Mitotic Karyotype Research Articles

Rates of cell proliferation in adenomatous, suppressed, and normal parathyroid tissue: implications for pathogenesis.

In previous studies, the birth rate of new cells in parathyroid adenomas measured at the time of surgical excision was shown to be much too low to account for growth of the tumors from a single cell in the time available, but comparison with normal rates was not possible. We measured the prevalence of cells expressing the Ki-67 antigen, a cell cycle marker, in 55 parathyroid adenomas using the MIB-1 antibody and microwave antigen retrieval; in 22 cases, separate measurements were made in nonadenomatous tissue from the same glands. In 10 cases complete maps of the gland profile were reconstructed to study the distribution of labeled cells. The proportion of Ki-67-positive cells, estimated by systematic random sampling, was used to calculate cell birth rate assuming a duration of Ki-67 expression of 24 h; the results were compared to rates previously determined in normal parathyroid glands by the same method. The geometric mean cell birth rate was 9.97%/yr, about double the normal rate of 5.4%/yr, but less than a third of the cases had values above the normal range. The corresponding value in nonadenomatous tissue was 2.58%/yr, about half the normal rate. In 10 cases studied in more detail, the cell birth rate was 12.3%/yr in the peripheral regions and 6.2%/yr in the central regions, a value not significantly different from normal. The results in adenomas are in reasonable agreement with previous estimates of cell birth rate of 13.7%/yr using [3H]thymidine labeling and 6.4%/yr using prevalence of the mitotic karyotype. The proportion of Ki-67-positive cells using unbiased sampling was about 50 times smaller than that in previous studies using selective sampling. Cell birth rates at the time of excision were about 20-25 times lower than initial rates estimated from modeling tumor growth by the Gompertz function. We conclude that 1) cell birth rate in parathyroid adenomas has fallen substantially during the growth of the tumors and is only modestly greater than normal; 2) the fall in cell birth rate had been greater in the central and presumably older regions of the adenoma than in the peripheral and presumably younger regions; 3) nonadenomatous tissue was suppressed with respect to its proliferative as well as its secretory function, presumably as a result of hypercalcemia; and 4) the progressive fall in cell birth rate, despite the accumulation of mutations that are supposed to increase cell birth rate, is most readily explained by the set-point hypothesis.

Synaptonemal complex analysis in spermatocytes of white sturgeon,AcipensertransmontanusRichardson (Pisces, Acipenseridae), a fish with a very high chromosome number

The surface-spreading synaptonemal complex (SC) technique was used to visualize the process of chromosome synapsis in white sturgeon spermatocytes. Pachytene nuclei had various numbers of univalents (0-3) and self-paired foldback elements with no obvious centromeric region (1-7) that may represent accessory chromosomes. The total SC length was 482 ( ±56) µm and the average number of SC elements per nucleus was 139 ( ±3.4). This SC number suggests a higher chromosome number than had been reported in previous mitotic studies (2n = 248 ± 8). There was variation in the SC count both within and between animals. A representative SC karyotype is presented and some differences between the mitotic and meiotic karyotypes for this species are discussed. There was no evidence of multivalent formation, suggesting that the process of diploidization has gone to completion in the males of this ancient polyploid species. Each SC had lateral elements of equal length, and no bivalent exhibited the atypical pairing behavior that is often characteristically associated with heteromorphic sex chromosomes, suggesting that the male is not the heterogametic sex in white sturgeon.

The relationship between genetic and cytogenetic maps of pea. I. Standard and translocation karyotypes

A detailed cytogenetical study of inbred lines of pea and their F1 hybrids has been undertaken to study the relationship between the cytogenetic map and the molecular linkage map. The mitotic karyotypes of a standard pea line, JI15, a translocation line, JI61, and line JI281, a line used in the production of a mapping population, are given. A chromosome rearrangement detected by cytogenetic analysis of mitotic chromosomes has been further defined by synaptonemal complex (SC) analysis and the study of metaphase I chromosome behaviour. This meiotic analysis has allowed a comparison of SC physical lengths, observed chiasma frequencies, and recombination frequencies, as estimated from the genetic map, as a means of comparing physical and genetic distances.

