Thermal adaptation involves higher expression levels of the lethal(2)-essential-for-life-like (l(2)efl) among the honeybee Apis mellifera L. subspecies

Apis mellifera yemenitica is the native honeybee of the Arabian Peninsula. It demonstrates unique morphological, behavioral, and molecular aspects to survive extreme summer temperatures dominating the region. In this study, relative expression of Apis mellifera lethal(2)-essential-for-life-like (l(2)efl) gene family (ID: 724405; 724488; 234274) were measured in A. m. yemenitica and A. m. carnica under desert (Riyadh) and semiarid (Baha) conditions of Saudi Arabia. Results demonstrated significantly higher day-long expression levels of l(2)efl mRNAs in A. m. yemenitica than in A. m. carnica under the same conditions. Under desert conditions of Riyadh, fold changes in expression levels of l(2)efl mRNAs were similar to 100x higher in A. m. yemenitica than the calibrator. In Baha (semiarid conditions), l(2)efl expression levels were very modest compared to those in Riyadh with significant interaction between location and subspecies. In conclusion, expression of l(2)efl (mRNAs) (724405; 724488; 234274) can be considered as a key component of A. m. yemenitica response to extreme desert temperatures characterizing the Riyadh region. On the other hand, the semi-arid conditions (Baha) are a more suitable habitat for A. m. carnica compared to Riyadh.