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1.
Differences in the mechanisms regulating reproduction between the northern red-backed vole (Clethrionomys rutilus) and large-toothed red-backed vole (Cl. rufocanus) have been revealed under vivarium conditions. In Cl. rufocanus, the date of birth is the most important ??signal?? factor for sexual maturation of male young of the year, while the effect of population density is significant only for males of the spring generation. Males of the summer generation fail to mature in the same year and are completely excluded from reproduction, which may be accounted for by a rise in the level of corticosterone (measured in fecal samples). Such a mechanism for regulating the numbers of reproductive individuals is absent in Cl. rutilus voles. Throughout the breeding season, males of this species respond to high population density by a decrease in the rate of sexual maturation. No definite relationship between sexual maturation and the level of adrenocortical activity has been revealed in Cl. rutilus.  相似文献   

2.
It is rather difficult to construct a system of gray voles of the tribe Microtini by a set of morphological and karyological characters because form generation is mosaic at these organization levels. The sequence of the mitochondrial cytochrome b gene was used to study the phylogenetic relationships and taxonomic position of the Central Asian subgenus Blanfordimys. Afghan vole Microtus (Blanfordimys) afghanus and Bucharian vole M. (Blanfordimys) bucharensis clustered with Pamir vole M. (Neodon) juldaschi, which is conventionally assigned to another subgenus. The last two species proved to be significantly closer to each other than either of them was to M. (Blanfordimys) afghanus, which disagrees with the monophyletic origin accepted for Blanfordimys. The genetic distances between the species of the subgenus Blanfordmys and M. juldaschi were comparable with the distances between the sister subgenera Microtus s. str. and Sumeriomys or Pallasiinus and Alexandromys and with the basal divergence of supraspecific clades in the subgenus Terricola. It was assumed that a special Central Asian group of species exists within the tribe Microtini and includes species of the subgenus Blanfordimys and M. juldaschi and that the subgenera Neodon and Blanfordimys should be revised.  相似文献   

3.
Molecular species identification from biological material collected at field sites has become an established ecological tool. However, extracting and amplifying DNA from degraded field samples, such as prey remains and feces that have been exposed to the elements, remains a challenge and costly. We collected 115 fecal samples of unknown small mammals, resembling fecal droppings of voles and mice (i.e., Cricetidae and Muridae), from a salt marsh in The Netherlands. We modified a previously published protocol into a relatively low-cost method with a PCR success of 95%. We demonstrate that species identification is possible for both Cricetidae and Muridae species using fecal samples of unknown age deposited in the field. For 90 samples, sequences of the variable control region in the mitochondrial genome were obtained and compared to published DNA sequences of small mammals occurring in north European salt marshes. A single sample, probably environmentally contaminated, appeared as Sus scrofa (n?=?1). We positively identified house mouse Mus musculus, being the positive control (n?=?1), and common vole Microtus arvalis (n?=?88). In 81 sequences of 251 nt without ambiguous bases, ten haplotypes were present. These haplotypes, representing the central lineage of the western subspecies M. arvalis arvalis, were separated by 20 mutations from published control region haplotypes of the western European lineages sampled in France. Unlike earlier studies of cytochrome b variation in coastal European populations, we did not find indications of recent purging of genetic variation in our study area.  相似文献   

4.
A trade-off between flight capability and reproduction is well known in adult females of the wing-dimorphic cricket Velarifictorus ornatus, but it is not clear whether such a trade-off exists in adult males of the species. In the present study, we investigated sexual maturation time, mating frequency, and the fertilization success of spermatophores after sequential mating in long-winged (LW) and short-winged (SW) adult males of V. ornatus to evaluate the potential reproductive advantage of the SW over the LW male morph. We found that the SW males of V. ornatus attained sexual maturity earlier and produced heavier spermatophores during the early stage after adult emergence than their LW counterparts. Additionally, within a 24-h mating period, the SW males showed a higher mating frequency, greater spermatophore weight, and shorter intermating time interval compared with their LW counterparts. Although females copulated with the two male morphs produced eggs of similar size, fertilization success by SW males was significantly higher than by the LW males. These results provide support for a trade-off between dispersal capability and reproduction success in wing-dimorphic males of V. ornatus.  相似文献   

