Mean personality domain scores by genotype for chimpanzees living in Chimpanzee Sanctuary Uto, the sanctuary in Guinea, and the combined sample.

†<p>The combined samples includes 26 subjects from Chimpanzee Sanctuary Uto, 21 subjects from Guinea, and a total of 10 subjects from the Kyoto University Primate Research Institute (<i>n</i> = 5), Higashiyama Zoo (<i>n</i> = 2), Itouzu-no-mori Zoo (<i>n</i> = 1), Kouchi Zoo (<i>n</i> = 1), and Tama Zoo (<i>n</i> = 1).</p

Summary table of the subjects' sex, age, genotype, and personality <i>T</i>-score^†.

<p>Note.</p>†<p><i>Mean</i> = 50 and <i>SD</i> = 10. Dom = Dominance, Ext = Extraversion, Con = Conscientiousness, Agr = Agreeableness, Neu = Neuroticism, Opn = Openness.</p><p>*Other Japanese chimpanzees include 5 subjects from the Kyoto University Primate Research Institute, 2 subjects from the Higashiyama Zoo, 1 chimpanzee from the Itouzu-no-mori Zoo, 1 chimpanzee from the Kouchi Zoo, and 1 chimpanzee from the Tama Zoo.</p

Effect of Tryptophan hydroxylase 2 polymorphism on chimpanzee personality trait: Linear regression analysis with sex and age as the covariates.

<p>Note.</p>†<p>MAF: minor allele frequency.</p><p>*The combined samples includes 26 subjects from Chimpanzee Sanctuary Uto, 21 subjects from Guinea, and a total of 10 subjects from the Kyoto University Primate Research Institute (<i>n</i> = 5), Higashiyama Zoo (<i>n</i> = 2), Itouzu-no-mori Zoo (<i>n</i> = 1), Kouchi Zoo (<i>n</i> = 1), and Tama Zoo (<i>n</i> = 1). Boldfaced values indicate statistically significant effects (<i>p</i><.05). Underlined values indicate trends (<i>p</i><0.1).</p

Insect Cell-Derived Cofactors Become Fully Functional after Proteinase K and Heat Treatment for High-Fidelity Amplification of Glycosylphosphatidylinositol-Anchored Recombinant Scrapie and BSE Prion Proteins

<div><p>The central event in prion infection is the conformational conversion of host-encoded cellular prion protein (PrP^C) into the pathogenic isoform (PrP^Sc). Diverse mammalian species possess the cofactors required for <i>in vitro</i> replication of PrP^Sc by protein-misfolding cyclic amplification (PMCA), but lower organisms, such as bacteria, yeasts, and insects, reportedly lack the essential cofactors. Various cellular components, such as RNA, lipids, and other identified cofactor molecules, are commonly distributed in both eukaryotes and prokaryotes, but the reasons for the absence of cofactor activity in lower organisms remain to be elucidated. Previously, we reported that brain-derived factors were necessary for the <i>in vitro</i> replication of glycosylphosphatidylinositol-anchored baculovirus-derived recombinant PrP (Bac-PrP). Here, we demonstrate that following protease digestion and heat treatment, insect cell lysates had the functional cofactor activity required for Bac-PrP replication by PMCA. Mammalian PrP^Sc seeds and Bac-PrP^Sc generated by PMCA using Bac-PrP and insect cell-derived cofactors showed similar pathogenicity and produced very similar lesions in the brains of inoculated mice. These results suggested that the essential cofactors required for the high-fidelity replication of mammalian PrP^Sc were present in the insect cells but that the cofactor activity was masked or inhibited in the native state. We suggest that not only RNA, but also DNA, are the key components of PMCA, although other cellular factors were necessary for the expression of the cofactor activity of nucleic acids. PMCA using only insect cell-derived substances (iPMCA) was highly useful for the ultrasensitive detection of PrP^Sc of some prion strains.</p></div

Distribution of PrP^Sc in cattle inoculated with BSE.

<p><b>A</b>. Tissue distribution of PrP^Sc in the terminal disease stage in cow 5550. Quadruplicate samples of each tissue and bodily fluid were serially amplified, and the samples were analyzed after each round of amplification (R1–R4) by WB after digestion with PK. Horizontal lines indicate the positions of molecular weight markers corresponding to 37 kDa, 25 kDa, 20 kDa, and 15 kDa. Ns: No seed control. <b>B</b>. Negative control reaction for serial PMCA in each tissue. Quadruplicate samples of each tissue and bodily fluid from uninfected cow 2914 were serially amplified, and the samples were analyzed by WB following digestion with PK after each round of amplification. C: Cervical region, T: Thoracic region, L: Lumbar region, nt: Not tested.</p

Mean incubation time of TgBoPrP mice following intracerebral inoculation.

