Protoplasts of a respiration-deficient rho strain of Saccharomyces cerevisiae were incubated with mitochondria isolated from various respiration-competent yeast species under conditions enabling transplacement of mitochondria. Respiration-competent cybrids were selected by plating the protoplasts on agar media containing a non-fermentable energy source. The resulting cybrids contained nuclear D...

The onset of prezygotic and postzygotic barriers to gene flow between populations is a hallmark of speciation. One of the earliest postzygotic isolating barriers to arise between incipient species is the sterility of the heterogametic sex in interspecies' hybrids. Four genes that underlie hybrid sterility have been identified in animals: Odysseus, JYalpha, and Overdrive in Drosophila and Prdm9 ...

Building on the recent experimental observation with ultracold atoms, we report the first experimental evidence of Efimov physics in a heteronuclear system. A mixture of ;{41}K and ;{87}Rb atoms was cooled to few hundred nanokelvins and stored in an optical dipole trap. Exploiting a broad interspecies Feshbach resonance, the losses due to three-body collisions were studied as a function of the ...

Comments by de Jong et al., Solter et al., and Sloggett question the ecological relevance of the abundant microsporidia found in the invasive ladybird Harmonia axyridis. We contend that there is abundant evidence that native ladybirds feed on H. axyridis eggs and that interspecific microsporidial transfer is a common phenomenon, supporting the proposed role of these parasites as biological weap...

Whatever else they should share, strains of bacteria assigned to the same species should have house-keeping genes that are similar in sequence. Single gene sequences (or rRNA gene sequences) have very few informative sites to resolve the strains of closely related species, and relationships among similar species may be confounded by interspecies recombination. A more promising approach (multilo...

Analysis of 71 ciprofloxacin-resistant (MIC > or = 4 microg/ml) Streptococcus pneumoniae clinical isolates revealed only 1 for which the quinolone resistance-determining regions of the parC, parE, and gyrB genes were genetically related to those of viridans group streptococci. Our findings support the occurrence of interspecies recombination of type II topoisomerase genes; however, its contribu...

Although tidepools are conspicuous components of rocky intertidal shores, their biotic communities have not been studied as extensively as those on emergent substrata. We examine processes regulating the structure of tidepool communities for comparison with emergent substrata. The physical environment of tidepools is highly regulated by the hdal cycle, although fluctuations in physical factors ...

Hybridization among animal species has recently become more recognized as an important phenomenon, especially in the context of recent radiations. Here we show that complex hybridization has led to contrasting patterns of genomic composition among closely related species of the Neotropical cat genus Leopardus. We show strong evidence of ancient hybridization and introgression between the pampas...

Genomic ANI (Average Nucleotide Identity) has been found to be able to replace DNA-DNA hybridization in prokaryote taxonomy. The ANI of each of the core genes that has a phylogeny congruent with the reference species tree of rhizobia was compared to the genomic ANI. This allowed us to identify three housekeeping genes (SMc00019-truA-thrA) whose ANI reflected the intraspecies and interspecies ge...

We use a time-dependent dynamical hydrodynamic model to study a collapse in a degenerate fermion-fermion mixture (DFFM) of different atoms. Due to a strong Pauli-blocking repulsion among identical spin-polarized fermions at short distances there cannot be a collapse for repulsive interspecies fermion-fermion interaction. However, there can be a collapse for a sufficiently attractive interspecie...