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1.
During swimming leg development, the number of setae present on the exopod and endopod of the bilobed bud, the transformed swimming leg with 1-segmented rami and the swimming leg with 2-segmented rami of copepods is analysed. For swimming leg 1, the most frequent number of setae on the presumptive rami of the bilobed bud is found at a higher percentage among copepod species than the most frequent number of setae for either the transformed swimming leg with 1-segmented rami or the swimming leg with 2-segmented rami. However, for swimming legs 2–4 the most frequent number of setae for the the transformed swimming leg with 1-segmented rami is found at a higher percentage of species than that on either the bilobed bud or the swimming leg with 2-segmented rami. Thus, in the cases of swimming legs 2–4, species with different numbers of setae on the presumptive exopod and endopod of the bud bilobed bud develop the same number of setae on the rami of the transformed swimming leg with 1-segmented rami. Increasing the number of species analysed is expected to make more robust the hypothesis that the number of setae on the transformed swimming leg with 1-segmented rami is conserved relative to the number of setae on the bilobed bud.  相似文献   

2.
Stoch  Fabio 《Hydrobiologia》2001,(1):525-531
The genus Diacyclops Kiefer, 1927 emend. Morton (1985) includes more than 100 species, widely distributed in all kinds of freshwater environments, and is the richest genus in the family Cyclopidae. Traditionally, Diacyclops species were defined according to differences in a few morphological characters; some characters (number of antennulary segments, segmentation pattern of swimming legs) are useful only in the separation of species groups, others (length of caudal rami and caudal setae) are highly variable even within the same population. During the study of the D. languidoides-group, minute morphological characters were used to differentiate between species (spinulation pattern and setation of antennary basis, setation and aesthetasc shape of male antennule, setation of mandibulary palp and maxilliped, shape of leg 4 basis) which allow to identify several valid species up to now concealed under the name `Diacyclops languidoides' (Lilljeborg, 1901). The coexistence of up to six congeneric species in the same sampling area: (a) supports the validity of the proposed taxonomic characters, (b) demonstrates that species richness may be highly underestimated in freshwater cyclopoid assemblages in absence of good taxonomic practice; and (c) requires an ecological explanation of species coexistence. The role of morphologically based taxonomy in order to solve general problems of distributional ecology and theoretical biology is explored.  相似文献   

3.
Human collagens of type I, III, IV, and V (CI, CIII, CIV, and CV) can be localized in different anatomic structures of the vessel wall. To investigate the role of vascular collagenous components in mural thrombus formation, the authors studied platelet adhesion to the wells of Falcon culture plates coated with: a) monomeric CI, CIII, CIV, and CV; b) fibrillar CI and CIII, and c) amorphous CIV and CV. On monomeric and amorphous CV, only initial attachment takes place, i.e. platelets bind to the surface without subsequent spreading. Platelet adhesion on monomeric and amorphous CIV proceeds more actively: the total level of adhesion is substantially higher than on CV, with up to 75% of adherent platelets spread out and single unspread platelets from suspension attached to the upper surface of spread platelets. On monomeric and fibrillar CI/CIII, formation of large multi-layer (thrombi-like) aggregates, with spread platelets at the basis, takes place along with processes characteristic for adhesion on CIV/CV. On the contrary, only fibrillar but not monomeric CI and CIII induce platelet aggregation in suspension. The data suggest that the ability of CI and CIII to induce platelet aggregation is fully conditioned by the genetic type of collagen and requires a simultaneous multivalent platelet-collagen interaction, which can be achieved by surface immobilization of collagen or formation of fibrillar structures in suspension.  相似文献   

4.
A new species of poecilostomatoid copepod, Hemicyclops spinulosus, is described from burrows of the ocypodid crab Macrophthalmus japonicus in an estuarine mud-flat in Tokyo Bay. The new species can be distinguished from its congeners by a combination of the segmentation and setation of first antenna, the ornamentation of maxilliped and the modified seta on the first segment of the endopod of legs 1–4. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