Meiotic behavior of the X1X2Y1Y2 quadrivalent of the primate Alouatta caraya.

A multiple sex chromosome system was found in three unrelated individuals of the primate Alouatta caraya. This mechanism is originated by a translocation between the Y chromosome and one of the autosomes (A7). Mitotic karyotypes show two small, acrocentric chromosomes (AY and YA), which are the translocation products. In metaphase I of male meiosis, there is a very long chain quadrivalent in which the order of the element is: X-YA-A7-AY. Segregation in the quadrivalent is alternate and gives balanced products. Synaptonemal complex karyotypes at pachytene show the structure of the quadrivalent made by the four axes. There is a slight difference in the relative length of AY and YA and the kinetochore of A7 aligns with that of AY. The synaptic pattern and changes in the quadrivalent during pachytene are described. Thin sections of the quadrivalent body show that the chromatin packing in the sex chromosome region is different from that of the autosomal region. This X1X2Y1Y2/X1X1XX2 sex chromosome system may be extended among other members of the genus Alouatta.

A standard cytogenetic map forAnopheles sundaicus(Diptera: Culicidae) and evidence for chromosomal differentiation in populations from Thailand and Indonesia

A standard photographic map of polytene chromosomes of Anopheles sundaicus was constructed from ovarian nurse cells and is described herein. Polytene chromosomes of wild specimens collected from 9 different geographical areas in Thailand and Indonesia have been analyzed. Specimens from these populations appear to share banding patterns with standard gene arrangements, except for some specimens from Purworejo, in Central Java, and South Tapanuli and Asahan, both of North Sumatra, which exhibited distinct banding patterns at the tip of chromosome X (Xb) compared with the standard sequence (Xa). Moreover, some specimens collected from Asahan, North Sumatra, consistently showed distinct loosely diffuse bands in zone 19 of chromosome arm 2R (2Rb) compared with the standard banding patterns (2Ra). The existence of the 2Rb pattern correlates perfectly with the presence of an extra block of centromeric heterochromatin in autosome 2 as revealed by mitotic karyotype analysis (2n = 6). These cytological differences have led to the recognition of 3 distinct forms, viz., A, B, and C, within the taxon An. sundaicus. In addition, forms A and C show a normal size for chromosome Y, (Y1), while form B has a relatively larger type of chromosome Y, (Y2). Form A is widely distributed in Thailand and Indonesia, while form B has been found in North Sumatra and Central Java. Form C, however, has been found only in Asahan, North Sumatra. Key words : Anopheles sundaicus, polytene chromosome map, mitotic karyotype, chromosomal differentiation.

Interspecific cross between cucurbita pepo L. and Cucurbita martinezii through in vitro embryo culture

Ten plants were obtained following culture of one hundred interspecific embryos derived from the cross between the wild species Cucurbita martinezii Bailey as a male and the cultivated Cucurbita pepo L., as a female parent. Immature embryos were septically (cultured) on Murashige and Skoog medium with 0.01 mg/l IAA and 0.1 mg/l KIN, which proved to be the best for squash embryo culture. Interspecific plants showed intermediate morphological characters between parents leaves and flowers. Moreover, biochemical analysis of the peroxidase isozymes as electrophoretic banding patterns showed the same intermediate trend with hybrid plants showing the majority of cultivated and wild parent bands. On the other hand, no great differences were detected between the hybrid and its parents for albumin banding patterns. Cytological studies of mitotic and meiotic chromosomes showed that hybrid root tips had the same number of chromosomes as the parents (2n=40). However mitotic chromosome karyotypes represent two main distinct groups in morphology, one from each parental species. Meiotic chromosomes of hybrids showed a high level of irregular univalent formation and low level of bivalents and chiasmata formation, supporting the conclusion that the genomes of the two species are quite different. Regarding powdery mildew and cucumber mosaic virus infectivity, both the hybrid plants and the wild parent proved to be resistant to both diseases, whereas, the cultivated parent proved to be highly susceptible.

Metaphase karyotypes of fruit flies of Thailand. I. Five sibling species of the Bactrocera dorsalis complex.

