中国云南洱海周边褐家鼠的体表寄生虫群落组成

褐家鼠Rattus norvegicus可能是云南省部分鼠疫流行区的储存宿主之一, 其体表的某些寄生虫种类可能是人类疾病的传播媒介。为了解洱海周边地带褐家鼠的体表寄生虫群落, 并对其医学和兽医学的重要性进行描述。用U检验和相关分析的统计方法对2003-2004年采自云南洱海（中国滇西北著名的淡水湖泊）周边地区的431头褐家鼠的体表寄生虫群落进行了研究。用构成比（C）, 侵染率(P)和平均丰富度(A)反映体表寄生虫的流行和密度状况。调查点位于我国11大鼠疫自然疫源地之一, 此地也是我国恙虫病和流行性出血热的流行地区。结果表明: 431头褐家鼠中307头寄生有体表寄生虫, 侵染率为71%。采集到的体表寄生虫有47种, 包括23种恙螨、16种革螨、6种蚤和2种吸虱, 其中16种以前已经被证明是人类疾病的媒介。结果提示褐家鼠的体表寄生虫物种多样性高。     

Ag-NOR chromosomal association patterns in Rattus rattus (Rafinesque, 1814) and Rattus norvegicus (Berkenhout, 1796) from the southern Iberian peninsula

A high frequency of satellite association phenomena in a number of specimens of Rattus rattus and R. norvegicus, captured on the coastal fringe of Málaga province (Southern Spain), was found. Only Ag-NOR bearing chromosomes participated in associations in both species. R. rattus is characterized by 14/18 heterologous and R. norvegicus by 5/5 and 13/13 homologous association types.     

Serological affinities of the oyster pathogen Perkinsus marinus (Apicomplexa) with some dinoflagellates (Dinophyceae)

The protozoan oyster pathogen Perkinsus marinus is classified in the phylum Apicomplexa, although molecular-genetic and ultrastructural evidence increasingly concur on its closer phylogenetic relationship with the dinoflagellates. To test for evidence of serological epitopes common to P. marinus and dinoflagellates, we probed 19 free-living and 8 parasitic dinoflagellate, or dinoflagellate-like, species for cross-reactivity with polyclonal antibodies to P. marinus. Three of 19 free-living dinoflagellates (16%), and 7 of 8 parasitic dinoflagellates (88%) were labeled by anti-P. marinus antibodies. In reciprocal immunoassays using polyclonal antibodies to the Hematodinium sp. dinoflagellate parasite of Norway lobsters, Nephrops norvegicus, P. marinus and the same 7 parasitic dinoflagellates labeled by anti-P. marinus antibodies, were again labeled. The dinoflagellate-like parasite of prawns Pandalus platyceros was not labeled by either antibody reagent. These reciprocal results confirm the presence of shared antibody-binding epitopes on cells of P. marinus and several dinoflagellates. The apparent widespread serological affinity between P. marinus and the parasitic dinoflagellates suggests a closer phylogenetic link to the syndinean dinoflagellate lineage. The consistent failure of the dinoflagellate-like prawn parasite to bind either antibody reagent shows that this parasite is serologically distinct from both P. marinus and Hematodinium-species parasitic dinoflagellates.     

Two new species of Aporhynchus (Cestoda: Trypanorhyncha) from deep water lanternsharks (Squaliformes: Etmopteridae) in the Azores, Portugal

New collections of cestodes from the spiral intestines of the lanternsharks Etmopterus spinax and Etmopterus pusillus off the island of Faial, in the Azores, Atlantic Ocean, have yielded 2 new species of trypanorhynchs belonging to Aporhynchus. Both species share the distinctive lack of all elements of the rhyncheal system that are characteristic of this genus. The identity of Aporhynchus norvegicus is clarified to allow it to be distinguished from A. menezesi n. sp., which also parasitizes E. spinax. This new species differs conspicuously from its congeners in that its mature and gravid proglottids are wider than long, rather than longer than wide, and also in its lack of spinitriches on the scolex. Aporhynchus pickeringae n. sp., the new species from E. pusillus , differs from all of its congeners except A. norvegicus in that it is a relatively delicate worm with relatively fewer testes. It also possesses fewer proglottids and a wider pedunculus scolecis than does A. norvegicus. Sections through the scolex of A. menezesi n. sp. support use of the term bothriate, rather than difossate, in reference to the scolex configuration of some trypanorhynchs. A key to the 4 species of Aporhynchus is provided.     

