排序方式: 共有36条查询结果,搜索用时 15 毫秒
1.
2.
3.
Discussions about the evolution of female mating preferences have often suggested that females should express multiple strong preferences when different male traits are correlated with different mating benefits, yet few studies have directly tested this hypothesis by comparing the strength of female preferences for male traits known to be correlated with different benefits. In the variable field cricket, Gryllus lineaticeps, females receive fecundity and fertility benefits from mating with males with higher chirp rates and life-span benefits from mating with males with longer chirp durations. Although females prefer higher chirp rates and longer chirp durations when the other trait is held constant, it is possible that they give priority to one of these song traits when both vary. In this study, we examined the relative importance of chirp rate and chirp duration in female mate choice using single-stimulus presentations of songs that varied in both chirp rate and chirp duration. Females expressed both directional and stabilizing preferences based on chirp rate, responding most strongly to a chirp rate approximately one standard deviation above the population mean. Females did not express preferences based on chirp duration, and did not express correlational preferences. These results suggest that females may give priority to the reproductive benefits provided by males that produce higher chirp rates. 相似文献
4.
Females commonly prefer to mate with males that provide greater material benefits, which they often select using correlated male signals. When females select higher-benefit males based on correlated signals, however, males can potentially deceive females by producing exaggerated signals of benefit quality. The handicap mechanism can prevent lower-quality males from producing exaggerated signals, but cannot prevent cheating by higher-quality males that choose to withhold the benefit, and this poses a major problem for the evolution of female choice based on direct benefits. In a field cricket, Gryllus lineaticeps, females receive seminal fluid products from males with preferred songs that increase their fecundity and lifespan. We tested the hypothesis that female behaviour penalizes males that provide lower-quality benefits. When females were paired with males that varied in benefit quality but had experimentally imposed average songs, they were less likely to re-mate with males that provided lower-quality benefits in the initial mating. This type of conditional female re-mating may be a widespread mechanism that penalizes males that cheat on direct benefits. 相似文献
5.
RET rearrangements in papillary thyroid carcinomas and adenomas detected by interphase FISH 总被引:5,自引:0,他引:5
Cinti R Yin L Ilc K Berger N Basolo F Cuccato S Giannini R Torre G Miccoli P Amati P Romeo G Corvi R 《Cytogenetics and cell genetics》2000,88(1-2):56-61
Activation of the RET protooncogene through somatic rearrangements represents the most common genetic alteration in papillary thyroid carcinoma (PTC). Three main rearranged forms of RET have been described: RET/PTC1 and RET/PTC3, which arise from a paracentric inversion of the long arm of chromosome 10, and RET/PTC2, which originates from a 10;17 translocation. We have developed a dual-color FISH approach to detect RET/PTC rearrangements in interphase nuclei of thyroid lesions. By using a pool of three cosmids encompassing the RET chromosome region and a chromosome 10 centromeric probe, we could discriminate between the presence of an inversion (RET/PTC1 and RET/PTC3) or a translocation (RET/PTC2). We have investigated a series of thyroid tissue samples from Italian and French patients corresponding to a total of 69 PTCs and 22 benign lesions. Among PTCs, 13 (18.8%) showed a RET rearrangement, and 11 (15.9%) of these carried an inversion (RET/PTC1 or RET/PTC3) in more than 10% of the nuclei examined. Activated forms of RET were also observed in three adenomas. RT-PCR analysis on the same samples confirmed the presence and the type of rearrangement predicted using FISH analysis. An interesting difference in the frequency and type of RET rearrangements was detected between the Italian and the French patients. Furthermore, we identified a putative novel type of rearrangement in at least one PTC sample. Several PTCs carried a significant number of cells characterized by a trisomy or a tetrasomy of chromosome 10. Overall, the FISH approach in interphase nuclei represents a powerful tool for detecting, at the single cell level, RET/PTC rearrangements and other anomalies involving the RET chromosome region. 相似文献
6.
