GAL4 enhancer trap targeting of the Drosophila sex determination gene fruitless

The fru4 allele of the sex determination gene fruitless is induced by insertion of a P[lacZ,ry+] enhancer trap element. This insert also acts to disrupt expression of the fru P1 promoter derived male-specific proteins, consequently impairing male courtship behavior. fru4 maps less than 2 kb upstream of the fru P3 promoter, whose function is essential for viability. We replaced this insert with a GAL4 element, P[GAL4,w+], recovering two lines with insertions in opposite orientations at the locus, one of which demonstrated fru-specific mutant phenotypes. Reporter expression of these lines recapitulated that of P3- and P4-derived proteins which, when correlated with a developmental and tissue specific survey of fru promoters' activities, uncovered a previously unsuspected complexity of fru regulation. These novel fru alleles provide the tools for manipulation of fru-expressing cells, allowing the consequent effects to be related back to specific fru functions and the regulatory units controlling these activities.     

Mate choice and competition in the barklouseLepinotus patruelis (Psocoptera: Trogiidae): The effect of diet quality and sex ratio

Courtship varies among individuals, partly because individuals differ in quality. To explore proximate factors affecting courtship behavior, I investigated the effect of diet quality on mate choice and competition in the barklouseLepinotus patruelis Pearman (Psocoptera: Trogiidae) in the laboratory. The effect of sex ratio on mate choice was also addressed. Some males were found to exhibit active mate choice, and rejected females in both male- and female-biased sex ratio groups, although they were more likely to do so in a female-biased sex ratio group. Diet quality affected male mate choice: males on high-quality diets were significantly more likely to reject females than males on low-quality diets. Males exhibited choice significantly more often than females, who showed no overt signs of choosiness. Both males and females competed for, access to mates: both sexes attempted to interfere with mounted pairs and females grappled. The choosiness of the male may have directly affected the incidence of female competition. The results also suggest that the patterns of mate choice inL. patruelis differ from those expected by conventional sex role theory.     

Observations on the mating behavior of the alfalfa blotch leafminer,Agromyza frontella (Rondani) (Diptera: Agromyzidae), and evidence of a female sex pheromone

The mating behavior of Agromyza frontella was studied under laboratory conditions. Adults were able to mate on the day of emergence, with no evident periodicity throughout the photophase. The host plant was essential for mating to occur, its presence affecting female receptivity rather than male copulatory behavior. Males generally entered a stationary phase once in the proximity of a female, before undertaking a final approach. This stationary behavior frequently resulted in male aggregations around a female, and under such conditions males exhibited a characteristic wing vibrating behavior. As male wing vibration was not an essential behavior for successful mating, and rarely occurred during male encounters in the absence of females or when only one male was near a female, it was considered as being primarily a male-male signal. The majority of females that mated exhibited an ovipositor pumping behavior that stimulated the male approach. However, such behavior was not essential to attract mates, as dead females elicited the entire sequence of male mating behavior. This suggested the presence of a cuticular sex pheromone, as reported for other species of higher Diptera. Whole virgin female (<24- h or 3- day-old) hexane extracts applied to male cadavers increased the time males spent on the plant, the number of contacts with the treated cadavers, the incidence of attempted copulations, and the wing vibrating behavior between males compared with controls using untreated cadavers. The results obtained indicate that females control copulation in A. frontella and that both semiochemical and visual cues are important in eliciting male mating behavior.     

Male-male behavior and sexual dimorphism of the ear of a zaprochiline tettigoniid (Orthoptera: Tettigoniidae)

The external anatomy of the auditory system of an undescribed zaprochiline tettigoniid (Genus nov. 22 Sp. 1, Australian National Insect Collection, Canberra) shows sexual dimorphism: the male appears to have no auditory spiracle equivalent to that seen in the female. Nocturnally active males aggregate around female required nectar sources in a random manner with regard to each other. There is limited evidence, either from song interaction or from their behavior in the field, that males respond to each other by acoustic cues. Laboratory trials, testing male phonotaxis, showed that movement was random with respect to a target group of caged calling males. In the field, the only signs of agonistic behavior consisted of an increased calling rate when males were close together. Taken together, these data suggest that the male may not preceive sound in the same way as the female.     

