In this paper, the authors discuss the role of epigenetics in determining castes. They traced the effects of Dnmt3-  a protein that's part of the epigenetic system and known to be involved in caste determination. My reading is that the paper verifies epigenetics are at work in queen creation based on nutrition and,  reveals an unexpected finding that the size of a queen cell also has an epigenetic effect on caste development. They assert that three-day-old larvae may be aware of their surroundings and that the larger queen cell has a similar effect on determining caste as nutrition does. Speaking from virtually knowing nothing about the subject, if cell size matters in queen determination can the size of larval cells also have an epigenetic effect?

>While the effects of nutrition on caste determination have been well studied, whether the size difference between worker and queen cells also contributes to caste determination is not clear. In this study we report the effects of both nutrition and cell-size on Dnmt3 activity, its gene expression, and the resulting phenotype of adult bees.

>It is well known that worker larvae up to 3 days old are still able to develop into a largely queen phenotype []. We therefore expected to observe no differences between the two groups of 3 day old larvae reared in different sized cells, because both received the same diet. Instead, we observed that in 3 day old larvae, all measured responses (Dnmt3 activity, expression, and percent methylation) were significantly different between the queen-cup and worker-cell reared larvae []. This suggested that even at 3 days old, the larvae somehow detected differences in their rearing environment, even though larvae are still relatively small (compared to worker cell size). These differences did not become strikingly larger when larvae were 5 days old []. Space restriction is the only explanation for the observed differences, because we removed the gravity factor (in the colony, queen cells are oriented differently from worker cells) in the laboratory larvae-rearing setting.

Diet and Cell Size Both Affect Queen-Worker Differentiation through DNA Methylation in Honey Bees (Apis mellifera, Apidae)
Yuan Yuan Shi, Zachary Y. Huang , Zhi Jiang Zeng , Zi Long Wang, Xiao Bo Wu, Wei Yu Yan


Bill Hesbach
Northeast USA 

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html