A L Basolo 《Proceedings. Biological sciences / The Royal Society》1998,265(1411):2223-2228
Female poeciliid fishes of the sister genera Xiphophorus and Priapella share a preference for males with swords, despite phylogenetic information suggesting that swords arose in Xiphophorus after the divergence of the two genera. This study examines the strength of sword and body-size preferences in a representative of both genera. A comparison of the preference functions reveals that the strength of the preference favouring a sword in P. olmecae is significantly stronger than that in X. helleri. This result demonstrates that the pre-existing bias is not evolutionarily fixed, and that there has been change in the bias favouring the sword, in either the Priapella lineage, or the Xiphophorus lineage, or in both. Although females in both species prefer conspecific males with swords, only X. helleri females also demonstrate a body-size preference. The preference functions for body size and sword length for X. helleri are not significantly different, whereas in P. olmecae the preference function for sword length is significantly stronger than for body size. These combined results indicate that an ancestral bias for body size cannot alone explain the pre-existing bias favouring a sword in P. olmecae. 相似文献
7.
Giusti L Cetani F Ciregia F Da Valle Y Donadio E Giannaccini G Banti C Pardi E Saponaro F Basolo F Berti P Miccoli P Pinchera A Marcocci C Lucacchini A 《Molecular bioSystems》2011,7(3):687-699
Parathyroid tumours are heterogeneous and in some cases the diagnosis may be difficult using histological features. In this study we used a two-dimensional electrophoresis (2D)/mass spectrometry (MS)-based approach to examine the global changes of parathyroid adenoma tissues protein profile compared to the parathyroid normal tissues. Validation of protein expression was performed by immunoblotting using specific antibodies. Ingenuity software was used to identify the biological processes to which these proteins belong and to construct a potential network. A total of 30 proteins were found to be differentially expressed, of which 22 resulted in being over-expressed. Proteins identified by 2D/MS/MS proteomics were classified into functional categories and a major change (≥ 2-fold) in terms of expression was found in proteins involved in response to biotic stimuli, cell organization and signal transduction. After Ingenuity analysis, 14-3-3 ζ/δ appears to be a key protein in the network of parathyroid adenoma, where it is linked to other proteins such as annexin A2, B box and SPRY domain-containing protein (BSPRY), p53 and epidermal growth factor receptor (EGFR). Our results suggest that the proteomic approach was able to differentiate the protein profiles of normal parathyroid and parathyroid adenoma and identify a panel of proteins which are differentially expressed. The functional role of these proteins in the network of intracellular pathways is discussed. 相似文献
8.
9.
Alexandra L Basolo 《Animal behaviour》2002,63(3):463-468
Female poeciliid fish of the sister genera Xiphophorus and Priapella share a mating preference favouring a sword, despite phylogenetic evidence that the sword arose in Xiphophorus. This conclusion is based on the presence of a preference favouring a sword in three unsworded species and one sworded species. Here I investigate the response to a sword in the poeciliid fish Heterandria bimaculata by testing females with conspecific males that differ in the presence or absence of a sword. Female H. bimaculata were found to prefer unsworded males, thus sworded males were discriminated against. I also tested the strength of female response; females did not show a differential response to males based on sword length. The preference for unsworded males could indicate that when new male traits arise, biases might oppose trait evolution, even in cases in which similar male traits in related taxa are favoured. Explanations for the female preference for unsworded males are discussed. 相似文献
10.
Congruence between the sexes in preexisting receiver responses 总被引:1,自引:1,他引:0
Preexisting receiver biases have been shown to affect how femalesdetect and respond to new conspecific traits in a mate choicecontext. Although preexisting biases have often been discussedin the context of female mate choice, these biases need notbe sex limited. In the genus Xiphophorus, swordtail males possessa sexually selected trait, the sword. Here I consider evidencethat the state of a bias favoring sworded conspecifics maybe generally shared by the sexes in taxa in which the sword
has not arisen. In three unsworded species of poeciliid fishes,both males and females prefer members of the other sex withswords. In a fourth species, males and females share the absenceof a response to a sword. This congruity between the sexessuggests that response biases may not be sex limited and thatthe sexes could historically share common mechanisms producingshared mating responses. Alternatively, selection may tendto result in parallel changes in biases in the sexes. Thiswork expands our understanding of receiver biases by usinga phylogenetic approach to examine whether biases are historicallyshared by the sexes and suggests that there can be general
congruence between the sexes in such biases. 相似文献