Influence of previous sexual experience and post-emergence rearing conditions on the mating behavior ofChryseida bennetti

Experiments were carried out to study the possible effects of a (first) sexual experience and prior rearing conditions on the subsequent sexual behavior ofChryseida bennetti (Hymenoptera: Eurytomidae), an ectoparasitoid of the bean weevilAcanthoscelides obtectus (Say) (Coleoptera: Bruchidae). A clear reduction in latency before male courtship was observed in experienced males. Multiple matings were performed both by naive and experienced males. A tendency to reduce the post-mating courtship behavior duration was observed in experienced males, although this reduction was not significant. Rearing conditions also seem to influence the mating behavior of this species: the number of copulations (with the same female) was reduced when males were reared in groups. On the contrary, isolated males performed multiple matings with both grouped and isolated females, although they mated 3 times only with isolated ones. Again, a reduction of the duration of the post-mating courtship behavior was observed both in grouped males and grouped or isolated females. It seems likely that males that have been reared in groups benefit from a certain influence of social experience that is reflected on their later sexual behavior.     

Variation in the life cycle of monogonont rotifers: Commitment to sex and emergence from diapause

1. A review of research on life-cycle events in field and laboratory populations of monogonont rotifers shows that there is great variation at multiple levels: (1) degree of sexual dimorphism; (2) occurrence and timing of sex; (3) propensity for sex during sexual periods; (4) factors controlling initiation of sex; and (5) timing and extent of emergence from diapause. There is no regular pattern where: (1) fertilised resting eggs hatch to start the growing season; (2) populations develop via female parthenogenesis during favourable conditions; and then (3) bisexual reproduction with resting-egg production occurs during later, unfavourable conditions.
2. Sexual reproduction in natural populations can occur throughout much of the growing season, be restricted to some period(s) during the growing season, or be completely absent. During sexual reproduction in both natural and laboratory populations, only some fraction of females produces males or resting eggs. This bet-hedging strategy can prevent a population crash and permits future population growth via female parthenogenesis. Selection against sexual reproduction, and rapid loss of sex, can occur.
3. Laboratory experiments with pond-dwelling species have identified specific environmental factors that induce sex in different species: (1) increasing population density; (2) dietary tocopherol (vitamin E) and (3) long photoperiods. These factors generally are associated with favourable conditions for population growth and production of energy-rich resting eggs: (1) large population size; (2) high probability of contacts between males and fertilisable females; and (3) nutritious diets. Endogenous factors can inhibit responses to these environmental inducers, and thus favour female parthenogenesis.
4. The timing of resting-egg hatching depends on: (1) occurrence of specific environmental conditions; (2) the minimum duration of obligate diapause; and (3) the genotype and physiology of females producing resting eggs. Hatching may occur shortly after oviposition, after a long diapause before or at the start of a new growing season, or throughout the growing season. Hatching can be massive and contribute substantially to population growth and genetic diversity.
5. Areas for future research include: (1) determining the timing and extent of sex and resting-egg hatching in more natural populations, especially those that are marine, benthic, sessile, and interstitial; and (2) identifying environmental and physiological factors controlling these events.

     

Dominance rank reversals and rank instability among male Lemur catta: the effects of female behavior and ejaculation

In this study, dominance rank instability among male Lemur catta during mating was investigated. Also, data on agonism and sexual behavior across five consecutive mating seasons in a population of L. catta on St. Catherines Island, USA, were collected. Instances of male rank instability were categorized into three types. Type 1 consisted of a temporary switch in the dominance ranks of two males, which lasted for a period of minutes or hours. Type 2 dyadic male agonistic interactions showed highly variable outcomes for a period of time during which wins and losses were neither predictable nor consistent. Type 3 interactions consisted of a single agonistic win by a lower-ranked male over a more dominant male. More Type 2 interactions (indicating greater dominance instability) occurred when males had not spent the previous mating season in the same group, but this trend was not statistically significant. The majority of periods of male rank instability were preceded by female proceptivity or receptivity directed to a lower-ranked male. As such, exhibition of female mate choice for a lower-ranking male appeared to incite male-male competition. Following receipt of female proceptivity or receptivity, males who were lower-ranking took significantly longer to achieve their first agonistic win over a more dominant male than did males who were higher-ranked. Ejaculation frequently preceded loss of dominance. In conclusion, temporary rank reversals and overall dominance rank instability commonly occur among male L. catta in mating contexts, and these temporary increases in dominance status appear to positively affect male mating success.     

