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1.
Suckling and allosuckling were studied in relation to the age and sex of fawns in a captive population of fallow deer (Dama dama) showing a high rate of allosuckling (73% of the suckling bouts). No difference occurred between the sexes in either the duration or frequency of suckling and allosuckling. The frequency of suckling bouts decreased rapidly during the first four weeks of life while the frequency of allosuckling bouts increased rapidly between the second and the third week and remained constant until the conclusion of the observations (11th week of life). Birth date affected allosuckling, with late-born fawns performing fewer and shorter allosuckling bouts. The lack of a negative relationship between suckling and allosuckling frequencies failed to confirm the hypothesis that allosuckling allows fawns to complete their milk requirements on foster mothers. Both inbreeding and crowding could explain the absence of particular relationship between fawns and foster mothers.  相似文献   

2.
Coprophagy is common in captive primates but has also been reported in the wild. For example, wild apes extract and reingest items from faeces. We term this behavior seed reingestion because the dung matrix is not consumed. We assessed the importance of seed reingestion in a population of savannah chimpanzees at Fongoli, southeastern Senegal, one of the hottest and driest areas of the species’ range, where chimpanzees have a relatively narrow dietary repertoire. We observed habituated chimpanzees on 122 d during 8 mo in 2005 and 2006, employing both focal subject and scan sampling of identified individuals for 1278 h of data collection. Chimpanzees reingested seeds of 2 species: Parkia biglobosa and Adansonia digitata. Both seed species have a hard protective shell, and the embryos are rich in proteins and lipids. Chimpanzees initially ate the fruit matrix pulp and swallowed intact seeds before reingesting and chewing/destroying seeds. Seed reingestion accounted for almost 2% of feeding time. We suggest that at Fongoli this behavior may be an adaptive strategy to maximize food intake, by softening the seed’s shell and making the seed’s content more accessible.  相似文献   

3.
Sexual coercion in the form of forced copulation has been used as a typical example to illustrate the conflict of interests between females and males. Among arthropods, forced copulation has been reported for some groups of insects and crustaceans, but not for arachnids. In the present work, we analyse and describe the behavioral patterns of mating behavior of the climbing camel-spider, Oltacola chacoensis, relating it to relevant morphological features, In this species, the male forcefully clasps the female’s genital region with his chelicerae and locks her fourth pair of legs with his pedipalps. In some cases, the cuticle of the female’s abdomen was damaged by this cheliceral clasping. In contrast to other camel-spiders, the female O. chacoensis never remained motionless during mating, but continuously shook her body, opening her chelicerae notably towards the male. Despite this coercive context, males performed copulatory courtship (tapping with pedipalps) and females showed an apparent cooperative behavior (they remained still during a short period of the sperm transfer phase). These results strengthen the idea that sexual coercion (in the form of forced copulation) and luring behavior (in the form of copulatory courtship) are not two mutually-exclusive male’s strategies during a single copulation.  相似文献   

4.
Summary A continuous line of epithelioid cells was established from explant skin tissues of the green sea turtle,Chelonia mydas. These cells, designated GTS, have been subcultured more than 60 times in commercially available mammalian cell culture medium supplemented with 5% bovine calf serum. Of those temperatures tested, optimal growth was achieved at 30°C although replication occurred between 16 and 37°C. These cells may be held as monolayers at 8°C or stored frozen in growth medium containing 10% dimethylsulfoxide at −70 or −196°C. The modal number of 55 chromosomes per cell is in agreement with the heterogametic female diploid number of this species. The GTS line represents the first established culture of normal epithelioid skin cells to be reported for a poikilothermic species.  相似文献   

5.
Extracellular tyrosol and tryptophol were produced and isolated from the phytopathogen fungus Ceratocystis adiposa cultivated in a rich broth. These compounds have not been previously reported in this Ceratocystis species, as its identification was established through spectroscopic methods (1H NMR, 13C NMR and MS). Productivity of tyrosol and tryptophol was 65.3 and 44 μg l−1 day−1, respectively, which were values higher than those reported to date. Tyrosol is a compound of pharmaceutical interest showing antioxidating activity, a property used in the treatment of atherosclerosis. Tryptophol is reported to have antibiotic and phytotoxic activity.  相似文献   