5.
The microbiota of whole crop corn silage and feces of silage-fed dairy cows were examined. A total of 18 dairy cow feces were collected from six farms in Japan and China, and high-throughput Illumina sequencing of the V4 hypervariable region of 16S rRNA genes was performed. Lactobacillaceae were dominant in all silages, followed by Acetobacteraceae, Bacillaceae, and Enterobacteriaceae. In feces, the predominant families were Ruminococcaceae, Bacteroidaceae, Clostridiaceae, Lachnospiraceae, Rikenellaceae, and Paraprevotellaceae. Therefore, Lactobacillaceae of corn silage appeared to be eliminated in the gastrointestinal tract. Although fecal microbiota composition was similar in most samples, relative abundances of several families, such as Ruminococcaceae, Christensenellaceae, Turicibacteraceae, and Succinivibrionaceae, varied between farms and countries. In addition to the geographical location, differences in feeding management between total mixed ration feeding and separate feeding appeared to be involved in the variations. Moreover, a cow-to-cow variation for concentrate-associated families was demonstrated at the same farm; two cows showed high abundance of Succinivibrionaceae and Prevotellaceae, whereas another had a high abundance of Porphyromonadaceae. There was a negative correlation between forage-associated Ruminococcaceae and concentrate-associated Succinivibrionaceae and Prevotellaceae in 18 feces samples. Succinivibrionaceae, Prevotellaceae, p-2534-18B5, and Spirochaetaceae were regarded as highly variable taxa in this study. These findings help to improve our understanding of variation and similarity of the fecal microbiota of dairy cows with regard to individuals, farms, and countries. Microbiota of naturally fermented corn silage had no influence on the fecal microbiota of dairy cows.  相似文献   

6.
Helicobacter spp. colonize the gastrointestinal tract of humans and animals and have been associated with gastrointestinal diseases. Antarctic habitats are considered pristine ecosystems, but the increase in human activity could be introducing human bacteria hosted into waters and wildlife. However, Helicobacter spp. occurrence has not been studied in Antarctica. The aim of our study was to detect the Helicobacter DNA in different water sources and penguin feces from Greenwich, Dee and Barrientos Islands during summer of 2012 and 2013. High Helicobacter proportion was observed in water sources amplifying the 16S rRNA (33/40) and 23S rRNA genes (37/40) by semi-nested PCR. Similar results were observed in feces from Gentoo penguins (16S rRNA: 32/39, and 23S rRNA: 28/39) and Chinstrap penguins (16S rRNA: 16/17, and 23S rRNA: 15/17) by PCR. The phylogenetic relationship of 16S rRNA and 23S rRNA sequences from penguin feces was closely related to Helicobacter brantae. Analyses of 16S rRNA sequences showed that the majority of water samples are related to penguin (3/6) and Helicobacter pylori (2/6) sequences, but the 23S rRNA sequences matched with Campylobacter and Arcobacter. These results show for the first time the presence of the genus Helicobacter in different Antarctica water sources and in Gentoo and Chinstrap penguin feces. A few 16S rRNA sequences are very closely related to H. pylori, but specific glmM and ureA H. pylori genes were not detected. More studies are needed to determine the Helicobacter species present in this ecosystem and to establish the human impact in these Antarctic Islands.  相似文献   