Redescription and surface ultrastructure of Pygidiopsis macrostomum (Digenea: Heterophyidae)

Pygidiopsis macrostomum Travassos, 1928, a poorly known species originally described from a single specimen from Rattus norvegicus (Erxleben, 1777) in Brazil, is redescribed on the basis of metacercariae from the mesenteries of naturally infected guppies Poecilia vivipara Bloch and Schneider, 1801 (Poeciliidae), and adults obtained from an experimental infection of hamsters. Pygidiopsis macrostomum is characterized by the absence of oral spines, vitellaria extending forward to ventral sucker, uterus reaching pharyngeal level, X-shaped excretory vesicle, and an oral sucker/acetabulum ratio of 1:0.8. The surface ultrastructure shows that the tegument of the metacercaria does not strongly differ from that of adults. The brush-shaped spines of P. macrostomum are similar to those reported for Pygidiopsis summa and Pygidiopsis ardeae, but no differences in spine shape were observed throughout the body.     

Conservation in the first internal transcribed spacer region (ITS1) in Hematodinium species infecting crustacean hosts found in the UK and Newfoundland

Parasitic dinoflagellates in the genus Hematodinium infect a number of decapod crustaceans in waters off the UK, including the Norway lobster Nephrops norvegicus and the edible crab Cancer pagurus. This study investigated sequence variability in the first internal transcribed spacer (ITS1) region of the ribosomal RNA complex of Hematodinium spp. infecting N. norvegicus, C. pagurus, and Pagurus bernhardus from 4 locations in the UK and from the Hematodinium sp. infecting Chionoecetes opilio from the province of Newfoundland and Labrador, Canada. Phylogenetic analysis of the Hematodinium ITS1 sequences from N. norvegicus, C. pagurus, P. bernhardus and C. opilio suggest that these crustaceans are infected with the same species of Hematodinium. Length variability of the ITS1 region was observed (324 to 345 bp) and attributed to 4 variable microsatellite regions (CATG)n' (GCC)nTCCGC(TG)n' (TA)n' and (GAA)n(GGA)n within the sequenced ITS1 fragment. The observed variation may be due to co-infection of the host crustacean with several different strains of Hematodinium or differences among copies of ITS1 region within the genome of a single parasite cell. The Hematodinium ITS1 sequence from N. norvegicus, C. pagurus, P. bernhardus and C. opilio isolates was sufficiently conserved in primer binding regions targeted by previous molecular diagnostic assays; therefore, we suggest that this assay could be used to screen for Hematodinium infections in these crustacean hosts.     

Vocalizations of nine species of rat (Rattus; Muridae)

The sounds produced by seven species of Rattus native to Australia and the Black rat ( R. rattus ) and the Brown rat ( R. norvegicus ), were investigated in the laboratory. Both audible and ultrasonic sounds were recorded and the ontogeny of the different vocalizations investigated. All nine species had the same basic repertoire of seven more or less discrete calls. Some calls varied more between the different species than did others. Similarly there were species' differences in the ease with which some calls could be elicited. Two major continua were identified, one audible and one ultrasonic. An attempt was made to put the vocalizations recorded into an evolutionary perspective.     

Small mammals and their ectoparasites from the Scottish islands of Handa (Sutherland), Muck, Pabay, Scalpay and Soay (Inner Hebrides)

Small mammals were trapped on five islands for short periods during the summers of 1964 and 1965, with the following results:
Handa: Rattus norvegicus only, probably no other species present.
Muck: Sorex araneus, S. minutus, Apodemus sylvaticus and Microtus agrestis; R. norvegicus also present.
Pabay: S. minutus and Neomys fodiens ; probably no other species present.
Scalpay: S. araneus, S. minutus and M. agrestis.
Soay: S. araneus and S. minutus ; rodents almost certainly absent.
Ectoparasites (fleas and Acarina) collected from these small mammals are tabulated.     