5.
Paranannopus trisetosus sp.n., P. singulosetosus sp.n., P. denticulatus sp.n., P. uniarticulatus sp.n., P. variabilis sp.n., P. kunzi sp.n. and Cylindronunnopus bispinosus sp.n. are described and classified to the three evolutionary groups within the genus Paranannopus. P. variabilis, P. kunzi and P. hicksi belong to the first evolutionary group with Enp P2-P4 3:3:2-segmented. All three species differ from each other and the closely related species in the setation of the swimming legs P1-P5 and to some extent in the segmentation of the Al. P. trisetosus belongs to the second group with Enp P2-P4 2-segmented, and it differs from the closely related P. atlanticus Coull in the setation of the segment 2 Exp P1, P4 and of the P5. P. singulosetosus, P. uniarticulatus and P. denriculutus represent the third evolutionary group with at most I-segmented Enp P2-P4. They differ from each other in the segmentation of the Enp P2-P4 and the setation of the swimming legs P2-P4 and to some extent in the segmentation of the Exp A2. Cylindronunnopus bispinosus differs from the closely related species C. elongatus (Becker et al. ) comb.n. in the setation of the P5. Updated keys are given for both genera. All species were collected at the Iceland-Faroe Ridge from depths between 435 and 2500 m.  相似文献   

6.
P. de Boer  R. M. Speed 《Chromosoma》1982,87(3):315-325
Meiosis of T70H/+, Ts(113)70H translocation trisomic male mice has been studied using C-banded preparations and 3H-thymidine autoradiography of the first meiotic division. Epididymal sperm counts and sperm morphology scores were also collected. As reported earlier, at the first meiotic division the translocation involved chromosomes 1, 13, 131 and 113 (twice) formed mainly three multivalent configurations: Chain III+II, CIV+I and CV. — The autoradiographic study indicated an abnormal, precocious spiralization pattern for the chromatin in CIV+I primary spermatocytes. These cells, occurring together with the CIII+II and CV configurations in recognizable groups, usually descending from single spermatogonial stem cells, are delayed through meiotic prophase. Both delay and disturbed chromosome spiralization in these cells are attributed to the uniform association of the univalent (I) chromosome 113 with the sex chromosomes during pachytene. Primary spermatocytes of the CIV+I configuration and those carrying a CV take longer to develop from metaphase I into secondary spermatocytes than does the CIII+II type. — In T70H tertiary trisomics with a similar chromosome imbalance, the majority of primary spermatocytes degenerates during the diakinesis-metaphase I stages of meiosis. Fertility is low in contrast to the translocation trisomics. Comparison between the two types leads to the conclusion, that trisomy per se reduces the size of the testes and that the univalent containing CIV+I primary spermatocytes, contrary to the almost uniformly 113 univalent carrying spermatocytes of the T70H tertiary trisomics are rescued by the neighbouring CIII+II and CV carrying cells to form normal secondary spermatocytes and morphologically normal sperm.  相似文献   

7.
We investigated the effects of a stable prostacyclin analogue, carbacyclin, on the interaction of platelets with collagen substrates differing in their ability to activate platelets: human collagens type I, III, IV and V (CI, CIII, CIV and CV), and commercial calf skin collagen type I (CSC). The total adhesion was measured using 51Cr-labelled platelets, and quantitative morphometry of adherent platelets was performed by scanning electron microscopy (SEM). Carbacyclin in the concentrations inducing a 10-fold rise in platelet cAMP did not affect the adhesion of platelets to weak substrates, CV and CSC, but reduced the adhesion to strong substrates, CIV (by 49%) and CI/CIII (by 78%), which stimulated massive spreading and formation of surface-bound aggregates respectively. Carbacyclin inhibited all morphological manifestations of platelet activation associated with adhesion: conversion of native discoid platelets to spherical ones on CSC; massive spreading on CIV; and aggregate formation on CI/CIII. Massive spreading and aggregation on a weak substrate (CSC) stimulated by arachidonic acid and thrombin was also inhibited by carbacyclin. Under the same concentration of agonists aggregation of platelets was more sensitive to the action of carbacyclin, than spreading. Strong collagen substrates CI, CIII and CIV, but not CV and gelatin, inhibited the carbacyclin-induced rise in platelet cAMP.  相似文献   

