Identity of euchromatic bands from man to Cercopithecidae

Summary The karyotypes of four species of Cercopithecidae: Cercopithecus aethiops tantalus, C. sabaeus, Erythrocebus patas, and Miopithecus talapoin are analysed with nearly all the banding techniques. They are compared with each other, and with the karyotypes of the Baboon P. papio and with that of man. It can be concluded that the quasi-totality or the totality of the euchromatin is common to all, but has undergone structural rearrangements, generally detectable. The heterochromatin, defined by C-band staining, and late-replicating DNA, in contrast, appears very variable: In particular, E. patas has acquired very large heterochromatic segments. The significance of these modifications is discussed.Technical assistance: A. M. Fosse and M. Lombard     

Cytological characterization of heterochromatin and rDNA inPinus radiata andP. taeda

Fluorochrome C-banding ofPinus radiata andP. taeda metaphase chromosomes showed many pericentromeric DAPI bands and interstitial CMA bands inP. radiata, and centromeric and interstitial CMA bands inP. taeda. Giemsa C-band patterns differed between the species with centromeric bands inP. radiata but no consistent bands inP. taeda. A karyotype ofP. radiata was developed based on banding patterns that distinguished all but two of the 12 pairs of chromosomes. In situ hybridization (ISH) using probes for high-copy ribosomal DNA (rDNA) showed 10 pairs of 18S–25S sites and two pairs of 5S sites in both species. Most of the sites were interstitial or centromeric.     

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.     

The complete karyotype of Aspergilius niger: the use of introduced electrophoretic mobility variation of chromosomes for gene assignment studies

A method is described for unambiguous assignment of cloned genes to Aspergillus niger chromosomes by CHEF gel electrophoresis and Southern analysis. All of the eight linkage groups (LGs), with the exception of LG VII, have previously been assigned to specific chromosomal bands in the electrophoretic karyotype of A. niger. Using a LG VII-specific probe (nicB gene of A. niger) we have shown that LG VII corresponds to a chromosome of about 4.1 Mb. Furthermore, genetic localization of three unassigned genes (glaA, agIA and pepA) in strains in which these genes had been replaced by a selectable marker gene led to a revised karyotype for the chromosomes corresponding to LGs VIII and VI. The revised electrophoretic karyotype reveals only 5 distinct bands. The presence of three pairs of equally sized chromosomes precluded assignment of genes to one specific chromosome in the wild-type strain. However, unambiguous chromosome assignment of cloned genes using CHEF-Southern analysis was demonstrated using a set of A. niger strains with introduced chromosomal size variation. The availability of these tester strains obviates the need to isolate or construct mutant. strains for the purpose of chromosome assignment.     

Banding patterns of the chromosomes of Erythrocebus patas (Schreber 1774) compared to other primate species

The karyotype of Erythrocebus patas was studied using G, Q and C bands and NOR staining and compared to those of Miopithecus talapoin, Macaca mulatta and Cercopithecus aethiops. The comparison shows a large number of homoeologies, but several chromosome pairs cannot be matched. The mechanisms that may have originated the karyotypes of these species are discussed.     

Intestinal parasites of sympatric Pan troglodytes and Papio Spp. at two sites: Gombe (Tanzania) and Mt. Assirik (Senegal)

Experimental and clinical parasitology need natural baselines or “controls”. We present normative data intestinal parasite loads in two genera of African primates. Wild Pan troglodytes and Papio spp. were studied at two sites: Gombe in Tanzania (P. anubis) and Mt. Assirik in Senegal (P. papio). Presence or absence of parasites, especially nematodes, was recorded from fecal specimens. Gombe's primates were more often infected than were Mt. Assirik's. At Gombe, but not at Mt. Assirik, chimpanzees seemed to have a higher incidence of infection than baboons. Comparison of three baboon troops yielded apparent differences in prevalence of infection. No differences in infection were found between the wet and dry seasons in Mt. Assirik's chimpanzees.     