Metabolism of fluoroacetate in the skink (Tiliqua rugosa) and the rat (Rattus norvegicus)

Administration of 100 mg sodium fluoroacetate (compound 1080) per kilogram body weight to T. rugosa resulted in a 3.4-fold increase in plasma citrate levels 48 h after dosing while administration of 3 mg sodium fluoroacetate per kilogram body weight to R. norvegicus produced a fivefold increase in plasma citrate levels within 4 h. Administration of 300 mg sodium fluoroacetate per kilogram body weight reduced the oxygen consumption of the skink by between 2.5 and 11% while in the rat, 2 mg sodium fluoroacetate per kilogram body weight reduced oxygen consumption by between 28 and 57%. Aconitate hydratase activity in extracts of liver acetone powders from T. rugosa was less inhibited by (-)erythrofluorocitrate (Ki: 0.065 mM) than that in extracts derived from R. norvegicus (Ki: 0.026 mM). The rate of defluorination of fluoroacetate in erythrocytes and in extracts of liver acetone powders of T. rugosa was 8- and 4.5-fold greater, respectively, than that found in similar preparations from R. norvegicus. A rapid rate of defluorination together with a low reliance on aerobic respiration favoured detoxification of fluoroacetate in T. rugosa rather than its conversion into fluorocitrate. Though defluorination in this species helped to minimize the immediate effects of fluoroacetate on aerobic respiration, it resulted in rapid depletion of liver glutathione levels.     

Cross-transmission of Eimeria spp. (Protozoa, Apicomplexa) of rodents--a review

A total of 169 cross-transmission attempts has been made with 44 (11.8%) of the 372 named species of Eimeria of rodents. Of these, 161 were rodent-to-rodent, 6 rodent-to-lagomorph, and 1 each rodent-to-carnivore and rodent-to-bird. None of the last three categories was successful. In the rodent-to-rodent combinations, 39 (80%) of the 49 attempts to transmit a coccidian species from one rodent species to another of the same genus were successful, and only 14 (12.5%) of the 112 attempts to transmit a coccidium to a rodent of a different genus were successful. Eight of the successful attempts were with E. chinchillae, which was the only truly euryxenous species of Eimeria in the group. Two successful attempts were between between the closely related rodent genera Spermophilus and Cynomys, and two were both of E. separata from Rattus norvegicus to some genetic strains but not to others of Mus musculus. One attempt with E. vermiformis from Mus musculus to Rattus norvegicus required treatment of the rat with the immunosuppressant dexamethasone to succeed. More cross-transmission studies are needed to determine the host spectra of the species of Eimeria and other coccidian genera, and to determine the roles of genetics and immunosuppression in their transmission.     

First record of molluscs naturally infected with Angiostrongylus cantonensis (Chen, 1935) (Nematoda: Metastrongylidae) in Brazil

Seeking the identification of Angiostrongylus cantonensis as a potential etiological agent of three clinical cases of eosinophilic meningitis, mollusc specimens were collected in the state of Espírito Santo, Brazil. The snails were identified as Sarasinula marginata (45 specimens), Subulina octona (157), Achatina fulica (45) and Bradybaena similaris (23). Larvae obtained were submitted to polymerase chain reaction and restriction fragment length polymorphism diagnosis. Their genetic profile were corresponded to A. cantonensis. Rattus norvegicus experimentally infected with third-stage larvae, developed menigoencephalitis, and parasites became sexually mature in the lungs. Additionally, larvae obtained from A. fulica snails, from S?o Vicente, state of S?o Paulo, also showed genetic profiles of this nematode. This is the first record of Brazilian molluscs infected with this nematode species.     

Cross-Transmission of Eimeria spp. (Protozoa, Apicomplexa) of Rodents—A Review

A total of 169 cross-transmission attempts has been made with 44 (11.8%) of the 372 named species of Eimeria of rodents. Of these, 161 were rodent-to-rodent, 6 rodent-to-lagomorph, and 1 each rodent-to-carnivore and rodent-to-bird. None of the last three categories was successful. In the rodent-to-rodent combinations, 39 (80%) of the 49 attempts to transmit a coccidian species from one rodent species to another of the same genus were successful, and only 14 (12.5%) of the 112 attempts to transmit a coccidium to a rodent of a different genus were successful. Eight of the successful attempts were with E. chinchillae , which was the only truly euryxenous species of Eimeria in the group. Two successful attempts were between the closely related rodent genera Spermophilus and Cynomys , and two were both of E. separata from Rattus norvegicus to some genetic strains but not to others of Mus musculus. One attempt with E. vermiformis from Mus musculus to Rattus norvegicus required treatment of the rat with the immunosuppressant dexamethasone to succeed. More cross-transmission studies are needed to determine the host-spectra of the species of Eimeria and other coccidian genera, and to determine the roles of genetics and immunosuppression in their transmission.     

