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Background and aims: Zephyranthes mesochloa, is a bulbous species with white flowers that inhabits the subtropical region of South America and presents different chromosome numbers. The aim of this work is to carry out the chromosome analysis of Z. mesochloa from northern Argentina, to contribute to the cytogenetic knowledge of the genus. M&M: Ploidy levels and somatic chromosome numbers were determined in individuals from 8 populations in northern Argentina using conventional staining. In addition, meiotic preparations with acetic carmine were performed on individuals from one population. Results: Seventy-five percent of the populations were diploid, with 2n = 2x = 12 and presented a karyotypic formula of 4m + 4sm + 4st. In two of the diploid populations, individuals with 2n = 13 were observed, with the presence of an additional metacentric chromosome, possibly a B chromosome. Microsporogenesis analysis, in diakinesis and metaphase I, of aneuploid cytotype (2n = 13), showed six bivalents and one univalent in all pollen mother cells analyzed. The remaining populations (25%) were tetraploids with 2n = 4x = 24 and karyotypic formula 8m + 8sm + 8st. Geographically, the distribution of cytotypes in Z. mesochloa is discontinuous. Conclusions: The duplicate karyotype formula in tetraploids regarding its con-specific diploids may indicate the origin of an autopolyploid cytotype. The available data allows us to consider the group of cytotypes as part of a polyploid complex with a basic number of x = 6. [ABSTRACT FROM AUTHOR]

Meiotic behavior is of great importance for the development of genetic improvement programs, especially in species such as vanilla (Vanilla planifolia Jacks.), which are severely affected by various biotic and abiotic factors derived from their narrow genetic base. Therefore, the present work was proposed with the objective of evaluating the meiotic behavior of the commercial morphotype "Mansa" from the municipality of "Papantla de Olarte" in Veracruz, Mexico. For this purpose, flower buds of different sizes were collected and fixed in Carnoy using the squash technique, followed by staining with 2% (w/v) acetocarmine to clearly observe all the stages of the meiotic process. Normal meiotic behavior and a haploid chromosome number (n = 8) were observed. These results may be useful for the development of breeding programs for this crop. [ABSTRACT FROM AUTHOR]

Talinum paniculatum is an adventitious herb widely distributed in the Argentina. This plant is considered as an economically important herbicide-resistant weed. This species shows two morphotypes in the field which are differentiated by shape, size and colour of their flowers leaves and fruits. The aims of this work were to determinate morpho-anatomical (leave and stem), cytogenetic and molecular traits of two morphotypes from Tucumán province (Argentina) and to establish differences between them. Classical morpho-anatomical and cytogenetic techniques were used, molecular analysis based on the ITS2 marker were performed. The results showed that morphological, anatomical, cytogenetic and molecular traits of T. paniculatum allow us to differentiate the MT1 and MT2 morphotypes. We concluded that MT1 match with T. paniculatum and MT2 is a different taxon still not described for the flora of Argentina. [ABSTRACT FROM AUTHOR]

Due to the increase in the incidence of Metabolic Syndrome worldwide, it is necessary to establish a comprehensive approach to the people who suffer from it and investigate aspects that contribute to delimit the specific mechanism of the development of metabolic modifications in order to anticipate complications through timely actions. In this sense, the objective of this documentary review is to point out the genetic influences involved in presenting them. For which a documentary review of essays and scientific articles was carried out virtually. Among the main results obesity is recognized as the nucleus of the syndrome as a result of alterations in genes the stimulation of proinflammatory cytokines the changes in lipid levels as well as the development of insulin resistance converge in a pathological state. In addition, several genes have been identified in specific chromosomes that suffer variations in the genetic chain sequence that leads to metabolic variability such as chromosome 16q12.2 and influences on the estrogen receptor gene. However, the genetic influence is not limited to these aspects but involves sex race age and is harmed by environmental factors that enhance the development of Metabolic Syndrome. Therefore, a broad field of work and approach to genetic influences in the development of this pathology is structured. [ABSTRACT FROM AUTHOR]

