A chromosome study ofSchistocephalus solidus (Müller, 1776) (Cestoda: Pseudophyllidea)

Analysis of Giemsa-stained metaphase plates of plerocercoids ofSchistocephalus solidus revealed the mode diploid number of chromosomes for this species as 2n=18. Chromosome pairs 1, 5, 6, 8 and 9 are metacentric, pairs 2, 4 and 7 are subtelocentric, and pair 3 is subtelocentric to acrocentric. The karyotype is characterised by mean absolute chromosome length between 1.9 and 5.9 m and a total chromosome length of the haploid complement of 32 m. A comparison with other known karyotypes of related species of pseudophyllidean cestodes was made.     

Comparative chromosomal studies on two minnow fish, Phoxinus phoxinus (Linnaeus, 1758) and Eupallasella perenurus (Pallas, 1814); an associated cytogenetic-taxonomic considerations

The present work provides new data on the banding pattern of two cyprinid fish species Phoxinus phoxinus and Eupallasella perenurus from Poland. C-banding, silver-staining (Ag), and fluorescent staining with chromomycin A₃ techniques were used to describe the karyotypes. Both of the species karyotypes of 2n=50 were characterised by one pair of acrocentric chromosomes, the largest in the set, and by two pairs of NOR-bearing chromosomes. In the chromosome set of Ph. phoxinus Ag-stained NORs were located on telomeres of two metacentric and two submetacentric chromosomes, but in most metaphases only one of the two homologous was observed. The karyotype of E. perenurus was characterised by Ag-NOR regions at a telomeric position on the shorter arm of two submetacentric chromosome pairs. In most metaphases only three NOR-bearing chromosomes were observed. In both investigated species the location of the A₃ positive signals corresponded with the location of Ag-stained NORs and these sites were associated with heterochromatin shown as C-bands. The results of cytogenetical studies on other related, mainly the North American phoxinins, species are compared and discussed.     

Cytotaxonomy and karyotype evolution inPhleum sect.Phleum (Poaceae) in Poland

Three taxa are distinguished in the sectionPhleum Griseb. in Poland:P. nodosum (2n = 14),P. pratense (2n = 42), and the third one unformally named hereP. commutatum (2n = 14). It corresponds morphologically toP. commutatum Gaud. reported as a tetraploid taxon (2n = 28) from other geographic regions. Giemsa C-banded karyotypes of these three taxa help clarify the taxonomic status ofP. commutatum and the origin of the hexaploidP. pratense. It is suggested that changes in the amount of telomeric heterochromatin played an important role in the evolution ofPhleum karyotypes.     

Notes on chromosomes of ten species of the genus chrysolina mots. (Coleoptera:Chrysomelidae)

SixChrysolina species from Catalonia and the Canary Islands (Spain), viz.americana, gemina, femoralis, cerealis, menthastri andpolita, have similar diploid karyotypes of 24 (sub)metacentric chromosomes, and show Xy sex-determining system.C. banksi andobsoleta have 2n ()=23; their karyotype is presumably derived from that of the former group by loss of the y chromosomes. InC. haemoptera andC. carnifex 40 elements appear in the diploid set. It seems that 2n=24 is the most frequent number in theChrysolina. Higher chromosome numbers have possibly originated through centric fissions, as the acrocentric shape ofC. carnifex chromosomes seems to suggest. The 2n=23 and 24 species feed onLabiatae, while the two higher chromosome number species are associated with plants belonging to other families.     

