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81.
The role of macrophages, their products, and the specific antibody response were examined during chronic Trichinella spiralis infection in BALB/c mice. Adult T. spiralis in intestines were detected from 5 to 20 dpi. Muscle larvae numbers peaked at 45 dpi and thereafter a reduction was noted. The highest numbers of macrophages in the peritoneal cavity of infected mice were obtained up to 30 dpi. The production of NO by macrophages in infected mice was suppressed at 5 dpi, and then NO release increased until 45 dpi. The levels of NO in plasma and urine were lower in infected mice during the entire experiment in comparison to control. The production of O(2)(-) in peritoneal macrophages was inhibited during the first two weeks after infection and then increased until 90 dpi. Circulating T. spiralis antigens in plasma and urine were detected from 5 to 30 dpi. Specific IgM and IgA in serum increased until 20 dpi. IgG, IgG(1), and IgG(2) levels in serum increased until 60 dpi. 相似文献
82.
Diapause in a New Zealand strain of codling moth (Cydia pomonella Linnaeus [Lepidoptera: Olethreutidae]) was induced in larvae by photoperiods of 15 h or less. Once diapause had been initiated, it could not be terminated by any combination of conditions tested for at least 20 days after cocooning. In diapausing larvae a low rate of pupation occurred at 25 °C under a long day (18 h) photoperiod. A high rate of pupation was achieved under a long day regime when larvae were decocooned, and provided with apple as nourishment. Diapause could be terminated predictably in 94–100% of larvae by 1) conditioning at 15 °C and constant darkness for periods of 40–100 days, then 2) chilling at 2±2 °C and constant darkness for 20–50 days followed by 3) any post-chill condition periods at 25 °C, 18 h photoperiod. Complete diapause termination was achieved when 100 days conditioning was followed by 30 days or 50 days post-chill period. Under these conditions, 76% termination occurred in the post-chill period after 10 days, and 93% after 25 days.To terminate diapause in codling moth larvae, we recommend that a 100 days conditioning followed by 30 days chilling and 50 days post chilling periods be used. 相似文献
83.
Adriana Alzate Fons van der Plas Fernando A. Zapata Dries Bonte Rampal S. Etienne 《Ecology and evolution》2019,9(4):1567-1577
Dispersal is thought to be an important process determining range size, especially for species in highly spatially structured habitats, such as tropical reef fishes. Despite intensive research efforts, there is conflicting evidence about the role of dispersal in determining range size. We hypothesize that traits related to dispersal drive range sizes, but that complete and comprehensive datasets are essential for detecting relationships between species’ dispersal ability and range size. We investigate the roles of six traits affecting several stages of dispersal (adult mobility, spawning mode, pelagic larval duration (PLD), body size, aggregation behavior, and circadian activity), in explaining range size variation of reef fishes in the Tropical Eastern Pacific (TEP). All traits, except for PLD (148 species), had data for all 497 species in the region. Using a series of statistical models, we investigated which traits were associated with large range sizes, when analyzing all TEP species or only species with PLD data. Furthermore, using null models, we analyzed whether the PLD‐subset is representative of the regional species pool. Several traits affecting dispersal ability were strongly associated with range size, although these relationships could not be detected when using the PLD‐subset. Pelagic spawners (allowing for passive egg dispersal) had on average 56% larger range sizes than nonpelagic spawners. Species with medium or high adult mobility had on average a 25% or 33% larger range, respectively, than species with low mobility. Null models showed that the PLD‐subset was nonrepresentative of the regional species pool, explaining why model outcomes using the PLD‐subset differed from the ones based on the complete dataset. Our results show that in the TEP, traits affecting dispersal ability are important in explaining range size variation. Using a regionally complete dataset was crucial for detecting the theoretically expected, but so far empirically unresolved, relationship between dispersal and range size. 相似文献
84.
