Effects of Environmental and Social Conditions on Homosexual Pairing in the Japanese Beetle (Popillia japonica Newman)

Homosexual pairing between males occurs under natural conditions in a wide variety of taxa, including many insect species, but few studies have investigated how environmental and social conditions affect same-sex pairing in insects. We investigated factors affecting homosexual pairing in male Japanese beetles (Popillia japonica Newman) in the field and in the laboratory. Specifically, we investigated how time of day, sex ratio, beetle density, and temperature affected the likelihood of homosexual pairing. In the field, male–male pairs constituted 1–6% of the pairs we collected. Homosexual pairs were more common in the afternoon than in the morning and the evening. Sex ratio, density, and temperature were all related to the likelihood of finding a homosexual pair, but the relationships were not linear. In the laboratory, higher male densities and relatively male-biased sex ratios were associated with an increase in the frequency of homosexual pairs. Homosexual pairs were more frequent at relatively low and relatively high temperatures. Males that mounted other males tended to be smaller than the males that they mounted. In addition, compared to males that were not homosexually paired, there was some indication that the mounting males were smaller, and the mounted males larger, than the unpaired males. Our data suggest that homosexual pairs are a result of males mistaking other males for females, and we hypothesize that the environmental and social factors cause changes in homosexual pairing through their effects on the frequency of pair formation and pair duration.     

Extracts of black and brown rice powders improve hepatic lipid accumulation via the activation of PPARα in obese and diabetic model mice

Rice powder extract (RPE) from black and brown rice (Oryza sativa L. indica) improves hepatic lipid accumulation in obese and diabetic model mice via peroxisomal fatty acid oxidation. RPE showed PPARα agonistic activity which did not differ between black and brown RPE despite a higher anthocyanin content in black RPE.     

Evidence of independent gene duplications during the evolution of archaeal and eukaryotic family B DNA polymerases

Eukaryotes and archaea both possess multiple genes coding for family B DNA polymerases. In animals and fungi, three family B DNA polymerases, alpha, delta, and epsilon, are responsible for replication of nuclear DNA. We used a PCR-based approach to amplify and sequence phylogenetically conserved regions of these three DNA polymerases from Giardia intestinalis and Trichomonas vaginalis, representatives of early-diverging eukaryotic lineages. Phylogenetic analysis of eukaryotic and archaeal paralogs suggests that the gene duplications that gave rise to the three replicative paralogs occurred before the divergence of the earliest eukaryotic lineages, and that all eukaryotes are likely to possess these paralogs. One eukaryotic paralog, epsilon, consistently branches within archaeal sequences to the exclusion of other eukaryotic paralogs, suggesting that an epsilon-like family B DNA polymerase was ancestral to both archaea and eukaryotes. Because crenarchaeote and euryarchaeote paralogs do not form monophyletic groups in phylogenetic analysis, it is possible that archaeal family B paralogs themselves evolved by a series of gene duplications independent of the gene duplications that gave rise to eukaryotic paralogs.      

Partial reconstruction of the microvillus core bundle: characterization of villin as a Ca(++)-dependent, actin-bundling/depolymerizing protein

The brush border, isolated from chicken intestine epithelial cells, contains the 95,000 relative molecular mass (M(r)) polypeptide, villin. This report describes the purification and characterization of villin as a Ca(++)-dependent, actin bundling/depolymerizing protein. Then 100,000 g supernatant from a Ca(++) extract of isolated brush borders is composed of three polypeptides of 95,000 (villin), 68,000 (fimbrin), and 42,000 M(r) (actin). Villin, following purification from this extract by differential ammonium sulfate precipitation and ion-exchange chromatography, was mixed with skeletal muscle F-actin. Electron microscopy of negatively stained preparations of these villin-actin mixtures showed that filament bundles were present. This viscosity, sedimentability, and ultrastructural morphology of filament bundles are dependent on the villin:actin molar ratio, the pH, and the free Ca(++) concentration in solution. At low free Ca(++) (less than 10(-6) M), the amount of protein in bundles, when measured by sedimentation, increased as the villin: actin molar ratio increased and reached a plateau at approximately a 4:10 ratio. This behavior correlates with the conversion of single actin filaments into filament bundles as detected in the electron microscope. At high free Ca(++) (more than 10(-6) M), there was a decrease in the apparent viscosity in the villin-actin mixtures to a level measured for the buffer. Furthermore, these Ca(++) effects were correlated with the loss of protein sedimented, the disappearance of filament bundles, and the appearance of short fragments of filaments. Bundle formation is also pH-sensitive, being favored at mildly acidic pH. A decrease in the pH from 7.6 to 6.6 results in an increase in sedimentable protein and also a transformation of loosly associated actin filaments into compact actin bundles. These results are consistent with the suggestions that villin is a bundling protein in the microvillus and is responsible for the Ca(++)-sensitive disassembly of the microvillar cytoskeleton. Thus villin may function in the cytoplasm as a major cytoskeletal element regulating microvillar shape.     