Chromosome localization and gene synteny of the major histocompatibility complex in the owl monkey,Aotus

Rodent cells were hybridized with owl monkey (Aotus) cells of karyotypes II, III, V, and VI. Aotus-rodent somatic hybrid lines preferentially segregating Aotus chromosomes were selected to determine the chromosomal location of the major histocompatibility complex and other genes with which it is syntenic in man. Based on correlation between concordant segregation of the chromosome as visualized by G-banding and expression of the Aotus antigens or enzymes in independent Aotus-rodent hybrid clones, we have assigned Aotus gene loci for the MHC, GLO, ME₁, SOD₂, and PGM₃ to Aotus chromosome 9 of karyotype VI (2n=49/50), chromosome 10 of karyotype V (2n=46), and chromosome 7 of karyotypes II and III (2n = 54 and 53). On the basis of banding patterns we previously postulated that these chromosomes of the different karyotypes were homologous. The gene assignments reported here provide independent evidence for that hypothesis. Aotus chromosomes 9 (K-VI), 10 (K-V), and 7 (K-II, III) are homologous to human chromosome 6 in that they all code for the MHC, GLO, ME₁, SOD₂, and PGM₃. The structural differences between these homologous chromosomes probably resulted from a pericentric inversion.Abbreviations used in this paper MHC major histocompatibility complex - HLA human lymphocyte antigen - PGM3 phosphoglucomutase-3 - ME₁ cytoplasmic malic enzyme-1 - SOD₂ superoxide dismutase-B - GLO glyoxalase 1 - OMLA owl monkey leukocyte antigens - K karyotype - ₂-M ₂-microglobulin - DMEM Dulbecco's modification of Eagle's medium - PEG polyethylene glycol - HAT hypoxanthine, aminopterin, and thymidine - KC1 potassium chloride - G-band-trypsin Giemsa band     

Cytotaxonomy of antarctic teleosts of the Pagothenia/Trematomus complex (Nototheniidae,Perciformes)

Summary The interspecific relationships and taxonomy of 12 antarctic coastal Nototheniids (the Pagothenia/ Trematomus complex) are still under discussion. Here we present karyological data on eight species in hope that further cytogenetic data can help to clarify phylogenetic problems. Pagothenia bernacchii (2n = 48) has a generalized karyotype which has not developed heterochromosomes. P. hansoni, P. borchgrevinki and Trematomus newnesi share very similar karyotypes with 2n = 46 for females and 2n = 45 for males. The difference between sexes is probably due to the development of a multiple sex-chromosome system with a neo-Y, typical of males, which originated from a centric fusion of an autosome (now X₂) with an undifferentiated Y. The chromosome morphology of the three species seems to be related to that of P. bernacchii. T. nicolai (2n = 58, 57) has a karyotype numerically and morphologically divergent from that of the above species; T. nicolai males may have developed a neo-Y through a tandem translocation. T. pennellii (2n = 32), T. loennbergii (2n = 28; 2n = 30 in a single female) and T. eulepidotus (2n = 24) show karyotypes with progressively fewer chromosomes but with an increasing number of large, bi-armed chromosomes. Such a symmetrization process is generally found in advanced poikilothermic Vertebrates and the three species of Trematomus could therefore be considered as karyologically derived. However, parallelism in the karyotype differentiation producing convergence in the chromosome morphology of distantly related species cannot yet be excluded.     

Stability of a multiple X chromosome system and associated B chromosomes in birch aphids (Euceraphis spp.; Homoptera: Aphididae)

Autosomal dissociations are a common feature of aphid karyotype evolution, but multiple X chromosome systems are rare. Birch-feeding aphids of the genus Euceraphis, however, have X₁X₂O males as a general rule, X₁ being always much larger than X₂. Only one species has XO males, and this condition appears to be secondary. Most Euceraphis karyotypes also have one or more, usually heterochromatic, elements that occur in the same numbers in both males and females, yet behave like X chromosomes at male and female meiosis I. They appear to be supernumerary, non-functional X chromosomes, although showing greater within-species stability in size and number than typical B chromosomes. Euceraphis gillettei forms a separate group within the genus and feeds on alders (Alnus species), yet has a similar system, and the two most closely related genera, Symydobius and Clethrobius, also have additional chromosomal elements possibly representing non-functional X chromosomes. Thus the multiple X chromosome system in these aphids seems to be a primitive condition.     

