条螽属和桑螽属雌性发声刺的比较观察

 报道了对尖翅条螽Ducetia attenuata Xia et Liu、日本条 螽D. japonica(Thunberg)、施氏条螽D. strelkovi Gorochov et Storozhenk o和中华桑螽K uwayamaea chinensis(Brunner)、长翅桑螽K. longipennis Shi et Zheng、札 幌桑螽K.sap porensis Mats.et Shir.的雌性发声刺的观察结果。这6个种的雌性发声刺在数量与 形态上具较明显的差异。     

Patterns of divergence in the effects of mating on female reproductive performance in flour beetles

Sexual selection can lead to rapid divergence in reproductive characters. Recent studies have indicated that postmating events, such as sperm precedence, may play a key role in speciation. Here, we stress that other components of postmating sexual selection may be involved in the evolution of reproductive isolation. One of these is the reproductive investment made by females after mating (i.e., differential allocation). We performed an experiment designed to assess genetic divergence in the effects of mating on female reproductive performance in flour beetles, Tribolium castaneum. Females were mated to males of three different wild-type genotypes at two different frequencies, in all possible reciprocal combinations. Male genotype affected all aspects of female reproduction, through its effects on female longevity, total offspring production, reproductive rate, mating rate, and fertility. Moreover, male and female genotype interacted in their effects on offspring production and reproductive rate. We use the pattern of these interactions to discuss the evolutionary process of divergence and suggest that the pattern is most consistent with that expected if divergence was driven by sexually antagonistic coevolution. In particular, the fact that females exhibited a relatively weak response to males with which they were coevolved suggests that females have evolved resistance to male gonadotropic signals/stimuli.     

Semiochemicals from ovaries of gravid females attract ovipositing female houseflies,Musca domestica

Chemical signals originating from the ovaries of gravid females of Musca domestica (Diptera: Cyclorrhapha: Muscidae) attract ovipositing females to common egg-laying sites. Behavioral experiments indicated that females preferred to oviposit in fermented wheat bran containing ovaries from reproductively mature houseflies. Females preferred to oviposit in fermented wheat bran than wet wheat bran. This effect was additive with the attraction to housefly ovaries. Solvent extracts from housefly ovaries were attractive to gravid females. Extracts obtained with hexane were most attractive to gravid females for egg laying, and extracts obtained with ethyl acetate attracted more egg laying than extracts obtained by dichloromethane. Gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS) analysis showed that tricosane and (Z)-9-tricosene were the main components of the hexane extracts. Both tricosane and (Z)-9-tricosene were shown to elicit dose-dependent aggregation of gravid females in oviposition bioassays, but high doses of either chemical were not attractive.     

Female choice in Drosophila: evidence from Hawaii and implications for evolutionary biology

Details of female choice of mate in Drosophila silvestris of Hawaii strikingly parallels epigamic behavioral systems in many other animals and may be common in other species of Drosophilidae. Females respond selectively to male circling, wing displays, songs and tactile stimulation with foreleg cilia, a quantitative character that is highly variable in some populations. I hypothesize that the female can exert choice based on these cues from individual males that differ genetically by quantitative trait loci. Laboratory tests show that one third of courting males are repeatedly rejected in favor of a minority of alpha males. This result imposes non-random mating at the local population level. Past multiple-choice lab tests, widely used to measure isolation between pairs of populations or species of Drosophila may be flawed, since random mating has been assumed in the interpretation of results. Pre-mating sexual selection is clearly a powerful intrapopulation force in population biology. This view creates difficulties for discerning any proposed simultaneous interpopulation selective events in the presence of strong female choice. The long-held theory assuming that there is significant selection for pre-mating isolation between groups is questionable.     

mdr1a deficiency corrects sterility in Niemann-Pick C1 protein deficient female mice

Niemann-Pick type C disease is a progressive neurological disease with cholesterol storage in liver, and npc1-/- mice share these features and are sterile. We have searched for the cause of sterility and found normal folliculogenesis and progesterone levels but lack of implantation. Multiple drug resistance (MDR) P-glycoproteins are plasma membrane proteins implicated in the movement of drugs and lipids across membranes. Their functions are inhibited by progesterone, which has been shown to alter cellular cholesterol homeostasis and has implicated P-glycoproteins in the movement of cholesterol to the endoplasmic reticulum. We have introduced the mdr1a knockout into the npc1 mutant line. While the neurological disease continues at its usual rate, preventing the females from taking care of their litters, npc1-/-, mdr1a-/- females became fertile. Although the mdr1a P-glycoprotein co-localizes with caveolae, neither caveolin-1 nor npc1 levels were significantly altered in the livers of double homozygotes. The absence of mdr1a was confirmed by immunoblotting, but npc1 deficiency was not associated with consistent changes in cerebellar mdr1a in mdr1a+/+ mice. The results show that a mdr1a mutation is an in vivo suppressor of female sterility in npc1 deficient mice.     