Corn is a crop of great importance in the world since it constitutes a basic component of the diet of the population; a production of 1026.61 million tons was estimated during the present year. Currently, there are many theories about the wild ancestors of corn, being Proto-Confite Morocho one of the primitive races in Peru, which is attributed as the ancestor of numerous native varieties. Therefore, knowledge of its genetic constitution is important since it gives us the possibility of finding phylogenetic affinities and indicators of systematic classification. The present study was carried out with the purpose of elaborating the karyotype of Zea mays ssp. mays 'native corn' ProtoConfite morocho and determine the number and morphology of the chromosomes. Corn seeds from the province of Virú, La Libertad, Peru, were used, while the experimental phase was developed in the Laboratory of Genetics and Molecular Biology at the National University of Trujillo, where metaphase plaques were obtained, selecting the best to perform the karyotype. It was concluded that the Zea mays ssp. mays 'native corn' Proto-Confite morocho presents 3 pairs of chromosomes ( 4, 4', 8, 8', 10, 10') submetacentric and 7 pairs of chromosomes (1, 1', 2, 2', 3, 3', 5, 5', 6, 6', 7, 7', 9, 9') metacentric, which average size are between 4.16 and 1.88 µm. [ABSTRACT FROM AUTHOR]

Number of chromosomes is important for evolutionary studies, phylogenetic, genetic and taxonomic improvement. Due the importance of chromosomes, this research was conducted in order to determine polyploidy on blackberries Rubus adenotrichos Schltdl, R. cymosus Rydb, R. humistratus Steud, R. palmeri Rydb, R. pringlei Rydby, R sapidus Schltdl; Tupi, Kiowa, Tupí x R. sapidus and Kiowa x R. sapidus. Chromosome counting was performed on somatic cells by crushing root tips. Chromosomes were observed and counted in metaphase for each one of specie, polyploidy was determined starting from 1x = 7. Morphological characteristics of each one of specie were based on qualitative descriptors of UPOV 2006. Blackberry showed variability in the number of chromosomal games: Rubus adenotrichos (2n = 2x = 14), R. cymosus (2n = 5x = 35), R. humistratus (2n = 2x = 14), R. palmeri (2n = 4x = 28), R. pringlei (2n = 3x = 21), R. sapidus (2n = 3x = 21); Tupi (2n = 2x = 21), Kiowa (2n = 2x = 28), Tupi x R. sapidus (2n = 2x = 21) and Kiowa x R. sapidus (2n = 2x = 28). Each one of the species presented particular characteristics that characterize them, however, it was not posible to determinate the morphological characteristics associate or define the poly-ploidy in the species analyzed. [ABSTRACT FROM AUTHOR]

The chromosome is a DNA molecule that maintains a characteristic structure and integrity by means of other molecules. Chromosomal abnormalities are conditions that results from a gain or loss of genetic material, responsible for congenital malformations in less than 2% of the newborns. There are two main groups: numerical and structural aberrations. Clinical evaluation and physical signs are necessary to suspect a chromosomal etiology. For diagnostic confirmation, karyotype is indicated, but other methodologies are available: FISH, MLPA and microarrays, each one of them in special cases. To provide a good quality of care, multidisciplinary approach is needed by studying and treating families with a person affected by a chromosomal abnormality. Consequently every clinical evaluation, diagnosis, health supervision and surveillance, including genetic counseling should be coordinated, and centered in the patient and his family. [ABSTRACT FROM AUTHOR]