8.
A new genus and species of calanoid copepod belonging to the family of Ridgewayiidae is described from an anchialine cave on the small island of Badija, Croatia. In the new species Badijella jalzici, body length varies from 720-870 µm in both sexes. The prosome is 6-segmented, the female urosome is 4-segmented and 5-segmented in the male. The antennules are symmetrical and 26-segmented in the female, and 23-segmented on right side in the male, with two areas of geniculation. The caudal rami are symmetrical and longer than wide. The mouthparts and swimming legs 1-4 are identical in both sexes. The female fifth leg is biramous and symmetrical; the male fifth legs are strongly developed, asymmetrical, biramous on both sides, endopods 2-segmented and exopods 2-segmented and complex in structure.  相似文献   

9.
We investigated the effects of a stable prostacyclin analogue, carbacylcin, on the interaction of platelets with collagen substrates differing in thier ability to activate platelets: human collagens type I. III, IV and V (CI, CIII, CIV and CV), and commercial calf skin collagen type I (CSC). The total adhension was measured using 51Cr-labelled platelets, and quantitative morphometry of adherent platelets was performed by scanning electron microscopy (SEM). Carbacyclin in the concentrations inducing a 10-fold rise in platelets cAMP did not effect the adhension of platelets to weak substrates, CV and CSV, but reduced the adhesion to strong substrates, CIV and *by 49%) and CI/CIII (by 78%), which stimulated massive spreading and formation of surface-boud aggregates respectively. Carbacyclin inhibited all morphological manifestations of platelet activation associated with adhension: conversion of native discoid platelets to spherical ones on CSC; massive spreading on CIV; and aggregate formation on CI/CIII. Massive spreading and aggregation on a weak substrate (CSC) stimulated by arachidonic acid and thrombin was also inhibited by carbacyclin. Under the same concentration of angonists aggregation of platelets was more sensitive to the action of carbacyclin, than spreading. Strong collagen substrates CI, CIII and CIV, but not CV and gelatin, inhibited the carbacyclin-induced rise in platelet cAMP.  相似文献   

10.
The mitochondrial oxidative phosphorylation (OXPHOS) system consists of four electron transport chain (ETC) complexes (CI–CIV) and the FoF1-ATP synthase (CV), which sustain ATP generation via chemiosmotic coupling. The latter requires an inward-directed proton-motive force (PMF) across the mitochondrial inner membrane (MIM) consisting of a proton (ΔpH) and electrical charge (Δψ) gradient. CI actively participates in sustaining these gradients via trans-MIM proton pumping. Enigmatically, at the cellular level genetic or inhibitor-induced CI dysfunction has been associated with Δψ depolarization or hyperpolarization. The cellular mechanism of the latter is still incompletely understood. Here we demonstrate that chronic (24 h) CI inhibition in HEK293 cells induces a proton-based Δψ hyperpolarization in HEK293 cells without triggering reverse-mode action of CV or the adenine nucleotide translocase (ANT). Hyperpolarization was associated with low levels of CII-driven O2 consumption and prevented by co-inhibition of CII, CIII or CIV activity. In contrast, chronic CIII inhibition triggered CV reverse-mode action and induced Δψ depolarization. CI- and CIII-inhibition similarly reduced free matrix ATP levels and increased the cell's dependence on extracellular glucose to maintain cytosolic free ATP. Our findings support a model in which Δψ hyperpolarization in CI-inhibited cells results from low activity of CII, CIII and CIV, combined with reduced forward action of CV and ANT.  相似文献   