We studied the species composition and life history patterns of shelter‐building microlepidoptera on the willow Salix miyabeana in Hokkaido, northern Japan. We identified 23 microlepidopteran species across seven families that constructed leaf shelters. Species in Tortricidae and Pyralidae comprised approximately 90% of the total number of sampled shelter‐building microlepidoptera that reached adult eclosion in the laboratory. Seasonal changes in the density of leaf shelters showed two peaks: early June and mid‐August. In June, caterpillars of Gypsonoma bifasciata, Gypsonoma ephoropa, Acleris issikii and Saliciphage acharis were the principal shelter builders, while in August shelters were constructed primarily by caterpillars of Nephopterix adelphella, A. issikii and S. acharis. Approximately 90% of leaf shelters were constructed on the top portions of shoots, suggesting that most shelter‐building caterpillars prefer to build leaf shelters here. 相似文献
85.
The response of V(1) ATPase of the tobacco hornworm Manduca sexta to Mg(2+) and nucleotide binding in the presence of the enhancer methanol has been studied by CuCl(2)-induced disulfide formation, fluorescence spectroscopy, and small-angle X-ray scattering. When the V(1) complex was supplemented with CuCl(2) nucleotide-dependence of A-B-E and A-B-E-D cross-linking products was observed in absence of nucleotides and presence of MgADP+Pi but not when MgAMP.PNP or MgADP were added. A zero-length cross-linking product of subunits D and E was formed, supporting their close proximity in the V(1) complex. The catalytic subunit A was reacted with N-4[4-[7-(dimethylamino)-4-methyl]coumarin-3-yl]maleimide (CM) and spectral shifts and changes in fluorescence intensity were detected upon addition of MgAMP.PNP, -ATP, -ADP+Pi, or -ADP. Differences in the fluorescence emission of these nucleotide-binding states were monitored using the intrinsic tryptophan fluorescence. The structural composition of the V(1) ATPase from M. sexta and conformational alterations in this enzyme due to Mg(2+) and nucleotide binding are discussed on the basis of these and previous observations. 相似文献
86.
Monthly trends shown by gonadosomatic indices, the prevalence of the different gonadal stages, and the size distribution of the oocytes, indicate that the large marine and commercially important plotosid Cnidoglanis macrocephalus spawns in Wilson Inlet between October and January. The conclusion that spawning occurs within this seasonally closed estuary was confirmed by the presence of males in large nests and by the capture of newly-hatched, yolk sac larvae from one of those nests. The fact that C. macrocephalus, which is also widely distributed in coastal marine waters throughout much of southern Australia, can spawn within Wilson Inlet would be of particular value to this species in those periods when closure of the estuary would preclude a seawards spawning migration. Sexual maturity is size dependent, with spawning rarely occurring before fish have reached a total length of 425 mm. Sexual maturity was attained by a few fish at the end of their second year, by several at the end of their third year and by most, if not all fish, at the end of their fourth year. Comparisons with data for the more northern and permanently open Swan Estuary indicate that C. macrocephalus also spawns within that system and that the spawning time of this species is related to water temperature. The adult male guards the larvae under its pelvic fins in burrows. The larvae increased in total length from 29 mm just after hatching to 43 mm in the 17–18 days after capture, during which time their yolk sac was resorbed. Details are given of the morphology, morphometrics, meristics and pigmentation of larval C. macrocephalus. In comparison with the larvae of three other plotosid genera, the larva of C. macrocephalus is far larger in size and more developed at hatching and takes a shorter time to transform into a juvenile. 相似文献
87.
