Diploid Types Research Articles

A Versatile Toolset for Genetic Manipulation of the Wine Yeast Hanseniaspora uvarum.

Hanseniaspora uvarum is an ascomycetous yeast that frequently dominates the population in the first two days of wine fermentations. It contributes to the production of many beneficial as well as detrimental aroma compounds. While the genome sequence of the diploid type strain DSM 2768 has been largely elucidated, transformation by electroporation was only recently achieved. We here provide an elaborate toolset for the genetic manipulation of this yeast. A chromosomal replication origin was isolated and used for the construction of episomal, self-replicating cloning vectors. Moreover, homozygous auxotrophic deletion markers (Huura3, Huhis3, Huleu2, Huade2) have been obtained in the diploid genome as future recipients and a proof of principle for the application of PCR-based one-step gene deletion strategies. Besides a hygromycin resistance cassette, a kanamycin resistance gene was established as a dominant marker for selection on G418. Recyclable deletion cassettes flanked by loxP-sites and the corresponding Cre-recombinase expression vectors were tailored. Moreover, we report on a chemical transformation procedure with the use of freeze-competent cells. Together, these techniques and constructs pave the way for efficient and targeted manipulations of H. uvarum.

Tandem duplications, eupolyploidy and secondary diploidization – genetic mechanisms of plant speciation and progressive evolution

The article considers the genetic mechanisms of plant speciation. The importance of interspecific hybridization and polyploidy (whole genome duplication, WGD) as the main mechanisms of plant speciation is shown. There are three main ways of transformations of the hybrid genome associated with speciation. In the first way, the ploidy of the offspring does not change in comparison with the parents’ ploidy; the genomes of hybrid lines are stabilized through backcrosses and introgression without polyploidization. In the second way, the interspecial hybridization followed by whole genome duplication. Then, the initially unstable neopolyploid genome gradually passes into a stable eupolyploid state with the preservation of the polyploid number of chromosomes but with the diploid type of chromosome conjugation in meiosis. This is a widespread and rapid mechanism of plant speciation and genus formation in higher plants, which ensured the morphological and genetic isolation and adaptability of at least 15 % of modern species of higher plants. However, this is a path that usually does not lead to aromorphoses, this is speciation at an already achieved level of complexity. The third way of speciation is realized through dysploidy and secondary diploidization of the genome. In this case, the neopolyploid undergoes significant genomic rearrangements and loses most of the duplicated gene copies, its number of chromosomes is radically reduced. In different individuals of a species that has embarked on the path of stochastic genome fractionation and dysploidy, the initial genetic redundancy of various genome components multiplied after WGD is transformed in an unpredictably unique way, which leads to a radical increase in intraspecific genomic and epigenetic polymorphism and provides rich material for natural selection. It was also shown that in eupolyploids and paleopolyploids, a significant role in heritable adaptations to environmental conditions and in anatomical and morphological innovations is played by segment and tandem duplications not associated with WGD. Some of the paleopolyploids, which turned out to be evolutionarily progressive morphotypes, possessing aromorphoses with diploidized genomes, give rise to new phylogenetic branches, new suprageneric taxa. The article proposes to assign both genera carrying a unique two-chromosomal genome Zingeria and Colpodium (x = 2; 2n = 4, 8, 12) into subtribe Zingeriinae Rodionov, subtrib. nov. – Type: Zingeria P. A. Smirn. In addition, the accomodation of the genera Helictochloa and Molineriella into one subtribe Helictochloinae Röser et Tkach seems to us unreasonable from a genomic point of view, since the fundamental difference between representatives of these two genera is that Molineriella species carry an unusual 4-chromosomal genome, while speciation in genus Helictochloa(2n = 14 – 154) goes through the combinations of different 7-chromosome subgenomes, denoted by the letters E, L, B, C, M, V, G, U. Therefore, we consider it necessary to assign Molineriella into a monogenic subtribe MolineriellinaeRodionov, subtrib. nov. – Type: Molineriella Rouy.

