排序方式: 共有39条查询结果,搜索用时 9 毫秒
21.
Dowen Mae I. Jocson Morgan E. Smeester Noah T. Leith Anthony Macchiano Kasey D. Fowler‐Finn 《Journal of evolutionary biology》2019,32(10):1046-1056
Variation in temperature can affect the expression of a variety of important fitness‐related behaviours, including those involved with mate attraction and selection, with consequences for the coordination of mating across variable environments. We examined how temperature influences the expression of male mating signals and female mate preferences—as well as the relationship between how male signals and female mate preferences change across temperatures (signal–preference temperature coupling)—in Enchenopa binotata treehoppers. These small plant‐feeding insects communicate using plantborne vibrations, and our field surveys indicate they experience significant natural variation in temperature during the mating season. We tested for signal–preference temperature coupling in four populations of E. binotata by manipulating temperature in a controlled laboratory environment. We measured the frequency of male signals—the trait for which females show strongest preference—and female peak preference—the signal frequency most preferred by females—across a range of biologically relevant temperatures (18°C–36°C). We found a strong effect of temperature on both male signals and female preferences, which generated signal–preference temperature coupling within each population. Even in a population in which male signals mismatched female preferences, the temperature coupling reinforces predicted directional selection across all temperatures. Additionally, we found similar thermal sensitivity in signals and preferences across populations even though populations varied in the mean frequency of male signals and female peak preference. Together, these results suggest that temperature variation should not affect the action of sexual selection via female choice, but rather should reinforce stabilizing selection in populations with signal–preference matches, and directional selection in those with signal–preference mismatches. Finally, we do not predict that thermal variation will disrupt the coordination of mating in this species by generating signal–preference mismatches at thermal extremes. 相似文献
22.
Comparing the shapes of regression functions 总被引:1,自引:0,他引:1
23.
Montgomery TA Rim YS Zhang C Dowen RH Phillips CM Fischer SE Ruvkun G 《PLoS genetics》2012,8(4):e1002616
Small RNAs--including piRNAs, miRNAs, and endogenous siRNAs--bind Argonaute proteins to form RNA silencing complexes that target coding genes, transposons, and aberrant RNAs. To assess the requirements for endogenous siRNA formation and activity in Caenorhabditis elegans, we developed a GFP-based sensor for the endogenous siRNA 22G siR-1, one of a set of abundant siRNAs processed from a precursor RNA mapping to the X chromosome, the X-cluster. Silencing of the sensor is also dependent on the partially complementary, unlinked 26G siR-O7 siRNA. We show that 26G siR-O7 acts in trans to initiate 22G siRNA formation from the X-cluster. The presence of several mispairs between 26G siR-O7 and the X-cluster mRNA, as well as mutagenesis of the siRNA sensor, indicates that siRNA target recognition is permissive to a degree of mispairing. From a candidate reverse genetic screen, we identified several factors required for 22G siR-1 activity, including the chromatin factors mes-4 and gfl-1, the Argonaute ergo-1, and the 3' methyltransferase henn-1. Quantitative RT-PCR of small RNAs in a henn-1 mutant and deep sequencing of methylated small RNAs indicate that siRNAs and piRNAs that associate with PIWI clade Argonautes are methylated by HENN-1, while siRNAs and miRNAs that associate with non-PIWI clade Argonautes are not. Thus, PIWI-class Argonaute proteins are specifically adapted to associate with methylated small RNAs in C. elegans. 相似文献
24.
GW Patton R Stephens IA Sidorov X Xiao RA Lempicki DS Dimitrov RH Shoemaker G Tudor 《BMC bioinformatics》2006,7(1):81
Background
Microarrays used for gene expression studies yield large amounts of data. The processing of such data typically leads to lists of differentially-regulated genes. A common terminal data analysis step is to map pathways of potentially interrelated genes. 相似文献25.
26.
RH Behrens Z Bisoffi A Björkman J Gascon C Hatz T Jelinek F Legros N Mühlberger P Voltersvik 《Malaria journal》2006,5(1):1-4
Background
Thick blood films are routinely used to diagnose Plasmodium falciparum malaria. Here, they were used to diagnose volunteers exposed to experimental malaria challenge.Methods
The frequency with which blood films were positive at given parasite densities measured by PCR were analysed. The poisson distribution was used to calculate the theoretical likelihood of diagnosis. Further in vitro studies used serial dilutions to prepare thick films from malaria cultures at known parasitaemia.Results
Even in expert hands, thick blood films were considerably less sensitive than might have been expected from the parasite numbers measured by quantitative PCR. In vitro work showed that thick films prepared from malaria cultures at known parasitaemia consistently underestimated parasite densities.Conclusion
It appears large numbers of parasites are lost during staining. This limits their sensitivity, and leads to erroneous estimates of parasite density. 相似文献27.
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29.
Lauren RH Krumpe Kathryn M Schumacher James B McMahon Lee Makowski Toshiyuki Mori 《BMC biotechnology》2007,7(1):65
Background
Amino acid sequence diversity is introduced into a phage-displayed peptide library by randomizing library oligonucleotide DNA. We recently evaluated the diversity of peptide libraries displayed on T7 lytic phage and M13 filamentous phage and showed that T7 phage can display a more diverse amino acid sequence repertoire due to differing processes of viral morphogenesis. 相似文献30.
Djian P; Phillips M; Easley K; Huang E; Simon M; Rice RH; Green H 《Molecular biology and evolution》1993,10(6):1136-1149
The involucrin genes of the mouse (Mus musculus) and the rat (Rattus
norvegicus) have been cloned and sequenced. The coding region of each gene
contains, at site P, a segment of repeats homologous to that of other
nonanthropoid mammals. In contrast to the repeats of species belonging to
different mammalian orders, many individual repeats of the mouse and the
rat can be matched. Both before and after the divergence of the two
species, these repeats have been the site of systematic alterations in
nucleotide sequence. One of the alterations is the correction of
nucleotides of one repeat by those of another. Corrected nucleotides may be
closely linked to flanking nucleotides that are uncorrected; the systematic
correction process therefore appears to be due to gene conversion. There is
a stretch of 18 reiterated CAGs in the segment of repeats of the Mus gene;
most of these reiterations were introduced recently, supporting the idea
that the gene was generated originally from poly CAG. An antiserum to a
synthetic peptide encoded by the segment of repeats of the Mus gene reveals
differentiation- specific expression of the gene in the epidermis.
相似文献