竹织叶野螟成虫求偶行为及其雌蛾性信息素分泌腺超微结构

【目的】蛾类昆虫性信息素的合成和释放与求偶行为的发生是一致的,其合成和释放的器官是性信息素腺体。为深入了解竹织叶野螟性信息素的分泌生理,开展了竹织叶野螟求偶行为及其性信息素腺体超微结构的研究。【方法】在光周期14L:10D、温度26±2℃、相对湿度80%±10％的室内条件下,观察研究了竹织叶野螟的求偶行为;依据求偶规律研究结果,选取最活跃日龄雌蛾,在暗期求偶高峰时间段,充分挤压其腹部末端,然后于第8节处横向切下,将切下的腹末标本处理后,借助显微镜和扫描电镜观察性信息素腺体的表面特征及超微结构。【结果】竹织叶野螟雌雄蛾求偶均具一定的程序性,且求偶行为只发生在暗期,暗期前5 h内雌蛾求偶率较低,6 h后求偶率明显升高,并在暗期7-8 h达到求偶高峰;求偶率与雌蛾日龄有密切关系,3日龄雌蛾求偶率最高,持续时间也最长。竹织叶野螟性信息素分泌腺位于腹部第8-9节节间膜上,是一完整的环状结构,显微镜下观察其分泌腺为一乳白色囊状体,扫描电镜下其腹面囊状体迂回褶皱多,大体分为3个褶皱区,除第1褶皱区外,其余褶皱区表面密布乳突、凹陷沟和刺状物,且刺状物顶端有孔;背面囊状体皱褶少,其表面形态与第2和第3褶皱区相似。【结论】研究结果有助于了解竹织叶野螟性信息素合成和释放的时辰节律,也为该虫性信息素的准确提取和鉴定、性信息素的生物合成及利用提供了科学依据。     

六星黑点豹蠹蛾成虫生殖行为特征与性趋向

六星黑点豹蠹蛾Zeuzera leuconotum Butler (Lepidoptera: Cossidae)是一种重要的园林害虫。在光周期L:D=14:10、温度19-32 ℃、相对湿度75%-85%条件下,对六星黑点豹蠹蛾的羽化、性比、交配行为及能力进行了观察,利用风洞技术和林间诱蛾试验验证了其性趋向。结果表明:六星黑点豹蠹蛾羽化期60 d左右,6月下旬为羽化高峰期,日羽化高峰出现在傍晚17:00-18:00,占全天羽化量的55.4%;雌雄性比为1:1.03;交配高峰期发生在进入暗期5-7 h,成虫1日龄后性成熟,一生交配1次;随雌蛾日龄增加,其交配率逐渐下降,交配时间提前,交配持续时间逐渐加长;雌蛾一生平均产卵378个,孵化率80%,未交配雌蛾平均产卵426个,孵化率0%;未交配雌蛾和雄蛾的平均寿命分别为5.56 d和3.83 d,交配过的雌蛾和雄蛾平均寿命分别为5.66 d和2.41 d,交配缩短雄蛾寿命;六星黑点豹蠹蛾种内个体间引诱作用主要为雌蛾引诱雄蛾,同性间不存在聚集行为;2-3日龄未交配雌蛾林间诱蛾量最高,显著高于1日龄和4-6日龄(P＜0.01)。依据研究结果,分析讨论了应用性信息素防治六星黑点豹蠹蛾的可行性,说明六星黑点豹蠹蛾是可利用性信息素进行防控的理想对象。     

Changes in sperm tail development associated with Y chromosome meiotic drive leading to an excess of males in the medfly Ceratitis capitata (Diptera: Tephritidae)

