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1.
Topotype specimens of the Middle OrdovicianHyolithes acutus Eichwald, 1840, which is the type of the genus that lent its name to a family, order, class, and even phylum according to some, andH. latus Eichwald, 1860 allow that genus and those species to be firmly established on a sound, morphologic basis. In addition, preservation of the types ofHyolithes striatus Eichwald, 1860 is sufficiently good to warrant reassignment toDorsolinevitus Syssoiev, 1958. In contrast, the type ofH. insularis Eichwald, 1860 is incompletely preserved, and this species is not recognizable beyond the type material. The concept of the family Hyolithidae is revised to more closely conform to the morphology ofHyolithes, with authorship herein ascribed toSyssoiev (1958) rather than toNicholson (1872). The stratigraphic distribution of these taxa suggests thatHyolithes as defined herein first appears in the Middle Ordovician, but extends into at least the Lower Devonian, as suggested by two species from the Barrandian region of the Czech Republic. Their geographic distribution further re-enforces the notion of two distinct paleobiogeographic provinces based on hyoliths, a Mediterranean province and Baltic province, with almost no mixing of hyolith faunas during the Ordovician.   相似文献   

2.
Genetic control of IgM responses to (T,G)-A — L   总被引:1,自引:1,他引:0  
The primary antibody response to aqueous immunization with a low molecular-weight lot of (T,G)-A — L (#420) was studied in congenic pairs of inbred mouse strains. Two new genetic controls were identified, both of which quantitatively regulate the production of IgM anti-(T,G)-A — L antibody. Testing of F1 and F2 progeny demonstrated that one of these genes is linked to the major histocompatibility (H-2) complex, and that high response is dominant over low response. Whether this gene is identical toIr-1A is not yet known. The other gene, designatedIg-TGAL M , is linked to the immunoglobulin heavy-chain allotype locus (Ig-1) and is expressed in a genedose dependent manner. Following secondary challenge with (T,G)-A — L 420, quantitative differences in IgG antibody response were observed inIr-1A high-responder congenics differing only at theIg-1 locus. Breeding studies, however, failed to demonstrate any linkage between this locus and the quantitative control of IgG anti-(T,G)-A — L antibody. These data demonstrate thatH-2-linked immune response genes can regulate IgM as well as IgG antibody responses, that genetic control of the IgM response to (T,G)-A — L is linked toIg-1, and that bothH-2-linked andIg-1-linked genes may simultaneously affect an IgM antibody response to the same antigen.Abbreviations used in this paper are (T,G)-A — L poly-l-(Tyr,Glu)-poly-d,l-Ala-poly-l-Lys - NMS normal mouse serum - SRBC sheep red blood cells - i.p. intraperitoneal - PBS phosphate-buffered saline - RAMG polyvalent rabbit anti-mouse globulin - 2-Me 2-Mercaptoethanol - 2-MeS 2-Me-sensitive - PFC plaque-forming cells - ABC antigen-binding cells  相似文献   

3.
(1) The ability to produce cephalodia is usually a genus-specific character in lichens. (2)Lecidea shushanii Thoms., is a member of the genusTephromela, closely related toT. aglaea. It is not clear, whether or not the cephalodia of this taxon are true cephalodia or colonies of epiphytic cyanobacteria and whether or notLecidea shushanii is an independent species. (3)Lecidea dovrensis Nyl., is, in contrast to the traditional concept, not conspecific withLecidea alpestris Sommerf., but an earlier name forLecidea pallida Th. Fr. (4)Lecidea dovrensis is described in some detail. Chemically the species is characterized by the presence of isousnic acid (previously unknown in lecideoid lichens). It is restricted to areas north of the 60th parallel with an oceanic climate. (5) In connection with the attempt to clarify the taxonomic relationships ofLecidea dovrensis, figures of ascus apical structures of the following species are given (marked by an asterisk are genera where we found discrepancies with published data):Austrolecia antarctica, Catillaria chalybeia, Lecidea alpestris, L. caesioatra, L. limosa, Lecidoma demissum, Koerberiella wimmeriana, Micarea assimilata, M. crassipes, M. melaenida, M. prasina, Pilophorus robustus, Placodiella olivacea, Placolecis opaca, Porpidia trullisata, Protoblastenia rupestris, Psilolechia lucida, Psorula rufonigra, Squamarina gypsacea, Xanthopsorella texana. (6) Among crustaceous lichens we find no groups related toLecidea dovrensis. We supportTimal's concept of including this species in the genusPilophorus. Pilophorus, as well asLecidea dovrensis is characterized by the same ascus type, by a similar structure of thallus, cephalodia, paraphyses, and ascocarp (although there is no pseudopodetium developed inLecidea dovrensis), and the presence of isousnic acid. In addition, both taxa are restricted to cool oceanic climates and non-calciferous substrates. The following combination is proposed:Pilophorus dovrensis (Nyl.)Timdal, Hertel & Rambold, comb. nova. (7) The species of theLecidea alpestris-group form an independent genus, probably near toAustrolecia Hertel.
Frau Prof. Dr.Elisabeth Tschermak-Woess zu ihrem 70. Geburtstag gewidmet.  相似文献   

