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1.
E. B. Vinogradova 《Entomological Review》2008,88(2):129-138
Monitoring of local populations of the urban mosquito Culex pipiens pipiens f. molestus was carried out in St. Petersburg (Russia) in 1999–2006 for the first time. It included the estimation of the autogeny rate, mean fecundity and wing length of females, sex ratio, and siphonal index of the larvae. The mosquitoes were found in 27 out of the 39 examined basements of dwelling houses in five city districts. The perennial populations can exist only in heated basements flooded with sewage or mixed waters with high level of organic pollution and temperature between 10 and 34°C. Most of the local populations are characterized by high autogeny rate: 80–100% of females lay the first egg batch without blood-feeding, ensuring a long-term existence of autonomous local populations. The mean wing length and mean fecundity varied both between and within local populations, ranging from 3.1 to 5.4 mm and from 32.9 to 105.7 eggs per female, respectively. A significant positive correlation was revealed between autogeny rate and fecundity, on the one hand, and the wing length of females, on the other hand. The latter, in its turn, is affected by the temperature and pollution of basement waters during the larval development. Monitoring of the local populations of the urban mosquito in St. Petersburg has shown them to possess high reproductive potentials, a normal sex ratio, and no infections. The sanitary, hydrotechnical (first of all drainage of basements) and mosquito control measures are necessary in order to reduce mosquito abundance and prevent their further dispersal in the city. 相似文献
2.
The composition of the essential oil from the wormwood sage (Artemisia frigida Willd., Asteraceae) of populations growing in the Altai Territory, the Altai Republic, the Khakass Republic, the Tuva Republic,
and the East-Kazakhstan region of the Republic of Kazakhstan and the representative species of the silver-leaved wormwood
Artemisia argyrophylla Ledeb. growing in the Republic Altai has been studied by chromato-mass spectrometry. An analysis of 15 samples of the essential
oil from A. frigida obtained over a period from 1999 to 2007 indicates that samples from different populations have similar sets of the main
components: α-pinene (0.2–7.8%), camphene (1.9–5.8%), 1,8-cineole (8.9–33.8%), camphor (6.7–40.0%), borneol (3.9–12.3%), terpine-4-ol
(1.5–6.5%), bornyl acetate (1.4–22.0%), and germacrene D (1.4–14.6%). Some samples contain substantial amounts of α- and β-thujones
(in total up to 19.1%), which are completely absent in other samples. Some samples contain santolina alcohol (up to 13.8%)
and its acetate (up to 4.8%). As differentiated from A. frigida, the essential oil of A. argyrophylla contains yomogi alcohol (1.2%), artemisia ketone (12.9%), artemisia alcohol (3.1%), artemisia alcohol acetate (3.9%), and
small amounts of camphor (3.2%), borneol (0.3%), and bornyl acetate (0.2%). 相似文献
3.
Titers of immunoglobulin IgG against phases I and II of Coxiella burnetii were determined in 241 students of the Faculty of Medicine by ELISA method and the respective risk factors were evaluated, e.g., rural and urban life, consumption of milk, contact with animals and gender, which may be associated with exposure to C. burnetii. Phase I antibodies (Abs) were detected in 59 serum samples (24.4 %) at antibody level of 1: 100–1: 400. Phase II Abs were
found in 179 persons (74.2 %). The titers were in the range of 1: 100–1: 1600. The titer ≥1: 800 of IgG was used as a cut-off
level, and was detected only in 20 students (8.2 %). No significant difference in the prevalence of Abs was detected either
between the students living in rural and urban environment (78.8 and 73.2 %, respectively) or between males and females (74.0
and 74.7 %, respectively). Abs were detected more frequently in raw milk consumers (68.1 %) and in students who kept some
animals (73.7 %). 相似文献
4.