6.
Non‐offspring nursing (allosuckling) is costly for lactating females. It is reasonable to assume, therefore, that mechanisms have evolved to control the frequency of allosuckling. It is suggested that the synchronization of nursing between females could be such a mechanism. The aim of this study was to investigate whether nursing synchronization is related to the timing of nursing behaviour of paired sows and the behaviour of alien piglets in relation to allosuckling. Specifically, we predicted that: (i) nursing synchronization will increase if there is a real risk of allosuckling compared with a situation where there is none, (ii) nursing synchronization indeed reduces allosuckling and, therefore, those nursings with allosuckling attempts will be less closely synchronized than those without allosuckling attempts and (iii) in non‐synchronized nursings, the sows will more often employ another strategy to reduce allosuckling, namely, they will make the nursings non‐nutritive by not releasing milk. Ten pairs of sows and their litters were used in this study. For each pair, the two sows were housed individually until their litters were weaned; however, their litters had access to both sows from day 11 post‐partum. The behaviour of the 10 pairs of sows with their litters was videotaped for 6 h on days 10, 11, 17 and 24 post‐partum. The frequency of allosuckling attempts, non‐nutritive nursings and allosuckling during milk ejection was analysed for every pair for every day of observation. The observed frequency of nursing synchronization was high. The median interval between the start of a nursing within one pair of sows was 32 s. The first prediction was supported as synchronization became significantly tighter when piglets were given the possibility to allosuckle on day 11 [Cochran–Mantel–Haenszel (CMH) statistics, p < 0.0001]. The second prediction was also supported; the nursings were less closely synchronized when there were allosuckling attempts (CMH statistics, p < 0.05). Of all nursings, 36% had an allosuckling attempt; however, only 17% resulted in real allosuckling. Evidence in favour of the third prediction was also found as non‐nutritive nursings were more frequent in non‐synchronized nursings (CMH statistics, p < 0.05). Finally, real allosuckling during milk ejection was unrelated to the degree of nursing synchronization, as in less synchronized nursings, the sows responded to allosuckling attempts by not releasing milk. Our results suggest that sows are not able to completely suppress allosuckling; however, they can reduce its frequency through nursing synchronization and non‐nutritive nursings.  相似文献   

7.
The immunological function of allosuckling   总被引:1,自引:0,他引:1  
Young mammals are unable to mount an efficient immune response against invading pathogens. Until their immune system is mature mothers transmit to their young immunological compounds during lactation. Given that genetic and foster mothers can assume this protective role, we propose that young mammals may gain immunological benefits by suckling more than one nursing female, a behaviour referred to as "allosuckling". This hypothesis has so far not been considered as a potential explanation for the propensity of young mammals to suckle foster mothers. However, pathogen transmission through milk during allosuckling may reduce the immunological net benefit that young gain, and furthermore allosuckling may increase pathogen transmission between foster and genetic mothers implying costs of allosuckling for all participants. Here, we develop the immunological function of allosuckling hypothesis (IFA) as a potential explanation for intra-and interspecific variation in allosuckling frequency. We present published experimental evidence for the assumption that immunological benefits of allosuckling depend on the immunological status of the offspring, the foster and the genetic mothers. Finally, we give predictions arising from the IFA hypothesis and propose that the IFA may provide a new explanation as to why neonates suckle various females and why foster females often refuse to nurse nonoffspring.  相似文献   

8.
Ascomata of a powdery mildew-like fungus have been found on Carpinus laxiflora in Tochigi Prefecture of Japan since 2003. The morphological and molecular characteristics of this fungus are reported, and a new species, Erysiphe fimbriata, is proposed. It has large chasmothecia (200–250 μm in diameter) with long (up to 4–5 mm in length), fimbriate appendages arising from the upper half of the chasmothecia and turning upward, and numerous asci (22–38 per chasmothecium). Erysiphe fimbriata is a unique fungus both genetically and morphologically.  相似文献   