A simple parameter of dispersion index that serves as an adjunct to karyotype asymmetry

In order to refine the measure of karyotype asymmetry a new chromosomal parameter of dispersion index is proposed that has the potential to decipher even the minor karyotypic variations, thus permitting further evolutionary gradations to the karyotype asymmetry classes of Stebbins. The higher the dispersion index, the more specialized would be the karyotype. The dispersion index takes into account the variance lor gradual change in chromosome size within a complementvis-a-vis variance for the position of centromere in a karyotypic totality. The dispersion index is calculated as the proportionate measure of centromeric gradient to the coefficient of variation for chromosome length; wherin centromeric gradient = length of median short arm — length of median chromosome. Thus, the three most important karyotypic criteriaviz., differences in: absolute chromosome size, position of centromere and relative chromosome size, are all covered in the proposed parameter. The effectiveness of dispersion index has been tested on a plant taxa,Papaver L., where karyomorphological details, nuclear DNA content, and morphotaxonomic parameters have been amply elucidated from an evolutionary stand point. It is hoped that dispersion index would find immense utility in delimiting species interrelationships particularly in the closely related taxa, when applied in conjunction with other systematic parameters.     

Analysis of different banding patterns and late replicating regions in chromosomes of Allium cepa,A. sativum and A. nigrum

Different banding procedures and preferential Giemsa staining of late replicating DNA-rich regions were carried out in metaphase chromosomes of three species belonging to different sections of the genus Allium (A. cepa, A. sativum and A. nigrum). The banding, as well as the late replicating patterns were species-specific. The late replicating pattern proved to be, in all cases, the more detailed, and represented the highest percentage of the karyotype differentially stained. Lower percents of the karyotype positively stained were accounted for by C-banding, by modified C-banding and by N-banding. In A. cepa interphase nuclei the pattern of constitutive heterochromatin fitted well with that of late replicating DNA-rich regions, but the coincidence with that revealed by C-banding was only partial. This supports the suggestion that late replicating regions may be considered to be a special category of heterochromatin. On the other hand, it seems that not all C-banded material replicates at the end of the S phase. By the modified C-banding, stained centromere dots or small bands, as well as bands at the NORs are observed.     

The karyotype of Clivia mirabilis analyzed by differential banding and fluorescence in-situ hybridization

The karyotype of the recently described species Clivia mirabilis was analyzed by differential chromosome staining with Giemsa, chromomycin, and DAPI and by fluorescence in-situ hybridization with 5S and 45S rDNA probes. Like the other five Clivia species it was shown to have a unique karyotype, although its karyotype was similar in several respects to that of C. gardenii, differing in having only one pair of chromosomes with CMA bands compared with two pairs in C. gardenii and lacking any DAPI-positive bands. The evolutionary relationships of the species and their karyotypes are discussed.     

Comparative cytogenetics of three economically important Piper L. species from the Brazilian Amazon

The species Piper hispidinervum, Piper aduncum, and Piper affinis hispidinervum have essential oils with high levels of safrole, dillapiole, and sarisan, respectively. Safrole is important for pharmaceutical and chemical industries, while dillapiole and sarisan are promising compounds to control insects and fungi. These species are very similar morphologically and their taxonomy is controversial. Divergent hypotheses consider P. aduncum and P. hispidinervum either as a single species or as distinct taxa, while P. affinis hispidinervum is inferred to be a natural hybrid or a chemotype of P. hispidinervum. Delimiting the taxonomic boundaries would be helpful for germplasm conservation and breeding programs. This study aimed to undertake a detailed analysis of P. aduncum, P. hispidinervum, and P. affinis hispidinervum karyotype and rDNA sites. Genomic in situ hybridization (GISH) was used to establish genomic homology among species and to test the natural hybridization hypothesis for origin of P. affinis hispidinervum. Karyotype traits were similar for all three species: 2n = 26 small chromosomes, predominantly metacentric. All three species exhibited CMA+ bands on the secondary constriction of chromosome pair 4. A size-heteromorphic 35S rDNA site was co-localized with the CMA+ band. A 5S rDNA site was located in the proximal region of chromosome pair 7. The patterns of genomic hybridization revealed that the repetitive DNA fraction of the species is highly similar in terms of proportion of genome, sequence type, and distribution. Our findings did not allow us to differentiate the three species and point to the importance of deeper genomic studies to elucidate the taxonomic controversy.

