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11.
Queen control of egg fertilization in the honey bee 总被引:3,自引:0,他引:3
The study investigated the precision with which honey bee queens can control the fertilization of the eggs they lay. Because
males and workers are reared in different-sized cells, the honey bee is one of the few Hymenoptera in which it is possible
for the experimenter to know which type of egg a queen “intends” to lay. Eggs were collected from both worker and drone (male)
cells from four honey bee colonies. Ploidy of the embryo was determined using polymorphic DNA microsatellites. All 169 eggs
taken from worker cells were heterozygous at at least one microsatellite locus showing that the egg was fertilized. All 129
eggs taken from drone cells gave a single band at the B124 locus, strongly suggesting haploidy. These data show that honey
bee queens have great, and quite possibly complete, ability to control the fertilization of the eggs they lay. Data from the
literature suggest that in two species of parasitoid Hymenoptera (Copidosoma floridanum, Colpoclypeus florus) females have great, but not complete, ability to control fertilization.
Received: 23 December 1997 / Accepted after revision: 17 May 1998 相似文献
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15.
Guido Pennings 《黑龙江环境通报》2002,22(12):1123-1129
The arguments against the use of preimplantation genetic diagnosis (PGD) for non-medical sex selection are analysed. It is concluded that the distinction between medical and non-medical reasons is difficult to maintain, that the disproportionality of means and end is not a decisive counterargument and that the fear of damage to the reputation of PGD does not justify the refusal of controversial applications. Moreover, since non-medical sex selection does not belong to basic health care, it should not be equally accessible to all. The position defended in this article is founded on two basic principles: (1) medical reasons have priority on non-medical reasons, and (2) personal reasons do not qualify for public funding. In order to respect both principles, it is proposed that restrictions should be installed to control the number of requests for social sexing and that a tax should be imposed on these elective services. The tax should compensate the society for the investment it made in the training and education of the physician. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
16.
I. Nishiumi Satoshi Yamagishi Hiromi Maekawa Chikashi Shimoda 《Behavioral ecology and sociobiology》1996,39(4):211-217
In many polygynous animals, parents invest more heavily in individual sons than in daughters. However, it is unclear if these
differences in investment are a consequence of sex differences in the demand of offspring related to sexual size dimorphism
or a consequence of parental manipulation. Here, we report on parental food delivery frequency in relation to brood size and
brood sex ratio in a wild population of polygynous great reed warblers Acrocephalus arundinaceus. We used the polymorphic microsatellite loci on the Z chromosome to sex chicks. We found that paternal feeding frequency
(times/h per nest) increased not with brood size, but with the proportion of males in the brood, although the demand per nest
was more closely related to brood size than to brood sex ratio. Additionally, the increase in rate of paternal feeding frequency
in relation to the brood sex ratio was much higher than the increase in rate of nestling food demands. Maternal feeding frequency
was independent of both brood size and brood sex ratio. These results strongly suggest that fathers preferentially invest
in their sons. We propose that parents can afford sex-biased parental care in animals in which food provisioning is enough
for all offspring to survive.
Received: 22 January 1996/Accepted after revision: 30 June 1996 相似文献
17.
X. Fu J. Tabata T. Takanashi S. Ohno S. Tatsuki Y. Ishikawa Y. Huang H. Honda 《Chemoecology》2004,14(3-4):175-180
Summary. The sex pheromone of Ostrinia orientalis
(Lepidoptera: Crambidae) was analyzed by gas chromatography–electroantennographic detection (GC–EAD), GC–mass spectrometry and a series of bioassays. Three EAD-active
compounds were detected in the female sex pheromone
gland extract, and identified as tetradecyl acetate (14:OAc),
(Z)-11-tetradecenyl acetate (Z11-14:OAc) and (E)-11-tetradecenyl acetate (E11-14:OAc). The titers (ratio) of 14:OAc, Z11-14:OAc and
E11-14:OAc in 3-day-old virgin
females were 0.49 ng (10), 4.86 ng (98) and 0.10 ng (2),
respectively. In a wind-tunnel bioassay, the 98:2 blend of
Z11- and E11-14:OAc, but not Z11-14:OAc alone, elicited
the same male behavioral responses as virgin females and
crude gland extracts. 14:OAc was inactive by itself, and did
not show any synergistic effect on the binary blend.
Field trapping experiments also confirmed the attractiveness
of the binary blend to O. orientalis
males. Based on
these results, we concluded that the sex pheromone of
O. orientalis
is a 98:2 mixture of Z11-14:OAc and
E11-14:OAc. This sex pheromone is very similar to that of the Z-type European corn borer,
O. nubilalis. The present
finding raises the question of whether O. orientalis
, which is indistinguishable from O. nubilalis
based on external morphology,
is a biologically distinct species independent from
O. nubilalis. 相似文献
18.
19.
Thomas W. Pike 《Behavioral ecology and sociobiology》2005,58(4):407-413
A number of recent reports have documented offspring sex ratio biases in birds. However, to date the potential mechanisms that have been put forward to explain the proximate basis for these deviations are entirely speculative. Using a captive population of domestic pigeons (Columba livia domestica), I tested the hypothesis that mothers in relatively poor physical condition should overproduce daughters by manipulating maternal body condition around the time of egg laying by continuous egg removal and differing feeding regimes. During treatment, females were fed a controlled quantity of food. This, combined with the high energetic costs of repeated egg production caused a significant reduction in maternal body weight. In contrast, during control when food was available ad libitum, maternal body weight did not decline, despite repeated egg production. No significant deviation from parity was evident in the sex ratio of either the first or second eggs during control, whereas during treatment a significant female bias was evident in not only the first egg, but also in the second egg. The absence of single-egg clutches, the rarity of infertile eggs and the lack of laying delays between eggs strongly suggests that the mechanism of sex ratio adjustment in pigeons occurs prior to ovulation. The highly skewed sex-distribution within the two-egg clutches and the unexpectedly large amount of variation in the yolk weight of eggs produced during treatment (but not control) are consistent with the expectations of pre-ovulatory selective resorption of wrong sex ovarian follicles. 相似文献
20.
荔枝花雄蕊和雌蕊发育过程中碳氮化合物的动态变化 总被引:10,自引:0,他引:10
比较分析了荔枝花性决定中碳氮化合物的动态变化。结果发现:C/N较大有利于雄蕊分化,反之则有利于雌蕊分化;氨基酸含量较高有利于雌蕊分化,雄蕊的氨基酸含量仅为雌蕊的一半。脯氨酸与花粉育性存在着密切相关关系。另外,探讨了雌蕊或雄蕊败育的生理意义,在长期的进化中,败育的雌蕊或雄蕊“废物”重新被利用,为同一花中迅速发育的雌蕊或雄蕊提供能量和物质的需求,表5参13。 相似文献