<p>Mean incubation time of TgBoPrP mice following intracerebral inoculation.</p

The effect of polysaccharides on the amplification of PrP^Sc derived from BSE-affected cattle.

<p><b>A</b>. The effect of sodium dextran sulfate with a high molecular weight (MW) ranging from 900 to 2000 kDa (sodium dextran sulfate, DSS-H) on BSE-PrP^Sc amplification. The PrP^Sc seed (10% brain homogenate) was diluted to 10⁻² to 10⁻³ in PrP^C substrate, and the diluted samples were amplified in the presence of DSS-H at 0–1%. The samples before (left panel) and after (right panel) amplification were analyzed by WB after digestion with PK. “N” designates controls in which the PrP^C substrate alone was treated in the same manner. <b>B</b>. The effect of dextran compounds on BSE-PrP^Sc amplification. The PrP^Sc seed was diluted to 10⁻⁴, and amplification was performed in the presence or absence (“No additive”) of dextran compounds at 0.5%. “No seed” designates the control in which the PrP^C substrate alone was amplified without dextran compounds. DSS-L: sodium dextran sulfate with a low MW, ranging from 5 to 6 kDa; DSP: potassium dextran sulfate (1.5 to 1.9 kDa); DEAE-dextran hydrochloride (50 kDa); dextran I (15–20 kDa), II (35–50 kDa), III (50–70 kDa), IV (200 kDa), and V (190–230 kDa). <b>C</b>. The effect of glycosaminoglycans (sodium chondroitin sulfate C: CSS; sodium heparan sulfate: HSS; heparan sulfate proteoglycan: HSPG) and a sulfated polysaccharide (λ-carrageenan: λ-Cag) on BSE-PrP^Sc amplification. The PrP^Sc seed was diluted to 10⁻⁴, and amplification was performed in the presence of each reagent at the final concentration indicated in the figure.</p

Optimal DSP concentration for BSE PrP^Sc amplification.

<p>The PrP^Sc seed was diluted to 10⁻⁴, and amplification was performed in the presence of the potassium dextran sulfate (DSP). “N” designates the control in which only PrP^C substrate was amplified.</p

BSE-PrP^Sc detection sensitivity.

<p><b>A</b>. The PrP^Sc seed was diluted to 10⁻⁴ to 10⁻¹¹ with PrP^C substrate, and samples were serially amplified in the presence of 0.5% potassium dextran sulfate (DSP). The duplicate amplified samples were analyzed after each round of amplification (R1–R4) by WB after PK digestion. <b>B</b>. No spontaneous generation of PrP^Sc was observed. Samples labeled “1” to “8” contained only PrP^C substrate and were amplified in the presence of 0.5% DSP.</p

Cofactor activities of various cell lysates for <i>in vitro</i> conversion of Bac-PrP and brain-derived PrP^C.

<p>(A) IMAC-purified Bac-PrP was used as the PrP^C source, and Chandler PrP^Sc (diluted 1∶1000) was amplified in the presence of <i>Prnp^0/0</i>BH, PK- and heat-treated HF, SF21 and N2a lysates. Non-treated cell lysates (HF, SF21 and N2a) were also used for comparison of amplification. The PMCA products were digested with PK (50 µg/ml) at 37°C for 1 h, and analyzed by Western blotting. NA indicates the result of amplification without additives (IMAC-purified Bac-PrP alone). (B) IMAC-purified PrP^C derived from Tga20 mouse brains (Br-PrP^C) was used as the PrP^C source, and Chandler PrP^Sc (diluted 1∶1000) was amplified in the presence of <i>Prnp^0/0</i>BH, PK- and heat-treated HF, SF21, N2a or <i>Escherichia coli</i> lysates. The PMCA products were digested with PK (50 µg/ml) at 37°C for 1 h, and analyzed by Western blotting. NA indicates the result of amplification without any additives (IMAC-purified Br-PrP^C alone). Normal mouse BH (BH) was also used as a PrP^C source for comparison of amplification. The amount of IMAC-purified Br-PrP^C (approximately 750 ng/100 µl reaction solution) used as the PrP^C source was almost equal to that of the PrP^C contained in the 10% normal mouse BH (right panel). The western blot images are composite photos comprising band images from different gels.</p