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1.
The expression of 4, 6, and 1 integrin subunits has been investigated on somein vitro andin vivo murine metastatic variants derived from Lewis lung carcinoma (3LL). By the use of monoclonal antibodies which recognizes different epitopes of 6, 1, and 4 subunits we demonstrate that 6 and 1 subunits are expressed in all metastatic variants of 3LL irrespective of their metastatic potential, whereas 4 subunit is expressed only in highly metastasizing cells of 3LL. Northern blots of different metastatic variants probed with 1 and 4 subunits demonstrate thata) significant amounts of 1 mRNA were detected in all metastatic variants of 3LL;b) mRNA corresponding to the described entire coding sequence of 4 subunit is expressed only on highly metastasizing cells of 3LL. We conclude that 4 subunit is specifically expressed in highly metastasizig cells of 3LL while is undetectable in lower metastasizing ones.  相似文献   

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Beobachtungen über Nest und Nestbautechnik von Winter- und Sommergoldhähnchen(Regulus regulus, R. ignicapillus) im Freiland und in Volieren zeigen:
1.  Die Neststandorte von WG und SG gleichen einander, ihre Brutreviere können sich überlappen.
2.  Das Nest zeigt 3 deutlich getrennte Schichten. Die Außenschicht besteht aus Spinnstoff, Moos, Flechten — Moose (bei WG auch Flechten) bilden die Mittelschicht, Federn und Haare die Polsterung. Hochgebirgsnester weisen gegenüber Mittelgebirgsnestern einen Materialzuwachs besonders in der Mittel- und Polsterschicht auf.
3.  Der Nestbau dauert ca. 20 Tage, Zweitnester können rascher entstehen.
4.  Die Bautechnik wechselte mit fortschreitendem Bau. Baubewegungen für Grundgerüst, Rohbau und Polsterung waren verschieden. 14 (WG) bis 15 (SG) Baubewegungen konnten unterschieden und den 3 Bauphasen zugeordnet werden: a) Bei der Anlage des Grundgerüsts wurden die Tragästchen mit Spinnstoff bedeckt/umwickelt. Die Gespinste wurden dabei abgerieben, verspannt, und beim Außen säubern mit dem Ast fest verbunden. b) Der Rohbau entstand durch weiteres Einbringen von Spinnstoff und zunehmend häufiger Moosen/Flechten. Die Wände wurden durch Wegschieben (bzw. Einvibrieren) der Baustoffe geformt und gefestigt, beim WG auch maskiert, der Boden durch Unten säubern geschlossen. Zuletzt eingestopfte Moose der Mittelschicht wurden verstrampelt, der Rand durch Verstreichen verstärkt und geglättet. c) Die Mulde wurde mit Federn/Haaren ausgekleidet, das Polstermaterial durch Strampeln geordnet, sperrige oder auffallende Polsterstoffe wieder entfernt. Gleichzeitig wurde der Nestrand eng zusammengezogen, die Tragästchen von Spinnstoffresten gesäubert; SG verdeckten durch aufgesteckte Federn die Nestmulde.
5.  Die beiden Arten stimmten auch in ihrer Nestbautechnik weitgehend überein. Auffälligster Unterschied war, daß sich SG am Nestbau nicht beteiligen und nur begleiten. Doch führten juvenile beider Arten fast alle Baubewegungen spielerisch aus. Unterschiede gab es auch in den Baubewegungen der : SG vibrierten beim Wegschieben (2 e) und Randverstreichen (2 g) und verdeckten die Mulde durch aufgesteckte Federn.
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Ueda T  Naoi H  Arai R 《Genetica》2001,111(1-3):423-432
In bitterlings (Acheilognathinae) C- and Ag-banding karyotypes of 6 species-subspecies collected in China and South Korea were analyzed. The chromosomal constitution of 2n=46 (4SM+42ST) in Rhodeus atremius fangi was quite different from that of 2n=48 (8M+20SM+20ST) in other species-subspecies in Rhodeus. It was concluded from the analysis of banded chromosomes that the increase in number of ST during the karyotype change from 2n=48 to 2n=46 was achieved by a series of pericentric inversions from 24 M-SM to 24 ST, and the decrease in the diploid number was caused by an additional tandem fusion of 4 ST chromosomes, forming a new ST pair in the 2n=46 karyotype. The karyotype of Tanakia koreensis, T. signifer, and Acheilognathus macropterus is 2n=48 (8M+20SM+20ST), 2n=48 (8M+20SM+14–16ST+4–6 A), 2n=44 (14M+16SM+14ST), respectively. In R. ocellatus ocellatus, T. koreensis, T. signifer and A. macropterus, karyotype changes from 2n=48 to 2n=44 due to centric fusion and inversion have also been estimated. It was suggested that C-banding heterochromatin was greatly concerned with the karyotype evolution in bitterlings.  相似文献   