11.
An endoparasitic copepod is reported from the urinary bladder of a fish for the first time. Endoparasitic copepods on fish hosts are extremely rare and the impact of colonization of this novel microhabitat on the biology of the parasite is discussed. This curious association was reported from two different host families of Neotropical freshwater fishes, Erythrinidae and Cichlidae, collected from the Cristalino River, a tributary of the Araguaia River, in Brazil. The copepod is fully described using light and scanning electron microscopy. Urogasilus brasiliensis n. g., n. sp. represents a new genus and species of the family Ergasilidae and can be distinguished from other genera by its unique tagmosis, in which the fourth and fifth pedigerous somites and the genital double-somite are all fused to form an elongate trunk. The anal somite is the only free abdominal somite present. The pattern of leg segmentation is also unique, with legs 1 to 3 each having a 2-segmented endopod and leg 4 reduced to a single seta. The discovery of ovigerous female ergasilids in the urinary bladder of a fish is novel and this discovery represents a good model for further studies on the adaptations to an endoparasitic lifestyle.  相似文献   

12.
Common shrews display two types of Robertsonian (Rb) heterozygosity: simple (where CIII configurations are formed at meiosis I) and complex (which have longer meiotic chains or rings). Based on an analysis of large sample sizes (over 100) of MII cells per specimen, we estimated the non-disjunction frequency in seven Rb homozygotes and 21 complex Rb heterozygotes (CIV and CV) of Sorex araneus Linnaeus, 1758. The analysis showed high betweenindividual variability. The mean level of non-disjunction in homozygotes (2.01%) was significantly lower than in CIV and CV heterozygotes (4.27% and 5.78%, respectively). The study demonstrated that non-disjunction frequency in male CIV and CV heterozygotes was similar to that in simple heterozygotes in the common shrew.  相似文献   

13.
The development of all copepodid stages of a brackish calanoidcopepod Tortanus (Eutortanus) derjugini from western Korea isinvestigated. Homologies of segmentation and setation in adultcharacters are traced through all copepodid stages. The fourthand fifth pedigers are secondarily fused at the moult to theadult. Antennulary setation shows sexual dimorphism first atstage IV. The exopod of leg 1 is divided into two segments withoutaddition of any element at the moult to stage II, while an innerseta on the first segment is newly added at the moult to stageIII. This pattern differs from the basic pattern proposed forother copepods, in which the division of the exopod is precededby the formation of an element or both occur at the same time.In the fifth leg of the male some elements are suppressed duringthe final moult into the adult. The ontogenetic analyses indicatethat adult characters of some subgenera of Tortanus are expressedby their suppressions at the developmental phases. Suppressionof elements is important for the evolution of Tortanus.  相似文献   

14.
Johnsson  R. 《Hydrobiologia》2001,(1):431-440
Two new artotrogids are recorded from Madeira Island. A new species of Cryptopontius, associated with algae, differs from its congeners in the number of antennular segments, setation of the antennal exopod, setation and length of the maxillule lobes, and setation of both rami of the first and fourth legs. The second new artotrogid belongs to Dyspontius.It was associated with Gerardia savagliae Lacaze-Duthiers, 1864 (Cnidaria: Zoanthidea) and differs from its congeners in cephalothorax shape, siphon length and setation of the maxillule lobes.  相似文献   

15.
Metahuntemannia triarticulata sp.n., M. arctica sp.n. and M. bifida sp.n. arc described. M. triurficulata and M. arctica belong to the 'spinosa' group within the genus Metahuntemannia Smirnov. From the closely related species, M. triarticulata differs in the possession of 3-segmented Enp P3, M. arctica in the segmentation of the Al, and both new species in the setation of their swimming legs P1–P5. M. hifida belongs to the 'talpa' group within Metahuntemannia and differs from the closely related species in the setation of the swimming legs P2–P4. The species relationships and the phylogeny within the genus are discussed. All species were collected at the Iceland-Faroe Ridge from depths between 435 and 2500 m.  相似文献   

