Chromosome studies of 8 species of parrots of the families Cacatuidae and Psittacidae (Aves: Psittaciformes)

The karyotypes of 7 species of Psittaciformes new to cytology are described: Cacatua galerita, Calyptorhynchus magnificus and Probosciger aterrimus of the Cacatuidae, and Ara macao, A. ararauna, Amazona viridigenalis and Psittrichas fulgidens of the Psittacidae. For reasons of comparison the karyotype of Melopsittacus undulatus is also described. These karyotypes are compared to 8 psittaciform karyotypes previously recorded. There is a remarkable heterogeneity of karyotypes in the Psittaciformes. Nevertheless, it seems possible to recognize Cacatua, Calyptorhynchus and probably also Probosciger (Cacatuidae) by their karyotypes as a clearly related group. The karyotypes of these cacatuids also bear some resemblance to that of Loriculus (Psittacidae). The psittacid genera Amazona, Ara, Nestor, Melopsittacus, Psittacula, Psittacus and Psittrichas are karyologically heterogeneous, but their karyotypes show certain relationships. The karyotype of Brotogeris is very different from those of other psittacids.     

The Giemsa banding patterns of the standard and four reconstructed karyotypes of Vicia faba

The Giemsa banding patterns of the standard karyotype of Vicia faba and of four new karyotypes with easily interdistinguishable chromosomes due to interchanges and inversions are described and compared with the data of other authors on preferential Giemsa staining in Vicia faba. All karyotypes contain 14 easily reproducible marker bands which characterize chromosome segments known to be heterochromatic. It is shown that the preferential Giemsa staining of chromosome regions is a valuable tool for the localization of translocation and inversion points in the chromosomes of the reconstructed Vicia karyotypes. A close correlation exists between banding patterns, segment extension by incorporation into chromosomal DNA of azacytidine and mutagen-specific clustering of induced chromatid aberrations in the new karyotypes.     

The use of karyotyping in the systematics of yeasts

The use of electrophoretic karyotyping in systematics of yeasts is discussed. New data are provided on the karyotypes of the medically important fungiHortaea werneckii, Filobasidiella (=Cryptococcus)neoformans, andMalassezia species.Hortaea werneckii has twelve to eighteen bands of chromosomal DNA, ranging in size between 500 and 2300 kb. The karyotypes ofFilobasidiella neoformans consist of seven to fourteen bands of chromosomal DNA. The varietiesneoformans andbacillispora cannot be separated by their karyotypes, and no obvious correlation was found with serotypes, geography or habitat. All strains ofMalassezia pachydermatis studied have similar karyotypes consisting of five bands, whereas inM. furfur, four different karyotypes are prevalent. However, each of these karyotypes is stable.     

A miscellaneous collection of bird karyotypes

In the framework of a project on bird sexing for zoos, orcein stained karyotypes were studied of 16 species belonging to 7 avian orders, viz.Tinamus solitarius (Tinamiformes),Scopus umbretta, Jabiru mycteria, Mycteria cinerea, Ciconia (=Dissoura) (episcopus) stormi andC. (=D.) e. episcopus (Ciconiiformes),Aburria pipile cumanensis, A. p. grayi, Penelope purpurascens, Lagopus lagopus andArborophila orientalis (Galliformes),Phalcoboenus megalopterus (Falconiformes),Burhinus magnirostris (Charadriiformes),Carpococcyx renauldi (Cuculiformes), andCeratogymna (=Bycanistes) subcylindricus andC.(=B.) bucinator (Coraciiformes). With the exception ofCiconia (=Dissoura) e. episcopus, all these karyotypes are new to cytology. They are briefly described and compared to karyotypes of the respective families and orders known from the literature. Cytotaxonomic implications are briefly discussed. The karyotypes ofBurhinus magnirostris (2n=42),Ceratogymna subcylindricus (2n=44) andC. bucinator (2n=40) exhibit the lowest diploid chromosome numbers hitherto found in birds. Of these, the twoCeratogymna species almost completely lack microchromosomes.     