7.
Three hundred and sixty presumptive lactic acid bacteria (LAB) isolated from pregnant sows, newborn, suckling, and weaned piglets were preliminarily screened for anti-Salmonella activity. Fifty-eight isolates consisting of Lactobacillus reuteri (n = 32), Lactobacillus salivarius (n = 10), Lactobacillus mucosae (n = 8), Lactobacillus johnsonii (n = 5), and Lactobacillus crispatus (n = 3) were selected and further characterized for probiotic properties including production of antimicrobial substances, acid and bile tolerance, and cell adherence to Caco-2 cells. Eight isolates including Lact. johnsonii LJ202 and Lact. reuteri LR108 were identified as potential probiotics. LJ202 was selected for further use in co-culture studies of two-bacterial and multiple-bacterial species to examine its inhibitory activity against Salmonella enterica serovar Enteritidis DMST7106 (SE7106). Co-culture of LJ202 and SE7106 showed that LJ202 could completely inhibit the growth of SE7106 in 10 h of co-culture. In co-culture of multiple-bacterial species, culturable fecal bacteria from pig feces were used as representative of multiple-bacterial species. The study was performed to examine whether interactions among multiple-bacterial species would influence antagonistic activity of LJ202 against SE7106 and fecal coliform bacteria. Co-culture of SE7106 with different combinations of fecal bacteria and probiotic (LJ202 and LR108) or non-probiotic (Lact. mucosae LM303) strains revealed that the growth of SE7106 was completely inhibited either in the presence or in the absence of probiotic strains. Intriguingly, LJ202 exhibited notable inhibitory activity against fecal coliform bacteria while LR108 did not. Taken together, the results of co-culture studies suggested that LJ202 is a good probiotic candidate for further study its inhibitory effects against pathogen infections in pigs.  相似文献   

8.
The species status of a rare species Eumicrotremus eggvinii from the family Cyclopteridae has been revalidated. Some authors considered its specimens as males of close species E. spinosus. In the Zoological Institute collection, males of E. spinosus that are morphologically similar with females of this species have been found. This is evidence of absence of sexual dimorphism in E. spinosus. In new samplings from waters of the Franz Josef Land archipelago (Barents Sea), a specimen of E. eggvinii was found and described. The opinion of some authors that individuals of E. eggvinii represent males of E. spinosus is refuted. A new finding widens the species area to the northeastern limits of the Barents Sea. The number and character of distribution of bone plaques remain reliable taxonomic characters.  相似文献   

9.
Three oligo-raker species (≤19 rakers on the first gill arch) of the genus Melamphaes have been considered. A new species, M. papavereus, out of the group “M. typhlops” has been described from the Bay of Bengal of the Indian Ocean. M. simus and M. hubbsi out of the group “M. simus” have been revised. M. simus inhabits all oceans between 40° N and 40° S. M. hubbsi has been known from single specimens caught in the central part of the South Atlantic between 11° and 19° S.  相似文献   

10.
The American cockroach, Periplaneta americana, excretes feces containing aggregation pheromones to attract conspecific individuals. It is thought that these pheromones play an important role in establishing and maintaining colonies. However, despite previous extensive efforts, the aggregation pheromones of P. americana have not been isolated. It is also unclear whether the aggregation pheromones of P. americana are truly biosynthesized by the insect, as most previous experiments extracted chemicals from feces. Here, we investigate the tissue localization of aggregation agents in P. americana. To reduce the effects of diet-derived odorants, we developed a new diet for P. americana consisting of only agar and sugars, and tested the attractiveness of fecal extracts from animals reared on this new diet. Our results show that the aggregation agents of fecal extracts are insect-derived, and the extracts from the midgut evoke stronger behavioral responses than those from other parts of the alimentary tract. This suggests that the midgut may be the production site or the storage organ of the aggregation agents. Thus, our data will facilitate the future identification of the aggregation pheromones of P. americana.  相似文献   

11.
Genders of dioecious species often show secondary sexual dimorphisms (not directly related to the sex organs), which may be related to reproductive demand for resources during the year. Our working hypothesis stated that phenology influences yearly sex-specific pattern of foliar nitrogen concentration in dioecious species. The concentration of carbon (C) and nitrogen (N) of last year’s needles (on part of twigs where strobili are bearing) was measured in 1-month intervals from March to November in Taxus baccata L. and Juniperus communis L. separately for males and females. Seasonal C concentration of needles was unrelated to gender, probably due to storage elsewhere in the plants. Needles of J. communis females had higher N concentration in March and April but this dropped to the same level as males after flowering and vegetative growth began. This suggests that females of J. communis, a species of N-poor habitats, have a long-term strategy of N storage. Nitrogen concentration was not different between the sexes during the rest of the growing season. In T. baccata, N concentration was higher in males throughout the analysed period, but the highest differences were in the period of intensive shoot elongation and radial growth. The high demand for N in the period of intensive growth and female cone maturation may result in restrictions in the vegetative growth of females. The results indicate that the time (phenology) and species-specific strategy significantly affect the concentration of N in females and males.  相似文献   

