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121.
Senescence of immune defence in Bombus workers 总被引:1,自引:0,他引:1
Claudie Doums Yannick Moret Elmar Benelli Paul Schmid-Hempel 《Ecological Entomology》2002,27(2):138-144
Abstract 1. Senescence in workers of social insects is a particularly intriguing life-history trait as the future fitness of workers relies primarily on age-dependent survival rate. The pattern of senescence of immune defence traits was investigated under laboratory conditions in workers of two bumble bees: Bombus terrestris and B. lucorum .
2. In both species, there was a significant decrease with age in the ability to encapsulate a foreign object (a global measure of the efficiency of immune systems). This pattern of senescence was observed in all colonies in B. terrestris (seven) and B. lucorum (eight) assayed, even though, for the latter, there was some heterogeneity among colonies.
3. In B. terrestris , two other measures of immune defence were taken: the relative percentage of fat body in the abdomen and the concentration of haemocytes (the immune defence cells). The quantity of fat body increased only slightly with age and there was no effect for the concentration of haemocytes. Interestingly, the concentration of haemocytes decreased strongly after an encapsulation response, regardless of the age of workers.
4. The importance of the senescence pattern observed for the immune defence traits is discussed in the context of the social biology of workers. 相似文献
2. In both species, there was a significant decrease with age in the ability to encapsulate a foreign object (a global measure of the efficiency of immune systems). This pattern of senescence was observed in all colonies in B. terrestris (seven) and B. lucorum (eight) assayed, even though, for the latter, there was some heterogeneity among colonies.
3. In B. terrestris , two other measures of immune defence were taken: the relative percentage of fat body in the abdomen and the concentration of haemocytes (the immune defence cells). The quantity of fat body increased only slightly with age and there was no effect for the concentration of haemocytes. Interestingly, the concentration of haemocytes decreased strongly after an encapsulation response, regardless of the age of workers.
4. The importance of the senescence pattern observed for the immune defence traits is discussed in the context of the social biology of workers. 相似文献
122.
Denise Busson Bernadette Limbourg-Bouchon Marie-Christine Mariol Thomas Preat Claudie Lamour-Isnard 《Development genes and evolution》1988,197(4):221-230
Summary
Fused is a segmentation gene belonging to the segment-polarity class. Mutations at thefused locus are known to display pleiotropic effects, causing zygotically determined anomalies of ovaries and of some adult cuticular
structures, and maternally determined embryonic segmentation defects. In order to determine the amorphic phenotype offused and to study the genetical basis of its pleiotropy, newfused alleles (18 viable and 11 lethal) were isolated. The phenotype of these mutants and of others already known are described,
taking into account zygotic and maternal effects. The main results provided by this analysis are as follows. Firstly, allfused alleles show the whole complex fused phenotype, and a good correlation is observed between the strength of the wing and segmentation
defects, suggesting that a single function is involved in both processes. Secondly, all embryonic and larval lethals carry
deficiencies which allow us to localizefused between the 17C4 and 17D2 bands of the X-chromosome. Thirdly, the 24 viable and 2 pupal lethals examined behave as point
mutants, as shown cytologically or by Southern blot analysis. However, only one of them, the pupal lethalfu
mH63 was proven to carry a nullfused allele, since it displays in germ-line clones a strong maternal phenotype and a very low zygotic rescue, similar to those
of the small deficiencyDf(1)fu
z4. The phenotype of the amorphic mutant indicates that zygotic ezpression offused is required for normal metamorphosis, while maternal expression is necessary for a normal segmentation pattern, since a complete
loss offused expression during oogenesis cannot be compensated zygotically. 相似文献