16.
In the course of a comparative analysis of the species included in the copepod genus Monstrillopsis Sars, a new species of the genus was discovered. The new species, Monstrillopsis chilensis n. sp., was found in a plankton sample collected in coastal waters off central Chile in the Southeastern Pacific. The adult female is similar to females of the type species M. dubia Scott and related forms but differs from its congeners by a combination of characters including: (1) a pair of small cephalic processes present between bases of antennules; (2) deep corrugations present on proximo-lateral surface of fifth pedigerous somite; (3) exopodal lobe of fifth leg not distally elongated; and (4) endopodal lobe of fifth legs short. This is the first record of the genus in the Southeastern Pacific and the second record of any monstrilloid in Chile. A comparative analysis of the species assigned to Monstrillopsis allowed a clarification of the generic characters and limits. The most important apomorphic characters in the genus are the presence of four caudal setae and modifications of the male antennule; other potentially useful characters are the pattern of antennule segmentation and the uniform presence of a reduced inner lobe of the fifth leg. The female of Monstrilla reticulata Davis should be retained in Monstrilla, but the purportedly conspecific male is probably a Monstrillopsis. Monstrillopsis ciqroi Suárez-Morales and M. angustipes Isaac should be transferred to Monstrilla. Haemocera filogranarum Malaquin is probably a species of Monstrillopsis. Monstrillopsis zernowi is tentatively retained in this genus as an aberrant form. A key for the identification of the species of this genus is included.  相似文献   

17.
The occurrence and age structure of an Antarctic ice-associated copepod, Paralabidocera antarctica, were investigated using a light trap under fast ice near Syowa Station. Sampling was carried out between May and November 1984. P. antarctica were found in high numbers in the traps on 1-2 and 23-24 November. No copepods were found in any trap between May and October. The timing of the absence and occurrence of P. antarctica in the light traps coincided with their ice-dwelling and pelagic life-phases. More than 99% of the total catch was taken in the traps set in the water immediately below the ice in both sampling periods on 1-2 and 23-24 November. The age structure of the P. antarctica populations consisted of copepodite stage III (CIII) to adult and IV (CIV) to adult, respectively. The earlier population was dominated by CIV and CV and the later one by adults. The behavior pattern of P. antarctica is suggested to be controlled by phototactic and thigmotactic traits, and their habitat change from sea ice to seawater may occur by trade-off between two behavioral traits with the acquisition of swimming ability.  相似文献   

18.
A new genus and species of copepod, Mihbaicola sakamakii n. g., n. sp., belonging to the siphonostomatoid family Hatschekiidae, is described based on the females collected from inside the tissue of the branchiostegal membrane in three species of the groupers, Epinephelus fasciatus (Forsskål) (type-host), E. merra Bloch and Cephalopholis leopardus (Lacépède), collected off Okinawa-jima Island and Iriomote-jima Island, Ryukyu Archipelago, North Pacific Ocean. The new genus can be distinguished from other hatschekiid genera by a combination of the following characters in the female: the head is composed of the cephalosome and the pedigerous somite; the cephalothorax is expanded into a pair of posteroventral lobes carrying leg 1; legs 1 and 2 are biramous and composed of the protopod and both rami are 2-segmented; leg 3 is absent; and leg 4 is represented by a rounded lobe with a chitinous pointed apical process.  相似文献   

19.
20.
Cellulases of Sporotrichum cellulophilum, CII1, CII2, CII3, CII5, CIII1, CIII2, and CIV1 were purified to homogeneity by column chromatographies and preparative electrophoresis. The specific activity of CII3 was the highest (100 units/mg), while the activities of CII5, CIII1, and CII2 were low (12–17 units/mg). The molecular weight of CII2 was 19,000, while those of the others ranged from 46,000–63,000. All the cellulases were glycoproteins except for CII2. Three monoclonal antibodies (Mab CII11, Mab CII12, and MabCII13) were prepared against CII1, and Mab CIV11 against CIV1. From the immunological reactivities, it was found that CII1, CIII2, and CIV1 had a common antigenic site recognized by Mab CII11, Mab CII12, and Mab CII13, while CII12 and CVI1 had a different antigenic site that was recognized by Mab CIV11, MabCII11, MabCII12, MabCII13, and MabCIV11 did not react with CII2, CII3, CII5, and CIII1. The classification of these cellulases was discussed.  相似文献   

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