12.
The phylogenetic position of the Olkhon mountain vole (Alticola olchonensis Litvinov, 1960) was studied using the sequences of four nuclear (BRCA, GHR, LCAT, and IRBP) and one mitochondrial (cyt. b) gene. Until now multiple studies of the systematic position of this vole had been based exclusively on morphological data, while the major taxonomic references contain contradictory information regarding both the subgeneric and species status of this animal. It was established that the molecular data and morphology data allow us to concern the Lake Baikal vole unambiguously as a part of the nominative subgenus Alticola instead of Aschizomys.  相似文献   

13.
14.
Micropleura huchzermeyeri n. sp. (Camallanida: Dracunculoidea: Micropleuridae) is described from the peritoneal cavity of Crocodylus niloticus Laurenti (Reptilia: Crocodylidae), based on a detailed study of its morphology using light and scanning electron microscopy. The new species is compared with its congeners, M. australiensis Moravec, Kay & Hobbs, 2004, M. vazi Travassos, 1933 and M. vivipara von Linstow, 1906 from crocodilians, and with M. indica Khera, 1951 from chelonian hosts. It can be distinguished from these by the length of its spicules, which are longer than in all described species and a combination of characters, including the presence of prominent lateral caudal papillae on the level of the cloaca in males, the presence of conspicuous phasmids on the female tail, the pre-equatorial position of the vulva and the length of the first-stage larvae. Micropleura huchzermeyeri n. sp. is further characterised by having 14 cephalic papillae in both sexes and ten pairs of caudal papillae in males. This is the first report of a representative of the genus Micropleura von Linstow, 1906 from a crocodilian in the Afrotropical region. Micropleura helicospicula Dey Sarkar, 2003 is considered a species incertae sedis.  相似文献   

15.
The structure of the abdominal and pregenital segments and genitalia of males was studied in Pyrellia rapax (Harris, 1780) and Musca autumnalis De Geer, 1776 (Muscidae, Muscini). The musculature of these species is compared with that in Musca domestica Linnaeus, 1758 (Muscidae) and Scathophaga stercoraria (Linnaeus, 1758) (Scathophagidae), previously investigated by O.G. Ovtshinnikova. Morphological analysis of sclerites and muscles of abdominal and pregenital segments and genitalia of males in Pyrellia rapax, Musca autumnalis, and M. domestica demonstrates processes of reduction in Musca as compared with P. rapax and S. stercoraria.  相似文献   

16.
The features, population characteristics of reproduction, nutrition, and lifestyle of an extremely poorly studied narrow-range species of underground rodents—the false zokor (Myospalax aspalax)—have been described on the basis of original field materials. The data were obtained within the Russian part of the species range in Zabaikal’skii krai. The false zokor is characterized by a pronounced sexual dimorphism in body size (males are larger) and a predominance of females in the population. Mating takes place in April; at other times of the year, zokors lead a solitary lifestyle. The size of the brood is small: 3.7 embryos per breeding female. Their preferred food is bulbs and rhizomes of Allium, Thermopsis, Phragmites, and Leymus. In Eastern Transbaikalia, they are active in winter.  相似文献   

