Homospecific combinations of alleles at mc1r (H or K) and oca2 (h or k) are significantly more frequent than heterospecific combinations (binomial p = 0.0002).

<p>Homospecific combinations of alleles at mc1r (H or K) and oca2 (h or k) are significantly more frequent than heterospecific combinations (binomial p = 0.0002).</p

Homospecific combinations of alleles (HOM = hhHH or kkKK) at pairs of unlinked loci are significantly more common than heterospecific combinations (HET = hhKK or kkHH).

<p>Other combinations have frequencies close to expected values. 2A: Averages of the 19 pairwise comparisons from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079903#pone-0079903-g004" target="_blank">Figure 4</a>. 2B: Averages of the six mc1r pairwise comparisons from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079903#pone-0079903-g004" target="_blank">Figure 4</a>.</p

A simplified phylogeny of <i>Astyanax</i> showing the relationships of the populations discussed herein[17], [20].

<p>The thick lines represent the subterranean phases of the cave lineages. Node A was estimated to be 6.7 mya <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079903#pone.0079903-OrnelasGarcia1" target="_blank">[17]</a>. No dating is available for the other nodes, except that node D is more recent than node C.</p

Allelic content of sperm DNA compared to that of zygotic (fin clip) control DNA.

<p>The ordinate is the ratio of the peak heights for the two alleles in gametic DNA divided by the corresponding ratio for control DNA, or its reciprocal, if less than 1.0. Four different classes of loci were tested: those that had exhibited low transmission bias in the pedigree analysis vs. those that had exhibited high transmission bias, further partitioned by whether the males tested were inter-lineage hybrids (hybrid) or non-hybrids/intra-lineage hybrids (pure). The hybrid/high class of loci was significantly more deviated from unity than either the hybrid/low or the pure/high classes.</p

Genomic Consequences of Ecological Speciation in <i>Astyanax</i> Cavefish

<div><p>The cave environment is consistently radically different than the surface environment because it lacks light, and animals adapting to cave life are subject to strong selective forces much different than those experienced by their ancestors who evolved in the presence of light. As such, their divergence from surface ancestors and eventual speciation is likely to be driven by the shift in ecology. We report here that hybrids between cave and surface <i>Astyanax mexicanus</i> fishes produce offspring with allelic frequencies that differ significantly from Mendelian expectations both for transmission ratios and for independent assortment of unlinked markers. Comparison of allelic content of DNA from fin clips and sperm pools show that the transmission ratio distortion likely occurs during spermatogenesis. Departures from expectations of independent assortment are essentially epistatic phenomena generating linkage disequilibrium. A novel analysis of the epistatic interactions reveals an apparent network of interactions among genes known or suspected to be involved in cave adaptation, implying that the epistasis arose as a “by product” of the divergence due to cave adaptation.</p></div

Allelic biases in sperm from males that were non-hybrid or hybrid within a lineage versus from males that were hybrids across lineages.

<p>Entries in the table are the ratios of peak heights for the two alleles segregating at the locus in DNA from sperm, standardized against the ratio of peak heights from zygotic DNA (fin clips from the same males). Larger numbers signify greater deviations from 1∶1 segregation in the sperm DNA. The TRD index was calculated from the observed allelic distributions in the PSF2 cross and is the ratio of the frequency of the more common allele divided by that of the less common allele. Not all loci were informative (heterozygous) in each male.</p>?<p>Non-hybrid fish, one each from the surface population, and the Yerbaniz, Tinaja and Pachón cave populations. Abbreviations: Pach = Pachón cave, Yerb = Yerbaniz cave, Tina = Tinaja cave, Moli = Molino cave, Micos = Micos cave, Epi = epigean surface population. *p<0.05, **p<0.001. Asty136 is a hybrid F₂ progeny within the old lineage. Asty188, Asty41, and Asty39 are hybrid F₂ pedigrees across lineages.</p

Three linkage groups (LGs) mapped in the PSF2 cross.

<p>Nearly all the loci on LG 10 exhibited preferential transmission of the surface alleles (red) while nearly all the loci on LG 12 exhibited preferential transmission of the Pachón cave alleles (blue). LG 11 exhibited little evidence of biased transmission. Full maps are found in Supporting Information. NB!: The linkage groups of <i>Astyanax</i> have not yet been standardized. All LG numbering is cross specific. LG numbers do not correspond between crosses.</p

A network of genes (or closely linked loci) exhibiting significant epistatic interactions.

<p>Nodes are genes and edges denote epistatic interactions significant at p<0.05 (χ²>9.5, df = 4, analysis of a 3by 3 genotype matrix). Genes depicted are candidates for cave related phenotypes. The red edges signify interactions in which the ratio of Hom/Het was significantly greater than 1.0 (χ²>3.85, df = 1). Nodes in contact with one another signify genes that are linked.</p

Paramagnetic MgF₂ Nanocrystals for ¹⁹F Magnetic Resonance Imaging

MgF2-based formulations have unique physicochemical properties, making them attractive for diverse applications. Here, we show the ability to control the morphology of Sm3+-doped, paramagnetic MgF2 nanocrystals (Sm:MgF2 NCs) for use as nanosized imaging agents for 19F-magnetic resonance imaging (19F-MRI). By reducing the temperature of the reaction mixture from 160 to 110 °C and shortening the reaction time from 16 to 3 h, the morphology of the fabricated oleate-coated Sm:MgF2 NCs was transitioned from rod-shaped to spherical-shaped nanofluorides, both with a characteristic high-resolution liquid-state 19F-NMR resonance at −198 ppm. Further coating the surface of the spheric Sm:MgF2 NCs with a phospholipid layer resulted in a water-soluble formulation that was used to show its detectability with 19F-MRI

GPe neurons exhibit negligible interactions between pairs of neurons.

<p>Cross-correlations in the two species. Below the blue line: cross-correlations during a time window of ±1 s in four units recorded simultaneously in primates. Above the blue line: same in rats. Red lines in every cross-correlogram represent the lower and upper confidence levels (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045421#s2" target="_blank">Methods</a>).</p