Mitotic chromosomes of three populations of Agave cocui near Mochima National Park (10°23'45'' N, 64°21'20'' O, 41 m a.s.l.), Morro de Puerto Santo (10°42'43'' N, 63°09'50'' O, 72 m a.s.l.) and Playa Medina (10°42'58'' N, 63°00'42'' O, 35 m a.s.l.), Sucre state, Venezuela were analyzed. Conventional protocols were applied through temporal glass preparing for mitosis and karyotyping, photomicrographs records and computer analysis. The highest frequency of metaphase cells was observed at 8:00 and 9:00 a.m. Karyotype was consistently diploid 2n=2x=60 with 25 pairs of small chromosomes (0.83-2.10 µm) m type, and five largest pairs (3.68 to 4.97 µm) sm and st (with satellites). Asymmetry index A1 = 0.74 and A2 = 0.65 confirm bimodal karyotype in this species. Populations were similar, and idiogramatic formula is 50m+8sm+2stsat. These results represent the first report of count and classification of chromosomes in A. cocui. [ABSTRACT FROM AUTHOR]

Background: Cytogenetics has revealed that the development of brain tumors might be induced by molecular alterations. The association of chromosomal imbalances with survival will allow for the prognosis and treatment of these tumors to be assessed. The objective of this study was to determine chromosomal imbalances and overall and disease-free survival in pediatric patients with astrocytoma and the association between chromosomal imbalances and survival. Methods: Medical charts of patients diagnosed with astrocytoma according to records from 1995 to 2005 were reviewed. Paraffin blocks were retrieved in order to extract tumor material and a comparative genomic hybridization technique was used to search for chromosomal gains and losses. Results: Out of 35 patients, 31 had at least some alteration in chromosomes 1, 5, 9 or 18, the latter with gains or losses in 65.7 % of the patients. By histology, 7/9 pilocytic astrocytomas had alteration of chromosome 9, and in 5/6 anaplastic astrocytomas, of chromosome 18. Patients with alterations in these chromosomes had a worse survival. Conclusions: The results of this study suggest that there is an association between the anaplastic histology and chromosome 18 alterations, as well as between diffuse astrocytoma and alterations in chromosome 5, which could be relevant in the Latin American population. [ABSTRACT FROM AUTHOR]

Objective. The cell cycle and chromosomic description of Espeletiopsis muiska was studied in meristematic cells of root tips obtained from in vitro culture of embryos on MS medium supplemented with IBA. Materials and methods. Root tips at different times of day were collected and the cells in each mitotic phase were counted. With this information, the cell cycle length and mitotic activity was determined at its peak hours. Description of chromosomes and elaboration of karyotype of the specie was done with a protocol that allows obtaining metaphase chromosomes. Results. Regarding the cell cycle length, we found that the interface includes the 94.65% and mitosis the 5.35% of total cell cycle. Regarding the mitotic phases, the prophase lasts longer, 1.92%, while the anaphase is the shortest, 0.96%. As to mitotic hour, meristematic cells of root tips showed an increased activity between 10:30 and 11:15. 19 pairs of chromosomes with similar lengths, similar centromeric indices and asymmetrical karyotype were found in this cytogenetic study. Conclusions. The detailed study of the chromosomes revealed a chromosome complement 2n=38+2B, two chromosomes with microsatellite terminals and one with a secondary constriction. [ABSTRACT FROM AUTHOR]

Fragmentation of animal and plant populations typically leads to genetic erosion and increased probability of extirpation. Although these effects can usually be reversed by re-establishing gene flow between population fragments, managers sometimes fail to do so due to fears of outbreeding depression (OD). Rapid development of OD is due primarily to adaptive differentiation from selection or fixation of chromosomal variants. Fixed chromosomal variants can be detected empirically. We used an extended form of the breeders' equation to predict the probability of OD due to adaptive differentiation between recently isolated population fragments as a function of intensity of selection, genetic diversity, effective population sizes, and generations of isolation. Empirical data indicated that populations in similar environments had not developed OD even after thousands of generations of isolation. To predict the probability of OD, we developed a decision tree that was based on the four variables from the breeders' equation, taxonomic status, and gene flow within the last 500 years. The predicted probability of OD in crosses between two populations is elevated when the populations have at least one of the following characteristics: are distinct species, have fixed chromosomal differences, exchanged no genes in the last 500 years, or inhabit different environments. Conversely, the predicted probability of OD in crosses between two populations of the same species is low for populations with the same karyotype, isolated for <500 years, and that occupy similar environments. In the former case, we recommend crossing be avoided or tried on a limited, experimental basis. In the latter case, crossing can be carried out with low probability of OD. We used crosses with known results to test the decision tree and found that it correctly identified cases where OD occurred. Current concerns about OD in recently fragmented populations are almost certainly excessive. [ABSTRACT FROM AUTHOR]