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Hybridizations ofElymus nutans andE. jacquemontii were carried out with one species ofPseudoroegneria (S genome), and 20Elymus species, each containing either of the SH, SY, SYH, or SYW genomes. Chromosome configurations were analysed at metaphase I of the two target taxa and their interspecific hybrids. It is concluded that (i)E. nutans is an allohexaploid containing the SYH genomes, andE. jacquemontii is an allotetraploid having the SY genomes; (ii) the genomic affinity is associated with the geographic distance between the species studied; (iii) minor genomic structural rearrangements have occurred within the hexaploid taxon ofE. nutans.  相似文献   

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One cultivar (GR876) and two advanced Ohio soft red winter wheat lines (OH413 and OH414), with Kavkaz in their pedigrees, were examined for the presence of the Kavkaz, 1RS/1BL rye/wheat chromosome translocation. Another advanced line (OH416), with Amigo in its pedigree, was examined for the presence of the Amigo, 1RS/1AL translocation. Only two satellited chromosomes were observed in most mitotic root-tip cells from GR876, OH413, and OH414, compared to four in most cells from OH416. Heteromorphic bivalents were observed in most PMCs from hybrids produced by crossing GR876, OH413, and OH414 as females to Chinese Spring. No heteromorphic bivalents were observed in PMCs from OH416 x Chinese Spring hybrids. When GR876 and the Ohio lines were hybridized with Chinese Spring dimonotelosomic-1B, telosomic trivalents, consisting of the short- and longarm telosomes paired with chromosome 1B, were only observed in PMCs from 43-chromosome hybrids involving OH416. The long-arm telosome paired with the translocation chromosome, while the short-arm telosome remained unpaired in all other 43-chromosome hybrids. Separation of gliadin proteins from GR876 and the Ohio lines by PAGE revealed that secalin bands for GR876, OH413, and OH414, migrated similarly to the secalins for Kavkaz. Bands for OH416, identified as possible secalins, migrated similarly to those for Amigo. Cultivar GR876 and advanced Ohio soft red winter wheat lines OH413 and OH414 carry the Kavkaz translocation, while OH416 carries the Amigo translocation.Communicated by K. Tsunewaki  相似文献   

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Borges AR  Gaspar VP  Fernandez MA 《Genetica》2000,108(1):101-105
The mitotic chromosomes of Bradysia hygida(Diptera:Sciaridae) neuroblast cells are described together with their morphometric data. Giemsa-stained neuroblast chromosomes from female and male larvae confirm the chromosome number of this species, 2n=8 (XX) and 2n=7 (XO), respectively. The karyotype assembly reveals two metacentric autosomic pairs, the A and B chromosome; a subtelocentric, the C chromosome, the smallest one; and a sexual unequal metacentric pair, X chromosome, in female karyotype and a one sexual metacentric X chromosome in male. The implications of the unequal X chromosome pair are discussed.  相似文献   

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Interspecific hybridizations were carried out between the two tetraploidsElymus caucasicus andE. longearistatus, and 23 tetraploids and hexaploids ofElymus containing SH, SY, SYH, and SYW genomes and representing various geographical regions. Meiotic pairing was studied in the two target species and their hybrids. It is concluded from this study that (i) interspecific hybridization is fairly easy to perform although strong reproductive barriers exist between the species; (ii)Elymus caucasicus andE. longearistatus are allotetraploids, and share the diverged SY genomes; (iii) the divergence of SY genomes is correlated with the geographic distance between theElymus spp. studied.  相似文献   

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Experiments on the European earwig (Forficula auricularia L.) were made determine the efficiency of prey capture and defence reactions of the damson-hop aphid (Phorodon humuli (Schrank)).The older the earwig the more efficient was its search for aphids. Adult aphids waxed early earwig instars successfully. Young earwigs did not choose but encountered and captured young aphids more successfully than older ones, allowing older aphids to reproduce successfully.  相似文献   

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The chromosome number in the damselflyEnallagma cyathigerum (Charp.) is 2n =27, 2n =28, n =14 (13). The sex determining mechanism is XX-XO, the X segregates postreductionally in the male.  相似文献   

