ISSN:0008-7114    

DOI:10.1080/00087114.1990.10796998

出版商:Taylor & Francis    

年代:1990

数据来源: Taylor

摘要:

Qualitative and quantitative studies of interphase nuclei of barley and rye showed that centromeres occupied the region in the nucleus with the highest proportion of chromatin. Telomeres occupied the opposite end of the nucleus where much less chromatin was present. The pattern was consistent among C-banded nuclei in the light microscope and nuclei in the electron microscope. Microdensitometer scans suggested that the darkly stained centromeric region in the nucleus contained more than twice the proportion of DNA present in the lighter, telomeric, region.

ISSN:0008-7114    

DOI:10.1080/00087114.1990.10796999

出版商:Taylor & Francis    

年代:1990

数据来源: Taylor

摘要:

Pig and cattle follicular oocytes were stained by a counterstain- enhanced-fluorescence technique with Chromomycin A3-Distamycin A-DAPI (4,6- Diamidino-2-phenylindole) (CCD) as DNA-specific staining dyes. This method provided a clear visualization of the nuclear structures in pig and cattle oocytes. The cytogenetic stages found consisted of two major types; type I, with fine chromosomal filaments (bivalents), predominant in oocytes originating from small follicles (<1 mm); and type II, characterized by a pronounced clustering of chromatin, predominant in oocytes originating from large follicles (>2 mm). The majority of the porcine and bovine Giemsa stained chromomeres displayed DAPI bright and CMA3pale staining. Thus, they resemble mitotic G- and Q-bands in their staining behaviour.

ISSN:0008-7114    

DOI:10.1080/00087114.1990.10797000

出版商:Taylor & Francis    

年代:1990

数据来源: Taylor

摘要:

In the present study the karyological characteristics of three species of the genusGlycyrrhizaL. were described. Nine populations ofG. echinata, one of G.glabra, and one of G.lepidota, which are known to be well differentiated morphologically, ecologically, and phytogeographically, but to have stable chromosome numbers, were examined. For each population the morphological type, total and relative lengths of chromosome pairs, the centromeric index, and index of karyotype asymmetry were determined. Significant differences in the karyotype were observed both between the species and between the populations ofG. echinata.

ISSN:0008-7114    

DOI:10.1080/00087114.1990.10797001

出版商:Taylor & Francis    

年代:1990

数据来源: Taylor

摘要:

A cytological analysis of thirty-seven accessions ofGasteriahas shown that this genus is very uniform chromosomally. All the species have a bimodal karyotype of eight large and six small chromosomes. Karyotype variability between the species is no more than that found between individuals of a single species showing thatGasteriais composed of taxa more closely related than in other genera.

ISSN:0008-7114    

DOI:10.1080/00087114.1990.10797002

出版商:Taylor & Francis    

年代:1990

数据来源: Taylor

摘要:

Karyotype of European leuciscine cyprinid speciesAspius aspiusfrom various river basins of Europe have been described. It consists of 7 pairs of metacentric, 14 pairs of submetacentric and 4 pairs of subtelocentric to acrocentric chromosomes including the «marker» leuciscine subtelocentric pair. According to its morphology, the karyotype is substantially the same as found in many other species of European leuciscine cyprinids. The only significant and remarkable difference is the localization of nucleolar organizer regions (NORs) as visualized by both silver staining and C-banding. Contrary to other species of European leuciscins, chromosomal NORs are located on the longer arms of the smallest pair of acrocentrics. This finding as well as the intraspecific karyotype variability ofA. aspiushas been discussed on the basis of our data as well as previous reports.

ISSN:0008-7114    

DOI:10.1080/00087114.1990.10797003

出版商:Taylor & Francis    

年代:1990

数据来源: Taylor

摘要:

The chiasma distribution patterns of 4 Acridinae species were studied. The preliminary results show that inParga xanthopterathe chiasmata are mostly located in the distal and proximal regions of the bivalents. Due to a relatively high frequency of bivalents with 2 chiasmata, the chiasma frequency was relatively high (15.8/cell).Gymnobothrus cruciatus, Machaeridia bilineataandCannula gracilisall show proximal localization in the 8 longer chromosome pairs. Chiasma distribution in the 3 smaller pairs seemed to be random. OneC. gracilisindividual was also heterozygotic for an extra heterochromatic supernumerary segment on the distal end of chromosome 11. This caused a redistribution of chiasmata in the carrier bivalent as well as an increase in chiasma frequency. The mean cell chiasma frequency forG. cruciatuswas 11.00, forM. bilineata11.13, forC. gracilis(basic karyotype) 12.06 and for the individual with the extra segment 13.86.

ISSN:0008-7114    

DOI:10.1080/00087114.1990.10797004

出版商:Taylor & Francis    

年代:1990

数据来源: Taylor

摘要:

Karyological studies of some taxa of the generaHimantoglossum, Orchis, SerapiasandSpiranthes(Orchidaceae) from Apulia are reported. Karyotypes of the taxa studied reveal interesting differences. A particular marker chromosome pair, with a satellite on the short arm and a microsatellite on the long arm, has been observed in the generaHimantoglossumandOrchis. Karyotypes ofOrchis morioL. andO. papilionaceaL. showed a great morphologic similarity. In the taxa of the genusOrchiswith 2n= 42 chromosomes some plants carry B-chromosome.

ISSN:0008-7114    

DOI:10.1080/00087114.1990.10797005

出版商:Taylor & Francis    

年代:1990

数据来源: Taylor

摘要:

Well differentiated banding patterns along the European eel(Anguilla anguilla)chromosome arms were produced with chromomycin A3/distamycin A/DAPI (CDD) and DAPI/actinomycin D sequential counterstain-enhanced fluorescence techniques. Thus, they gave convincing evidence for the occurrence of DNA base composition specific bands and hence, of a higher order genomic compartmentalization.

ISSN:0008-7114    

DOI:10.1080/00087114.1990.10797006

出版商:Taylor & Francis    

年代:1990

数据来源: Taylor

摘要:

A comparison of high resolution G- and R-banding in cattle and river buffalo chromosomes was performed at the 500 band level. Close banding homologies between the two species were apparent. However a loss of pericentromeric G-positive band in chromosome arms lp, 2q, 4p and 5q and a retention of pericentromeric G-positive bands in chromosome 3 and R-positive banding patterns in the five biarmed pairs of river buffalo were observed. A comparison between sex chromosomes of the two species revealed that (a) river buffalo X and Y chromosomes were longer than cattle sex chromosomes, (b) the distal R-positive (G-negative) band in cattle Y chromosome appeared larger than the corresponding one in river buffalo Y chromosome and (c) two pericentric inversions characterized the differences between the submetacentric cattle and acrocentric river buffalo sex chromosomes.

ISSN:0008-7114    

DOI:10.1080/00087114.1990.10797007

出版商:Taylor & Francis    

年代:1990

数据来源: Taylor