Acta Entomologica Sinica ›› 2022, Vol. 65 ›› Issue (5): 577-586.doi: 10.16380/j.kcxb.2022.05.005

• RESEARCH PAPERS • Previous Articles     Next Articles

Effects of CO2 narcosis on the ovarian development of virgin queens of Apis cerana cerana (Hymenoptera: Apidae)

ZHOU Jian-Yang1,2,3, SONG Hua-Li1,2,3, DENG Ping1,2,3, TAO Kun-Ling1,2,3, TANG Xiang-You1,2,3, YAN Le-Le1,2,3, ZHANG XiaoYan1,2,3, SHI Peng1,2,3, XU Jin-Shan1,2,3,*   

  1.  (1. College of Life Sciences, Chongqing Normal University, Chongqing 401331, China; 2. Engineering Research Center of Biotechnology for Active Substances, Ministry of Education, Chongqing 401331, China; 3. Chongqing Key Laboratory of Vector Insect, Chongqing 401331, China)
  • Online:2022-05-20 Published:2022-05-08

Abstract: 【Aim】 To clarify the dynamic changes of reproductive system of queens of the Chinese honeybee (Apis cerana cerana) after emergence, and to explore the effects of CO2 narcosis on the ovarian development of their virgin queens. 【Methods】 Through artificial breeding technology and storage of the queens, we obtained different day-old virgin queens of A. cerana cerana, observed the morphological characteristics of their reproductive system after emergence, and determined the morphological indexes of their reproductive system including the body weight, ovarian weight, diameter of spermatheca, and number of ovarioles. After the virgin queens were narcotized with different concentrations (50%, 75% and 90%) of CO2 in two consecutive days (at the 5- and 6-d-old, respectively) for 8 min, and different day-old virgin queens were respectively narcotized with 75% CO2 for 1-3 times (each time for 8 min), the morphological characteristics of the ovaries of the 10-d-old queen were observed by paraffin section and HE staining, and their ovarian weight and the length of the largest oocyte of ovaries were detected. Meanwhile, the relative expression level of vitellogenin gene (Vg) in the head of the 10-d-old queens was measured by real-time fluorescence quantitative PCR (RT-qPCR). 【Results】 The number of ovarioles and the diameter of spermatheca of the queens of A. cerana cerana did not fluctuate obviously with the age increasing. However, the ovarian weight of queens increased obviously during the 6-12-d-old and then tended to be stable. As compared to the control (not subjected to CO2 narcosis), narcosis with 50%, 75% and 90% CO2 resulted in the increase of the ovarian weight and the length of the largest oocyte of queens of A. cerana cerana and the upregulation of the relative expression level of Vg gene in the queen head. Moreover, narcosis with 75% CO2 twice significantly promoted the ovarian development of A. cerana cerana queens. 【Conclusion】 The ovaries of A. cerana cerana queens present obvious developmental changes after emergence, and CO2 narcosis can accelerate their ovarian development.

Key words: Apis cerana cerana, queen, CO2 narcosis, reproductive system, ovary; vitellogenin