4.
Dominant progressive hearing loss and vestibular dysfunction DFNA9 is caused by mutations of the human COCH gene. COCH encodes cochlin, a highly abundant secreted protein of unknown function in the inner ear. Cochlin has an N-terminal LCCL domain followed by two vWA domains, and all known DFNA9 mutations are either missense substitutions or an amino acid deletion in the LCCL domain. Here, we have characterized the auditory phenotype associated with a genomic deletion of mouse Coch downstream of the LCCL domain. Homozygous Coch −/− mice express no detectable cochlin in the inner ear. Auditory brainstem responses to click and pure-tone stimuli (8, 16, 32 kHz) were indistinguishable among wild type and homozygous Coch −/− mice. A Coch-LacZΔneo reporter allele detected Coch mRNA expression in nonsensory epithelial and stromal regions of the cochlea and vestibular labyrinth. These data provide functional evidence that DFNA9 is probably not caused by COCH haploinsufficiency, but via a dominant negative or gain-of-function effect, in nonsensory regions of the inner ear.Tomoko Makishima, Clara I. Rodriguez contributed equally  相似文献   

5.
Eocryphops andPlagiolaria are revised and a new species,E. albertii, is described from the Eifelian of Morocco.“Trimerocephalus” cyclophthalmus Walther, 1907, a species long assigned toEocryphops, is regarded as a junior subjective synonym of the type species ofPlagiolaria, Pl, plagiophthalma. Eocryphops originated in the evolutionary lineage leading toPhacops (s.str.), whereasPlagiolaria was probably derived fromLochkovella. Although they have been linked with the Late Devonian group of small-eyed and blind phacopids includingCryphops and its relatives. neitherEocryphops norPlagiolaria is ancestral to these forms. Confirmed occurrences ofEocryphops andPlagiolaria are from regions that were situated on the North Gondwana margin or on plates associated with this margin.  相似文献   

6.
Zusammenfassung A. sagittata (Bertol.) DC. von zehn Herkünften aus Europa ist mit 2 n=16 diploid.A. hirsuta (L.)Scop. s. str. einschließlich der sicherlich hierhergehörigen var.glaberrima Wahlenb. von 30 europäischen Herkünften ist mit 2 n=32 tetraploid; diploide Pflanzen konnten beiA. hirsuta s. str. nicht gefunden werden.
Summary A. sagittata (Bertol.) DC. from 10 different places in Europe has 2 n=16 chromosomes and is diploid.A. hirsuta (L.)Scop. s. str., its var.glaberrima Wahlenb. being included, has been investigated from 30 provenances in Europe, it has the tetraploid chromosome number 2 n=32, diploid plants could not be found in this species.A. hirsuta var.glaberrima (2 n=32) is surely belonging toA. hirsuta s. str. and not toA. allionii (2 n=16).
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7.
T. Raghunath 《Mycopathologia》1966,30(3-4):209-215
Summary 1. A new species ofAlternaria isolated from the diseased plants ofCarum copticum L.Peucedanum graveolens Benth. &Hook f. andFoeniculum vulgare Mill. is described and compared with other species affecting Umbelliferae.2. TheCoriandrum isolate described by the writer asAlternaria poonensis Raghunath is a shy sporulator in artificial culture with long beaked muriform spores formed singly at the end of comparatively short conidiophores.3. The isolate from the other three host plantsCarum copticum L.,Peucedanum graveolens Benth. &Hook f. andFoeniculum vulgare Mill. is named asAlternaria umbellifericola sp. nov. and is a profusely sporulating species, forming long chains of spores with rudimentary beak.4. TheCoriandrum isolate (Alternaria poonensis) has a narrower temperature range (25–30° C) than theCarum isolate (20–35° C) for optimum sporulation.5. TheCoriandrum isolate is pathogenic toCarum but not toDaucus carota L.6. TheCarum isolate is pathogenic toDaucus carota but does not infectCoriandrum sativum L.7. TheCoriandrum isolate has a wider host range among the Umbelliferae than theCarum isolate.Part of the M.Sc. thesis submitted to the Poona University, 1964.  相似文献   

