genetic and genomic analyses focus on Kenyan specimens. Here, we constructed a chromosome-scale reference genome assembly for H.glaber, along with new reference assemblies of both the Damaraland mole-rat (Fukomys damarensis) and guinea pig (Cavia porcellus) genomes to aid annotation. We leveraged our H.glaber assembly, along with modern whole-genome sequencing, to characterize the genetic diversity of specimens deriving from Kenya, southern Ethiopia, and eastern Ethiopia. We found the Kenyan and southern Ethiopian specimens to be closely related to each other and highly diverged from eastern Ethiopian specimens. We also found specimens collected from nearby locations in southern Ethiopia to be more closely related to Kenyan specimens than to each other. This unexpected distribution of shared genetic diversity highlights the importance of local migration barriers to gene flow in wild H.glaber populations.

ecology↗

pH profiling of mitochondrial sub-compartments reveals that IF1 is essential to prevent ATP hydrolysis under OXPHOS conditions

The classical view of oxidative phosphorylation is that a proton motive force PMF generated by the respiratory chain complexes fuels ATP synthesis. Under glycolytic conditions, ATP synthase in its reverse mode also can contribute to the PMF. Here, we dissected the two functions of ATP synthase and the role of its inhibitory factor 1 (IF1) under different metabolic conditions in detail. pH profiles of mitochondrial sub-compartments were recorded with high spatial resolution in live mammalian cells by positioning a pH-sensor directly at F1 and FO of ATP synthase, complex IV and in the matrix. Our results clearly show that ATP synthase activity is substantially controlling the PMF and that IF1 is essential under OXPHOS conditions to prevent reverse ATP synthase activity due to an almost negligible {Delta}pH. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=183 SRC="FIGDIR/small/430746v2_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@1a975eforg.highwire.dtl.DTLVardef@7ddb49org.highwire.dtl.DTLVardef@c7a128org.highwire.dtl.DTLVardef@2559e8_HPS_FORMAT_FIGEXP M_FIG C_FIG HIGHLIGHTSO_LIThe {Delta}pH along and across the inner mitochondrial membrane is not homogeneous C_LIO_LIThe proton motive force at cristae tips is controlled by F1 FO ATP synthase C_LIO_LIUnder OXPHOS conditions, the pH difference between FO and F1 of active ATP synthase is almost negligible (1.2 proton vs. 1 proton equivalent) C_LIO_LIIF1 is required to prevent the onset of ATP hydrolysis under OXPHOS conditions C_LI

cell biology↗