Hemoglobin affinity in Andean rodents

Blood hemoglobin oxygen affinity (P50) was measured in three Andean species and in the laboratory rat (control), all raised near sea level. Chinchilla lanigera (Molina, 1792) has an altitudinal habitat range from low Andean slopes up to 3000 m., while Chinchilla brevicaudata (Waterhouse, 1848) has an altitudinal range from 3000 to 5000 m. The laboratory type guinea pig, wild type guinea pig (Cavia porcellus), (Waterhouse, 1748), and laboratory rat (Rattus norvegicus) were also raised at sea level. The Andean species had high hemoglobin oxygen affinities (low P50) compared with the rat. Chinchilla brevicaudata had a higher affinity than Chinchilla lanigera. The wild type guinea pig had a higher affinity than the laboratory type. As has been shown in other species, this is another example of an inverse correlation between the altitude level and the P50 values. This is the first hemoglobin oxygen affinity study in Chinchilla brevicaudata.     

Effects of vaginal-cervical stimulation in seven species of muroid rodents.

Six species of muroid rodents (Peromyscus californicus, P. eremicus, P. gossypinus, Mesocricetus auratus, Rattus norvegicus and R. rattus) were given artificlal vaginal-cervical stimulation in an attempt to induce pseudopregnancy. Some females of each species became pseudopregnant, but it was not clear that stimulation patterns mimicking the copulatory patterns of conspecific males were more effective than other patterns of stimulation. In the non-domesticated species (Peromyscus and R. rattus) a few females responded to a variety of stimulus conditions, and no species differences in responsiveness among the wild species were evident. The established laboratory rodents (R. norvegicus, M. auratusy were markedly more responsive to artificial stimulation, suggesting possible effects of domestication on fecundity and reactions to handling- Microtus ochrogaster, an induced ovulator, ovulated in response to vaginal-cervical stimulation only if one intromission from a male was also provided. No other differences in the responses of reflex and spontaneous ovulators were apparent.     

Single-cell quantitative RT-PCR analysis of Cpt1b and Cpt2 gene expression in mouse antral oocytes and in preimplantation embryos

Among crustacean Decapoda numerical chromosome variability is frequent, and it has been hypothesized that the presence of supernumerary chromosomes accounts for this variability. Thanks to the improvement of cytogenetic analysis by chromosomal banding techniques, supernumerary B chromosomes (Bs) have been demonstrated in Nephrops norvegicus, Homarus americanus,Palinurus elephas and P. mauritanicus, belonging to different crustacean families. In all four species Bs were variable in number, mainly heterochromatic and undigested by various endonucleases, and in meiosis they showed non-Mendelian segregation. Compared to the other chromosomes of the complement, the Bs are very small in almost all species, but some of them were very large in N. norvegicus.     

The independent evolution of two closely related satellite DNA elements in rats (Rattus).

We have identified and determined the sequence and organization of a new rat satellite DNA in Rattus rattus, the roof rat. This satellite DNA, which we call R. rattus satellite I', consists of tandem arrays of a 185 base pair (bp) repeat unit that we call a'. a' is 86% homologous to a 185 bp portion of the 370 bp repeat unit of the previously described rat satellite [Pech et al. (1979) Nucleic Acids Res. 7, 417-432] present in the common laboratory rat species, R. norvegicus. We can thereby distinguish two 185 bp portions of the satellite I 370 bp repeat unit: "a" (homologous to a') and "b". Satellite I has the structure (a,b)n, and satellite I' has the structure (a')n. Like a, a' is only about 60% homologous to b and fails to hybridize to b. Although R. norvegicus and R. rattus contain about the same total concentration of satellite sequences, R. norvegicus contains essentially only the a,b type (satellite I), whereas R. rattus contains a' type (satellite I') and lesser amounts of the a,b type (satellite I). The a,b type (satellite I) in R. rattus is very similar to that in R. norvegicus as judged both by hybridization and by the presence of all but one of the major restriction enzyme sites that characterize the R. norvegicus satellite I. In R. rattus the a' and a,b repeat units are not detectably present in the same tandem array. All of the sequence differences between a' (R. rattus) and a (R. norvegicus) can be accounted for by simple base substitutions, and the implication of this and other features of rat satellite DNA structure for satellite DNA evolution are discussed.     