Nomenklatur,Chromosomenzahlen und Evolution vonArabis auriculata Lam.,A. nova Vill. undA. verna (L.) R.Br. (Brassicaceae)

Zusammenfassung Auf Grund des Holotypus im Herbarium P-LA wird der NameArabia auriculata Lam. als korrekter Name für die am weitesten verbreitete Species der SectionAlomatium DC. emend. O. E.Schulz wieder eingeführt, als deren Typusart sie zugleich vorgeschlagen wird.A. auriculata Lam. 1783 wurde in letzter Zeit fälschlich in europäischen Floren mit dem jüngeren Synonym A. recta Vill. 1789 belegt und in vorderasiatischen Floren A. nova Vill. 1779 genannt.A. nova Vill. ist jedoch eine europäisch-submediterrane Art, die nicht mitA. auriculata Lam. conspecifisch ist. A. auriculata undA. nova sind diploid (2 n=16),A. verna ist tetraploid (2 n=32, diese Zahl wird erstmals veröffentlicht). A. auriculata undA. nova sind vorwiegend autogam,A. verna ist ebenfalls selbstkompatibel und trotz ihrer auffälligeren Blüten fakultativ autogam. Die drei wärmeliebenden Arten sind normalerweise einjährig, manchmal jedoch auch zweijährig. Als Einjährige sind sie in der Gattung als abgeleitet anzusehen.

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Nomenclature, chromosome numbers and evolution ofArabis auriculata Lam.,A. nova Vill., andA. verna (L.) K.Br. (Brassicaceae)

Summary Based on its holotype in the herbarium P-LA the nameArabis auriculata Lam. 1783 is re-established as the correct name of the widespread annual species, which was falsely called A. recta Vill. 1789 in recent European floras, and A. nova Vill. 1779 in recent floras of Western Asia. It is shown that A. nova Vill. refers to a European species of the submediterranean region, which is not conspecific withA. auriculata Lam. A. auriculata Lam. is proposed to be the lectotype ofArabis L. sect.Alomatium DC. emend. O. E.Schulz, comprising the species discussed here. A. auriculata andA. nova are diploids (2 n=16),A. verna is a tetraploid (2 n=32); the latter chromosome number is reported here for the first time. A. auriculata andA. nova are predominantly self-fertilizing,A. verna (though having more conspicuous flowers) is self-compatible and thus facultatively autogamous as well. The three thermophilous species are normally annual, only sometimes biennial. As annuals they are to be regarded as evolutionary derived within the genusArabis.

     

Über eine menschenpathogene,aus Lungenveränderungen gezüchtete neue Spezies vonPeyronellaea

Zusammenfassung Aus Granulomen der Lunge einer 49jähr. Frau konntePeyronellaea n. sp. in Reinkultur isoliert werden. Aufgrund vergleichender mykologischer Untersuchungen vonPeyronellaea glomerata (Cda.) (Goidanich) u.Peyronellaea hominis (Agostini etTredici)G. Goidanich mit dem von uns isolierten Stamm wird letzterer auf Vorschlag vonWesterdijk als Spezies nova beschrieben. Mykologische Daten werden in Einzelheiten angeführt. Nach intraperitonealer Einimpfung erweist sich der Stamm für weisse Mäuse als fakultativ pathogen. Es wird kurz auf die im Schrifttum aufgeführten Mitteilungen von Peyronellaeose eingegangen.

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Summary From granules in the lungs of a 49-year-old womanPeyronellaea n. spec. was cultured. The isolated fungus was compared with cultures ofPeyronellaea glomerata (Cda.) G. Goidanich andPeyronellaea hominis (Agostini et Tredici) G. Goidanich and as suggested by Westerdijk, described as species nova. Mycological characteristics are described. Cultures intraperitoneally injected into mice produce sporadic lesions in the visceral organs. A summary of available literature is given.