8.
BMP4 maintains self-renewal of mouse embryonic stem cells (ESCs) in collaboration with LIF. Here, we report the identification of a novel key BMP target gene, cochlin (Coch) in mouse ESCs. Coch can be significantly up-regulated by BMP4 specifically in ESCs but not in somatic differentiated cells, and this up-regulation is dependent on the BMP signaling mediators Smad1/5 and Smad4. Overexpression of Coch can partially substitute BMP4 to promote self-renewal of mouse ESCs together with LIF, whereas knockdown of Coch impairs self-renewal marker gene expression even in the presence of both BMP4 and LIF. Further studies showed that COCH could mimic BMP4 in repressing neural differentiation of mouse ESCs upon LIF withdrawal and the inhibitory effect of BMP4 on neural differentiation is compromised by Coch knockdown. Taken together, our data suggest that COCH is a part of the downstream target network of BMP signaling and serves as another important effector to fine-tune mouse ESC fates.  相似文献   

9.
The ontogeny of the flower and the fruit of the Macaronesian endemicCeballosia were investigated morphologically and anatomically by SEM and LM. The fruit does not break into four mericarps, but splits into two two-seeded carpids. Exo- and mesocarp wither after fruit-ripening and the endocarp constitutes the remaining outer wall. Within the stony endocarp tubular parenchymatic isles develop which are linked with the mesocarp. Subsequent disintegration pretends additional locules in the mature fruit. Similar pericarp formations are also found in someHeliotropium species but result from a different ontogeny. Therefore, although a close relationship ofCeballosia toHeliotropium is obvious, the taxon should be treated as a separate genus.Carpological investigations in theHeliotropioideae (Boraginaceae) 2. For part 1 seeHilger (1987).  相似文献   

10.
Pleistocene porcupine remains from China allocated toAtherurus sp.,Atherurus cf.macrourus andTrichys cf.fasciculata, and from Vietnam toAtherurus macrourus have been studied. These fossils have been compared with the type material of the PleistoceneA. karnuliensis Lydekker, 1886 from India and with the extant speciesA. macrourus (Linnaeus, 1758) andTrichys fasciculata (Shaw, 1801). As a result, all fossil specimens studied are allocated toA. karnuliensis.  相似文献   

11.
1. Interactions between multiple predators can modify prey risk and profoundly alter ecological community dynamics. Further, ontogenic prey size changes are known to mediate prey risk through refuge effects. Understandings of these biotic factors is important for robust quantifications of natural enemy effects on target species, yet their combined influence lacks investigation. 2. Functional responses were used to quantify the predatory impacts of Notonecta glauca (water boatman; Ng) and Gammarus pulex (river shrimp; Gp) towards four different larval instars of Culex pipiens in container-style habitats. Using conspecific pairs of predators, multiple predator effects (MPEs) of both predator species were examined across larval prey sizes, and prey preference tests were applied to examine prey selectivity across predator–prey body size ratios. 3. Both predators were able to feed on C. pipiens across their larval ontogeny; however, Ng consumed significantly more larvae than Gp. Functional responses of Ng were typically Type IIs, whereas Gp trended towards sigmoidal Type IIIs. Predation by pairs of Ng and Gp showed independent MPEs towards first-, third-, and fourth-instar stages (except predation by Gp at higher densities of fourth-instar) stages, whereas, for second-instar stages, Ng showed synergistic MPEs and Gp showed antagonistic MPEs. Both predators preferred late instar mosquitoes (Ng: fourth instar; Gp: third instar). These preferences reflected predator:prey weight–length ratios, showing that relative sizes of predators and prey are important factors in prey selectivity. 4. The results obtained in the present study demonstrate that MPEs, combined with intraspecific prey preferences, may modulate trophic interactions within ecosystems. Therefore, such effects should be increasingly considered to further the understanding of agent efficacies.  相似文献   