9.
Although relatively rare, adoptions have been reported in a number of mammals, involving almost exclusively individuals of the same species, and hardly ever between species or across genera. Adoption remains poorly documented and its proximate causes are controversial. Here, we describe a unique case of a cross‐genus adoption within a small community of common bottlenose dolphins (Tursiops truncatus) at Rangiroa Atoll in French Polynesia. It involves a foster female adopting a presumed melon‐headed whale (Peponocephala electra) calf while already mothering its presumed biological offspring. While the inclusive fitness hypothesis can be rejected for this adult female mother, acquisition of parental skills is also unlikely to have driven adoption in parallel to natural motherhood. We argue that the primiparous foster mother’s inexperience and personality may have contributed to factors driving such non‐adaptive behavior. We also propose that the adoptee’s persistence in initiating and maintaining an association with the adult female bottlenose dolphin could have played a major role in the adoption’s ultimate success, as well as the persistence of this cross‐genus adoption after the disappearance of the biological offspring. A brief discussion of adoption and hybridization within the Delphinidae taxon is included to identify how this cross‐genus adoption fits into context of marine mammal parental care.  相似文献   

10.
Seasonal differences in the critical thermal maximum are revealed in Amur sleeper Perccottus glenii at the age of 1+ and 2 years. Maximum values of the critical thermal maximum determined by two criteria (rotation of the body and immobile gill covers) are registered in the summer, and minimum values of this parameter are observed in the winter. Maximum thermal resistance is registered at a low water heating rate (0.2–0.4°C/h), and minimum resistance is reported for a heating rate 5.0–10.5°C/h. The difference between the values of the critical thermal maximum assessed by two criteria reaches 1–2°C. Features of behavior of Amur sleeper are described at different heating rates. Based on the characteristics of thermal adaptation (critical thermal maximum and optimal temperature for growth), Amur sleeper is similar to warm water eurythermal species (goldfish Carassius auratus and carp Cyprinus carpio).  相似文献   

11.
We describe a new karyotype for Cavia magna Ximenez, 1980 from an estuarine island and the karyotype of Cavia aperea Erxleben, 1777 from an adjacent mainland. The species have differences in diploid number (2n), autosomal fundamental number, quantity, and distribution of heterochromatin as dissimilar distributions of the nucleolus-organizing regions (Ag-NORs). The C. aperea karyotype has a diploid number of 64 as previously reported for C. aperea and most other Cavia species. In contrast, this new C. magna karyotype exhibits a variant diploid number of 2n = 62, considering that previous work reported a karyotype of 2n = 64 for C. magna. The discovery of a distinct diploid number within C. magna represents the first record of intra-specific chromosomal variation in a species of Caviidae. The diploid number of 2n = 62, heterochromatin quantity, Ag-NOR distributions, and inversed X chromosome from this population of C. magna are as seen in the geographically proximate (Cavia intermedia Cherem Olimpio and Ximenez; intermediate Cavy). These data provide further evidence supporting C. magna as the sister species of C. intermedia.  相似文献   

12.
In crickets Gryllus bimaculatus, flight has been shown to be able to promote aggressive encounters between males and to suppress escape behavior. The aim of this study was to examine the influence of flight on male behavior in male–female interactions. We found that flown males demonstrate enhanced courtship behavior. The latency of calling song was significantly shorter, while the relative total duration of singing as well as the duration of singing episodes longer in flown males than in the control. Mating rate was also significantly higher in the experimental group containing flown males. The results suggest that, in addition to previously reported effects on aggressiveness and escape, flying has a profound accelerating effect on male courtship behavior.  相似文献   

13.
Chymosin as an important industrial enzyme widely used in cheese manufacture. The yeast Kluyveromyces lactis is a promising host strain for expression of the chymosin gene. However, low yields (80 U/ml in shake flask cultures) were obtained when the K. lactis strain GG799 was used to express chymosin. We hypothesized that the codon-usage bias of the host may have resulted in inefficient translation and chymosin production. To improve expression efficiency of recombinant calf chymosin in K. lactis strain GG799, we designed and synthesized a DNA sequence encoding calf prochymosin using optimized codons, while keeping the G + C content relatively low. We altered 333 nucleotides to optimize codons encoding 315 amino acids. In shaking flask culture, chymosin activity was 575 U/ml in the strain expressing the optimized gene, a sevenfold higher expression level compared with the non-optimized control. SDS–PAGE analysis revealed that the purified recombinant calf chymosin had a molecular mass of 35.6 kDa, the same as the molecular weight of native calf chymosin. Alpha-casein, beta-casein, and kappa-casein were incubated with the recombinant calf chymosin from K. lactis strain GG799 or chymosin from calf stomach and the breakdown products were analyzed by SDS–PAGE. Both the recombinant calf chymosin and the native calf chymosin specifically hydrolyzed kappa-casein. Our results show that codon optimization of the calf chymosin gene improves expression in K. lactis strain GG799. Genetic manipulation to optimize codon usage has important applications for industrial chymosin production.  相似文献   