Bartosz Łozowski Andrzej KędziorskiMirosław Nakonieczny Piotr Łaszczyca 《Comptes rendus biologies》2014,337(5):325-331
Parnassius apollo (Lepidoptera: Papilionidae) has already disappeared or is under threat of extinction in many of its former habitats. It has been documented that weather conditions – anomalies in particular – contributed to this process. In this study, we combined developmental data obtained previously for the last-instar Apollo larvae (collected in 1996, 1997, and 2003) with corresponding meteorological data to assess the effects of ambient temperature and rainfall episodes on the duration and the completion of the instar. For comparing the temperature effect, we applied the degree-day concept. We found significant positive correlation between the number of rainy days during the instar development (x) and its duration time (y): y = 8.293 + 0.936x (± 2.813) (r = 0.662, P < 10−7). Logarithmic transformation of the growth curves of the last-instar Apollo larvae revealed that there was no difference in growth among females; however, there was slower growth of males in 2003 in comparison to 1996. Growth (y) of female Apollo larvae as a function of instar duration (x) can by described by one common equation, irrespectively of the year: y = 317.6 + 502.3 lnx (± 263.3) (r = 0.82, P < 10−4). 相似文献
88.
We may expect butterflies as ectotherms to have particularly active life‐history stages that occur in the warmest and lightest times of the year; however, there are temperate species that are active when climatic conditions seem unfavourable and photoperiod short, such as the Taylor's checkerspot (Euphydryas editha taylori). For such species, studies suggest that even subtle changes to microclimate can potentially impact populations. Thus, understanding how in situ variations in microclimate influence the Taylor's checkerspot butterfly could provide much needed insights into more effective management. We conducted a series of surveys that explored (i) adult habitat use, (ii) final instar larval distribution and (iii) adult movement up to and across site boundaries at two sites in Oregon, USA, in 2010 and 2011. We found that in situ habitat use by the Taylor's checkerspot butterfly was strongly influenced by microclimate. Both adult activities and final instar larvae distribution were clustered within the warmest areas of the sites. Moreover, adults did not use up to 59% and larva up to 90% of their sites, despite vegetation structure and composition being uniform. More specifically, butterfly habitat use increased with increasing ground temperatures, and we found that areas with the highest ground temperatures were more exposed to direct sunlight. Similarly, we found that butterflies tended to only move through sunlit site boundaries. We conclude that the Taylor's checkerspot is sensitive to changes in its thermal environment at fine spatial scales. Our results highlight the importance of microclimate as an indicator of habitat quality, and establishing the thermal criteria in which species of concern exists may provide valuable insights into the implications of climate change. 相似文献
89.
Kimberly A. Selkoe Oscar E. Gaggiotti Brian W. Bowen Robert J. Toonen 《Molecular ecology》2014,23(12):3064-3079
What shapes variation in genetic structure within a community of codistributed species is a central but difficult question for the field of population genetics. With a focus on the isolated coral reef ecosystem of the Hawaiian Archipelago, we assessed how life history traits influence population genetic structure for 35 reef animals. Despite the archipelago's stepping stone configuration, isolation by distance was the least common type of genetic structure, detected in four species. Regional structuring (i.e. division of sites into genetically and spatially distinct regions) was most common, detected in 20 species and nearly in all endemics and habitat specialists. Seven species displayed chaotic (spatially unordered) structuring, and all were nonendemic generalist species. Chaotic structure also associated with relatively high global FST. Pelagic larval duration (PLD) was not a strong predictor of variation in population structure (R2 = 0.22), but accounting for higher FST values of chaotic and invertebrate species, compared to regionally structured and fish species, doubled the power of PLD to explain variation in global FST (adjusted R2 = 0.50). Multivariate correlation of eight species traits to six genetic traits highlighted dispersal ability, taxonomy (i.e. fish vs. invertebrate) and habitat specialization as strongest influences on genetics, but otherwise left much variation in genetic traits unexplained. Considering that the study design controlled for many sampling and geographical factors, the extreme interspecific variation in spatial genetic patterns observed for Hawaìi marine species may be generated by demographic variability due to species‐specific abundance and migration patterns and/or seascape and historical factors. 相似文献
90.
This paper analyzes the DNA code of several species in the perspective of information content. For that purpose several concepts and mathematical tools are selected towards establishing a quantitative method without a priori distorting the alphabet represented by the sequence of DNA bases. The synergies of associating Gray code, histogram characterization and multidimensional scaling visualization lead to a collection of plots with a categorical representation of species and chromosomes. 相似文献