A review of chromosomal variation in Dugesia japonica and D. ryukyuensis in the Far East

The chromosome numbers of Dugesia japonica Ichikawa et Kawakatsu, 1964, are n = 8, 2x = 16 and 3x = 24; those of Dugesia ryukyuensis Kawakatsu, 1976, are n = 7, 2x = 14 and 3x = 21. The karyotypes of both species include diploid, triploid and mixoploid; aneuploidic and mixoaneuploidic karyotypes may occur. In 785 specimens studied of D. japonica, the occurrence rates of specimens having each karyotype are substantially the same (29–37%). Diploid sexual specimens represented nearly 10% of the total and virtually no triploid or mixoploid sexual specimens were found. The diploid karyotype can be inherited by both sexual and asexual reproduction; the triploid and mixoploid karyotypes will be inherited only by asexual reproduction. In 51 specimens studied of D. ryukyuensis, the different karyotypes are diploid (ca 39%), triploid (ca 57%) and mixoploid (ca 4%). Diploid sexual specimens represented nearly 25% of the total; sexual specimens with tripooidic karyotypes made up nearly 27%. The diploid, triploid and mixoploid karyotypes were also found in juveniles hatched from cocoons. The diploid karytyype is inherited by both sexual and asexual reproductions; the other karyotypes may be inherited by parthenogenesis or self-fertilization (including pseudogamy) and asexual reproduction.     

KARYOTYPIC DATA ON NORTH AND CENTRAL AMERICAN ZAMIACEAE (CYCADALES) AND THEIR PHYLOGENETIC IMPLICATIONS

Chromosome numbers and karyotypes of species from four American Zamiaceae (Cycadales) are reported. Zamia shows interspecific and intraspecific chromosome variation, whereas Microcycas, Ceratozamia, and Dioon have constant karyotypes within each genus. In Zamia, all karyotypes have the same number of submetacentric and acrocentric chromosomes, but they differ in the number of metacentric and telocentric chromosomes. Centric fission of metacentric chromosomes is proposed to explain the karyotypic variation in this genus. Zamia shows karyological relationships with Microcycas and Ceratozamia, whereas Dioon appears very distinct from the other American cycad genera. Affinity among Zamia, Ceratozamia, and Microcycas karyotypes and distinctiveness of Dioon karyotypes are supported by comparative analysis of phenotypic characters in the four genera.     

Cytogenetic studies of two land-planarian species from Brazil: Geoplana marginata and Issoca rezendei (Tricladida,Terricola)

The chromosome complement and the C-banded karyotypes of specimens of Geoplana marginata auct. and of Issoca rezendei (Schirch) were investigated. The diploid and fundamental numbers of the two species were identical (2n = 14; FN = 28). Their karyotypes were similar except for the morphology of chromosome pair 6. Their C-banding patterns differed in quantity and localization of the constitutive heterochromatin. The similarity in karyotypes of these species support the hypothesis, proposed earlier on morphological grounds, that the genera Geoplana Stimpson and Issoca Froehlich are closely related. G. marginata and I. rezendei are the first land planarian species of the Neotropical Region to have their karyotypes described.     

Spontaneous chromosome rearrangements in an established cell line of Drosophila melanogaster

The chromosomal situation of the GM₃ line of Drosophila melanogaster was observed over a period of one year. From an initial homogeneous condition a karyotypic polymorphism evolved; four different karyotypes, identified by fluorescence patterns, emerged in the population and continued to multiply. The chromosomal rearrangements giving rise to the new karyotypes involved only heterochromatic sections.     

Karyotypes of 16 populations of eight species in the genus Polygonatum (Asparagaceae) from China

The karyotypes of 16 populations belonging to eight species of Polygonatum from China were analysed. The chromosome numbers and karyotypes of P. omeiense, P. adnatum and P. hirtellum and the diploidy of P. tessellatum are reported for the first time. The basic chromosome numbers were x = 11, 13, 14 and 15. Based on Stebbins' karyotypic classification, the four karyotypes were recognized as 2B, 3B, 2C and 3C. Considering the arm ratio and individual chromosome size, it was concluded that the possible evolutionary trend of the karyotypes in Polygonatum was from 2B to 3C. The results show that: (1) satellite heterozygosity occurs in many species of this genus; (2) mixoploidy and B chromosomes occur in some species; and (c) karyotypes are different in different species and even in different populations of the same species. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 245–254.     

Chromosomal evolution in the genus Clethrionomys

The karyotypes of Clethrionomys rufocanus and C. glareolus are presented using G- and C-banding techniques. There is intraspecific polymorphism in Clethrionomys rufocanus for a pericentric inversion. The main difference between the karyotypes of the two species is considered to result from a reciprocal translocation.     