Reevaluation of brush border motility: calcium induces core filament solation and microvillar vesiculation

The report that microvillar cores of isolated, demembranated brush borders retract into the terminal web in the presence of Ca(++) and ATP has been widely cited as an example of Ca(++)-regulated nonmuscle cell motility. Because of recent findings that microvillar core actin filaments are cross-linked by villin which, in the presence of micromolar Ca(++), fragments actin filaments, we used the techniques of video enhanced differential interference contrast, immunofluorescence, and phase contrast microscopy and thin-section electron microscopy (EM) to reexamine the question of contraction of isolated intestinal cell brush borders. Analysis of video enhanced light microscopic images of Triton- demembranated brush borders treated with a buffered Ca(++) solution shows the cores disintegrating with the terminal web remaining intact; membranated brush borders show the microvilli to vesiculate with Ca(++). Using Ca(++)/EGTA buffers, it is found that micromolar free Ca(++) causes core filament dissolution in membranated or demembranated brush borders, Ca(++) causes microvillar core solation followed by complete vesiculation of the microvillar membrane. The lengths of microvilli cores and rootlets were measured in thin sections of membranated and demembranated controls, in Ca(++)-, Ca(++) + ATP-, and in ATP-treated brush borders. Results of these measurements show that Ca(++) alone causes the complete solation of the microvillar cores, yet the rootlets in the terminal web region remain of normal length. These results show that microvilli do not retract into the terminal web in response to Ca(++) and ATP but rather that the microvillar cores disintegrate. NBD-phallicidin localization of actin and fluorescent antibodies to myosin reveal a circumferential band of actin and myosin in mildly permeabilized cells in the region of the junctional complex. The presence of these contractile proteins in this region, where other studies have shown a circumferential band of thin filaments, is consistent with the hypothesis that brush borders may be motile through the circumferential constriction of this “contractile ring,” and is also consistent with the observations that ATP-treated brush borders become cup shaped as if there had been a circumferential constriction.     

Comparison of three mammalian cell-lines with respect to their sensitivities to hyperthermia, gamma-rays and U.V.-radiation.

Three types of cultured mammalian cells, from a rat ureter carcinoma (RUC-2), from a mouse mammary carcinoma (M8013), and from a Chinese hamster lung cell-line (CH-V79), have been compared with respect to various treatments. Using cloning assay, the sensitivity of these cell-lines was measured for ionizing radiation, U.V.-light and for temperatures of 41 degrees, 42 degrees, 43 degrees, 44 degrees and 45 degrees C. RUC-2 cells are the least sensitive to these treatments, except for 45 degrees C. M8013 is sensitive to gamma-rays and U.V.-irradiation. CH-V79 is sensitive to gamma-radiation and hyperthermia. Since sensitivity to one type of treatment does not correlate with similar susceptibility to the others, it is concluded that different mechanisms may be involved in inactivation by these treatments.     

A systematic approach to identifying urothelial cells likely to be polysomic by fluorescence in situ hybridization

OBJECTIVE: To determine which nuclear morphologic and background features are most associated with normal and abnormal chromosome patterns in urine cells evaluated by fluorescence in situ hybridization (FISH) with Vysis UroVysion (Downers Grove, Illinois, USA). STUDY DESIGN: One hundred specimens were analyzed and the nuclear morphologic and background features compared between FISH-negative (disomic) and -positive (polysomic) cases. RESULTS: Our data show that polysomic urothelial cells have significantly (p < 0.001) weaker DAPI nuclear counterstaining, nuclear enlargement, more irregular nuclear shape and more chromatin clumping when compared to disomic cells. CONCLUSION: These findings indicate that there are specific staining and nuclear cytologic features that can help identify cells that have a high probability of being polysomic by FISH. This information may help cytologists decrease the time required to evaluate urine specimens by FISH and may aid in the development of instruments that automate FISH analysis.     

Male participation in family planning: results from a qualitative study in Mpigi District, Uganda

The aim of this study was to determine men's perceptions about family planning and how they participate or wish to participate in family planning activities in Mpigi District, central Uganda. Four focus group discussions were conducted with married men and with family planning providers from both the government and private sector. In addition, seven key informants were interviewed using a semi-structured interview guide. The results indicate that men have limited knowledge about family planning, that family planning services do not adequately meet the needs of men, and that spousal communication about family planning issues is generally poor. However, almost all men approved of modern family planning and expressed great interest in participating. The positive change of the beliefs and attitudes of men towards family planning in the past years has not been recognized by family planning programme managers, since available services are not in line with current public attitudes. A more couple-oriented approach to family planning is needed. Measures could include, for example, recruiting males as family planning providers, offering more family planning counselling for couples, and promoting female-oriented methods with men and vice versa.