     

Kritsche Betrachtungen zur Nomenklatur argentinischer Wildkartoffeln

Summary Continuing the critical publications on the nomenclature of the Argentine wild potatoes, set on in 1956, now the results of 5 years' studies of the seriesAcaulia are discussed. This series is to be found in the highlands of the Cordilleras and its vegetation limit is at about 4700 m above sea-level. The frost-resistance ofS. acaule andS. aemulans is remarkably high (up to minus 10°). ForS. acaule cytological determinations have proved again the already known number 2n=48, besides this in the province of Jujuy a species with 2n=36 has been found, being probably a hybrid ofS. acaule andS. alticolum. This species with 36 chromosomes is increasingly spreading in certain arid areas in an altitude of 4000 m. ForS. aemulans the chromosome number 2n=24 is published for the first time. Reciprocal crosses under greenhouse conditions betweenS. aemulans (2n=24) andS. acaule (2n=48) showed no success. In opposition to the view ofHawkes the author insists onS. aemulans being a good species, endemical for the arid mountains of Famatina and Ambato in the provinces of La Rioja and Catamarca. Having been collected in 1907 for the last time, nowS. aemulans has anew been found by the author in the Famatina mountains.As toS. acaule and its numerous varieties and related species the author holds the following opinion: The termsS. depexum, Schreiteri, punae, subexinterruptum, checcae, caulescens, chorruense established byBitter, Bukasov, Juzepzuk, andHawkes, are superfluous, the real range of variability is moreover much greater. To illustrate this point of view some examples were set.By its valuable resistance-genes againstRhizoctonia, frost, and Virus,S. acaule, at present, has gained considerable importance for plant breeding. For this reason we think it the more necessary to elucidate the systematical and cytological problems of the whole SeriesAcaulia.

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Mit 8 Abbildungen     

Karyosystematics of thePhleum alpinum polyploid complex (Poaceae)

The karyotypes of three taxa from thePhleum alpinum group of sect.Phleum (P. alpinum subsp.rhaeticum, 2n = 14,P. commutatum, 2n = 28, and informally namedP. commutatum, 2n = 14) were investigated by Giemsa C-banding. The overall similarity of diploid genomes suggests thatP. alpinum subsp.rhaeticum andP. commutatum are closely related — their karyotypes vary only with respect to their average amounts of telomeric heterochromatin. TheP. commutatum genome contains less telomeric heterochromatin than the genome ofP. alpinum subsp.rhaeticum, but in theP. alpinum group as a whole almost fluent transition between low (1.5%) and high (25.5%) amounts of telomeric heterochromatin was observed among populations. In the karyotype of tetraploidP. commutatum, seven distinguishable chromosome types were observed. Each of them is represented at somatic metaphase by four chromosomes. C-band structure of karyotype and average amount of telomeric heterochromatin suggest that this taxon has originated from hybridization between two related diploid forms of theP. commutatum — P. alpinum complex.     

The karyotype ofLimnobium spongia (Hydrocharitaceae)

The somatic chromosomes ofLimnobium spongia have been studied for the first time. Its number is 2n = 24; the karyotype is composed of 5 m pairs + 3 sm pairs + 4 st pairs. Pairs 3 and 11 bear microsatellites. Results are compared with previous chromosome reports for the family, mainly as regards the taxonomic status ofLimnobium versusHydromystria; our findings seem to support the point of view of those who favour the independence of both generic entities.The first author is member of the Carrera del Investigador (CONICET, Argentina) and the second one fellowship from the same institution.     

Giemsa C-banded karyotypes of some diploidArtemisia species

Detailed C-banded karyotypes of eight diploidArtemisia species from three different sections are reported together with preliminary observations on three additional related diploid species. In the majority, the overall amount of banding is relatively low. Bands are mostly confined to distal chromosome regions; intercalary banding is virtually absent and centromeric heterochromatin is also scarce. With the exception ofA. judaica there is in general great uniformity in karyotype structure but considerable interspecific variation in total karyotype length (and hence DNA content) ranging from 44 µm inA. capillaris (2n = 18) to 99 µm inA. atrata (2n = 18).A. judaica (2n = 16; total karyotype length 97 µm) was distinguished by its karyomorphology, with one large non-banded metacentric chromosome pair and 7 pairs of smaller terminally banded meta- or submetacentric chromosomes.     