Chromosome counts and karyotypes in Chaetoseris and Stenoseris (Asteraceae‐Cichorieae) from the Hengduan Mountains of SW China

Abstract Chaetoseris and Stenoseris are two morphologically close genera from the tribe Cichorieae of the sunflower family and they are endemic in alpine eastern Himalayas to the Hengduan Mountains of SW China. Mitotic chromosome numbers and karyotypes are reported for 12 populations representing eight species of Chaetoseris and two species of Stenoseris from the Hengduan Mountains region. Eight species are new and the other two provide confirmation of previous reference. All Chaetoseris and Stenoseris taxa are diploidy with 2n= 16 and their basic number is tentatively suggested as x= 8. Karyotypes of Chaetoseris and Stenoseris are similar to each other with 2A and 2B for the former and 2A for the latter. Cytological data of chromosomal numbers and karyotypes support a close relationship of the two genera. Currently no polyploids are found for these two genera and it seems that polyploidization has played a minor role in their evolutionary speciation in the Hengduan Mountains region.     

Evolution of karyotypes and differentiation in 13 Rattus Species

Karyotypes of 13 Rattus species collected in Asia and Oceania were analysed with special interest to karyotype evolution and species differentiation. They were classified into three groups according to their karyotype similarity. Four species (R. annandalei, R. exulans, R. muelleri and R. norvegicus) with 2n=42 and a karyotype similar to some of the polymorphic karyotypes in the Asian black rats (R. rattus) are classified into the first group. Pericentric inversion of some acrocentrics seemed to have caused the differentiation of these species. The other four species (R. bowersii, R. fuscipes, R. leucopus and R. conatus) with similar karyotypes as the above group, but lower chromosome numbers than 2n=42 are classified into the second group. Robertsonian fusion in some acrocentrics observed in the first group are suggested to have caused the development of the species in this group. The remaining four species (R. sabanus, R. canus, R. huang and R. niviventer) with karyotypes markedly different from the above two in having a fewer number of small metacentrics are classified into the third group. They seemed to be more primitive karyotypes than the other Rattus species. By the comparison between the polymorphic karyotypes in the black rat, and karyotypes in its related species it was suggested that the former had occurred as primary events to the differentiation of the latter. Parallelism between the karyotype evolution and the species differentiation was discussed.Contribution No. 874 from the National Institute of Genetics, Japan. Supported by a grant-in-aid from the Ministry of Education of Japan (No. 92159 and 92332).     

Variation in karyotypes of Dugesia japonica japonica (Turbellaria) from Ôsaka Prefecture,Central Japan

An analysis of the karyotypes of Dugesia japonica japonica Ichikawa et Kawakatsu, 1964, from 30 localities of seven river systems in Ôsaka Prefecture, Central Japan, revealed a total of 26 karyotypes of which 12 are new-found varieties. More than two karyotypes were found in many localities. The mixoaneuploidic triploid karyotype showed the widest distribution (21 localities), orthoploidic diploid karyotype and orthoploidic mixoploid of diploid and triploid karyotype were next (13 localities, respectively), and other karyotypes (triploidic aneuploid, orthoploidic triploid and mixoploid of triploid & tetraploid) were also found. Some correlation of karyotype with elevation was also detected.     

Phylogenetic interpretation of chromosomal and nuclear-DNA-content data in the genus Blennius (Blenniidae: Perciformes)

The haploid DNA content and karyotypes of eight species of Blennius are studied. Six species had 2n=48, two had 2n=46.The karyotypes of these species have been compared with those of related species of the genus and it was suggested that pericentric inversions played an important role in the evolution of their karyotypes. No sex chromosomes were morphologically identifiable in these gonochorist species. The data are discussed in connection with possible lines of evolution within the genus.     

Metaphase karyotype differentiation in eight species of the montium subgroup of Drosophila

The metaphase karyotypes of eight species of the montium species subgroup of Drosophila are described, of which the information pertaining to six species is new to the literature. Each of these species studied was distinctly different from the others with respect to the metaphase chromosomes, this remarkable degree of differentiation being mainly due to the extensive variability of the 4th and of the Y chromosomes.     