12.
Cynoglossopsis somaliensis H. Riedl, sp. nov., is described as a new species of the hitherto monotypic genusCynoglossopsis Brand which is closest related toCynoglossum L. but has to be included inBoraginoideae-Eritrichieae from the way the nutlets are attached to the gynobasis.
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13.
Summary A. According toMellon,Locke andShinn, the bacteriostatic action of sulfanilamide is due to the inactivation of (bacterial) catalase and the resulting accumulation of hydrogen peroxide. The probability of this theory is discussed. B. Catalase activity was studied by means ofPhotobacterium Fischeri, as an oxygen indicator. By adding hydrogen peroxide to the tested cultures of bacteria it has been demonstrated, that: I.Bacterium coli, Photobacterium Fischeri andStreptococcus haemolyticus (strainAronson) contain catalase. II. Sulfanilamide does not inactivate the catalase in blood. III. Sulfanilamide does not inactivate bacterial catalase nor does it affect the production of catalase in the growing culture containing the drug. So we have to conclude that the assumption of catalase inactivation to be the essential factor in sulfanilamide action on bacteria will not lead us to the solution of the problem. First communication:L. K. Wolff andH. W. Julius, Ann. de l'Inst. Pasteur62, 616, 1939.  相似文献   

14.
A fossil skull, Stw 53, from the Plio/Pleistocene of Sterkfontein, in South Africa, has been referred toHomo habilis Leakey, Napier, andTobias, 1964. Reappraisal of its putative hominine affinity reveals a closer resemblance toAustralopithecus africanus Dart, 1925. The skull, as reconstructed, is too small forH. habilis; with no indication of brain expansion overA. africanus; has a facial angle outside the hominine range, but identical with that ofA. africanus; and whose teeth are not elongated but display buccolingual expansion. Although it was found in the same strata (Member 5) as stone tools, there is no causal connection. It has been dated faunistically at 2–1.5 my BP, but due to an unconformity it is suggested that it could be older. In spite of its late date, Stw 53 shows no intermediate characters which could support a trend towardsH. habilis orA. robustus Broom, 1938. It may, therefore, represent a relict population ofA. africanus.  相似文献   

15.
Silene thebana Orph. exBoiss. is transferred as a subspecies toS. fabaria (L.)Sm., resulting in the new combinationS. fabaria (L.)Sm. subsp.thebana (Orph. exBoiss.)Melzh. The chromosome count of 2n = 24 is recorded for the first time for this taxon.Dedicated to Prof. DrK. H. Rechinger on the occasion of his 80th birthday, 16th October 1986.  相似文献   

16.
Tillandsia carminea is a new, morphologically and ecologically distinct species, related toT. stricta Solander, which occurs in the Serra dos Orgaos near Teresopolis, Brazil. It has been taken forT. rosea Lindley, but new investigations have shown thatT. rosea is a synonym toT. stricta and thatT. carminea is a good and distinct species.
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17.
Summary E. coli KB (Benzer) differs from other common laboratory strains in possessing a glycyl sRNA synthetase with a 50 to 100 times elevated K m for glycine. The degree of charging of glycyl sRNA in this strain can be increased by supplementing the growth medium with glycine. The altered enzyme has been used as a marker by which to map its structural gene. Linkage analysis of recombinants from uninterrupted matings, and cotransduction (80%) of the synthetase withxyl, indicate that this gene is located betweenxyl andmalt, close toxyl, at min 69.5 on the map drawn byTaylor andThoman (1964).  相似文献   

18.
A new species,Thomsonia sumawongii Bogner, is described from Thailand. Relationships toTh. napalensis and betweenThomsonia, Pseudodracontium andAmorphophallus are discussed.Allopythion hookeri Schott has to be eliminated as dubious.
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19.
Three species ofOcruranus Liu, 1979 are described from the Bastion Formation of North-East Greenland, of late Early Cambrian (middle Dyeran of North American usage) age, representing the youngest record of a genus originally described from the earliest Cambrian Meishucunian Stage of China. An accompanying species, tentatively assigned toXianfengella He &Yang, 1982, seems also to be present in South Australia in strata of late Early Cambrian (Botoman of Siberian usage) age, although also this genus was described originally from the Meishucunian.Ocruranus andXianfengella from China have been interpreted as possibly parts of coeloscleritophoran scleritomes, perhaps halkieriids, rather than individual molluscan shells. Their shell form is not typical of helcionelloids which otherwise dominate the Early Cambrian molluscan record, but conclusive evidence of affinity is not forthcoming from the Greenland records. New taxa:Ocruranus septentrionalis n. sp. andOcruranus tunuensis n. sp.   相似文献   

20.
Amorphophallus nicolsonianus species nova, with cylindrical or napiform corms, is the only representative of the sect.Rapyogkos in India. All the other hitherto known species of this region have globose or depressed globose corms. The new species is related to some Indochinese species and toA. hildebrandtii ( Engl.)Engl. & Gehrm. from Madagascar.  相似文献   

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