Developmental plasticity allows genomes to encode multiple distinct phenotypes that can be differentially manifested in response to environmental cues. Alternative plastic phenotypes can be selected ...through a process called genetic assimilation, although the mechanisms are still poorly understood. We assimilated a seasonal wing color phenotype in a naturally plastic population of butterflies (
) and characterized three responsible genes. Endocrine assays and chromatin accessibility and conformation analyses showed that the transition of wing coloration from an environmentally determined trait to a predominantly genetic trait occurred through selection for regulatory alleles of downstream wing-patterning genes. This mode of genetic evolution is likely favored by selection because it allows tissue- and trait-specific tuning of reaction norms without affecting core cue detection or transduction mechanisms.
Rodents are taxonomically diverse and have evolved a variety of traits. A mechanistic understanding of such traits has remained elusive, however, largely because genome editing in non-traditional ...model species remains challenging. Here, using the African striped mouse (Rhabdomys pumilio), we describe TIGER (targeted in vivo genome editing in rodents), a method that relies on a simple intraoviductal injecting technique and uses recombinant adeno-associated viruses (rAAVs) as the sole vehicle to deliver reagents into pregnant females. We demonstrate that TIGER generates knockout and knockin (up to 3 kb) lines with high efficiency. Moreover, we engineer a double-cleaving repair rAAV template and find that it significantly increases knockin frequency and germline transmission rates. Lastly, we show that an oversized double-cleaving rAAV template leads to an insertion of 3.8 kb. Thus, TIGER constitutes an attractive alternative to traditional ex vivo genome-editing methods and has the potential to be extended to a broad range of species.
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•An in vivo rAAV-based genome-editing method (TIGER) was developed in R. pumilio•TIGER generates knockout and knockin striped mouse lines with high efficiency•A double-cleaving repair rAAV template increases knockin rate and transmission•An oversized double-cleaving rAAV template leads to an insertion of 3.8 kb
Li et al. develop TIGER (targeted in vivo genome editing in rodents), a single-step in vivo genome-editing method. Using African striped mice (Rhabdomys pumilio), they show that TIGER generates knockout and large knockin lines with efficiency. Due to its simplicity, TIGER can potentially be extended to other rodent species.
Abstract
Lepidopteran wing scales play important roles in a number of functions including color patterning and thermoregulation. Despite the importance of wing scales, however, we still have a ...limited understanding of the genetic mechanisms that underlie scale patterning, development, and coloration. Here, we explore the function of the phenoloxidase‐encoding gene
laccase2
in wing and scale development in the nymphalid butterfly
Vanessa cardui
. Somatic deletion mosaics of
laccase2
generated by CRISPR/Cas9 genome editing presented several distinct mutant phenotypes. Consistent with the work in other nonlepidopteran insect groups, we observed reductions in melanin pigmentation and defects in cuticle formation. We were also surprised, however, to see distinct effects on scale development including complete loss of wing scales. This study highlights
laccase2
as a gene that plays multiple roles in wing and scale development and provides new insight into the evolution of lepidopteran wing coloration.
The addition of O2 to gas mixtures in time projection chambers containing CS2 has recently been shown to produce multiple negative ions that travel at slightly different velocities. This allows a ...measurement of the absolute position of ionising events in the z (drift) direction. In this work, we apply the z-fiducialisation technique to a directional dark matter search. We present results from a 46.3 live-day source-free exposure of the DRIFT-IId detector run in this new mode. With full-volume fiducialisation, we have achieved the first background-free operation of a directional detector. The resulting exclusion curve for spin-dependent WIMP-proton interactions reaches 1.1 pb at 100 GeV/c2, a factor of 2 better than our previous work. We describe the automated analysis used here, and argue that detector upgrades, implemented after the acquisition of these data, will bring an additional factor of ≳3 improvement in the near future.
Characterization of the Hamamatsu R11780 12 in. photomultiplier tube Brack, J.; Delgado, B.; Dhooghe, J. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2013, Letnik:
712, Številka:
C
Journal Article
Recenzirano
Odprti dostop
Future large water Cherenkov and scintillator detectors have been proposed for measurements of long baseline neutrino oscillations, proton decay, supernova and solar neutrinos. To ensure ...cost-effectiveness and optimize scientific reach, one of the critical requirements for such detectors are large-area, high performance photomultiplier tubes (PMTs). One candidate for such a device is the Hamamatsu R11780, a 12 in. PMT that is available in both standard and high quantum efficiency versions. Measurements of the single photoelectron response characteristics, relative efficiencies of the standard and high quantum efficiency versions, a preliminary measurement of the absolute quantum efficiency of the standard quantum efficiency version, and a two-dimensional scan of the relative efficiency across the photocathode surface are presented in this paper. All single photoelectron investigations were made using a Cherenkov light source at room temperature at a gain of 1×107. These results show that the R11780 PMT is an excellent candidate for such large optical detectors.
Phenotypic variation among species is a product of evolutionary changes to developmental programs
. However, how these changes generate novel morphological traits remains largely unclear. Here we ...studied the genomic and developmental basis of the mammalian gliding membrane, or patagium-an adaptative trait that has repeatedly evolved in different lineages, including in closely related marsupial species. Through comparative genomic analysis of 15 marsupial genomes, both from gliding and non-gliding species, we find that the Emx2 locus experienced lineage-specific patterns of accelerated cis-regulatory evolution in gliding species. By combining epigenomics, transcriptomics and in-pouch marsupial transgenics, we show that Emx2 is a critical upstream regulator of patagium development. Moreover, we identify different cis-regulatory elements that may be responsible for driving increased Emx2 expression levels in gliding species. Lastly, using mouse functional experiments, we find evidence that Emx2 expression patterns in gliders may have been modified from a pre-existing program found in all mammals. Together, our results suggest that patagia repeatedly originated through a process of convergent genomic evolution, whereby regulation of Emx2 was altered by distinct cis-regulatory elements in independently evolved species. Thus, different regulatory elements targeting the same key developmental gene may constitute an effective strategy by which natural selection has harnessed regulatory evolution in marsupial genomes to generate phenotypic novelty.
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