H-Type 1 carbohydrate antigen expression by ovine endometrial cells

Our objective was to determine whether H-Type 1 carbohydrate antigen is expressed by ovine endometrial epithelial cells. Endometrium was obtained from sheep on days (D) 1, 5, 11, 13, and 15 of the estrous cycle or pregnancy and D17 and D19 of pregnancy. Immunofluorescence microscopy of frozen tissue sections revealed intense staining on the apical surface of glandular uterine epithelial (GE) cells from D11 to D17 of pregnancy. Light punctate staining of luminal uterine epithelial (LE) cells was present from D15 to D19 of pregnancy, with isolated areas of intense staining observed only on D15 of pregnancy. There were no noticeable differences in staining patterns on equivalent d of the estrous cycle. Immortalized sheep LE and GE cells were used to determine whether estradiol (E), progesterone (P), or E + P, with or without interferon tau (IFNtau), regulates H-Type 1 antigen expression in vitro. Intermittent punctate surface staining was observed on both cell lines independent of steroid treatment. Treatment with P or IFNtau increased H-Type 1 antigen expression (P < 0.01) and resulted in large aggregates of punctate staining. Domain-specific biotinylation and Western blotting of cell lysates from LE and GE cells were used to identify proteins carrying the H-Type 1 antigen. For both cell types, major immunoreactive apical membrane proteins were detected at 31, 33, 42, 55, 60, and 70 kDa. Therefore, the H-type 1 antigen is expressed mainly on GE cells during pregnancy recognition in utero and up-regulated by P and IFNtau on LE and GE cells in vitro.     

Familiarity and dominance relations among female sooty mangabeys in the Taï National Park

Dominance relationships of female sooty mangabeys have thus far been studied exclusively in captive groups. In captivity, adult females form a stable linear hierarchy as would be expected in species exhibiting strong contest competition. However, the same individuals do not exhibit other aspects of behavior that would be expected where contest competition occurs. For example, they show no kin‐based alliances leading to hierarchies in which the members of each matriline occupy adjacent ranks. The goal of this study was to provide the first data on dominance relationships of sooty mangabey females in their natural environment in the Taï National Park, Ivory Coast. In our study group, adult females formed a linear dominance hierarchy. Aggression over food increased in food patches, as would be expected for species that experience contest competition. Moreover, females formed highly differentiated social relationships, showing particular affinities with females of adjacent rank. Am. J. Primatol. 56:137–153, 2002. © 2002 Wiley‐Liss, Inc.     

Highly efficient transgene-independent recombination directed by a maternally derived SOX2CRE transgene

The Cre/loxP site-specific recombination system is a powerful tool that allows gene inactivation in a tissue- and time-specific manner. Several reports have shown that the Sox2Cre transgenic strain provides a very efficient means to delete gene function from the early epiblast (Hayashi et al.: Gene Expr Patterns 2:93-97, 2002; Vincent et al.: Genes Dev 17:1646-1662, 2003). Routinely, male studs carrying one null allele of the gene of interest and the Cre transgene are crossed to females homozygous for the conditional allele. Normally, excision is observed only in the progeny inheriting both the Cre transgene and the conditional allele. Here we report that when the Sox2Cre transgene is inherited maternally, excision occurs in all offspring irrespective of whether they carry the Cre transgene. Thus, Sox2Cre females provide a generally useful tool for rapid and efficient removal of loxP flanked sequences in vivo.     

Patterns of female dominance in Propithecus diadema edwardsi of Ranomafana National Park, Madagascar

Many lemur species are characterized by some form of female dominance, ranging from female feeding priority to complete female dominance, although this is a rare trait in primates and other mammals. The status of the Milne-Edwards' sifaka (Propithecus diadema edwardsi), a diurnal lemur, is ambiguous. Some short-term studies have found little or no aggression. The aim of the current, long-term study was to quantify the intersexual-dominance patterns of this sifaka. The distribution, outcome, and context of aggressive interactions were studied in four groups of wild sifakas. The majority of intersexual aggressive interactions were decided, with the loser expressing submissive behavior. Intersexual aggressive interactions occurred in all social contexts, and within all social contexts the females won the vast majority (92.7-96.0%) of aggressive interactions. While aggression rates were low (0.22/hr), this evidence suggests female dominance. We propose that female dominance exists because it provides a fitness advantage to both males and females.     

Phenotypic selection in hawkmoth-pollinated Platanthera bifolia: targets and fitness surfaces

Abstract.— The present study explored phenotypic selection on phenological and morphological reproductive traits in hawkmoth-pollinated Platanthera bifolia (Orchidaceae), a Eurasian perennial herb displaying bisexual, long-spurred flowers. The work was carried out during three flowering seasons (1993–1995) in a Swedish population. Fitness was estimated as the number of pollinia removed (male fitness) and fruits produced (female fitness). Targets and patterns of selection were compared between years and sex functions by the use of multiple linear regression (including correlational selection estimates, i.e., of combination of traits), analysis of covariance, and projection pursuit regression (PPR). Results from the nonparametric surface-fitting-method PPR showed that selection was mostly linear, thus justifying the use of the parametric methods. In all study years, male and female fitness were highest in plants with many flowers. This reflects that flower number sets an upper limit to fitness and that a large inflorescence attracts more pollinators. In 1994, the summer was dry and the average spur length of P. bifolia was shorter than in the other years. In this year, male and female fitness were positively related to spur length, apparently because the spur of short-spurred plants was somewhat too short relative to the tongue length of the local pollinator for optimal pollen export and import. Additionally, the dry weather in 1994 caused a tendency for correlational selection, which was not found in the other years of study. Among small individuals (apparently more sensitive to drought than large ones), early-flowering plants had higher male and female fitness. The results show that patterns of selection may vary both between years and between sex functions in perennial hermaphroditic plants. The present study is one of the first to consider correlational selection in plants, which probably is of common occurrence and deserves to be investigated more.