Natural populations of fruit flies of the Bactrocera dorsalis complex exhibit chromosomal variation based on differences in the amount and distribution of constitutive heterochromatin in the centromeric regions of the autosomes and the sex chromosomes. The chromosomal variation, coupled with differences in external morphology and host plant specific preferences, strongly suggest the existence of 5 closely related species within the B. dorsalis complex that have provisionally been designated B. dorsalis species B, C, D, and E in contrast with B. dorsalis s.s. (species A). Analysis of heterochromatin in autosomes and sex chromosomes has revealed 4 distinct groups of mitotic karyotypes. Bactrocera dorsalis is the only representative of Group I, which is characterized by the typical metacentric X chromosome and major blocks of centromeric heterochromatin in autosomes 5 and 6. Group 2 consists of species B and C, which show prominent landmarks of pericentric heterochromatin in all autosomes and in the X chromosome. Group 3 comprises species D, which is characterized by conspicuous blocks of pericentric heterochromatin in all autosomes but the long arm of the subtelocentric X chromosome is euchromatic and lacks a major portion of centromeric heterochromatin. Species E belongs to Group 4, which differs from Group 3 in having major blocks of heterochromatin at the distal portion of the X chromosome in addition to the prominent landmarks of pericentric heterochromatin in all autosomes. Chromosomal evolution among closely related species within the B. dorsalis complex clearly involves the presence or absence of constitutive heterochromatin in the centromeric regions of autosomes as well as in the X chromosome.

Mitotic karyotypes of Brassica campestris and Brassica alboglabra and identification of the B. alboglabra chromosome in an addition line

A Brassica campestris-alboglabra monosomic addition line (genome: AA + one chromosome from the C genome, 2n = 21) harbours the Brassica alboglabra (CC, 2n = 18) chromosome with the gene for erucic acid. In order to identify this chromosome, we have studied the mitotic prometaphase chromosomes of Brassica campestris (AA, 2n = 20), B. alboglabra, and the monosomic addition line. More pronounced differential staining and size differences of chromosomes were observed in B. campestris than in B. alboglabra. The karyotype of B. campestris was composed of four median (m), four submedian (sm), and two subterminal (st) chromosome pairs, while that of B. alboglabra was composed of three m, four sm, and two st chromosome pairs, provided that the length of the satellite was excluded when determining the arm ratio of the nucleolar chromosome. The alien chromosome from the C genome in the addition line was easily identified in the background B. campestris genome by its large size, its submedian centromere, and its differential staining pattern. When compared with the karyotype of B. alboglabra, the alien chromosome from the C genome in the monosomic addition line was revealed to be chromosome 4.

Karyotype and Chromosome Morphology of Parthenium argentatum.

The genus Parthenium contains plants which produce latex, although only P. argentatum produces the commercially important product, rubber, in sufficiently large quantities. Parthenium forms a natural polyploid series (Stebbins and Kodani 1944, Bergner 1944) and although many meiotic studies have been conducted, little mitotic karyological data has been published. This paper presents the first mitotic karyotype and idiogram of Parthenium argentatum (2n=36). In addition, a technique for production of well spread mitotic chromosome squashes is outlined.