Chromosomes of Syrphidae

In this report the karyotypes of 54 species of the tribe Milesiini and of four species of the tribe Myoleptini are described in detail with illustrations and idiograms. These species belong in the genera Lejota, Myolepta, Blera, Calliprobola, Criorhina, Hadromyia, Milesia, Somula, Sphecomyia, Spilomyia, Syritta, Temnostoma, Tropidia and Xylota. Six species have 2n = 8 chromosomes, 35 have 2n = 10 (including Xylota nemorum which has about 20 extra microchromosomes in some specimens), 15 have 2n = 12, one has 2n = 14, and Somula decora has 2n = 10 large chromosomes plus about eight microchromosomes. The mean total complement length (TCL) for 347 complements analysed in these tribes was 53.7 but there is great variation between TCL's of complements analysed even from a single fly. Karyotypes of species of Myolepta in the Myoleptini resemble in certain respects those of species of Tropidia in the Milesiini. Our observations support Currran's transfer of Lejota cyanea to the Milesiini. The 2n = 12 karyotypes of species of Blera, Criorhina, Lejota, Milesia, and to a lesser extent Sphecomyia, have some features in common. Spilomyia species have rather distinct 2n = 10 karyotypes. Certain species in Calliprobola, Syritta and Hadromyia are karyologically similar to some species of the genus Xylota in which species studied fall into fairly distinct karyological groups. These observations provide clear evidence of the accumulation of karyotypic variations in the origin of species in these two tribes.     

Heteromorphic sex chromosomes of lizardfish (Synodontidae): focus on the ZZ-ZW1W2 system in Trachinocephalus myops

The karyotype and DNA content of four lizardfish species (family Synodontidae), that is, Saurida elongata, Synodus ulae, Synodus hoshinonis and Trachinocephalus myops, were analyzed. The karyotype of T. myops significantly differed from that of the other three species having diploid chromosome number of 48 with mainly acrocentric chromosomes and the ZZ-ZW sex chromosome system. The chromosome number of male T. myops was 2n=26, while that of female T. myops was 2n=27. The karyotype consisted of 11 pairs of metacentrics, one pair of acrocentrics and, in addition, two large metacentrics in the male and a single large metacentric, a distinctly small subtelocentric and a microchromosome in the female. C-banding demonstrated that in the female the subtelocentric chromosome and the microchromosome were heterochromatic. The karyotype of T. myops was thought to be derived from a 48 chromosome type synodontid fish through the involvement of Robertsonian rearrangement; the rearrangement of the sex chromosomes proceeded during karyotype evolution. Among the chromosomes, the large metacentrics were determined to be neo-Z (a fusion of the original Z and an autosome), the microchromosomes the W₁ (originally W), and the subtelocentric chromosomes the W₂ (derived from an autosome pair). The miniaturization of W₁ and W₂ chromosomes and their heterochromatinization suggested that sex chromosomes in this species have been already highly differentiated. The findings on DNA content implied that the karyotype of T. myops evolved by centric fusion events without loss in DNA amount.     

Karyotype evolution in Tilapia: mitotic and meiotic chromosome analysis of Oreochromis karongae and O. niloticus x O. karongae hybrids

The karyotype of Oreochromis species is considered to be highly conserved, with a diploid chromosome complement of 2n = 44. Here we show, by analysis of mitotic and meiotic chromosomes, that the karyotype of O. karongae, one of the Lake Malawi chambo species, is 2n = 38. This difference in chromosome number does not prevent the production of inter-specific hybrids between O. niloticus (2n = 44) and O. karongae (2n = 38). Analysis of the meiotic chromosomes of the O. niloticus × O. karongae hybrids indicates that three separate chromosome fusion events have occurred in O. karongae. Comparison of the O. karongae and O. niloticus karyotypes suggests that these consist of one Robertsonian fusion and two fusions of a more complex nature.     

Elektronenmikroskopische Analyse der Musterbildung im Antheridium derPolypodiaceae

An electron microscopical investigation of the cell walls in young antheridia ofPolypodium crassifolium andPlatycerium alcicorne confirms the classical developmental model as postulated byStrasburger and byKny. The structure of the basal cell walls, both of the funnel cell and of the operculum, and especially the evidence of plasmodesmata in those walls, disprove the widely accepted interpretation presented 1951 byDavie.