     

Chromosome diversity and evolution in tribe Lilieae (Liliaceae) with emphasis on Chinese species

In this paper, karyotype data of the tribe Lilieae in China were analyzed and been superimposed onto a phylogenetic framework constructed by the internal transcribed spacer to investigate the karyotype evolution. Ten parameters for analyzing karyotype asymmetry were assessed and karyotypic idiogram of five genera of Lilieae were illustrated. The results showed that, the relationship of genera in Lilieae that inferred from Maximum Parsimony criteria and Bayesian Inference were congruent with previous studies, which focused on higher level of Liliales. The karyotype showed distinctive among genera, mainly expressed on the location and amount of secondary constrictions and intercalary satellites: the genus Notholirion have neither of them, and the genera Cardiocrinum and Fritillaria have the secondary constriction alone; the genera Lilium and Nomocharis showed both features, and the distribute pattern of the intercalary satellites showed similarity among related clades. The asymmetry that assessed by several methods indicated that the evolution trend of Lilieae did not follow a single direction, but different in each genus. On the sectional level of the genus Lilium (including Nomocharis) the karyotype evolution included three major periods. Combining the chromosomal structure variations and karyotype asymmetry, the chromosome diversity and evolution in Lilieae were quite clear in the light of molecular inference.     

Molecular phylogeny and karyotype differentiation in <Emphasis Type="Italic">Paratelmatobius</Emphasis> and <Emphasis Type="Italic">Scythrophrys</Emphasis> (Anura,Leptodactylidae)

Paratelmatobius and Scythrophrys are leptodactylid frogs endemic to the Brazilian Atlantic forest and their close phylogenetic relationship was recently inferred in an analysis that included Paratelmatobius sp. and S. sawayae. To investigate the interspecific relationships among Paratelmatobius and Scythrophrys species, we analyzed a mitochondrial region (approximately 2.4 kb) that included the ribosomal genes 12S and 16S and the tRNAval in representatives of all known localities of these genera and in 54 other species. Maximum parsimony inferences were done using PAUP* and support for the clades was evaluated by bootstrapping. A cytogenetic analysis using Giemsa staining, C-banding and silver staining was also done for those populations of Paratelmatobius not included in previous cytogenetic studies of this genus in order to assess their karyotype differentiation. Our results suggested Paratelmatobius and Scythrophrys formed a clade strongly supported by bootstrapping, which corroborated their very close phylogenetic relationship. Among the Paratelmatobius species, two clades were identified and corroborated the groups P. mantiqueira and P. cardosoi previously proposed based on morphological characters. The karyotypes of Paratelmatobius sp. 2 and Paratelmatobius sp. 3 described here had diploid chromosome number 2n = 24 and showed many similarities with karyotypes of other Paratelmatobius representatives. The cytogenetic data and the phylogenetic analysis allowed the proposal/corroboration of several hypotheses for the karyotype differentiation within Paratelmatobius and Scythrophrys. Namely the telocentric pair No. 4 represented a synapomorphy of P. cardosoi and Paratelmatobius sp. 2, while chromosome pair No. 5 with interstitial C-bands could be interpreted as a synapomorphy of the P. cardosoi group. The NOR-bearing chromosome No. 10 in the karyotype of P. poecilogaster was considered homeologous to chromosome No. 10 in the karyotype of Scythrophrys sp., chromosome No. 9 in the karyotype of Paratelmatobius sp. 1, chromosome No. 8 in the karyotypes of Paratelmatobius sp. 2 and of Paratelmatobius sp. 3, and chromosome No. 7 in the karyotype of P. cardosoi. A hypothesis for the evolutionary divergence of these NOR-bearing chromosomes, which probably involved events like gain in heteochromatin, was proposed.     