Late embryogenesis abundant gene LEA3 (Gh_A08G0694) enhances drought and salt stress tolerance in cotton

Plants have evolved a complex and organized response to abiotic stress that involves physiological and metabolic reprogramming, transcription control, epigenetic regulation, and expressions of thousand interacting genes for instance the late embryogenesis abundant (LEA) proteins are expressed in multiple environmental variables during the plant developmental period, and thus play critical role in enhancing drought and salt stress tolerance. A comprehensive molecular and functional characterization of the LEA3 gene was carried out in cotton under abiotic stress conditions in order to elucidate their functions. Seventy eight genes were identified in cotton, and were clustered into six clades moreover; the LEA genes were more upregulated in the tissues of the tetraploid cotton compared to the diploid type. A key gene, Gh_A08G0694 was the most upregulated, and was knocked in tetraploid cotton, the knocked out significantly increased the susceptibility of cotton plants to salinity and drought stresses, moreover, several ABA/stress-associated genes were down regulated. Similarly, overexpression of the key gene, significantly increased tolerance of the overexpressed plants to drought and salinity stress. The key gene is homologous to GhLEA3 protein, found to have strong interaction to key abiotic stress tolerance genes, voltage-dependent anion channel 1 (VDAC1) and glyceraldehyde-3-phosphate dehydrogenase A (gapA).

TINGKAT PLOIDI PAKU SAYUR (Diplazium esculentum) PADA KETINGGIAN YANG BERBEDA DI GUNUNG SEMERU

Polyploidy is a condition when the individual has more than two genomes, this polyploidy phenomenon is common in fern plants and one of the causes that is suspected to cause polyploidy events is cold temperatures. Therefore, this research aims to determine the level of ploidi fern vegetables (Diplazium esculentum) at different altitude in Semeru Mountain. This research is an experimental research using Completely Randomized Design (CRD). The object used is the Diplazium esculentum taken from different altitude (500 masl, 1500 masl, and 2500 masl) in Semeru Mountain. The next step is making the preparatory and chromosomal counts were then calculated on 5 root hood cells and each cell was counted for 3 repetitions. The data obtained were analyzed by one way Anova analysis with SPSS. The research results showed that there were differences in ploidy levels of Diplazium esculentum at different altitude indicated by F count (126.849) > F table 0,05 (3.885). Diplazium esculentum located at an heights of 500 masl showed the result of diploid cytological type (2n) which has an average number of chromosomes was 62.934; at an heights of 1500 masl indicated the result of triploid cytological type (3n) which has an average number of chromosomes was 80.334; while at an heights of 2500 masl has an average number of chromosomes as much as 106.4 with tetraploid cytological type results (4n). Thus it can be concluded that there is a difference in ploidy level of Diplazium esculentum at each altitude in Semeru Mountain.

Aggregation of a parthenogenetic diploid embryo and a male embryo improves the blastocyst development and parthenogenetic embryonic stem cell derivation

Parthenogenetically derived mammalian embryos, with no paternal genome, are not viable and die, largely from defective placental growth attributed to a lack of paternal effect, resulting in the low blastulation rate and low derivation efficiency of parthenogenetic embryonic stem cells (pESCs). Therefore, the present study, by the optimization of parthenogenetic embryo production and the aggregation of the parthenogenetic diploid embryo and the identified male embryo, aims to investigate a method to improve the development of parthenogenetic embryo and pESC derivation in mice. Using different chemical combinations for the optimization, we found that the heterozygous diploid type had a significantly higher blastulation rate than the haploid type (P < 0.05). The treatment of strontium chloride (SrCl2) combined with cytochalasin B for 4 h produced the highest heterozygous diploid rate and blastulation rate. Our self-made concave hole system was used for the aggregation of the parthenogenetic heterozygous diploid embryo with the male embryo identified by the duplex PCR method, and we found that the chimeric embryo had an improved rate of blastulation and pESC isolation.

Characterization of degradation and heterozygote balance by simulation of the forensic DNA analysis process

Simulation experiments were used to show the impact of varying extraction efficiency, aliquot proportion, and PCR efficiency on the heterozygote balance of a range of diploid and haploid cells. Reducing either parameters introduces variance. It is well-known that the variance in heterozygote balance increases as the amount of DNA is reduced. Surprisingly the distribution is in fact diamond shaped — the variance start to decrease at very low amounts of DNA. Simulations suggest that pristine diluted DNA is an acceptable approximation in validations to infer heterozygote balance. However, the difference in distribution of the variance between diploid and haploid cell types may, under some circumstances, need to be considered in statistical models. Finally, we exemplify how simulations can be used to predict the outcome of PCR for degraded samples. Visualizing the predicted DNA profile as an electropherogram can help to identify the best approach for sample processing.