Karyomorphological studies of theIxeris dentata complex on Mount Ishizuchi

The karyotypes of four taxa in theIxeris dentata complex collected from Mt. Ishizuchi were investigated.I. dentata subsp.dentata var.dentata f.dentata had 2n=21 in all the examined individuals and its karyotypes were classified into four different types. Var.dentata f.amplifolia showed 2n=21 in all individuals and had three different karyotypes.I. dentata subsp.dentata var.albiflora showed 2n=21 and two different karyotypes.I. dentata subsp.alpicola showed three different karyotypes with 2n=21 and four different ones with 2n=28. Judging from the results of the karyotype analyses, the morphological variation of chromosomes in theI. dentata complex is assumed to be in the process of increasing asymmetry in the shape of chromosomes. Following Levitzky's principle, it can be said that the a-, b-, and c-chromosomes exist in different advanced stages in the process of chromosome variation. The c-group chromosomes are at the most advanced stage in morphological variation, the b-group in the second and the a-group in the least advanced stage. The above-mentioned structural diversity of chromosomes may be related to apomictic reproduction of theI. dentata complex.     

On the karyology of trematodes of the genus Microphallus and their intermediate gastropod host,Littorina saxatilis I. Chromosome analysis of three Microphallus species

The karyotypes of three marine trematode species of the genus Microphallus (Microphallidae), M. pygmaeus, M. piriformis and M. triangulatus, the most typical parasites of Littorina saxatilis (Gastropoda), are similar and include 9 pairs of bi-armed chromosomes, of which two pairs are represented by large meta- and submetacentrics, and 7 pairs are smaller chromosomes. It is proposed that the ancestral trematode karyotype consisted of 20 chromosomes and, therefore, the karyotypes of the microphallids are the advanced ones.     

Karyotypic comparison among Cebuella pygmaea,Callithrix jacchus and C. emiliae (Callitrichidae,Primates) and its taxonomic implications

The karyotype of Cebuella pygmaea (2n=44) obtained by G-, C-banding, and NOR-staining is described. This species presents a heteromorphic C band in the intersticial region of the short arm of chromosome 2. The data obtained were compared with those previously described for the karyotypes of Callithrix jacchus and Callithrix emiliae. The three species differ in the amount and distribution of non-centromeric constitutive heterochromatin. The importance of the variation in constitutive heterochromatin for the phylogeny of the group is discussed. Comparison of the karyotypes in terms of G-banding patterns showed that C. pygmaea and C. emiliae differ from C. jacchus by a Robertsonian translocation and a paracentric inversion, whereas C. pygmaea and C. emiliae differ from each other by a reciprocal translocation between an acrocentric autosome and the short arm of the submetacentric chromosomes that distinguishes their karyotypes from that of C. jacchus. The possible evolutionary paths followed by the karyotypes of the three species are discussed.     

Karyological and taxonomic studies of Dugesia japonica from the Southwest Islands of Japan-II

The karyotypes of Dugesia japonica from the southern part of the Southwest Islands of Japan (the Nansei Shotô) include diploidy, triploidy, mixoploidy, and mixoaneuploidy. Animals having karyotypes based on n = 8 were found on Okinawa Island, Ishigaki Island, Iriomote Island, and Yonaguni Island, while animals having karyotypes based on n = 7 were found on Okinawa Island, Miyako Island, and Ishigaki Island. Toward the northern end of this island chain, at Tanegashima Island, Yakushima Island, and Amami-Ôshima Island, karyotypes based on n = 8 occurred; and on one of these, Tanegashima Island, n = 7 also occurred. Our data provide further support of the karyotypical distinction between the two subspecies of D. japonica: D. j. japonica has karyotypes based on n = 8 and D. j. ryukyuensis has karyotypes based on n = 7. Taking into consideration the geological history of the Southwest Islands and the ties of their faunas to those of adjacent areas, we can explain the current geographical distribution of the two subspecies in these islands as the result of two separate invasions by D. japonica, one in the Miocene and one after the early Quaternary.     

CYTOGENETIC STUDIES OF SOME HYPOCHOERIS SPECIES (COMPOSITAE) FROM BRAZIL

Karyotypes of nine Brazilian taxa of genus Hypochoeris were studied utilizing root-tip mitotic metaphases. Two distinct groups were found. One group includes six species that showed high asymmetric bimodal karyotypes, while the second group has two species that have a karyotype similar to those observed in European species. All the species have karyotypes with 2n = 8 that are very uniform within each group, with only small morphological differences. Nucleolar organizing region and C-band patterns are shown for H. brasiliensis.