The Karyotype of the White-Winged Dove

Chiarelli and Capanna (1973) point out the significance of karyotypes as a species-specific aspect of the phenotype. They also discuss the potential of a species' karyotype to evolve largely independent of the genotype thereby providing an additional suite of characters for karyological analysis. This paper presents the first description of the karyotype of the White-winged Dove (Zenaida asiatica). Karyotypes were prepared and examined from three populations of White-winged Doves in southwestern Texas. These included locations in Apline (Brewster County), Pharr (Hidalgo County), and the Sierra Vieja Mountains (Presidio County). Standard mitotic karyotypes were prepared from bone marrow cells following the techniques of Patton (1967), Hsu and Patton (1969), and Lee (1969). Additional material was prepared from spleen tissue. Chromosomes were subsequently stained in 2% Giemsa solution. Elevation of the mitotic index was accomplished following the yeast technique described by Lee and Elder (1980). Differential staining of nucleolus organizer regions (NORs) of mitotic chromosomes was accomplished following the technique of Howell and Black (1980). Meiotic chromosome spreads, from testicular tissue of reproductively active males, were prepared in much the same manner as the mitotic except that a 1% sodium citrate solution was used for the hypotonic incubation phase following homogenization in several drops of 2.2% sodium citrate solution. Karyotypes of members of the genus Zenaida have a diploid chromosome number range of 2n = 76 (for Z. auriculata) (De Lucca and De Aguiar 1976) to 2n = 78 (for Z. macroura) (Benirschke and Hsu 1971). Analysis of well-spread metaphase chromosome sets from White-winged Doves establishes a diploid chromosome number that ranges from 2n = 76 to 2n = 80 (Fig. 1). This variation was noted within individuals as well as between individuals. The karyotype of the White-winged Dove contains five macrochromosomal autosome pairs that are biarmed with the remainder being acrocentric. These macrochromosome pairs (#1, #2, #4, #5, and the Z sex chromosome) are all classified as submetacentric (more metacentric). The #3 chromosome pair is classified as acrocentric. The remainder of the chromosome pairs and the W sex chromosome were small acrocentric microchromosomes. These designations were made on the basis of centromere indices and follow the terminology ofLevan et al. (1964). The fundamental number for the White-winged Dove ranged from 84 (when 2n = 76) to 88 (when 2n = 80). Haploid chromosome numbers ranged from n = 38 to n = 40. No occurrences of abnormal synapsis were observed. The mitotic chromosomes ranged in mean length from 7.7 tm to 4 tm. Group 2 consists of chromosome pairs #4, #5, and the Z sex chromosome, all of which have a mean

Synaptonemal complex karyotyping: an appraisal based on a study ofCrepis capillaris

A synaptonemal complex (SC) karyotype for Crepis capillaris, based on SC measurements from 92 surface-spread pachytene nuclei, was compared with the mitotic karyotype of this species in order to evaluate the specific and general validity of SC karyotyping and to assess its potential for high resolution physical mapping. Although there are obvious similarities between the SC and mitotic karyotypes of Crepis capillaris, detailed quantitative comparisons reveal that they differ in some respects, both with regard to the relative lengths of entire chromosomes and arm ratios. The arm ratio differences between SC and mitotic chromosomes are evident in both the A and C chromosomes and reflect the distribution of C-banding heterochromatin. Based on this comparison, heterochromatin appears to be underrepresented in SC length. However, the relative lengths of entire A and C chromosome SCs do not conform to this model and suggest that some other factor or factors are also influencing SC lengths differentially. It is concluded that the non-agreement of SC and mitotic karyotypes does not invalidate the use of SCs for karyotyping and physical mapping purposes provided that any differences are understood and characterized as far as possible.

Mitotic karyotype analysis in theVignagenus by means of an image analyser

SUMMARYDetailed karyotypes of four Vigna species were obtained by means of an image analyzer. One cultivated species, cowpea (V. unguiculata) and three wild species (V. vaxillata, V. luteola and V. oblongifolia) were studied. Their karyotype formulas were as follows: msc + 6m + 4sm for V. unguiculata (2n = 22); msc + 8m + 2sm in V. oblongifolia and V. vaxillata (2n = 22) and smsc + 9m + sm in V. luteola (2n = 22). Marker chromosomes were also identified within each species, thus making possible the species identification by using their correspondent karyotype.