Background
The Notostraca is a small but ancient crustacean order with a contrasting combination of a conservative morphology and a wide range of reproductive modes. The tadpole shrimp Triops cancriformis, includes bisexual – the putatively ancestral state -, androdioecious and hermaphrodite populations. As hermaphroditism and androdioecy confer a colonisation advantage, we expect the postglacial colonisation of northern Europe to have been effected by lineages with such reproductive modes. Therefore, N European populations should be composed of closely related lineages reflecting a recent range expansion. In contrast, glacial refugia in the south should contain bisexual populations with high haplotype diversity and more population structuring. To test these hypotheses, we analysed the geographic distribution of reproductive modes based on new and published sex ratio data. In addition, we investigated the European phylogeography of T. cancriformis by sequencing over a 1000 bp of mitochondrial DNA (mtDNA) in individuals from a large sample of populations of the three recognised subspecies. 相似文献5.
Sexual reproduction of the brooding sponge <Emphasis Type="Italic">Rhopaloeides odorabile</Emphasis>
Sexual reproduction of Rhopaloeides odorabile, a common Great Barrier Reef sponge, was quantified using histological sections from samples collected over two reproductive
seasons. Rhopaloeides odorabile is viviparous and gonochoristic with a male biased sex ratio (2.5:1). Commencement and cessation of gametogenesis coincides
with rising and falling sea surface temperatures (≈24–29°C). Spermatogenesis occurs from October until January. Females initiate
oogenesis in September with the asynchronous development of oocytes, embryos and larvae occurring within the brood chambers.
A larval release period of 5–6 weeks occurs during January and February. The minimum size of reproductive individuals was
176 cm3 for females and 192 cm3 for males. The total reproductive output for both sexes shows a positive correlation with size. A relative reproductive output
index quantified the maximum reproductive investment at approximately 1 and 3% of the total choanoderm for females and males,
respectively, which represents a lower range of reproduction in comparison to other viviparous sponges. Low reproductive output
in R. odorabile may be offset by an extended spawning period, alleviating the risk of releasing larvae in potentially adverse conditions
via one synchronised spawning event and increasing overall larval survival. 相似文献
6.
Brook trout Salvelinus fontinalis populations have declined in much of the native range in eastern North America and populations are typically relegated to
small headwater streams in Connecticut, USA. We used sibship reconstruction to infer mating systems, dispersal and effective
population size of resident (non-anadromous) brook trout in two headwater stream channel networks in Connecticut. Brook trout
were captured via backpack electrofishing using spatially continuous sampling in the two headwaters (channel network lengths
of 4.4 and 7.7 km). Eight microsatellite loci were genotyped in a total of 740 individuals (80–140 mm) subsampled in a stratified
random design from all 50 m-reaches in which trout were captured. Sibship reconstruction indicated that males and females
were both mostly polygamous although single pair matings were also inferred. Breeder sex ratio was inferred to be nearly 1:1.
Few large-sized fullsib families (>3 individuals) were inferred and the majority of individuals were inferred to have no fullsibs
among those fish genotyped (family size = 1). The median stream channel distance between pairs of individuals belonging to
the same large-sized fullsib families (>3 individuals) was 100 m (range: 0–1,850 m) and 250 m (range: 0–2,350 m) in the two
study sites, indicating limited dispersal at least for the size class of individuals analyzed. Using a sibship assignment
method, the effective population size for the two streams was estimated at 91 (95%CI: 67–123) and 210 (95%CI: 172–259), corresponding
to the ratio of effective-to-census population size of 0.06 and 0.12, respectively. Both-sex polygamy, low variation in reproductive
success, and a balanced sex ratio may help maintain genetic diversity of brook trout populations with small breeder sizes
persisting in headwater channel networks. 相似文献
7.
G. N. Dorovskikh 《Inland Water Biology》2010,3(2):165-169
The state of populations of the crucian carp Carassius carassius L. and the copepod parasite Lernaea cyprinacea L. was studied after 10 years of a sharp decrease in their abundance. Only one generation of Lernaea cyprinacea species was recorded each year. The alteration of the parasite generation occurred in the second half of July. Changes in
the age structure of the copepod population did not affect the distribution pattern of its abundance in the host population,
but the values of the K exponent changed in accordance with alterations of the parasite generations. By 2007 the sex ratio in the population became
equal, males and females differed in their lengths and weights, and three dimensional groups were found in the catches. It
is thought that males and females of the crucian carp have different roles in the maintenance of the L. cyprinacea abundance. The dominating fish sizes and the level of the host infection by copepods remained the same as in 1997–2003. 相似文献
8.