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Petitpierre E  Garnería I 《Genetica》2003,119(2):193-199
The chromosomes of ten species of Cyrtonus and the genome sizes of six are surveyed. Among the total of 15 chromosomally studied species, 11 have 2n=28 chromosomes and a 13+Xyp male meioformula, three have 2n=40 and 19+Xyp and one 2n=46 and 22+Xyp. All but one species with 28 chromosomes show only metacentric or submetacentric chromosomes, whereas the species with 40 and 46 chromosomes display some telocentrics or subtelocentrics, that are probably derived from the former by centric fissions. However, since the number of major chromosome arms is strikingly higher in these latter species (NF=70 and 78) than in the 28-chromosome species (mostly NF=56), other chromosomal rearrangements such as pericentric inversions or heterochromatin accretions could also be involved. The genome sizes display a narrow range, from 1C=0.6–1.22pg, and they are not significantly correlated with the chromosome numbers. Some possible factors implied in the rough chromosomal evolution of Cyrtonus are discussed in relation to a few other genera of the subfamily Chrysomelinae.  相似文献   

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1.  Action potentials of the mesothoracic tympanic organ's two receptor units (Al and A2) were recorded extracellularly. The impulse activity of both receptor units rises beyond resting activity when stimulated by airborne sound.
2.  The time course of the excitation of both receptor units appears to be phasic-tonic (Fig. 4).
3.  The influence of stimulus intensity and its time course on the excitation of both receptor units was studied (Figs. 5–8).
4.  The threshold curves of the receptor units Al and A2 for airborne sound were determined in the frequency range between 0.3 to 20 kHz. The two receptor units differ. Receptor unit Al shows a distinct threshold minimum, whereas the threshold curve of the less sensitive receptor units A2 appears more flat (Fig. 9).
5.  The threshold curves of the receptor units on the left body side differ from those on the right. The threshold minimum of unit Al left is absolutely lower than that of Al right and lies at higher frequencies (Fig. 10).
6.  As observed under the light microscope, vibrations of the organ's base and bulb differ from one side of the body to the other (Fig. 11).
7.  Removing the bulb influences the mode of oscillation of the base as well as the threshold curves of the receptor units.
8.  A hypothesis is proposed regarding the function of integumentary structures on the membrane in stimulus transformation.
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Contrary to the generally accepted life history theory regarding sequential hermaphroditism (size-advantage model), we have recently identified mini males in Lythrypnus dalli, the bluebanded goby. These are small (female-sized) fish that appear male based on their external genitalia. We investigated the reproductive anatomy and demography of these mini males. Based on their small size and the sexual plasticity of this species, we expected that mini males are not actually reproductively functioning males. However, when we examined their gonad anatomy, with particular attention to the male-typical accessory gonadal structure (AGS), we found that mini males have gonads that are comparable to those of nesting males in relative size and the percentage of tissue that is male (testicular and AGS). Although this is contradictory to theories of sperm competition in alternative male phenotypes, reproductive strategies of these two types of males were clearly distinguishable based on their AGS content – as described in other examinations of differing ejaculate quality in alternative male phenotypes in the Gobiidae. Regular sampling of the L. dalli population showed that mini males make up a small fraction of the small size classes and that as the breeding season progressed, mini male frequency decreased and standard length increased significantly – thus allowing us to discuss their role within the social system. Based on these findings as well as comparisons with other species with multiple male phenotypes, we can begin to categorize L. dalli males as either bourgeois or parasitic, primarily based on their secondary sex characteristics and AGS contents.  相似文献   

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The angular distribution of the optical axes of the ommatidia in the eyes of waterstriders (Gerris lacustris) has been investigated using antidromic illumination.
1.  Each eye contains about 920 ommatidia arranged in approximately 40 nearly horizontal rows (Figs. 5, 6).
2.  There is an acute zone (visual streak) of ±5° around the eye equator with high vertical resolution (Fig. 9).
3.  The horizontal interommatidial angle oh varies little with altitude and is in the frontal parts of the eye equal to the (horizontal) interrhabdomere angle rh (Fig. 10).
4.  Above and below the visual streak the eye is adapted to the perception of relative height or depth constancy (Fig. 13).
5.  Reconstruction of the viewing directions of the rhabdomeres in the visual streak reveals that characteristic groups of rhabdomeres in different ommatidia coincide in their receptive fields. Optical prerequisites for two types of neural superposition can be found: one of medium neural summation but highest sampling frequency, the other of highest neural summation at the cost of resolution (Fig. 11).
6.  The correspondence of the limits of resolution due to diffraction and finite sampling frequency is discussed.
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