CDC7-independent G1/S transition revealed by targeted protein degradation.

The entry of mammalian cells into the DNA synthesis phase (S phase) represents a key event in cell division1. According to current models of the cell cycle, the kinase CDC7 constitutes an essential and rate-limiting trigger of DNA replication, acting together with the cyclin-dependent kinase CDK2. Here we show that CDC7 is dispensable for cell division of many different cell types, as determined using chemical genetic systems that enable acute shutdown of CDC7 in cultured cells and in live mice. We demonstrate that another cell cycle kinase, CDK1, is also active during G1/S transition both in cycling cells and in cells exiting quiescence. We show that CDC7 and CDK1 perform functionally redundant roles during G1/S transition, and at least one of these kinases must be present to allow S-phase entry. These observations revise our understanding of cell cycle progression by demonstrating that CDK1 physiologically regulates two distinct transitions during cell division cycle, whereas CDC7 has a redundant function in DNA replication.

Commercially Available Essential Oil Formulas as Repellents Against the Stored-Product Pest Alphitobius diaperinus.

The main aim of the presented paper is to assess the potential repellent effect of selected essential oils (EOs) against the lesser mealworm (Alphitobius diaperinus), which can cause economic losses in storage and in the poultry industry. Due to the development of pesticide resistance in A. diaperinus populations, as well as an attempt to limit extensive use of potentially harmful pesticides in food-related industries, there is a strong need for the development of alternative methods of dealing with A. diaperinus infestations. Because of their cost-effectiveness, availability and low vertebrate toxicity, EOs are promising agents in pest management. In the presented paper four off-the-shelf EOs: mint, vanilla, lemon and citronella (and mixtures of them) were tested as potential repellents. Moreover, a novel preference assay, providing an extended analysis of the preference and the locomotor response, was used. The most effective EOs were: citronella and lemon. EOs mixtures were generally more repellent than individual EOs, with the lemon and vanilla 1:1 mixture acting as the strongest repellent. A few of the tested EOs caused significant alterations to the locomotor activity, although no direct relation was observed. In conclusion, EOs can be potentially used as repellent agents in A. diaperinus management. Additionally, data on the locomotor activity may lead to designing better push-pull strategies in pest management.

Repellent Effect of Volatile Fatty Acids on Lesser Mealworm (Alphitobius diaperinus).

Volatile fatty acids (VFAs) are a group of common metabolites and semiochemicals mediating information transfer between higher organisms and bacteria, either from microbiome or external environment. VFAs commonly occur among various insect orders. There are numerous studies exploring their influence on the behavior of different insect species. In relation to the papers published by J. E. McFarlane in 1985, we assessed the effects of formic, acetic, propionic, butyric and valeric acids on the spatial preference of the lesser mealworm (Alphitobius diaperinus), a common pest of stored food grain products and the poultry industry. The main aim of the presented study was to provide new angles in VFA research, recreating the classical study both with new methods and on economically significant pest species. This paper presents a novel method of continuous, simultaneous assessment of site preference and the travelled distance in a constant-flow olfactometer. All the tested VFAs, except valeric acid, had a significant repellent effect, with formic acid being effective even at the lowest used concentration. Additionally, the VFAs significantly altered the distance travelled by the insects. The obtained results indicate a potential role for VFAs in the olfactory guided behavior of A. diaperinus. It is suspected that the reaction to the presence of VFAs may deviate from the specificity of species' original habitat.