In this study we analyzed the results of 432 consecutive chromosome studies performed in peripheral blood lymphocytes, corresponding to patients referred to a service of Genetic Diagnostic Laboratory - Scientific Medical Center- in Río Cuarto, Córdoba. The objectives were to determine the prevalence of chromosome abnormalities and relate the significance of the results obtained with the clinical diagnosis. An observational descriptive crosssectional study of the results of the karyotypes was carried out. Karyotypes were obtained from lymphocyte cultures according to conventional methodology. A 6.94 % of the patients under study were newborns, 53.47% were infants and children up to 12 years, 6.71% adolescents and 32.87% adults. Variations were found in 117 karyotypes: in 14 of them we observed normal variants and in 103 (23.84% of the total) chromosomal abnormalities, additionally 2 of them had also normal variants. Out of the 103 karyotypes with chromosomal abnormalities, 63.10% (n = 65) corresponded to numerical alterations and 24.27% (n = 25) to structural abnormalities. Within the structural chromosomal alterations observed, 44.00% (n = 11) were deletions, and less frequently we detected inversions, translocations and markers. In the remaining12.62% (n = 13) we observed fragile X chromosome (n = 9), one sex reversal and gaps (n = 3). The prevalence of chromosomal abnormalities found in the different age groups emphasizes the need for karyotyping and highlight the importance of cytogenetics especially in neonatology, pediatrics, endocrinology, obstetrics and gynecology. [ABSTRACT FROM AUTHOR]

A cytogenetic analysis using surface spreading and air drying was performed to analyze the mitotic chromosomes of Karwinskia calderonii, K. parvifolia and K. subcordata. The results confirm a diploid number 2n = 24 and a basic number x = 12. All species showed a somatic complement characterized by small meta- and submetacentric chromosomes. The smallest pair of each complement carried a secondary constriction and a satellite. Morphological and numerical constancy in the chromosome complements agree with previous studies in other species of the genus. Results suggest some kind of nucleotypic differentiation related to geographic factors as latitude and altitude. [ABSTRACT FROM AUTHOR]

The karyotype of the tropical gar Atractosteus tropicus is described from conventional Giemsa-staining of 295 mitotic chromosome slides from 120 larvae and 15 adults (five females and ten males) from Tabasco, southern of Mexico. The diploid number 2n = 56 chromosomes was calculated (73 spreads from 206 larval and 208 adult metaphases). Variation on chromosome number was from 46 (4.4%) to 64 (3.9%) chromosome elements on larval samples, whereas 58 (11.7 %) chromosomes were the second most abundant after the diploid number of 2n = 56 (35%). Such variation was related with the presence of mobile microchromosomes. The karyotype was determined from six clear chromosome spreads photographed from three females and three males. The averaged karyotype was integrated by eight pairs of metacentric (m) chromosomes, four submetacentric (sm) pairs, eight telocentric (t) pairs and eight pairs of telocentric microchromosomes (*t). The fundamental number was FN = 80 chromosome arms. We saw no sexual differences on chromosome structure. [ABSTRACT FROM AUTHOR]