Genome analysis of Thinopyrum junceiforme and T. sartorii

Genome constitutions of Thinopyrum junceiforme (A. Löve and D. Löve) A. Löve (2n = 4x = 28) and T. sartorii (Boiss. &Heldr.) A. Löve (2n = 4x = 28) were determined by studying (i) meiotic pairing patterns in hybrids involving the two species and other pertinent hybrids; (ii) mitotic chromosome karyotypes based on length, arm ratio, and satellites; and (iii) C-banding patterns. New hybrids synthesized and reported are T. sartorii × T. bessarabicum (2n = 3x = 21), T. sartorii × (T. bessarabicum × T. elongatum) amphidiploid (2n = 4x = 28), and the reciprocal of the latter. Mean meiotic pairing in the triploid hybrid and the two tetraploid hybrids were 3.83 I + 3.92 II + 3.11 III, 0.931 + 7.46 II + 0.62 III + 2.44 IV + 0.07 V + 0.03 VI, and 3.41 I + 9.39 II + 0.74 III + 0.88 IV, respectively. Based on the chromosome pairing data, it can be concluded that T. junceiforme and T. sartorii have two versions (Jb and Je) of the J genome and behave like true allotetraploids owing to bivalentization. Karyotype analyses of the species and their hybrids with T. bessarabicum revealed minor structural differentiations of the genomes in the two species. Thinopyrum sartorii has one genome basically unchanged from the Jb genome of T. bessarabicum while another is a modified Je genome of T. elongatum. One genome of T. junceiforme is modified from Jb and the other is modified from Je. There are two pairs of large and one pair of small satellites in T. sartorii, but there are only one pair of each in T. junceiforme. Thinopyrum junceiforme is rich and T. sartorii is poor in interstitial C-bands for both sets of genomes. Thinopyrum sartorii has larger terminal C-bands on the Jb genome chromosomes than those of T. junceiforme. These organizational changes of chromosomes could not be detected by studying chromosome pairing alone. However, this study demonstrates that meiotic pairing is the first criterion for determining basic genome symbols. Other techniques, such as those involving chromosome banding, isozymes, and DNA probes, may then be used to detect differences in chromosome (or DNA) organization and gene expression.Key words: genome, hybrid, meiosis, karyotype, chromosome banding, speciation.

The Unique G-banded Mitotic Karyotype of the Turkish Hamster(Mesocricetus brandti).

G-banded studies of the chromosome complement of the Turkish hamster (Mesocricetus brandti) reveal unique variations in the sex chromosomes and chromosome 16 when compared to previously published karyotypes. Details of the characteristics of the present mitotic karyotypes of male and female are presented.

Effect of recombinant human IL-3 on the mitotic index and karyotype of hemopoietic cells

The proliferative induction by hemopoietic growth factors may provide a useful tool to improve the mitotic yield of hemopoietic cells, allowing a more accurate cytogenetic analysis in hematologic malignancies. For such a purpose, we studied the effects of the recombinant human IL-3 (rhIL-3) on the mitotic index and the karyotype of bone marrow cells from 14 patients with myelodysplastic (MDS) and myeloproliferative syndromes (MPS). The mitotic response to IL-3 of normal bone marrow samples was also evaluated. Total bone marrow cells were cultured for 24 to 72 hours either in presence or absence of rhIL-3. In most cases, IL-3-stimulated samples showed a considerably higher (4–70 times) mitotic index than unstimulated controls. Although a great patient-to-patient variability was observed, a common pattern of mitogenic response to IL-3 emerged among MPS, MDS, and normal cases. At 48 hours of incubation, the mean mitotic index from MPS and MDS cases stimulated with IL-3 was significantly higher ( p < 0.01) than unstimulated controls, whereas the mean mitotic increase from normal samples did not reach statistical significance ( p > 0.1). Even though not statistically evaluable, a similar trend of response was observed at 24 and 72 hours of culture. Chromosome studies of MPS and MDS cases showed the same karyotype either in stimulated and unstimulated samples.

Karyotype and chromosome banding in the reed frogHyperolius viridiflavus ommatostictus (Amphibia, Anura, Hyperoliidae)

C-banding and mithramycin staining were used to characterize the karyotypes of 10 specimens of the African reed frog Hyperolius viridiflavus ommatostictus from Tanzania. The diploid chromosome number is 2n = 24. Although no heteromorphic sex chromosomes were present in the mitotic karyotypes, in many diakineses of male meiosis one or two bivalents exhibited an end-to-end arrangement. In the laboratory 7 out of 24 females changed sex spontaneously. This indicates that an XY/XX system of sex determination operates in H. viridiflavus ommatostictus.