     

Chromosome variation in the plethodontid salamander,Aneides ferreus

Karyotype variation in the plethodontid salamander, Aneides ferreus, has been analysed. 358 individuals from 14 populations, representing the major portion of the range of this salamander, have been karyologically examined. In A. ferreus, n=14. When the chromosomes are arranged in a decreasing relative length series, the karyotype is heteromorphic with respect to chromosome number 13, which may be either telocentric (T) or subtelocentric (ST). Variation in the heteromorphism over the range of the species is sex related, and probably also reflects relative population sizes. The heteromorphism in the isolated populations of A. ferreus on Vancouver Island, British Columbia, Canada, resembles a WZfemale/ZZmale sex chromosome dimorphism, suggesting the possibility that chromosome number 13 may be involved in sex determination in this population. The possibility that chromosome number 13 is involved in sex determination in all populations of A. ferreus is discussed. Our data suggest that the ancestral A. ferreus karyotype was homomorphic for T (T/T), and that the ST was derived from the T by a pericentric inversion. In peripheral populations, only the W homologue has been affected, whereas in central populations both the W and the Z chromosomes have been rearranged. Comparisons are made with other species of Aneides for which karyological information is available, and it is concluded that chromosome rearrangements have played an important role in the evolution of the genus. In C-banded chromosomes of A. ferreus, staining is most intense at the centromere regions of the larger chromosomes and is absent only in some of the smaller chromosomes. Implications of this C-banding pattern are discussed.     

Karyotype analysis and heterochromatin differentiation with Giemsa C-banding and fluorescent counterstaining inCephalanthera (Orchidaceae)

Detailed studies of the chromosomes of the three Austrian species of the genusCephalanthera showed them all to have basically similar karyotypes. BothC. damasonium (2n = 36) andC. longifolia (2n = 32) have three large and several classes of smaller chromosome pairs. The karyotype ofC. rubra (2n = 44) is composed of four large and several groups of smaller pairs. The heterochromatin in these species amounts to about 10% of total karyotype length. All the chromosomes have Giemsa-positive centromeres, but only a few have intercalary or terminal bands. Using differential fluorescent staining with DAPI/actinomycin D, quinacrine/actinomycin D (both A-T specific), and chromomycin A₃/distamycin A (G-C specific) three different types of major heterochromatic bands can be characterized in respect of their satellite DNA composition: highly A-T rich, slightly A-T rich, and very G-C rich. The chromosomes ofC. longifolia contain more A-T rich C-bands than those ofC. damasonium, while the latter's have more G-C rich heterochromatin. In both species several C-bands appear as secondary constrictions or gaps in the Feulgen-stained chromosomes, but most likely, in each species there is only one pair of chromosomes where the secondary constrictions function as nucleolus organizing regions. No major intraspecific variation could be observed except on one small chromosome pair ofC. longifolia which had a heteromorphic C-band in most individuals. Possible pathways of karyotype evolution involving polyploidy and Robertsonian events are discussed.     

Taxonomic studies ofAsarum sensu lato

The karyotype and the C-banding pattern in two species ofHexastylis andAsarum epigynum were analysed in detail, and the results obtained were compared with those of the other species ofAsarum, Asiasarum andHeterotropa previously reported. The present results were partially different from the previous reports related to the karyotypes of these species. The karyotype observed in two species ofHexastylis (2n=26) was represented by ten pairs of metacentric chromosomes and three pairs of small subtelocentric chromosomes, which is very similar to that ofAsiasarum in eastern Asia. The C-banding patterns ofHexastylis andAsiasarum, however, were clearly different from each other. A striking difference was found in one of the three pairs of small subtelocentric chromosomes. A Formosan speciesAsarum epigynum had the somatic chromosome number 2n=12 and a highly asymmetrical karyotype composed of mainly subtelocentric chromosomes. These karyological features were remarkably different from those of the other groups inAsarum s.l.