17.
This study investigated the gastrointestinal microbiota in three genetically identical cloned dogs (A, B and C) by somatic cell nuclear transfer. We collected feces from three cloned dogs and their feed to investigate gastrointestinal microbiota using both culture-dependent and culture-independent methods. A total of 962 strains from the feces of cloned dogs were isolated using aerobic and anaerobic culture methods. The dominant microorganisms were Enterococcus faecalis and Enterococcus faecium in all fecal samples. In particular, the fecal sample from cloned dog C had similar proportions of three species (E. faecalis, E. faecium and Lactobacillus murinus). In all, 29 DNA fragments were identified by PCR-denaturing gradient gel electrophoresis (DGGE) analysis. The highest DGGE band intensities were for E. faecalis from cloned dogs A and C and for Clostridium sordellii from cloned dog B, with relative intensities of 15.2, 17.7 and 14.4%, respectively. The other strains identified from the cloned dogs were Chryseobacterium soldanellicola, Escherichia coli, L. murinus, Streptococcus alactolyticus, Weissella confusa and uncultured bacterium. Some microbes isolated from the fecal samples, including C. soldanellicola and W. confuse, were derived from the feed. Overall, gastrointestinal microbiota of all genetically identical cloned dogs, maintained under the same environmental and feeding conditions, showed similar profiles in terms of species diversity analyzed by PCR-DGGE, although there were proportional differences in the amounts of bacterial species. To our knowledge, this is the first report to investigate and compare gastrointestinal microbiota of three genetically identical dogs.  相似文献   

18.
Bactrocera carambolae and B. dorsalis (Diptera: Tephritidae) are extremely destructive pests of fruits and vegetables in the Asia-Pacific region. Earlier reports have described that B. carambolae and B. dorsalis, respectively, use mainly star fruit and mango, suggesting a certain level of host partitioning which can be ascribed neither to differences in larval food qualities nor host-specific parasitoid mortality. This study specifically examined reproductive interference (antagonistic sexual interaction) between B. carambolae and B. dorsalis as a potential factor strongly affecting their host partitioning. We observed mating behaviors, especially interspecific courtships and mating, by cohabiting the conspecific and heterospecific pairs together. Consequently, we quantified their effects on the reproductive success of females. Males of both species frequently courted their own females, but they also courted females of other species. Courtship refusal by females was not selective in males of either species. This incomplete discrimination of both sexes led to frequent occurrences of interspecific sexual interactions in both species, but only B. carambolae females showed reduced reproductive success. These results suggest that B. dorsalis, superior in reproductive interference, can occupy high-quality mango, whereas B. carambolae, inferior in reproductive interference, must use low-quality star fruit.  相似文献   

19.
Environmental sampling yielded two yeast species belonging to Microstromatales (Exobasidiomycetes, Ustilaginomycotina). The first species was collected from a leaf phylloplane infected by the rust fungus Coleosporium plumeriae, and represents a new species in the genus Jaminaea, for which the name Jaminaea rosea sp. nov. is proposed. The second species was isolated from air on 50% glucose media and is most similar to Microstroma phylloplanum. However, our phylogenetic analyses reveal that species currently placed in Microstroma are not monophyletic, and M. phylloplanum, M. juglandis and M. albiziae are not related to the type species of this genus, M. album. Thus, Pseudomicrostroma gen. nov. is proposed to accommodate the following species: P. glucosiphilum sp. nov., P. phylloplanum comb. nov. and P. juglandis comb. nov. We also propose Parajaminaea gen. nov. to accommodate P. albizii comb. nov. and P. phylloscopi sp. nov. based on phylogenetic analyses that show these are not congeneric with Jaminaea or Microstroma. In addition, we validate the genus Jaminaea, its respective species and two species of Sympodiomycopsis and provide a new combination, Microstroma bacarum comb. nov., for the anamorphic yeast Rhodotorula bacarum. Our results illustrate non-monophyly of Quambalariaceae and Microstromataceae as currently circumscribed. Taxonomy of Microstroma and the Microstromataceae is reviewed and discussed. Finally, analyses of all available small subunit rDNA sequences for Jaminaea species show that J. angkorensis is the only known species that possess a group I intron in this locus, once considered a potential feature indicating the basal placement of this genus in Microstromatales.  相似文献   

20.
Tubeufia was named for a sexual morph taxon. However, several asexual morph species have been accommodated in this genus as well. In our study, four new species of Tubeufia, viz. T. filiformis, T. latispora, T. laxispora and T. mackenziei, are described and illustrated. The phylogenetic placement of the new species is confirmed by analysis of combined ITS, LSU and TEF1α sequence data. A key to Tubeufia species is provided and the new species are compared with similar fungal taxa.  相似文献   

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