Effect of brood developmental temperature on the homing capability and memory related gene expression of worker bees Apis mellifera L．
Author of the article:YUAN An** GUO Ya-Hui HUANG Xiao LIAO Chun-Hua WU Xiao-Bo***
Author's Workplace：Honeybee Research Institute, Jiangxi Agricultural University, Nanchang 330045, China
Key Words：Apis mellifera ligustica, developmental temperature, homing rate, memory genes
Abstract：[Objectives] The objective of this experiment was to explore the effects of developmental temperature on the homing capability and memory related gene expression levels of worker bees Apis melliferaL. [Methods] Three honeybee colonies of equal population size were used in experiments. Each queen was confined within an empty frame to lay eggs for 48 hours. Each frame was then separated into three equal sections after larval cells had been capped and the three sections were placed in different incubators and incubated at either 33, 35, or 37℃, until hatching took place. Relative humidity in each incubator was 75%±5%. New born worker bees from each incubator were marked with different colors and returned into their natal colonies. The homing rates of foragers over distances of 1 km and 2 km, and the expression levels of three memory related genes [the glutamate receptor type A gene (GluRA), the N-methyl-D-aspartic acid receptor 1 gene (Nmdar1) and the tyramine receptor type 1 gene (Tyr1)], in day-old (newly emerged), 10-day-old, and 20-day-old worker bees, were measured and compared. [Results] Homing rates in GroupsⅡandⅢwere significantly higher than in GroupⅠ(P<0.05), but there was no significant difference between Groups II and III (P>0.05). GluRA and Nmdar1 were more highly expressed in newly emerged bees, 10-day-old bees and 20-day-old bees in GroupsⅡandⅢcompared to GroupⅠ(P<0.05), but there was no significant difference between GroupsⅡandⅢ (P>0.05). Tyr1 was more highly expressed in newly emerged bees in GroupⅡthan in GroupsⅠandⅢ(P<0.05), but there was no significant difference between Groups ⅠandⅢ(P>0.05). There was also no significant difference in Tyr1 expression in 10-day-old bees and 20-day-old bees among all three groups (P>0.05). [Conclusion] Lower developmental temperatures may affect the homing ability and expression of memory related genes in Apis mellifera ligustaca workers.