תפריט נגישות
ניגודיות עדינהניגודיות גבוהה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם תפריט נגישותניגודיות עדינהניגודיות גבוההמונוכרוםהדגשת קישוריםחסימת אנימציהפונט קריאסגוראיפוס הגדרות נגישותלהורדת מודול נגישות חינםA. Hefetz
Nestmate recognition in the desert ant, Cataglvphis niger (Hymenoptera: Formicinae), is mediated via epicuticular hydrocarbons and relies on the formation of a gestalt colony odor. In turn, colony gestalt is mediated via the postpharyngeal gland (PPG) whereby hydrocarbons from different sources accumulate and mix, constituting the so-called 'gestalt organ'. Since ants in which the PPG is removed synthesize the hydrocarbons normally, we hypothesized that these are biosynthesized de novo in one of the body tissues and thereafter transported to the PPG and the epicuticular surface. The present study tested several predictions that stem from the above hypothesis. We examined the ability of PPG, cuticular preparations and the fat body to synthesize hydrocarbons in vitro, looked for their presence in the hemolymph, and explored the role of the crop in the internal circulation of hydrocarbons. The chemical analyses revealed that both the hemolymph and the crop contained the same hydrocarbons that are tbund in the PPG. Whereas in the hemolymph their amount was very low, the crop contained as much hydrocarbons as did the PPG. Using radioactive precursors in vitro, we demonstrated that the fat body is the major site of hydrocarbon biosynthesis. The PPG, on the other hand, failed to synthesize hydrocarbons, but nonetheless showed good de novo biosynthesis of other lipids. Biosynthetic studies in vivo using intact and decapitated ants revealed the presence of newly synthesized hydrocarbons in the crop in intact but not in decapitated ants, indicating that the PPG is the major source of crop hydrocarbons. These results confirm and enlarge the proposed model for hydrocarbons circulation in C. niger. They are synthesized by the tat body, released to the hemolymph, and transported to the cuticle and the PPG. In the PPG they are admixed with hydrocarbons from other ants by trophallaxis, and reapplied to the cuticle by selfgrooming. Hydrocarbons also pass from the PPG to the crop. Although we do not know yet the role of the alimentary canal in hydrocarbon circulation, we suggest that it may serve as a clearing outlet for the PPG. Regularly emptying the PPG of its hydrocarbons should tacilitate the updating of its content and adjusting it to the colony gestalt through exchange with other ants. [L]
A. Hefetz
Nestmate recognition in the desert ant, Cataglvphis niger (Hymenoptera: Formicinae), is mediated via epicuticular hydrocarbons and relies on the formation of a gestalt colony odor. In turn, colony gestalt is mediated via the postpharyngeal gland (PPG) whereby hydrocarbons from different sources accumulate and mix, constituting the so-called 'gestalt organ'. Since ants in which the PPG is removed synthesize the hydrocarbons normally, we hypothesized that these are biosynthesized de novo in one of the body tissues and thereafter transported to the PPG and the epicuticular surface. The present study tested several predictions that stem from the above hypothesis. We examined the ability of PPG, cuticular preparations and the fat body to synthesize hydrocarbons in vitro, looked for their presence in the hemolymph, and explored the role of the crop in the internal circulation of hydrocarbons. The chemical analyses revealed that both the hemolymph and the crop contained the same hydrocarbons that are tbund in the PPG. Whereas in the hemolymph their amount was very low, the crop contained as much hydrocarbons as did the PPG. Using radioactive precursors in vitro, we demonstrated that the fat body is the major site of hydrocarbon biosynthesis. The PPG, on the other hand, failed to synthesize hydrocarbons, but nonetheless showed good de novo biosynthesis of other lipids. Biosynthetic studies in vivo using intact and decapitated ants revealed the presence of newly synthesized hydrocarbons in the crop in intact but not in decapitated ants, indicating that the PPG is the major source of crop hydrocarbons. These results confirm and enlarge the proposed model for hydrocarbons circulation in C. niger. They are synthesized by the tat body, released to the hemolymph, and transported to the cuticle and the PPG. In the PPG they are admixed with hydrocarbons from other ants by trophallaxis, and reapplied to the cuticle by selfgrooming. Hydrocarbons also pass from the PPG to the crop. Although we do not know yet the role of the alimentary canal in hydrocarbon circulation, we suggest that it may serve as a clearing outlet for the PPG. Regularly emptying the PPG of its hydrocarbons should tacilitate the updating of its content and adjusting it to the colony gestalt through exchange with other ants. [L]