Anna Skoracka 《Evolutionary ecology》2008,22(5):607-616
Recent studies have shown that certain host populations of the cereal rust mite Abacarus hystrix are highly specialized in their host use and it is likely that reproductive isolation exists between them. Here I verified
this expectation by testing for reproductive barriers between ryegrass and quackgrass populations of A. hystrix. I performed reciprocal crosses between individuals from both populations and observed results of crosses. Leaves of the
three grass species, ryegrass, quackgrass and wheat, were used as mating arenas. I used two criteria to determine reproductive
barriers between strains: the proportion of female progeny and viability of progeny. If studied populations of this haplodiploid
species are reproductively isolated a male-biased sex ratio and/or hybrid progeny of reduced viability would be expected.
I found that in the presence of quackgrass and ryegrass pre-zygotic barriers between studied populations exists. On wheat
I observed asymmetry in reproductive barriers. Between females from quackgrass and males from ryegrass a pre-zygotic barrier
existed (only males obtained). However, the opposite reciprocal cross (females from ryegrass and males from quackgrass) produced
progeny of both sexes. A male-biased sex ratio and low adult emergence suggests that post-zygotic mechanisms acted here. Low
viability of progeny obtained from crosses in which females from ryegrass were engaged suggests that the origin of the female
nymph acted as a predictor of hybrid inviability. The pattern of sterility observed in the cereal rust mite indicates that
in the presence of three hosts (ryegrass, quackgrass and wheat) pre- and post-zygotic reproductive barriers between quackgrass
and ryegrass populations of this mite exist. In addition to host fidelity (which acts as pre-zygotic barrier) there are post-zygotic
barriers to gene flow. 相似文献
9.
Rebecca J. Lewis 《International journal of primatology》2008,29(5):1249-1270
The size and composition of a social group can influence the reproductive success of its members. I examined the hypothesis
that residents actively try to manipulate group size and composition in Verreaux’s sifaka (Propithecus verreauxi verreauxi). I collected behavioral data from 21 individuals in 5 social groups from November 2000 to March 2002 in the Kirindy Forest
(C.F.P.F.) of western Madagascar. I investigated the affiliative and agonistic behaviors of resident males and females toward
other group members to determine whether residents attempt to manipulate the costs and benefits of group membership. I also
examined 3 cases of immigration attempts and 1 case of emigration. As expected, group members facilitated the residency of
subordinate members of the opposite sex. For example, females sought out the subordinate males, responded to their calls,
and even groomed them more. However, intrasexual relationships were also important for establishing or maintaining residency.
The data, in conjunction with the observations of immigration and emigration events, suggest that resident individuals of
both sexes attempt to influence group size and composition. I suggest that single–male groups are not the norm in Propithecus verreauxi verreauxi because females encourage, and males do not discourage, multiple males to reside in the group to increase group stability
and to reduce the risk of infanticide. 相似文献
10.
Rossana Perrone Omar Macadar Ana Silva 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2009,195(5):501-514
Brachyhypopomus pinnicaudatus (pulse-type weakly electric fish) is a gregarious species that displays reproductive behavior and agonistic encounters between
males only during the breeding season. During social interactions, in addition to its basal electric organ discharge (EOD),
fish emit social electric signals (SESs) in the contexts of reproduction and intrasexual aggression. We reproduced natural
behavior in laboratory settings: SESs recorded in the field are indistinguishable from those observed in our experimental
setup. SESs are nocturnal, change seasonally and exhibit sexual dimorphism. This study provides an exhaustive characterization
and classification of SESs produced by males and females during the breeding season. In male–female dyads, males produce accelerations
and chirps while females interrupt their EODs. The same SESs are observed in male–male dyads. We present a novel, thorough
classification of male chirps into four independent types (A, B, C, and M) based on their duration and internal structure.
The type M chirp is only observed in male–male dyads. Chirps and interruptions, both in male–female and male–male dyads, are
emitted in bouts, which are also grouped throughout the night. Our data suggest the existence of a sophisticated electric
dialog during reproductive and aggressive interaction whose precise timing and behavioral significance are being investigated. 相似文献
11.