Cytogenetic characterization of the neotropical fish Brycon henni (Pisces: Characidae). Brycon henni, is a native fish from Western Colombia is important as food and in sport fishing, and could be cultured in waters between 18 and 28°C. A previous cytogenetic study in branchial cells indicated different chromosomal complements. Total blood samples were seeded in 4 ml Ham-F12 culture medium, supplemented with 0.5 ml Bovine Fetal Serum and 0.7 ml Phyitohemaglutinin M (Gibco®) during 96 hr at 28°C; an antimitotic factor (100μl Colcemid® 10%) was added. Cells were incubated in 10 ml KCl hypotonic solution (0.56%) for 24 min at 37°C, fixed in methanol; acetic acid (3: 1) three times, separated by centrifugations, extended drip, and the chromosomes slides were stained with 5% Giemsa (5%). The best metaphases (6 males and 8 females) were photographed. There was a diploid number of 50 chromosomes: Metacentrics (26M), Submetacentrics (16SM) and Subtelocentrics (8ST). The fundamental number is 100 arms. The evolutionary tendency is type B with no supernumerary chromosomes; a first pair of big metacentric chromosomes is characteristic for Brycon, while no chromosomic sexual heteromorfism was detected. [ABSTRACT FROM AUTHOR]

Over the past few years an important reduction in the number of nesting marine turtle Caretta caretta individuals has been registered in the Colombian Caribbean, raising the question of a possible extinction in the medium term. A conservation plan is needed. We studied the culture requirements for C. caretta lymphocytes and preliminary karyotype analysis for cytogenetic identification, immunological study and toxicology without the need to kill individuals. Peripheral blood samples were obtained from 47 individuals in Santa Marta, Colombia and tests were made until optimal conditions were established for lymphocyte culture. The karyotype had 56 chromosomes, 32 macrochromosomes and 24 microchromosomes. An ideogram showed that C. caretta has four groups of chromosomes. Sexual chromosomes were not observed. These results do not coincide with the karyotype described from the Pacific (Japan). The present study is the first to include a complete description of the chromosome morphology of turtles from the Atlantic Ocean. It is possible that one of the adaptive strategies of this species is genetic interchange with other species of the family, producing viable hybrids. Individuals in this study might be viable hybrids of C. caretta and further molecular studies are needed. [ABSTRACT FROM AUTHOR]

Karyotypes of the purple snails Plicopurpura pansa and Plicopurpura columellaris (Gastropoda: Muricidae). The karyotypes of the purple snails Plicopurpura pansa (Gould, 1853) and P. columellaris (Lamarck, 1816) were established from 17 and 13 adults, respectively; and from eight capsules with embryos of P. pansa. In P. pansa were counted 59 mitotic fields in the adults and 127 in embryos; and 118 fields in P. columellaris. Chromosome numbers from 30 to 42 were observed in both species. Such a variation was notorious in each sample and there was no evidence of any relationship with tissue (gill, muscle and stomach). Both species has a typical modal number of 2n=36 chromosomes. Five good quality chromosome spreads were selected from adults of each species to assemble the karyotype. Classic cytogenetics statistics like relative lengths, arm ratio, centromeric index and the difference between long and short arms are presented. There were three pairs of metacentric and fifteen pairs of telocentric chromosomes in both species. This classification was not strong enough, so the chromosome complement by species was divided in four groups ("a", "b", "c" and "d") on the basis of relative lengths (p+q). A comparison of p+q in each chromosome pair was estimated within and between species by two ways analysis of variance and Tukey tests (P<0.05). Significant differences were identified among chromosome groups in each species; the differences between species were given by the first three pairs of chromosomes (group "a" biarmed) and the last two pairs (group "d" uniarmed). Deviations in chromosome number and relative lengths probably are given by chromosome rearrangements, related with chromosome polymorphism and presence of the atypical microchromosome "B". The fundamental number in both species was characterized by 42 chromosome arms. No sex chromosomes were identified. [ABSTRACT FROM AUTHOR]

