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Genetic screens in Drosophila melanogaster have long been used to identify genes found in a variety of developmental, cellular, and behavioral processes. Here we describe the characterization and mapping of a mutation identified in a conditional screen for genetic regulators of cell growth and cell division. Within a Flp/FRT system, mutant G.3.2 results in a reduction of mutant tissue and a rough eye phenotype. We find that G.3.2 maps to the gene cnk , providing further support that cnk is a critical gene in Drosophila eye development. This mutant was characterized, mapped and sequenced by undergraduate students within the Fly-CURE consortium., Competing Interests: The authors declare that there are no conflicts of interest present., (Copyright: © 2024 by the authors.)

The dissolution of porous materials in a flow field controls the fluid pathways through rocks and soils and shapes the morphology of landscapes. Identifying the dissolution front, the interface between the reactive and the unreactive volumes in a dissolving medium, is a prerequisite for describing dissolution-induced structure emergence and transformation. Despite its fundamental importance, the report on the dynamics of a dissolution front in an evolving natural microstructure is scarce. Here we show an unexpected, spontaneous migration of the dissolution front against the flow direction. This retraction stems from infiltration instability induced surface generation, which leads to an increase in reactive surface area when a porous medium dissolves in an imposing flow field. There is very good agreement between observations made with in situ, X-ray tomography and model predictions. Both show that the value of reactive surface area reflects a balance between flow-dependent surface generation and destruction, i.e. the "dry" geometric surface area of a porous material, measured without a flow field, is not necessarily the upper limit of its reactive surface area when in contact with reactive flow. This understanding also contributes to reconciling the discrepancies between field and laboratory derived solid-fluid reaction kinetics.

The structure and the strength of organic compound adsorption on mineral surfaces are of interest for a number of industrial and environmental applications, oil recovery, CO 2 storage and contamination remediation. Biomineralised calcite plays an essential role in the function of many organisms that control crystal growth with organic macromolecules. Carbonate rocks, composed almost exclusively of calcite, host drinking water aquifers and oil reservoirs. In this study, we examined the ordering behaviour of several organic compounds and the thickness of the adsorbed layers formed on calcite {10.4} surfaces. We used X-ray reflectivity (XRR) to study calcite {10.4} surfaces that were prepared in three alcohols: methanol, isopropanol and pentanol and one carboxylic acid: octanoic acid. All molecules adsorbed in self-assembled layers, where thickness depended on the density and the length of the molecule. For methanol and isopropanol, molecular dynamic simulations (MD) provided complementary information, which allowed us to develop a surface model. Branching in isopropanol induced slightly less ordering because of the additional degree of freedom. Pentanol and octanoic acid adsorbed as single monolayers. The results of this work indicate that adhered organic compounds from the surrounding environment can affect the surface behaviour, depending on properties of the organic compound.

Intramolecular cyclization of an alpha-carbon radical of ester carrying a chiral 2,4-pentanediol tether shows low stereoselectivity when the radical carbon has an alkyl substituent, while the selectivity becomes high to give a single stereoisomer (>99% pure) when the substituent is an aryl group. The difference in the selectivity is attributable to the change in the rate-determining step from the conformational process to the cyclization.

The properties of the pacemaker controlling the adult locomotor activity rhythm of the high-altitude Himalayan (haH) strain (Hemkund Sahib, 4121 m above sea level) of Drosophila helvetica are strikingly different from those of the low-altitude Himalayan (laH) strain (Birahi, 1132 m above sea level) of the same species. The haH strain has a unimodal activity pattern with a delayed peak occurring about 4.5 h after lights-on of the entraining light-dark (LD) cycle, while the laH strain has a bimodal activity pattern with the morning and evening peaks. It is rather unusual for a wild type strain of any Drosophila species to have a unimodal activity pattern during entrainment as observed in the haH strain. The single activity peak of the haH strain is regarded as a consequence of delayed morning peak merging with the evening one. Three experiments were performed to test this hypothesis. The first experiment examined whether the single activity peak could be dissociated into two components by LD cycles in which photoperiods varied from 10 to 16 h per 24 h. The haH strain again exhibited a unimodal activity pattern with a delayed peak in 10, 12, and 14 h photoperiods but a bimodal activity pattern in 16 h photoperiod. The laH strain had bimodality in 10 and 12 h photoperiods, unimodality in a 14 h photoperiod, but complete arrhythmicity in a 16 h photoperiod. In the second experiment, the haH flies were transferred from LD 16:8 to LL at 5 lux to confirm whether the bimodality of this strain in LD 16:8 cycles was not the result of masking by the long photoperiod of 16 h. Bimodality of the haH strain persisted in LL too; moreover, the morning component free-ran with period (tau) <24 h, while the evening component free-ran with tau>24 h. The third experiment examined the LL-induced splitting of activity peak of the haH strain. Flies were transferred from LD 12:12 cycles to LL at 0, 1, 5, and 15 lux. The haH strain was rhythmic in LL at 0 and 1 lux with a unimodal activity pattern. It was also rhythmic in LL at 5 lux, but the single activity peak was split into two discrete components; the morning component free-ran with tau<24 h, while the evening component free-ran with tau>24 h. This strain, however, was completely arrhythmic in LL at 15 lux. The laH strain was uniformly arrhythmic in LL at all levels of light intensity. These results suggest that the single but late activity component of the haH strain during entrainment appears to be the consequence of merging the delayed morning peak with the evening one as an adaptation to the environmental conditions at the altitude of origin of this strain, where these flies begin activity in the forenoon owing to non-permissible low temperature in the morning.

In previous research, it was determined that the altitude of origin altered the parameters of photic entrainment and free-running rhythmicity of adult locomotor activity of the high-altitude Himalayan (haH) strain (Hemkund-Sahib, 4121 m above sea level) of Drosophila helvetica compared to the low-altitude Himalayan (laH) strain (Birahi, 1132 m above sea level) of the same species. The present study investigated whether the altitude of origin also affects the parameters of the light pulse phase response curve (PRC) of the adult locomotor activity rhythm of the haH strain. Light pulse PRCs were determined for both strains against the background of constant darkness. Although both were "weak" or type 1 PRCs, the PRC for the haH strain differed from that of the laH strain in three basic parameters. The PRC for the haH strain was of low amplitude, had a protracted dead zone, and showed a ratio of the advance to delay region (A/D>1), while the PRC of the laH strain was characterized by high amplitude, absence of dead zone, and a A/D ratio<1. The asymmetric PRCs of these strains might explain the process of photic entrainment to 24 h light-dark cycles, as the long period of the free-running rhythm (tau) of the haH strain is complemented with a larger advance portion of its PRC (A/D>1), whereas the short tau of the laH strain is matched with a larger delay portion of its PRC (A/D<1). Prolonged dead zone and low amplitude in the PRC of the haH strain imply that the photic sensitivity of this strain has been drastically diminished as an adaptation to environmental conditions at the altitude of its origin. While adults of this strain begin activity in very bright light in the forenoon due to non-permissible low temperature in the morning, the converse is true for the laH strain.