14.
K. Tanaka  Y. Harada 《Mycoscience》2003,44(2):0115-0121
 Five species of the genus Lophiotrema are reported in this article. Of these, Lophiotrema vitigenum is described and illustrated as a new species. Three species, L. nucula, L. neohysterioides, and L. vagabundum, are newly added to the Japanease mycoflora. Lophiosphaera orientalis, Nodulosphaeria araucariae, and N. rosae, which had been recorded in Japan, are treated as synonyms of Lophiotrema fuckelii. A key to the species of Lophiotrema in Japan is given. Received: October 9, 2002 / Accepted: January 20, 2003 Acknowledgments We are grateful to Drs. Shuhei Tanaka (curator of YAM) and Ken Katumoto for the loan of fungal material. Correspondence to:K. Tanaka  相似文献   

15.
Several chromosome types have been recognized in Citrus and related genera by chromomycin A3 (CMA) banding patterns and fluorescent in situ hybridization (FISH). They can be used to characterize cultivars and species or as markers in hybridization and backcrossing experiments. In the present work, characterization of six cultivars of P. trifoliata (“Barnes”, “Fawcett”, “Flying Dragon”, “Pomeroy”, “Rubidoux”, “USDA”) and one P. trifoliata × C. limonia hybrid was performed by sequential analyses of CMA banding and FISH using 5S and 45S rDNA as probes. All six cultivars showed a similar CMA+ banding pattern with the karyotype formula 4B + 8D + 6F. The capital letters indicate chromosomal types: B, a chromosome with one telomeric and one proximal band; D, with only one telomeric band; F, without bands. In situ hybridization labeling was also similar among cultivars. Three chromosome pairs displayed a closely linked set of 5S and 45S rDNA sites, two of them co-located with the proximal band of the B type chromosomes (B/5S-45S) and the third one co-located with the terminal band of a D pair (D/5S-45S). The B/5S-45S chromosome has never been found in any citrus accessions investigated so far. Therefore, this B chromosome can be used as a marker to recognize the intergeneric Poncirus × Citrus hybrids. The intergeneric hybrid analyzed here displayed the karyotype formula 4B + 8D + 6F, with two chromosome types B/5S-45S and two D/5S-45S. The karyotype formula and the presence of two B/5S-45S chromosomes clearly indicate that the plant investigated is a symmetric hybrid. It also demonstrates the suitability of karyotype analyses to differentiate zygotic embryos or somatic cell fusions involving trifoliate orange germplasm. During the submission of this paper, we analyzed 25 other citrus cultivars with the same methodology and we found that the chromosome marker reported here can indeed distinguish Poncirus trifoliata from grapefruits, pummelos, and one variegated access of Citrus, besides the previously reported access of limes, limons, citrons, and sweet-oranges. However, among 14 mandarin cultivars, two of them displayed a single B/5S-45S chromosome, whereas in Citrus hystrix D.C., a far related species belonging to the Papeda subgenus, this chromosome type was found in homozygosis. Since these two mandarin cultivars are probably of hybrid origin, we assume that for almost all commercial cultivars and species of the subgenus Citrus this B type chromosome is a useful genetic marker.  相似文献   

16.
17.
In two experiments, we compared milk intake (assessed by weighing calves before and after suckling) and milk production (by hand milking hinds) in Iberian red deer both when calves sucked their mothers together (group-suckling experiment) and when mother and offspring were isolated (isolation-suckling experiment). In both experiments, the general lactation curve for calves increased to a peak and then decreased (type I, standard lactation curve in mammals), whereas the curve for hinds decreased from the start (type II). However, in the experiment on group suckling, calves ingested 17.2% more milk than that produced by their mothers from weeks 6 to 20. In both isolation- and group-suckling experiments, hinds showed an overproduction of milk decreasing from weeks 1 to 5. This decreasing overproduction coincides with a similar trend in calf mortality reported in the literature and might thus be aimed at ensuring calves have sufficient nutrients when mortality is highest. In addition, allosuckling observations in the group-suckling experiment showed an inverse relationship between milk production and percentage of allosucking attempts. Allosucking attempts were also more frequent after the milk overproduction period. Both findings suggest that allosuckling is a response to compensate for a reduced maternal milk supply. Copyright 2000 The Association for the Study of Animal Behaviour.  相似文献   

