Background: Evolution of resistance threatens the continued success of transgenic crops expressing insecticidal proteins. One of the key factors for successful resistance management is the timely implementation of monitoring programmes to detect early changes of resistance allele frequency in field populations. F(1)/F(2) screen, dose-response bioassays and field survey were used to monitor resistance to the Cry1Ac-expressing cotton in a field population of Helicoverpa armigera (Hübner), the primary target of transgenic Bt cotton in China.
Results: Field survey showed an increased trend of egg populations of H. armigera on Bt cotton in the Qiuxian area from 2003 to 2007. By using the F(2) screening procedure, the resistance allele frequency in the Qiuxian (Hebei, China) population of H. armigera collected during 2007 was estimated to be 0.075 (95% CI: 0.053-0.100), which was 12 times greater than that estimated 9 years ago. Dose-response bioassay with the field population collected from the same area showed a significant resistance level (11-fold) to Cry1Ac toxin compared to a laboratory susceptible strain.
Conclusion: This study documented a case of field-evolved resistance in H. armigera after several years of intensive planting of Bt cotton. Proactive tactics must be adopted to prevent further increase of resistance gene frequency in the Qiuxian region.
Key Laboratory of Evolution & Marine Biodiversity (Ministry of Education) and Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China.
The axolotl, a legendary creature with the potential to regenerate complex body parts, is positioned as a powerful model organism due to its extraordinary regenerative capabilities. Axolotl can undergo successful regeneration of multiple structures, providing us with the opportunity to understand the factors that exhibit altered activity between regenerative and non-regenerative animals. This comprehensive review will explore the mysteries of axolotl regeneration, from the initial cellular triggers to the intricate signaling cascades that guide this complex process.
This study intended to evaluate the clinical efficacy and safety of colistin sulfate aerosol inhalation in combination with ceftazidime-avibactam for the treatment of pulmonary carbapenem-resistant (CRKP) infection during the peri-operative period of liver transplantation. A retrospective analysis was designed to investigate 52 patients who developed pulmonary CRKP infection after liver transplantation between December 1, 2019, and November 30, 2022. On the basis of whether they received colistin sulfate aerosol inhalation, the patients were divided into the treatment group ( = 29) and the control group ( = 23).
Human mesenchymal stromal cells (MSCs) are attractive for both medical practice and biomedical research. Nonfreezing short-term storage may provide safe and simple transportation and promote the practical use of MSCs. We aimed to determine the duration of efficient storage at ambient temperature (22°C) of human dermal MSCs in different three-dimensional organization and to investigate the role of cell metabolic mode in the resistance to the ambient storage damaging factors.
This study compared the roles of extraparenchymal autonomic nervous system (ANS) control of cerebral blood flow (CBF) versus intraparenchymal cerebrovascular autoregulation in 487 patients with aneurysmal subarachnoid hemorrhage (SAH) and 413 patients with traumatic brain injury (TBI). Vasomotion intensity of extraparenchymal and intraparenchymal vessels were quantified as the amplitude of oscillations of arterial blood pressure (ABP) and intracranial pressure (ICP) in the very low frequency range of 0.02-0.
