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Zusammenfassung Männliche Ratten zeigen nach einmaliger oder wiederholter stark erhöhter O2-Zufuhr (3–5 at) Krämpfe und Lungenschäden und zum Teil Absterben. Schädigungen der Spermatogenese oder der Fertilität traten nicht auf.  相似文献   

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S Wada 《Experientia》1975,31(8):921-923
In compound eyes of flies, a morphological duality of the retinal structure has been found. The retinal patterns based on this property and their possible evolutionary trends are described.  相似文献   

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Acid rain affects egg-laying behavior of apple maggot flies   总被引:2,自引:0,他引:2  
Summary The tephritid fruit fly,Rhagoletis pomonella, is less likely to attempt oviposition in host fruit that have been exposed to acid rain or to a simulated acid rain solution (pH<3.8). Electrophysiological data suggest that acid rain residue on the fruit surface may interfere with the sensory mechanisms that the fly uses during recognition and acceptance of host fruit.9 December 1986  相似文献   

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Leptin is an adipocyte-derived hormone involved in a myriad of physiological process, including the control of energy balance and several neuroendocrine axes. Leptin-deficient mice and humans are obese, diabetic, and display a series of neuroendocrine and autonomic abnormalities. These individuals are infertile due to a lack of appropriate pubertal development and inadequate synthesis and secretion of gonadotropins and gonadal steroids. Leptin receptors are expressed in many organs and tissues, including those related to the control of reproductive physiology (e.g., the hypothalamus, pituitary gland, and gonads). In the last decade, it has become clear that leptin receptors located in the brain are major players in most leptin actions, including reproduction. Moreover, the recent development of molecular techniques for brain mapping and the use of genetically modified mouse models have generated crucial new findings for understanding leptin physiology and the metabolic influences on reproductive health. In the present review, we will highlight the new advances in the field, discuss the apparent contradictions, and underline the relevance of this complex physiological system to human health. We will focus our review on the hypothalamic circuitry and potential signaling pathways relevant to leptin’s effects in reproductive control, which have been identified with the use of cutting-edge technologies of molecular mapping and conditional knockouts.  相似文献   

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Summary The flies of aDrosophila melanogaster strain, called AO null as it lacks the enzyme aldehyde oxidase, are nevertheless able to detoxify acetaldehyde. It seems that this action could be attributed to aldehyde dehydrogenase, or some other enzyme which ressembles aldehyde dehydrogenase.This work was supported in part by a grant from the FNRS of Belgium.  相似文献   

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Résumé Des rats mâles traités oralement avec du sulfate de cyclohexylamine (220 mg/kg/jour) ont été accouplés à des femelles traitées ou non avec du sulfate de cyclohexylamine. Dans les 2 cas, il y a eu des descendants moins nombreux que chez les contrôles. Les résultats suggèrent que l'effet est transmis par les mâles traités et est, peut-être, causé par un dommage génétique exprimé avant l'implantation de l'embryon.  相似文献   

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J P Kabayo  M Taher  H Barnor 《Experientia》1988,44(9):802-803
Comparison of the survival, fecundity and offspring size of Glossina palpalis palpalis females fed reconstituted oven-dried blood, fresh, frozen/thawed, or reconstituted freeze-dried blood showed that oven-drying at 45 degrees C does not diminish the nutritional quality of blood. The significance of this finding is discussed with a view to optimizing costs and conditions of blood-diet storage and transportation in the context of mass-rearing of tsetse flies.  相似文献   

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Summary Comparison of the survival, fecundity and offspring size ofGlossina palpalis palpalis females fed reconstituted over-dried blood, fresh, frozen/thawed, or reconstituted freeze-dried blood showed that oven-drying at 45°C does not diminish the nutritional quality of blood. The significance of this finding is discussed with a view to optimizing costs and conditions of blood-diet storage and transportation in the context of mass-rearing of tsetse flies.  相似文献   

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Summary Female choice mating experiments showed virgin femaleD. melanogaster of the 3Adh genotypes chose heterozygous (Adh F /Adh S ) males most commonly. Inseminated females chose mates randomly, but the likelihood of a female remating was genotypically dependent.Acknowledgment. Financial support was provided by the Australian Research Grants Commitee.  相似文献   

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Several ceratopogonid flies are attracted to cantharidin and ingest it from both cantharidin-baits and from meloid beetles, one of the few known natural sources for cantharidin. Because meloids are absent in northern Bavaria, and certain canthariphilous flies of the genusAtrichopogon are temporarily associated with certain plants (Apiaceae, Aristolochiaceae), it was suggested that canthariphilous ceratopogonids might be generally attracted by chemically similar plant-derived compounds. At first the seasonal fluctuating attractancy, sex ratio and behaviour ofA. oedemerarum Storå was studied at cantharidin baits. Synthetic cantharidin analogues exhibited an attractancy forA. oedemerarum if the exo,exo-7-oxabicyclo[2.2.1]heptane skeleton of cantharidin was associated with a 2,3-dicarboxylic anhydride or a 2,3--lactone. According to structure-activity studies, the analogues seem to fit best into the active site of the receptor if the carbonyl function of the -lacton is in the exo- and 2-position. This is the first report indicating that molecules other than cantharidin are attractive for canthariphilous insects.  相似文献   

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J A McKenzie  J C Fegent 《Experientia》1980,36(10):1160-1161
Female choice mating experiments showed virgin female D.melanogaster of the 3 Adh genotypes chose heterozygous (AdhF/AdhS) males most commonly. Inseminated females chose mates randomly, but the likelihood of a female remating was genotypically dependent.  相似文献   

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Spermatozoa generated in the testis are immature and incompetent for fertilization. During their journey toward the egg, the sperm acquire fertility and achieving fertilization. These sperm modifications to ensure fertilization are induced by many female or male extra-sperm factors: for example, sperm motility-activating factors from the egg jelly, sperm attractants from the eggs, and decapacitation factors from the seminal plasma. The factors controlling sperm fertility are myriad and species specific; they may be peptides, sugar chains, or small organic compounds. Nevertheless, the fundamental mechanisms underlying fertilization must be common among all animals; increase in [Ca2+]i triggers all the steps in the process of fertilization, and cAMP plays important roles in many steps. Elucidating the dynamic functional and morphological changes in sperm cells is important for understanding the regulation of fertilization. Here, we introduce the diversity and generality of the control of sperm fertility. Received 28 April 2008; received after revision 13 June 2008; accepted 17 June 2008  相似文献   

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