Allelic diversity of S-RNase alleles in diploid potato species.

Key messageThe S-ribonuclease sequences of 16 S-alleles derived from diploid types of Solanum are presented. A phylogenetic analysis and partial phenotypic analysis support the conclusion that these are functional S-alleles.S-Ribonucleases (S-RNases) control the pistil specificity of the self-incompatibility (SI) response in the genus Solanum and several other members of the Solanaceae. The nucleotide sequences of S-RNases corresponding to a large number of S-alleles or S-haplotypes have been characterised. However, surprisingly, few S-RNase sequences are available for potato species. The identification of new S-alleles in diploid potato species is desirable as these stocks are important sources of traits such as biotic and abiotic resistance. S-RNase sequences are reported here from three distinct diploid types of potato: cultivated Solanum tuberosum Group Phureja, S. tuberosum Group Stenotomum, and the wild species Solanum okadae. Partial S-RNase sequences were obtained from pistil RNA by RT-PCR or 3′RACE (Rapid Amplification of cDNA Ends) using a degenerate primer. Full-length sequences were obtained for two alleles by 5′RACE. Database searches with these sequences identified 16 S-RNases in total, all of which are novel. The sequence analysis revealed all the expected features of functional S-RNases. Phylogenetic analysis with selected published S-RNase and S-like-RNase sequences from the Solanaceae revealed extensive trans-generic evolution of the S-RNases and a clear distinction from S-like-RNases. Pollination tests were used to confirm the self-incompatibility status and cross-compatibility relationships of the S. okadae accessions. All the S. okadae accessions were found to be self-incompatible as expected with crosses amongst them exhibiting both cross-compatibility and semi-compatibility consistent with the S-genotypes determined from the S-RNase sequence data. The progeny analysis of four semi-compatible crosses examined by allele-specific PCR provided further confirmation that these are functional S-RNases.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-016-2754-7) contains supplementary material, which is available to authorized users.

Inducing autotetraploids in cassava using oryzalin and colchicine and their in vitro morphophysiological effects.

Polyploid induction has been used for plant breeding to produce bigger and more robust plants than diploid types. The present study aimed to develop a methodology for in vitro induction of polyploidy in cassava. Apical and lateral microcuttings from the BRS Formosa variety were treated with six oryzalin concentrations for 24 and 48 h. The same methodology was used for colchicine with different concentrations. After 45 days of cultivation and an additional 45 days of subculture, the viability of the explants was assessed and plant acclimatization was performed. Ploidy was determined using flow cytometry. Oryzalin dose and exposure negatively affected cassava explant growth and development compared to untreated explants. Furthermore, apical and lateral explants responded differently to the treatments, showing a diversity in antimitotic sensitivity and effect that is tissue-type specific. In contrast, the doses of 1.25 to 6.25 mM colchicine resulted in high mortality of cassava explants. Therefore, the type of antimitotic affects the morphophysiological behavior of cassava plants in vitro, although apical explants have higher viability and regenerative capacity compared to lateral explants. In addition, the lateral explants have lower mixoploid rates compared to apical explants. Of the 310 plants generated by oryzalin treatments, 277 were diploid, 31 were mixoploid, and 2 were tetraploid. Exposure to oryzalin led to low rate of tetraploids and colchicine caused phytotoxic reactions and death of the explants. The tetraploids were multiplied in vitro to evaluate their yield in the field as well as their behavior against abiotic and biotic stress.

Phenotypic variation and performance of diploid subspecies of Dactylis glomerata L.

Dactylis glomerata L. is one of the best known examples of a polyploid complex that includes diploid (2n = 14), tetraploid (2n = 28) and hexaploid (2n = 42) types. The diploids, descending from the ancestors of the genus, are numerous, distinct forms adapted to specific environments and include all the morphological variation and ecological adaptation found in Dactylis. The objective of the present study was to shed more light on the differentiation of diploids and to obtain information for better exploiting the genetic resources of this species. To this end we carried out a discriminant analysis in the most widespread diploid subspecies based on a large number of morpho-physiological traits. We found that some characteristics, such as time to heading, time to flowering, vegetative regrowth, plant height and seed shattering are the most discriminant and enabled us to realize a more exact differentiation of the diploids with respect to the morphological criterion generally adopted. The results demonstrated that diploid taxa offer an interesting combination of relevant agronomical and ecological characteristics which could be useful in breeding programs to promote the use of this species in sustainable agriculture systems. We also performed cytological investigations and defined a general karyotype representative of the diploid Dactylis considered in this study.