Cytogenetics of the Hessian Fly: I. Mitotic Karyotype Analysis and Polytene Chromosome Correlations

The somatic haploid chromosome set of the Hessian fly, Mayetiola destructor (Say),consists of two autosomes and two sex chromosomes. Female somatic cells have pairs of each of these chromosomes (2n = 8). Male somatic cells have two pairs of autosomes and two monosomic sex chromosomes. C-banding revealed pericentromeric heterochromatin on one arm of each chromosome. Mitotic chromosomes were karyotyped using relative lengths, centromeric positions, presence of secondary constrictions, and position and length of C-positive regions. Silver nitrate stained pericentromeric, heterochromatic regions on all four chromosomes but did not stain the entire C-positive regions. In female larvae, four distinct polytene chromosomes were found in the basal region cells of the salivary glands. In male larvae, two distinct and two diffuse polytene chromosomes were found in basal region cells. Differential polytene chromosome morphology in male and female larvae, polytene chromosome indexes, and the position of the nucleolus were used to establish correlations between mitotic and polytene chromosomes. The diffuse morphology of the polytene sex chromosomes in male larvae was probably related to dosage compensation. The number of sex chromosomes in male and female larvae is discussed in relation to sex determination and the production of monogenous progenies.

Role of cytoplasm-specific introgression in the evolution of the polyploid wheats

Studies of N-banded mitotic and meiotic karyotypes of Triticum turgidum L. (2n = 28; AABB) and Triticum timopheevii Zhuk. (2n = 28; AAGG) and hybrids between them, along with observations of meiotic pairing between telocentrics of the AB-genome chromosomes and their respective homologues and homeologues in T. timopheevii, showed that chromosome 4 (m4) of Triticum monococcum L. is present (as 4A(t)) in T. timopheevii but is lacking in T. turgidum. Neither 4A nor 4B pairs with 4A(t), but 4A pairs with 4G and, for this reason and because of its banding pattern, must be considered a B-genome chromosome. T. timopheevii chromosomes 4A(t) and 3A(t) are involved in a reciprocal translocation, and 2A(t), 1G, 2G, and 5G are also involved in translocations. Chromosome arm 4BL occasionally pairs with 7G. The satellites are on the short arms of chromosomes 6A(t) and 6G of T. timopheevii and 1B and 6B of T. turgidum. It is suggested that (i) T. timopheevii orginated as an allotetraploid of Aegilops speltoides Tausch/T. monococcum and (ii) T. turgidum was derived from T. timopheevii by introgressive hybridization with an unknown diploid species, which contributed its distinctive cytoplasm, chromosome 4B or a substantial portion of it, and additional chromosome segments. Rapid fixation of 4B in T. turgidum was ensured by cytoplasm-specific transmission.

Polytene chromosome mapping in Ceratitis capitata (Diptera: Tephritidae)

Polytene chromosome reference maps of the five autosomes of Ceratitis capitata from male pupal orbital bristle trichogen cells are presented and a correlation is established between two of them and the two largest of the five autosomes in the haploid mitotic complement. Characteristic features of each chromosome are described identifying areas that are difficult to analyze and noting the existence of common alternative band expression. A quantitative analysis of the mitotic karyotype of C. capitata indicates that the two smallest autosome pairs cannot be reliably distinguished. This may present problems with future attempts to establish homologies between the remaining mitotic and polytene chromosomes. A comparison of polytene chromosome banding patterns from salivary gland and trichogen cells failed to find any homologous regions, or even to identify homologous chromosomes. The banding differences are not explained by variation in puffing patterns, heterochromatin expression, or polyteny levels, but appear to reflect fundamental differences in banding patterns of the chromosomes in each tissue. Key words: Ceratitis capitata, polytene chromosome map, mitotic chromosome measurements.

Further studies on chiasma distribution and interference in the human male.

Some unusual patterns of chiasma distribution were noted in a preliminary investigation of meiosis in an infertile male with an apparently normal mitotic karyotype and a normal mean autosomal cell chiasma frequency. A detailed investigation of chiasma distribution on all 22 autosomes revealed that several chromosomes showed a significant change in chiasma distribution and/or mean inter-chiasma distance in comparison with previously published controls. These findings are discussed in relation to the general patterns of chiasma localization in the human male and the role of interference.