Maíra N. Santos Paula M. Nogueira Fernando B. S. Dias Denise Valle Luciano A. Moreira 《Transgenic research》2010,19(6):1129-1135
Vector-born diseases cause millions of deaths every year globally. Alternatives for the control of diseases such as malaria
and dengue fever are urgently needed and the use of transgenic mosquitoes that block parasite/virus is a sound strategy to
be used within control programs. However, prior to use transgenic mosquitoes as control tools, it is important to study their
fitness since different biological aspects might influence their ability to disseminate and compete with wild populations.
We previously reported the construction of four transgenic Aedes fluviatilis mosquito lines expressing a Plasmodium- blocking molecule (mutated bee venom phospholipase A2–mPLA2). Presently we studied two aspects of their fitness: body size, that has been used as a fitness-related status, and the expression
of major enzymes classes involved in the metabolism of xenobiotics, including insecticides. Body size analysis (recorded by
geometric wing morphometrics) indicated that both male and female mosquitoes were larger than the non-transgenic counterparts,
suggesting that this characteristic might have an impact on their overall fitness. By contrast, no significant difference
in the activity of enzymes related to metabolic insecticide resistance was detected in transgenic mosquitoes. The implication
on fitness advantage of these features, towards the implementation of this strategy, is further discussed. 相似文献
12.
Margaret R. Clarke 《Primates; journal of primatology》2010,51(3):241-249
Natal emigration by male and female mantled howlers (Alouatta palliata), and subsequent immigration into breeding groups, is well documented for the free-ranging population on Hacienda La Pacifica,
Costa Rica, but secondary transfer was considered rare (Glander in Int J Primatol 3:415–436, 1992). Population surveys in
1998 and 2006 caused us to question our assumptions and to re-evaluate our long-term data set from a post hoc perspective.
We first identified all animals observed or captured as adults in more than one non-natal group anywhere in the population.
We then systematically analyzed joining or leaving by adults in seven groups tracked for various times from 1975 to 2005 for
patterns suggesting secondary transfer. Fourteen adults (nine females, five males) were found in two different non-natal groups
as adults. In addition, one male and one female that became dominant and reproduced in their natal group later transferred
to a second group, and one female was known to be a tertiary transfer. Data from the seven tracked social groups indicate
that 35% of all the males and 29% of all the females were potential secondary transfers. In these groups, males leaving or
joining was not associated with group size or absolute number of females. Females leaving or joining was not associated with
group size or absolute number of males, but females left groups with more females and joined groups with fewer females. Both
sexes left groups with unfavorable sex ratios for their sex and joined groups with sex ratios more favorable for their sex.
Since a favorable sex ratio is associated with reproductive success in other howler populations, this suggests secondary transfer
as a reproductive strategy. Other factors could also influence secondary transfer. 相似文献
13.
Size and reproductive traits of thalli of the epiphytic lichen Hypogymnia physodes (L.) Nyl. and concentrations of heavy metals (Cu, Fe, Cd, Zn, Pb) in them were determined in the region of the Middle Ural
Copper Smelting Plant, in two contrast zones of atmospheric pollution. The nonuniformity of populations in both size and reproductive
traits and metal concentration was demonstrated. A high heterogeneity of subpopulations growing on different phorophytes was
revealed. It is recommended to optimize data collection by taking samples from a larger number of trees (20–30) at a smaller
number of thalli (10–20) from one phorophyte. 相似文献
14.
Selection on traits conferring reduced predation may be opposed by selection on other traits associated with reproduction.