Mixed function oxidases in kidney and duodenum of camel,guinea pig and rat

The activities of the drug-metabolizing enzymes, aniline 4-hydroxylase, benzphetamine N-demethylase and 7-ethoxycoumarin O-deethylase have been measured in vitro in kidneys and duodenum of camels (Camelus dromedarius), guinea pigs (Cavia porcellus) and rats (Rattus norvegicus). In these species, levels of hepatic microsomal parameters namely microsomal protein, cytochrome P(450), cytochrome b(5) and NADPH-cytochrome c reductase have also been determined. In general, camels seemed to have the lowest enzyme activity when compared to rats and guinea pigs. Rats showed the highest activity in NADPH-cytochrome c reductase, aniline 4-hydroxylase and ethoxycoumarin O-deethylase among these species. However, guinea pigs showed the highest enzyme activity in cytochrome P(450), cytochrome b(5) and benzphetamine N-demethylase.     

Population distribution and zoonotic potential of gastrointestinal helminths of wild rats Rattus rattus and R. norvegicus from Jamaica

The population distribution and zoonotic potential of gastrointestinal helminths in a naturally infected population of wild rats (Rattus rattus and Rattus norvegicus) in Jamaica are described. One hundred and thirty (29.7%) of 437 rats captured in the study were infected: 104 (35%) of 297 R. rattus compared with 26 (18.6%) of 140 R. norvegicus. Nine species of gastrointestinal helminths were recovered: Raillietina sp. (0.2%), Trichuris sp. (0.2%), Rictularia sp. (0.7%), Syphacia obvelata (1.1%), Strongyloides ratti (1.4%), Hymenolepis diminuta (3.8%), Protospirura muricola (4.3%), Moniliformis moniliformis (11.2%), and Nippostrongylus brasiliensis (14.2%). In a logistic model, the single risk factor identified for both M. moniliformis and P. muricola was R. rattus, compared with R. norvegicus (OR = 8.369 and 9.714, respectively). In comparison, the risk factor predicted for infection with N. brasiliensis was the northeastern section of Jamaica (OR = 11.000) compared with western Jamaica. Rictularia sp. represents a new geographic distribution record for the Caribbean region. Hymenolepis diminuta, M. moniliformis, Raillietina sp., and Rictularia sp. are potentially zoonotic, but only human infection with H. diminuta has been previously reported in the Caribbean.     

Chromosomal Homology of Rabbit (ORYCTOLAGUS CUNICULUS) Linkage Group VI with Rodent Species

Homologous portions of linkage group (LG) VI in the rabbit Oryctolagus cuniculus, chromosome 8 in Mus musculus, and LG V of Rattus norvegicus have been observed. These linkage groups in Oryctolagus and Mus contain the extension locus (e), where recessive alleles are known in many species. Preliminary linkage data have added new loci to linkage group VI of the rabbit, revised the order and map distances on the linkage map, and by comparison with rodent species have strengthened the homology of LG VI in the rabbit with chromosome 8 of the mouse and with LG V of the rat. LG VI now contains five loci with the following order and intervening map distances: Es-1, Es-2 complex--6.3 +/- 2.1 cM--Est-1, Est-2 complex--18.5 +/- 3.7 cM--e.     

Opposite effects of tryptophan intake on motor activity in ring doves (diurnal) and rats (nocturnal)

The role of l-tryptophan as precursor of serotonin and melatonin synthesis on activity-rest rhythm was studied in ring doves, Streptopelia risoria, as a representative of diurnal animals and rats, Rattus norvegicus, as a typical nocturnal one. The animals were housed in cages equipped for horizontal activity recording in a thermostatized chamber and submitted to a 12/12h light/dark photoperiod (lights on at 08:00 h). After acclimatization, the animals received vehicle (methylcellulose) and l-tryptophan (240 mg/kg) by esophagic cannula 2h before the onset of either light or dark phase. Also, oral melatonin (2.5mg/kg) was tested for comparative purposes. After nocturnal l-tryptophan administration, rats showed increased activity (149%), while the opposite occurred in ring doves (39% decrease). No significant changes were found after diurnal l-tryptophan intake in either species. Melatonin produced effects similar to those of l-tryptophan. These results suggest that the effects of l-tryptophan administration are dependent on the nocturnal/diurnal habits of the studied species and, most probably, are mediated by increased melatonin synthesis.