A simplified molecular method for distinguishing among species and ploidy levels in European water frogs (Pelophylax)

Western Palearctic water frogs in the genus Pelophylax are a set of morphologically similar anuran species that form hybridogenetic complexes. Fully reliable identification of species and especially of hybrid ploidy depends on karyological and molecular methods. In central Europe, native water frog populations consist of the Pelophylax esculentus complex, that is, P. lessonae (LL), P. ridibundus (RR) and the hybrid form P. esculentus that can have different karyotypes (RL, LLR and RRL). We developed existing molecular methods further and propose a simple PCR method based on size‐differences in the length of the serum albumin intron‐1 and the RanaCR1, a non‐LTR retrotransposon of the chicken repeat (CR) family. This PCR yields taxon‐specific banding patterns that can easily be screened by standard agarose gel electrophoresis and correctly identify species in all of the 160 samples that had been identified to karyotype with other methods. To distinguish ploidy levels in LR, LLR and RRL specimens, we used the ratio of the peak heights of the larger (ridibundus specific) to the smaller (lessonae specific) bands of fluorescently labelled PCR products resolved on a capillary DNA sequencer and obtained a correct assignment of the karyotype in 93% of cases. Our new method will cut down time and expenses drastically for a reliable identification of water frogs of the P. esculentus complex and potentially for identification of other hybridogenetic complexes and/or taxa, and it even serves as a good indicator of the ploidy status of hybrid individuals.     

The Ap-Bp blood groups of baboons

Four isoimmunized baboons each produced isoantibodies defining a number of blood factors of baboon blood of which two, A^p and B^p, have been most intensively studied. The two blood factors determine the A^P-B^P blood group system which, judging from its serological behavior, may be the baboon analogue of the human M-N system and the chimpanzee V-A-B system. Tests for A^P-B^P types of 592 baboons showed striking differences in the distributions of the four types among the four sub-species, Papio cynocephalus, Papio anubis, Papio ursinus (South Africa) and Papio papio (Senegal). The baboon A^P-B^P types could also be demonstrated by tests on the red cells of geladas (Theropithecus gelada). If one assumes inheritance by multiple allelic genes, then the existence of only a single gene O^p need be invoked for Papio ursinus, three alleles O^p, A^p and B^p for Papio cynocephalus and Papio anubis, but four alleles for Papio papio including an allele, very frequent in that subspecies, which determines an agglutinogen having both blood factors A^p and B^p.     

Localisation of aphidicolin-induced break points in Holstein-Friesian cattle (Bos taurus) using RBG-banding

Fragile sites (FS) seem to play a role in genome instability and may be involved in karyotype evolution and chromosome aberrations. The majority of common fragile sites are induced by aphidicolin. Aphidicolin was used at two different concentrations (0.15 and 0.30 μM) to study the occurrence of FS in the cattle karyotype. In this paper, a map of aphidicolin induced break points and fragile sites in cattle chromosomes was constructed. The statistical analysis indicated that any band with three or more breaks was significantly damaged (P < 0.05). According to this result, 30 of the 72 different break points observed were scored as fragile sites. The Pearson correlation test showed a positive association between chromosome length and the number of fragile sites (r = 0.54). On the contrary, 21 FS were identified on negative R bands while 9 FS were located on positive R bands.     

Heterochromatin diversity in two species of Pellia (Hepaticae) as revealed by C-, Q-, N- and Hoechst 33258-banding

Giemsa C-banding of two liverwort species, Pellia epiphylla (L.) Corda (n=9) and P. neesiana (Gott.) Limpr. (n = X/Y + 8), identified each chromosome as unique. Almost the full complement of C-bands was defined by N-banding. Apart from minor variation in the prominence of certain bands, which were designated according to principles adopted in human cytology, the chief exceptions were the absence of bands 1p2, 1p4, 1q2, 1q4 and 7p6 from the N-banded karyotype of P. epiphylla and of band 7q25 from P. neesiana. Both quinacrine dihydrochloride and Hoechst 33258 showed reduced fluorescence in the constitutive heterochromatin of P. epiphylla. The effects of these two fluorochromes on P. neesiana, however, differed from each other and from their effect on P. epiphylla. Only one Q-band, the brightly fluorescing 1(X/Y)q24, occurred, whereas Hoechst 33258 resulted in considerable differentiation. The majority of C-bands were correlated with bright fluorescence with Hoechst 33258 but a few were dim. On the basis of these results, four major types of heterochromatin were identified in P. neesiana and two further types in P. epiphylla. They are discussed in the context of previously reported early replication of P. neesiana heterochromatin and point to considerable cytological evolution within these two species.     