The Mediterranean fruit fly Ceratitis capitata (Wied.) normally produces the sexes in equal ratio but strains carrying the Y chromosome meiotic drive MP (male‐producing) factor show an excess of males. This is associated with a loss of sperm, and abnormal sperm structure in terms of multiple axonemes, atypical numbers of mitochondrial derivatives, and sometimes an incorrect initial orientation of paracrystalline bodies to the axoneme. Sperms are bundled together within spermatocysts, and those with depleted content and abnormalities occur in the same MP testes as normal spermatocysts. The maximum number of sperms per cyst in control strains was 256, each with a single axoneme originating from a single centriole (kinetosome). The maximum per cyst in MP strains was also 256 but MP cysts contained up to 300 axonemes, providing evidence of multiplication of centrioles. The structural changes in MP sperm are discussed in relation to similar abnormalities reported in the mosquito Aedes aegypti inheriting the Y chromosome meiotic drive haplotype MD. The evolutionary significance of this phenomenon is considered. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 351–359.     

Temporal distribution of PBAN‐like immunoreactivity in the hemolymph of Mamestra brassicae females in relation to sex pheromone production and calling behavior

A direct enzyme‐linked immunosorbent assay has been developed and applied to the analysis of PBAN immunoreactivity in female hemolymph of the cabbage armyworm, Mamestra brassicae. PBAN‐IR determinations have been carried out with third scotophase insects at different times of the photoperiod. The rhythm of calling and the pattern of pheromone production by third scotophase females at different times of the photoperiod have also been determined. PBAN‐IR and calling are well correlated. However, whereas pheromone titers decrease, both PBAN‐IR levels and percentage of calling females remain high in the last hours of the scotophase. These results are discussed in the context of the regulation of sex pheromone biosynthesis in M. brassicae. Arch. Insect Biochem. Physiol. 40:80–87, 1999. © 1999 Wiley‐Liss, Inc.     

Temperature affects operational sex ratio and intensity of male-male competition: an experimental study of sand gobies, Pomatoschistus minutus

The operational sex ratio is intimately related to the intensityof sexual selection, but factors governing variation in theoperational sex ratio and their effects on mating competitionare still poorly understood. In this study, temperature wasfound to affect both the operational sex ratio and the intensityof male-male competitive interactions in the sand goby [Pomatoschistusminutus (Pallas)]. In an experiment with two different temperaturetreatments, the operational sex ratio became male biased inthe warm treatment (15°C) and males in that treatment interactedmore frequendy than in the cold treatment (8.5°C). Theseresults were as predicted since the potential reproductive rateof males increases faster with temperature than does the potentialreproductive rate of females. Thus, an environmental factor,water temperature, affects not only the reproductive rates ofthe sexes, but also the operational sex ratio and mating competition,and thereby the intensity of sexual selection. Operational sexratio was not found to be correlated with male behavior. Thismay suggest a direct effect of temperature or potential reproductiverates on mate competition. The mechanism behind the evolutionof such a direct relationship would, however, probably be theimpact of potential reproductive rates on operational sex ratio,which in turn direcdy affects sexual selection.     

低剂量60Co-γ辐射对棉铃虫蛾羽化、寿命、趋光行为和性信息素滴度的影响

为阐明低剂量辐射对棉铃虫Helicoverpa armigera (Hübner)生长发育、 成虫趋光行为和性信息素滴度的影响, 本试验设置5个辐照剂量, 记录棉铃虫蛾羽化率、 畸形率及寿命; 通过趋光行为学试验和单个腺体性信息素提取法, 检测了辐照(50 Gy)前后棉铃虫蛾趋光率和性信息素滴度的变化。结果表明： (1)在20 Gy剂量辐照下, 雌雄棉铃虫羽化率与对照相比分别降低了16.67%和20.00%, 畸形率均升高了10.00%,10,30,40和50 Gy辐照对棉铃虫蛾羽化率、 畸形率、 寿命均没有显著影响。(2)无论是光期还是暗期, 辐照后的棉铃虫蛾趋光率和性信息素滴度均有所上升, 其中趋光率提升幅度最大的是光期3日龄雌虫(28.33%±3.33%至91.67%±4.41%); 性信息素滴度提升量最大的是暗期5日龄雌蛾(36.27±4.26 ng至59.13±4.63 ng)。50 Gy辐照剂量会促进棉铃虫蛾的趋光行为和信息素的合成, 且棉铃虫蛾趋光率在设置的5个辐照剂量下无显著性差异。(3)棉铃虫蛾趋光率和性信息素滴度随着羽化日龄的增加有一个先上升后下降的变化趋势, 其中趋光率变化最大的是辐照组光期雌虫和辐照组暗期雄虫(二者均为91.67%±4.41%至3.33%±1.67%); 性信息素滴度变化最大的是辐照组暗期雌虫(71.00±5.22 ng至3.63±1.47 ng)。(4)在大多数处理中, 羽化率、 畸形率、 寿命及趋光率不存在雌雄差异。本研究为探讨辐照后棉铃虫趋光行为和体内生理生化的变化提供一定的理论基础依据, 同时也为利用物理、 化学通讯信息调控棉铃虫行为提供了新思路, 对害虫综合防治具有一定的参考价值。     