18.
Scydmaenine beetles are commonly described as predators specialized in capturing and feeding on armored mites of the order Oribatida, and documented cases of feeding on other live arthropods have not been known. Based on laboratory observations and a broad choice of Acari (armored and soft‐bodied) and other soil arthropods, food preferences and associated behavior of two scydmaenine species are clarified and described. Adults of Scydmaenus tarsatus ignored oribatid and mesostigmatan mites, but readily attacked and fed on a soft‐bodied Rhizoglyphus sp. (Acaridae), and on small springtails, especially on Ceratophysella denticulata (Hypogastruridae). A water drinking behavior was observed for this species, not reported previously in any Staphylinidae. Scydmaenus hellwigii ignored all tested Acari (including Rhizoglyphus) and scavenged on dead neanurine collembolans or freshly cut pieces of large springtails; a long term culture was maintained by feeding beetles with isotomid springtails. Previously reported strict specialization of Scydmaenus as a predator on Oribatida was not confirmed and it is concluded that the studied species feed on live soft‐bodied organisms and scavenge on dead arthropods.  相似文献   

19.
Leafy spurge (Euphorbia esula L.) is a perennial, invasive weed used as a model to study invasive plant behavior, because molecular tools (such as a deep expressed sequence tag database and deoxyribonucleic acid microarrays) have been developed for this species. However, the lack of effective in vitro regeneration and genetic transformation systems has hampered molecular approaches to study leafy spurge. In this study, we describe an efficient in vitro regeneration system. Three highly regenerative lines were selected by screening the in vitro regeneration capabilities of stem explants of 162 seedlings. The effects of various culture conditions on in vitro regeneration were then evaluated based on explant competence to form calluses and shoots. High rates of shoot regeneration can be obtained using a growth medium containing 1× woody plant basal medium and 1× Murashige and Skoog (MS) basal salts, 1× MS vitamins, 1.11 μM 6-benzylaminopurine, 1.97 μM indole-3-butyric acid, and 3% sucrose, pH 5.6–5.8. After 30 d culture, multiple shoots formed either directly from the stem or indirectly from the callus. This method is a requisite for the development of genetic transformation systems for leafy spurge and may be used to develop in vitro regeneration techniques for other species in the Euphorbiaceae.  相似文献   

20.
Bacterial leaf symbiosis is an intimate association between bacteria and plants in which endosymbionts are housed within leaf nodules. This phenomenon has been reported in three genera of Rubiaceae (Pavetta, Psychotria, and Sericanthe), but the bacterial partner has only been identified in Psychotria and Pavetta. Here we report the identification of symbiotic bacteria in two leaf nodulating Sericanthe species. Using 16S rRNA data and common housekeeping genetic markers (recA and gyrB) we studied the phylogenetic relationships of bacterial endosymbionts in Rubiaceae. Endosymbionts of leaf nodulating Rubiaceae were found to be closely related and were placed as a monophyletic group within the genus Burkholderia (β-Proteobacteria). The phylogenetic analyses revealed a pattern of strict host specificity and placed the two investigated endosymbionts at two distinct positions in the topology of the tree, suggesting at least two different evolutionary origins. The degree of sequence divergence between the Sericanthe endosymbionts and their relatives was large enough to propose the Sericanthe endosymbionts as new species (‘Candidatus Burkholderia andongensis’ and ‘Candidatus Burkholderia petitii’). In a second part of this study, the pylogenetic relationships among nodulating and non-nodulating Sericanthe species were investigated using sequence data from six chloroplast regions (rps16, trnG, trnL-trnF, petD, petA-psbJ, and atpI-atpH). Overall, genetic variation among the plastid markers was insufficient to enable phylogenetic estimation. However, our results could not rule out the possibility that bacterial leaf symbiosis originated once in a common ancestor of the Sericanthe species.  相似文献   

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