Here, we examined the hypothesis that traits associated with reproduction in Gammarus pulex are driven by predation. We studied G. pulex originating from ponds with two different kinds of predator regimes: (1) ponds with fish—often large, non-gap-limited predators
and (2) ponds without fish where invertebrates are the dominant predators—often small, gap-limited predators with a much more
restricted prey size range. We examined the body size of males and females in G. pulex amplexus pairs originating from fish and fishless ponds. We also examined, in the laboratory, their mating success, the number
of offspring per female and offspring mortality under different rearing conditions, with or without fish cue. Mating success,
defined as the percentage of amplexus pairs that produced live offspring, was higher for G. pulex from fishless ponds independent of rearing condition. Individuals from fish ponds were larger and they produced a higher
number of offspring which tended to be related to female body size. Offspring mortality was higher in populations from fish
ponds compared to populations from fishless ponds. Despite the higher offspring mortality, females from fish ponds had a higher
number of offspring alive after 13 weeks, which is the approximate time it takes for G. pulex to reach maturity. Our data imply that no trade-off between reducing body size to reduce mortality caused by fish and maximising
reproductive success exist in G. pulex from fish ponds. The strategy with many offspring may be the correct strategy in fishponds where predation pressure generally
is higher than in fishless ponds. 相似文献
15.
Moslem Papizadeh Mohammad Roayaei Ardakani Gholamhossein Ebrahimipour Hossein Motamedi 《World journal of microbiology & biotechnology》2010,26(7):1195-1200
Oil-polluted soils were sampled from National Iranian South Oil Company (NISOC) for isolation and screening of C–S and not
C–C targeted Dibenzothiophene (DBT) degrading microorganisms. Microbacterium sp. NISOC-06, a C–S targeted DBT degrading bacterium, was selected and its desulfurization ability was studied in aqueous phase and water-gasoline
biphasic systems. The 16srRNA gene was amplified using universal eubacteria-specific primers, PCR product was sequenced and
the sequence of nearly 1,500 bp 16srDNA was studied. Based on Gas Chromatography results Microbacterium sp. NISOC-06 utilized 94.8% of 1 mM DBT during the 2 weeks of incubation. UV Spectrophotometry and biomass production measurements showed
that the Microbacterium sp. NISOC-06 was not able to utilize DBT as a carbon source. There was no accumulation of phenolic compounds as Gibb’s assay showed. Biomass
production in a biphasic system for which DBT-enriched gasoline was used as the sulfur source indicated the capability of
Microbacterium sp. NISOC-06 to desulfurize gasoline. 相似文献
16.
The reproductive ecology of the gobiid fish Bathygobius fuscus was studied at Nobeoka, Miyazaki, Japan. Males of this species maintain small rock holes as a nest and females spawn an egg
mass on the wall of the nest. The males employed two forms of mating tactic: nest holding and sneaking. A nest holder stayed
in the nest and waited for a female to visit, whereas a sneaker intruded into a nest while a pair was engaged in reproduction.
Males larger than 55 mm standard length were always nest holders; those of smaller size employed both tactics. As the larger
males excluded the smaller males, the latter did not occupy a nest hole. With a decrease in the number of larger males, smaller
males changed their mating tactic from sneaking to nest holding. The results suggest that male Bathygobius fuscus adopt a conditional strategy whereby they change their tactic depending on their social status.
Electronic Publication 相似文献
17.
Wang Minqin Zhao Junsheng Peng Zhenying Guo Wei Wang Yun Wang Le Xia Guangmin 《Plant Cell, Tissue and Organ Culture》2008,92(2):121-130
In order to investigate chromosome elimination in symmetric somatic hybridization between Bupleurum scorzonerifolium and Arabidopsis thaliana, protoplasts were isolated from suspension cultures of both A. thaliana and B. scorzonerifolium parents. Biparental protoplasts were mixed at a rate of 1.5:1 and fused with PEG-method. After protoplast fusion, the products
were cultured in the P5 liquid medium for microcallus formation. Single cell lines formed from microcalli after subculturing
on the MB1 (Xia and Chen, Plant Sci 120:197–203, 1996) solid medium. The putative somatic hybrid cell lines were identified
by cytological and molecular analysis. Of the 132 somatic cell lines generated, 16 were identified as somatic hybrids, with
the phenotypes resembled B. scorzonerifolium parent. These hybrids showed a complete set of B. scorzonerifolium chromosome and 0–2 small chromosome(s) of A. thaliana. A few of them showed nuclear and cytoplasmic SSR fragments of A. thaliana. These hybrid cell lines could differentiate to green spots, buds/leaves through complementation of regeneration ability.
