Conservation of Bio synthetic pheromone pathways in honeybees Apis

Social insects use complex chemical communication systems to govern many aspects of their life. We studied chemical changes in Dufours gland secretions associated with ovary development in several genotypes of honeybees. We found that C28–C38 esters were associated only with cavity nesting honeybee queens, while the alcohol eicosenol was associated only with their non-laying workers. In contrast, both egg-laying anarchistic workers and all parasitic Cape workers from queenright colonies showed the typical queen pattern (i.e. esters present and eicosenol absent), while egg-laying wild-type and anarchistic workers in queenless colonies showed an intermediate pattern, producing both esters and eicosenol but at intermediate levels. Furthermore, neither esters nor eicosenol were found in aerial nesting honeybee species. Both esters and eicosenol are biosynthetically similar compounds since both are recognizable products of fatty acid biosynthesis. Therefore, we propose that in honeybees the biosynthesis of esters and eicosenol in the Dufours gland is caste-regulated and this pathway has been conserved over evolutionary time.     

Wax of a whitefly and its utilization by a chrysopid larva

Defense Mechanisms of Arthropods, no. 96; no. 95: Eisner et al.: Chemoecology (in press)     

Body condition and immune response in wild zebra finches: effects of capture, confinement and captive-rearing

Behavioural ecologists attempt to predict fitness in birds from estimates of body condition and immune capacity. We investigated how the stresses associated with capture, confinement and captive-rearing of wild zebra finches (Taeniopygia guttata) affected different elements of the immune system and body condition. Wild birds had higher heterophil:lymphocyte ratios and total leucocyte counts than aviary birds, presumably an outcome of mounting specific resistance to pathogens, but this response diminished significantly within 10 days of confinement. Wild birds had lower phytohaemagglutinin-A (PHA) responses than their aviary-bred counterparts possibly because energetic costs limited a general resistance response. Wild birds were heavier and had higher haematocrits than their aviary counterparts, but had less fat, although just 10 days of captivity significantly increased fat levels. Measures of body condition were of limited use for predicting immune responsiveness. We conclude that the different elements of the immune system and body condition respond independently, and often unpredictably, to many ecological and behavioural stressors.     

Prenatal diagnosis of inborn errors in peroxisomal β-oxidation

In recent years, an increasing number of inherited diseases in man have been recognized in which there is an impairment in the peroxisomal β-oxidation of very-long-chain fatty acids. In general, these disorders are associated with severe neurological and physical abnormalities and death within the first years of life. In this paper we describe our experience with regard to the prenatal diagnosis of a number of different inborn errors of peroxisomal β-oxidation. Eleven pregnancies at risk were monitored by measuring very-long-chain fatty acid levels as well as very-long-chain fatty acid β-oxidation in cultured chorionic villous fibroblasts and/or amniotic fluid cells. Five affected fetuses were identified. It is concluded that prenatal diagnosis in this group of diseases can be done reliably using cultured chorionic villous fibroblasts or amniotic fluid cells.     

Prenatal diagnosis and outcomes of five cases of mosaicism for an isochromosome of 20q

Five cases of mosaicism for an isochromosome of 20q have been detected from a total of 50 000 cases analysed for prenatal diagnosis by amniocentesis. Karyotypes were designated mos 46,X_/46,X_,i(20q). In all cases, the abnormal cell line was detected in more than one primary culture, thus fulfilling the criterion for true (level III) mosaicism. Indications for prenatal diagnosis were parental anxiety (two cases), low maternal serum alpha-fetoprotein (AFP) (two cases), and high maternal serum AFP (one case). Level II ultrasounds on all five fetuses were normal, and the abnormal cell line was never detected in fetal blood and/or cord blood. All five pregnancies were continued and had normal outcomes, with birth weights ranging from 2.4 to 3.8 kg. The development of all five children has been normal, with the oldest child in the study now 4 years of age. We suggest that the abnormal cell line in each case was of extrafetal origin, and that this may be one of the more common examples of this phenomenon, occurring in approximately 1/10000 prenatal diagnoses. Mosaicism i(20q) may have been missed in the past because of the higher resolution necessary to detect this subtle change.