稻纵卷叶螟对性信息素和花香的嗅觉行为反应及在其种群监测中的应用

[目的]明确稻纵卷叶螟Cnaphalocrocis medinalis生理状态对性信息素和花香气味的嗅觉行为反应的影响,以及在田间性信息素和花香气味诱蛾量的动态.[方法]于2020年在广西、湖南、浙江、四川5个试验点,通过田间网捕、花香气味和性信息素诱捕稻纵卷叶螟成虫,结合解剖卵巢和精巢,比较性信息素和花香诱捕的基本迁...     

Helicoverpa zea males (Lepidoptera: Noctuidae) respond to the intermittent fine structure of their sex pheromone plume and an antagonist in a flight tunnel

Abstract. We investigated the behavioural response of male Helicoverpa zea (Boddie) to the fine-scale structure of an odour plume experimentally modified in a wind tunnel by using an air-pulsing device. Male H. zea flew upwind to pulsed filaments of a binary pheromone blend of (Z)-11-hexadecanal (Z11-16:Ald) and (Z)-9-hexadecanal (Z9-16:Ald) in the ratio of 20:1. Sustained upwind flight in experimentally altered intermittent plumes was dependent on concentration, as well as the frequency of generation of odour filaments. At a loading of 10μg of the major pheromone component, Zll-16:Ald, which gave an emission rate of approximately that released by a female H. zea , sustained upwind flight and source contact correlated positively with filament delivery rate, becoming significant at a minimum filament delivery rate of 2/s. Decreases in upwind progress and source location were recorded at a loading of 1 μg of Z11-16:Ald. At this suboptimal dosage, a high filament generation rate of 10/s was necessary for significant upwind progress and source contact. When an interspecific compound: (Z)-11-hexadecenyl acetate (Z11-16:OAc), was added to the attractive pheromone binary aldehyde blend of H. zea at a proportion of 10% of the major pheromone component, and pulsed from the same source, there was a significant reduction in sustained upwind progress and source location by males, indicating that Z11-16:OAc is antagonistic to the upwind progress of H. zea. However, Z11-16:OAc was less antagonistic when its filaments were isolated and alternated with pheromone filaments, indicating a strong effect of the synchronous arrival of odour filaments on the antenna needed for antagonism of upwind flight.     

Associations between two novel rSNPs in 5'-flanking region of the bovine casein gene cluster and milk performance traits

Ten evolutionary conservative sequences with high identity level to homological sequences in other mammal species were revealed in 5'-flanking region of casein's genes cluster. Five novel SNPs located inside of the evolutionary conservative regions were identified. The binding sites were revealed to be present in one allelic variant of four detected SNPs. So these SNPs were considered as rSNPs. Significant differences of allelic frequencies were revealed between beef cow's group and dairy cow's group in two rSNPs (NCE4, NCE7, p<0.001). Different alleles of those two rSNPs were shown to be associated with some milk performance traits in Black-and-White Holstein dairy cows. Significant difference of protein percentage has been found between cows with G/G and A/A genotypes (P<0.05) and A/G and A/A genotypes (P<0.05) for NCE4 polymorphism. The groups of animals with genotypes G/G and A/G for NCE7 polymorphism were significantly different in milk yield at the first lactation (kg) (P<0.01), milk fat yield (kg) (P<0.05) and milk protein yield (kg) (P<0.01). For the last trait the difference was significant also between cows with genotypes G/G and A/A for rSNP NCE7 (P<0.05).