Objectives: To demonstrate the frequency of chromosomic alterations and their relationship to the growth velocity of in vitro meningioma cells cultures. Data obtained in previous studies have shown that there is a kinship between chromosomic alterations, the risk of recurrence and tumor stage. Materials and methods: Samples taken during meningioma resection surgery from any location were cultured. The samples were obtained from patients at the University Hospital, the Rafael Uribe Clinic and private clinics, previous informed consent either from patients or their relatives. Cell cultures were performed, speed of growth was measured, and the karyotype was obtained in order to define the chromosomic alterations present in each tumor. Results: 47% of the meningiomas studied showed different chromosomic alterations or besides monosomy of the chromosome 22 that according to previous publications are associated to tumoral progression and represent a recurrence risk greater than 10%. Conclusions: The cytogenetic studies and the in vitro cellular growth velocity of the tumoral cells could be excellent complements of the surgical result and the pathology study, contributing to establish the risk of recurrence, so helping to define the patient's prognosis. [ABSTRACT FROM AUTHOR]

Hibiscus section Furcaria is a natural group of plants that presently includes 109 recognized taxa. Taxa are found in subsaharan Africa, India, southeastern Asia, Malesia, Australia, islands of the Pacific basin, the Caribbean, North, Central, and South America. The basic chromosome number is x = 18. In nature, ploidy levels range from diploid to decaploid. The taxa exhibit a remarkable amount of genome diversity. At least 13 genomes have been identified, some distributed widely and others with more restricted distributions. No modern taxonomic monograph of Hibiscus section Furcaria exists, but a number of regional studies have appeared that are essentially global in extent. Also, a number of studies of chromosome numbers and genome relationships have been published. The present paper includes a census of all the presently accepted taxa, the geographical distribution of each taxon, and chromosome numbers and genome designations of the 49 taxa for which the information is available. Important mechanisms of speciation include genome divergence at the diploid level, followed by hybridization and allopolyploidy, significant species radiation at the tetraploid and hexaploid levels, and the development of even higher levels of allopolyploids. [ABSTRACT FROM AUTHOR]

The most important characteristics for genotype were studied on rhizobial strains, isolated from forage legume species, indigenous to Sancti-Spiritus province, Cuba, with the aim of regarding genetic diversity and to obtain data for further taxonomic position. The DNA-DNA homology test, as well as the determination of plasmids and the localization of nod genes BCI were used. Tests showed the presence of several genomic species. On the other hand, common nodulation genes BCI were localized chromosomally. These results indicate that evaluated strains are genetically closed to Bradyrhizobium genus. However, a deeply study on this field is recommended. [ABSTRACT FROM AUTHOR]

Bilateral anophtalmos is a rare defect and less frequent entity. Congenital abscence of any ocular structure or arrest development or only an hystological sample may be present. Eyelids may be present and often adhered but can be separated. Anophtalmos can be associated to Sox² chromosome or 20bp gene depletion. Approximate incidence is 1:1000 wich demands to report this case in order to increase the numbers in the literature and to analyze the diagnosis, treatment and progress related to this rare defect. [ABSTRACT FROM AUTHOR]

Psychotic syndromes secondary to genomic disorders have low prevalence and may easily go unnoticed in the daily clinical practice. The velo-cardio-facial syndrome or DiGeorge syndrome (VCFS/DGS) is the genomic disorder most frequently associated to an interstitial deletion of the 22q11 region, with an incidence of one per every 4,000 newborns. Clinical manifestations constitute a constellation of cardiac, facial, urogenital and psychiatric disorders, among which schizophrenia or schizophreniform disorder stand out with an incidence of about 30% over the lifetime. In the following, we present the case of a 21 year old female patient who was admitted to the hematology service of our hospital due to pancytopenia secondary to metimazole, who had non-specified psychiatric background and who received antipsychotic treatment. [ABSTRACT FROM AUTHOR]