Detection of Genome Donor Species of Neglected Tetraploid Crop Vigna reflexo-pilosa (Créole Bean), and Genetic Structure of Diploid Species Based on Newly Developed EST-SSR Markers from Azuki Bean (Vigna angularis)

Vigna reflexo-pilosa, which includes a neglected crop, is the only one tetraploid species in genus Vigna. The ancestral species that make up this allotetraploid species have not conclusively been identified, although previous studies suggested that a donor genome of V. reflexo-pilosa is V. trinervia. In this study, 1,429 azuki bean EST-SSR markers were developed of which 38 EST-SSR primer pairs that amplified one product in diploid species and two discrete products in tetraploid species were selected to analyze 268 accessions from eight taxa of seven Asian Vigna species including V. reflexo-pilosa var. glabra, V. reflexo-pilosa var. reflexo-pilosa, V. exilis, V. hirtella, V. minima, V. radiata var. sublobata, V. tenuicaulis and V. trinervia to identify genome donor of V. reflexo-pilosa. Since both diploid and tetraploid species were analyzed and each SSR primer pair detected two loci in the tetraploid species, we separated genomes of the tetraploid species into two different diploid types, viz. A and B. In total, 445 alleles were detected by 38 EST-SSR markers. The highest gene diversity was observed in V. hirtella. By assigning the discrete PCR products of V. reflexo-pilosa into two distinguished genomes, we were able to identify the two genome donor parents of créole bean. Phylogenetic and principal coordinate analyses suggested that V. hirtella is a species complex and may be composed of at least three distinct taxa. Both analyses also clearly demonstrated that V. trinervia and one taxon of V. hirtella are the genome donors of V. reflexo-pilosa. Gene diversity indicates that the evolution rate of EST-SSRs on genome B of créole bean might be faster than that on genome A. Species relationship among the Vigna species in relation to genetic data, morphology and geographical distribution are presented.

Cytogeography of essential oil chemotypes of Eremophila longifolia F. Muell (Scrophulariaceae)

Previous studies have demonstrated that the widely distributed desert plant Eremophila longifolia has at least six geographically defined essential oil chemotypes. The focus of the present study is to extend and enhance information concerning known chemotypes and to investigate the involvement of cell nuclei ploidy in this variation. Forty field collected specimens of E. longifolia were taken from most of the mainland states of Australia then subjected to hydrodistillation to produce essential oils, which were then chemically characterised. Ploidy was determined using relative fluorescence of cell nuclei stained with propidium iodide, measured in a flow cytometer. Using principal component analysis (PCA), at least three essential oil chemotypes, in addition to the six already described, were identified in the present study. Previously described high yielding essential oil chemotypes were also characterised in terms of diploidy. For the first time diploid populations were identified in New South Wales, correlating with high yielding isomenthone/menthone and karahanaenone chemotypes. Furthermore, the separate diploid population previously described from Western Australia was demonstrated to be the safrole/methyl eugenol type, which is restricted to a small geographic range in far north-west Western Australia (Murchison District). All other chemotypes were shown to be tetraploid, including apparently randomly emerging individuals, representative of chemotypes producing low yields of isomenthone/menthone and karahanaenone similar in composition to the high yielding diploid types.

Apomixis in different ploidy levels of cassava

Two polyploid hybrids between cassava (Manihot esculenta) cultivar 307-2 and its wild relatives M. glaziovii and M. anomala, were studied to examine the relationship between ploidy level and the production of seeds without fertilization. A clearing method was applied to assess ovule sizes as an indication of multiembryony. The diploid cultivar 307-2 had regular 18 bivalents at meiotic metaphase 1 while the polyploid types showed chromosome configurations varying from 3 to 4 quadrivalents and 28 to 30 bivalents. A total of 14% of studied ovules of the polyploid hybrid involving M. glaziovii were multiebryonic, while the percentage of multiembryony was as low as 2% in the polyploid hybrid M. anomala×M. esculenta. Diploid hybrid types did not show any multi embryony. Adventitious embryos were found and documented for the first time in polyploid hybrids M. esculenta×M. glaziovii. The association of multiple embryo formation with ovary size and pollination showed that apomictic embryos form independently from fertilization. Simple iodized carmine stain for measuring pollen viability proved as efficient as the sophisticated Alexander method.