The chromosomes elimination of A. thaliana was discussed.
Wang Minqin and Zhao Junsheng contributed equally to the work. 相似文献
18.
Summary. The paper describes two methods of the synthesis of ethyl (3R,4S)- and (3S,4S)-4-[(benzyloxycarbonyl)amino]-5-[(tert-butyloxycarbonyl)amino]-3-hydroxypentanoates, useful for the syntheses of edeine analogs. Differently N-protected (S)-2,3-diaminopropanoic acid was used as a substrate in both procedures. The absolute configuration of newly generated asymmetric
carbon atoms C-3 in β-hydroxy-γ,δ-diamino products was assigned by means of 1H NMR spectroscopy after their transformation into corresponding piperidin-2-ones.
Received May 24, 2002 Accepted October 10, 2002 Published online December 18, 2002
Acknowledgment The authors are indebted to the Faculty of Chemistry, Technical University of Gdańsk for financial support.
Authors' address: Zbigniew Czajgucki, M. Sc., Department of Pharmaceutical Technology and Biochemistry, Faculty of Chemistry, Technical University
of Gdańsk, 11/12 Narutowicza St., 80-952 Gdańsk, Poland, Fax +48 58 347 11 44, E-mail: zmczaj@wp.pl 相似文献
19.
A. Kh. Tambiev S. G. Vasilieva A. A. Lukyanov 《Moscow University Biological Sciences Bulletin》2011,66(4):133-137
The salt tolerance of two representatives of genus Spirulina (Arthrospira) Spirulina platensis and Spirulina maxima has been investigated. They both are the wide-spread objects of photobiotechnology and it has been shown that the content
of 5–15 % sea-water in medium has not caused the decreasing of biomass yield more than 15–20% as compared with control. The
further decreasing of biomass was proportionate to sea-water content in medium. The investigation of reactivity of native
(intravital) exometabolites secreted into cultural medium has showed that the sea-water content influence the oxidative activity
(OA) of exometabolites and hour’s rhythmics. 相似文献
20.
Kottackal Poulose Martin A. K. Pradeep Joseph Madassery 《Acta Physiologiae Plantarum》2011,33(4):1141-1148
Trichopus zeylanicus subsp. travancoricus (known as Arogyapacha), an endangered ethnomedicinal plant of the Western Ghats of South India, serves as the major source
of the commercial drug Jeevani. The present study established a long-term high frequency in vitro propagation protocol for Arogyapacha. Callus obtained from
the branch–petiole explants cultured on Murashige and Skoog (MS) medium with 4.5 μM 2,4-dichlorophenoxyacetic acid upon subculture
to medium with different concentrations of 6-benzyladenine (BA) either alone or in combination with an auxin favoured shoot
morphogenesis. Medium with 13.3 μM BA alone facilitated high frequency shoot bud (mean of 93.2) formation. Medium with lower
concentrations of BA (4.4, 6.6 and 8.8 μM) alone or in combination with lower concentration of α-naphthaleneacetic acid (NAA)
or indole-3-butyric acid (IBA) favoured better shoot growth than 13.3 μM BA containing medium, but with reduced number of
shoot buds. Subsequent cultures on medium with lower concentrations of BA and also on MS basal media facilitated shoot formation
as well as growth of shoots. The shoot regeneration potential showed no decline up to 5 years. Culture of the in vitro-derived
whole branch–leaf explants on MS basal medium developed shoots directly from the node. On medium with 19.6 μM IBA, the whole
branch–leaf explants induced nodular callus from the node, which developed shoots later. Subsequent cultures on medium with
BA exhibited high frequency shoot formation. The transfer of shoots after 10–15 days culture on half-strength MS medium containing
2.7 μM NAA to half-strength basal medium induced a mean of 11.3 roots. Field survival of plantlets relied on the soil mix:
a 1:4 ratio of sand and red-soil exhibited the highest plantlets survival (86.6%). RAPD profile of the source plant and plants
regenerated from calli after 4 years showed no polymorphism. The established plantlets with morpho-floral features similar
to that of the source plants flowered normally and set fruits. 相似文献