Giemsa C-banded karyotypes inCapsicum (Solanaceae)

Giemsa C-banding is applied for the first time inCapsicum, allowing preliminary karyotype differentiation of six diploid species. Comparison of interphase nuclei and heterochromatic C-bands reveals striking differences between taxa and contributes to their taxonomic grouping. Therefore, C-banding appears to be a powerful tool for the cytogenetics and karyosystematics of the genus. Banding patterns are characterized by the omnipresence of centromeric bands and a variable number of smaller to larger distal bands, with the addition of intercalary bands in some cases. Satellites are always C-positive. Relationships between species and possible trends of karyotype evolution are discussed, with special reference to the origin of x = 13 from x = 12 and the increase of heterochromatin, regarded as advanced features.Chromosome studies inCapsicum (Solanaceae), III. For the first and the second part seeMoscone (1990, 1993).     

Resolution of Acanthamoeba castellanii chromosomes by pulsed field gel electrophoresis and construction of the initial linkage map

Pulsed field gel electrophoresis has been used to resolve chromosome-sized DNA molecules in fungi and parasites but has not yet been used successfully to examine the chromosomes of other lower eukaryotes used extensively for biochemical research such as Acanthamoeba, Physarum, and Dictyostelium. Here we show an electrophoretic karyotype of the protozoan Acanthamoeba castellanii using orthogonal field alternating gel electrophoresis (OFAGE). There are about 20 small chromosomes ranging in size from 220 kb to >2 Mb. We have assembled initial linkage groups assigning all of the cloned Acanthamoeba genes to chromosome-sized DNA molecules. Actin, suggested to have three or more non-allelic genes, maps to at least eight distinct chromosome bands. Two myosin II genes localize to two different chromosomal bands while myosin IB and 18S rRNA map to unresolved larger chromosomes.Abbreviations OFAGE Orthogonal field alternating gel electrophoresis     

Nucleolar organiser region (NOR) location in karyotypes of Australian ground frogs (family Myobatrachidae)

Nucleolar organiser regions (NORs) were examined in over 90% of the species of Australian ground frogs (familiy Myobatrachidae), including representatives from all twenty currently recognised genera and the three subfamilies. Throughout the family, location of the NOR within the karyotype showed considerable variation yet karyotype morphology showed uniformity. The precise mechanism(s) whereby variation in NOR location evolved while karyotype morphology was unchanged remains uncertain. Comparison of the two major subfamilies showed that the Limnodynastinae had a greater diversity of NOR location than the Myobatrachinae. The limnodynastine genus,Heleioporus, was the only one to show multiple NOR sites in several species. NOR location was particularly stable within most polytypic genera. Differences in NOR location within the remaining polytypic genera (Heleioporus, Limnodynastes, Neobatrachus, Philoria andRanidella) pointed to taxonomic discriminations that were generally consistent with recent proposals based on other criteria.     

Comparative cytogenetic analysis of Cestrum (Solanaceae) reveals different trends in heterochromatin and rDNA sites distribution

Species of Cestrum L. (Solanaceae) exhibit large variability in the accumulation of repetitive DNA, although their species possess a stable diploid number with 2n = 16. In this study, we used chromosome banding and fluorescence in situ hybridization (FISH) to characterize the karyotypes and populations of two species, Cestrum nocturnum L. and C. mariquitense Kunth. We also performed a karyotype comparison using 16 idiograms, of which 4 were developed in this study and 12 were obtained from the literature. Cestrum nocturnum displayed more bands than C. mariquitense, but the latter exhibited greater interpopulational variation in the band patterns. There was a tendency for large bands to be located at intercalary/terminal regions and for small bands to be located at intermediate/proximal regions. The idiogram comparison revealed a large variation in the amount, distribution, and size of heterochromatic bands. FISH with rDNA probes revealed stability in the number and location of 5S sites, while 45S was more variable in size and number of sites. Although 45S rDNA always appeared in the subterminal regions, this DNA family exhibited a mobility among chromosome pairs. These data highlight the dynamic of repetitive DNA families in these genomes, as well as the contribution for intra- and interspecific karyotype differentiation in Cestrum.