SITOLOGI DAN TIPE REPRODUKSI Pteris multifida Poir. (PTERIDACEAE)

Cytological observations have been carried out by several researchers in South China, Japan, Ceylon, Hongkong, Himalaya and Java. The results from various regions showed that P. multifida had a fairly high genetic variation, namely diploid, triploid and tetraploid types. Therefore cytological and reproductive study on P. multifida from its geographical distribution areas need to be done. The objectives of this research were to observe the somatic chromosome number and reproductive type of P. multifida, and to recognize the relationship between morphological variation and its ploidy level as well as stomatal index. Plants were collected from several localities in Bogor. Ploidy level was determined by observing somatic chromosome number by using squash methods. Reproductive type was determined by counting spore number in each sporangium. Morphological characters examined were the stipe, lamina, pinnae, veins, and indusium. Observations of stomata and epidermis of leaves were done by making an incision paradermal leaf. Pteris multifida has two ploidy level and reproduction type, namely apogamous triploid (2n = 87) and sexual tetraploid (2n = 116). The two ploidy levels could not be distinguished based on morphological characteristics, but they can be differentiated by their epidermal cells number. Apogamous triploid has fewer number of epidermal cells, the sexual tetraploid has a greater number of epidermis.

Alterations of reproduction system in a polyploidized cassava interspecific hybrid

The objective of this research was to examine how much polyploidy may affect seed and root formation in cassava interspecific hybrids Manihot esculenta Crantz xM. oligantha Pax. A polyploid type was induced by colchicine treatment to lateral buds followed by propagating vegetatively arising stems. Cytogenetic and anatomical analyses were made on both polyploid and diploid types. The polyploid type showed extensive chromosome pairing and pollen viability. Multiembryonic ovule frequency increased in polyploid plants. Stalks became woody and propagation through roots difficult, the edible roots increased, however, in size.

Antioxidant phytochemicals and gingerol content in diploid and tetraploid clones of ginger ( Zingiber officinale Roscoe)

Fresh rhizomes of 18 diploid and tetraploid genotypes of Indian ginger, including commercial cultivars and experimental genotypes, were assayed for gingerol content and antioxidant activity. The tetraploid ginger type was derived from the respective diploid ginger by shoot tip culture. [6]-Gingerol was identified as the major pungent phenolic compound in all samples (mean 1354.78 ± 470 μg/g), while [8]- (mean 180.94 ± 45 μg/g) and [10]-gingerol (mean 234 ± 79 μg/g) occurred in lower concentrations. The total gingerol content of the tetraploid type was much higher than that of the respective diploid type and especially the [10]-gingerol. Both diploid and tetraploid types of the cv. Meghalaya Local contained the highest level of gingerol. At both ploidy levels, the genotypes showed significant differences in phenols and antioxidant activities. Correlation of total phenolics with different antioxidant assay at both diploid and tetraploid level was linear and strong to moderate. For genotypes at both ploidy levels, antioxidant activity (BCO) was determined especially by [6]-gingerol while [8]- and [10]-gingerol did not affect BCO. These results demonstrated that in the tetraploid types of ginger, the gingerol content and antioxidant activity were higher than in the diploid ones.

Multiple patterns of rDNA evolution following polyploidy in Oryza

Ribosomal ITS sequences are commonly used for phylogenetic reconstruction because they are included in rDNA repeats, and hence are ubiquitous and present in high copy number. Ribosomal rDNA repeats often undergo rapid concerted evolution within and between arrays. Interspecific hybridization merges divergent repeat types in a single nucleus, setting in motion evolutionary processes leading to coexistence, maintenance of paralogs, origin of novel sequence variants, loss of arrays, or inter-array sequence homogenization via concerted evolution. Here we examined ITS polymorphism within and among six Oryza tetraploids of varying genomic composition to infer the extent and direction of concerted evolution following allopolyploid speciation. We demonstrate that different polyploids have experienced varying fates, including maintenance or homogenization of divergent arrays, even among allopolyploids having the same genomic origins but in different geographic locations. Bidirectional concerted evolution, in which arrays become homogenized to alternative progenitor diploid types in different allopolyploid derivatives, is evident among species in one clade. Our results exemplify the panoply of outcomes for ribosomal DNA evolution following allopolyploid speciation.

In vitro polyploidization of Mecardonia tenella, a native plant from South America

Mecardonia tenella is an herbaceous plant widely distributed in the temperate region of South America. Both plant architecture and flower size are characteristics that can be improved to become a viable new ornamental plant. Chromosome doubling by the use of agents such as colchicine is an available methodology to this end. Nodal segments from in vitro grown plants of M. tenella were submerged in the following doses of colchicine in 1% (v/v) dimethyl-sulfoxide (DMSO) solution (%, v/v): 0.0, 0.001 and 0.01 (24 and 48 h). The DNA content of the regenerated plants was measured by flow cytometer. A total of 68 tetraploid plants were detected out of 126 colchicine treated plants. The flowers and leaves of the tetraploid plants were bigger compared to those from the wild diploid type (control). Under field conditions, the selected tetraploid plants showed a more compact shape than the control plants.

폐흡충의 이배체와 삼배체 vasa 유전자 분석 및 특징

In this study, we isolated, characterized, and compared the vasa homologous genes of diploid and triploid Paragonimus westermani and localized VASA homologous proteins in both lung fluke types. Open reading frames of Pw-vasa-2n and Pw-vasa-3n were of 1812 bp, and encoded deduced proteins of 622 amino acids with calculated molecular weights of 69.0 kDa and 68.9 kDa and pI`s of 9.11 and 9.03, respectively. A comparison of these two VASA deduced protein sequences showed that only 6 of the 622 amino acids differed. The deduced sequences of Pw-VASA-2n and Pw-VASA-3n contained eight consensus sequences characteristic of the DEAD-box protein family and their N-terminal regions contained four arginine-glycine-glycine (RGG) motifs. These two lung fluke VASA-like proteins were more similar to those of other VASA proteins than to those of other DEAD-family proteins isolated from several organisms (planarian, zebra fish, mouse, and human). vasa homologous gene transcription and VASA protein expressions in triploid type lung flukes was slightly stronger than in the diploid type. Immunostaining showed that testes and a portion of the ovaries of both diploid and triploid lung flukes reacted strongly to anti-Pw-VASA antibody.

Chromosome doubling induces apomixis in a cassava×Manihot anomala hybrid

A new species was synthesized artificially by chromosome doubling of an interspecific hybrid between cassava and Manihot anomala. The ensuing polyploid type exhibits an apomictic nature and maintains its morphological characteristics in the progeny. It showed a 29% frequency of multiembryonic sacs in its examined ovules whereas the multiembryonic sacs were absent in the diploid type.

Relation of DNA ploidy to genetic aberrations detected by chromosomal CGH and FISH in gastric adenocarcinomas

We analyzed DNA copy number aberrations (DCNAs) by chromosomal comparative genomic hybridization (CGH) in 93 consecutive sporadic gastric adenocarcinomas. In addition, numerical aberrations in chromosomes 7, 11, 17, and 18 were evaluated by fluorescence in situ hybridization (FISH). Gastric cancers were divided on the basis of nuclear DNA content measured by laser scanning cytometry (LSC) into two groups, 36 DNA diploid (1.0 <or= DNA index (DI) < 1.2) and 57 aneuploid (DI >or= 1.2) cancers. The most frequent gain and loss of DNA copy number were found at 8q21-23 and 19p13.3, respectively, in both diploid and aneuploid cancers. Diploid cancers were further divided on the basis of genetic aberrations into major type and subtype cancers. The diploid cancer group included nine subtype cancers that showed large numbers of DCNAs; the mean number of DCNAs detected by CGH was 26.7 per tumor. This value was much larger in these diploid subtype cancers than diploid major type cancers (mean, 5.2 per tumor, p<0.0001). These nine cancers were also characterized by large intercellular variations in chromosome copy numbers that were not detected in the 27 major diploid type cancers. The aneuploid cancer group included only three subtype tumors that showed only a small number of DCNAs (mean, 3 per tumor) and minimal intercellular variations in chromosomal copy number. These data indicate that gastric adenocarcinomas can be divided into three types; aneuploid, major diploid type and diploid subtype cancers. Large-scale studies are necessary to clarify the differences in biological characteristics and underlying genetic mechanisms between these types.