Polysomy and supernumerary chromosomes in Ornithogalum umbellatum L. (Liliaceae)

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 19-25 ◽  
Author(s):  
C. Ruiz Rejón ◽  
R. Lozano ◽  
M. Ruiz Rejón
Keyword(s):  
Key Words ◽  
Natural Population ◽  
Sierra Nevada ◽  
High Frequency ◽  
Variable Number ◽  
B Chromosomes ◽  
Structural Variants ◽  
Satellite Chromosome ◽  
Supernumerary Chromosomes ◽  
Numerical Variation

One hundred bulbs of Ornithogalum umbellatum L. have been analyzed cytogenetically in one natural population collected from the Sierra Nevada of Spain. Three types of plants were identified: (i) diploid plants (2n = 18, 26%); (ii) diploid plants with a variable number of B chromosomes (1–8 B's, 40%); and (iii) polysomic plants (2n = 19–23) with or without B's (34%). B's are of two types: metacentric and acrocentric and are associated with three types of abnormalities: (i) failure of the A chromosomes to move to the poles at anaphase I; (ii) nondisjunction of some A chromosomes at anaphase II; and (iii) the occurrence of tetraploid sporocytes. The B's are isopycnotic, do not associate with the A's, and invariably occur as univalents at first meiosis but show no tendency for elimination. All members of the complement except the satellite chromosome, no. 6, have been detected in a trisomic or a tetrasomic condition. Additionally some unusual structural variants, not present in the diploid standard complement, appear in some polysomic individuals. The polysomic elements are euchromatic, stable, and they do not associate either with normal chromosomes or with B's. The polysomic elements form univalents when they are trisomic and bivalents when tetrasomic. The fact that a high frequency (94%) of the polysomic elements also carry B's suggests that these two forms of numerical variation are interrelated in origin. Key words: Ornithogalum umbellatum, polysomy, supernumerary chromosomes.

Occurrence and Origin of Supernumerary Chromosomes in Partamona (Hymenoptera: Apidae: Meliponini)

2016 ◽  
Vol 150 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Diana P. Machado ◽  
Elder A. Miranda ◽  
Mariana C. Dessi ◽  
Camila P. Sabadini ◽  
Marco A. Del Lama
Keyword(s):  
High Frequency ◽  
Scar Marker ◽  
Sequence Data ◽  
Low Frequency ◽  
B Chromosomes ◽  
First Report ◽  
Supernumerary Chromosomes

Samples from 861 colonies of 12 Partamona species from 125 Brazilian localities were analysed for a SCAR marker specific to the B chromosomes of P. helleri. We identified the SCAR marker in 6 of the 12 species analysed, including 2 (P. gregaria and P. chapadicola) from the pearsoni clade. This is the first report on the presence of this marker in Partamona species that are not included in the cupira clade, which indicates that the B chromosomes probably are more widespread in this genus than previously thought. The analysis revealed a high frequency of the SCAR marker in the samples of P. helleri (0.47), P. cupira (0.46), and P. rustica (0.29), and a low frequency in P. aff. helleri (0.06). The frequency of the marker in P. helleri was correlated with the latitude of the sampling locality, decreasing from north to south. Sequence data on the SCAR marker from 50 individuals of the 6 species in which the presence of this marker was shown revealed a new scenario for the origin of the B chromosomes in Partamona.

Meiotic stability of B chromosomes and production of macrospermatids in Aiolopus strepens (Orthoptera: Acrididae)

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 5-10 ◽  
Author(s):  
J. A. Suja ◽  
C. Garcia de la Vega ◽  
J. S. Rufas
Keyword(s):  
Key Words ◽  
Natural Populations ◽  
B Chromosomes ◽  
Supernumerary Chromosomes ◽  
Mitotic Instability ◽  
Meiotic Stability ◽  
Intercellular Connections

Four males from several Spanish natural populations of Aiolopus strepens were found to carry B chromosomes. These are short and acrocentric and are identical in the different individuals. They show mitotic instability and meiotic stability. When present in odd numbers one unpaired B is generally observed, while in even numbers they usually form bivalents. In no case were lagging B's observed. B chromosomes do not affect nucleolar expression. A significant increase in the number of macrospermatids is found in individuals with B's. This is more pronounced in follicles containing odd numbers of supernumerary chromosomes. A possible explanation based on an assumed influence of B univalents on the maintenance of intercellular connections is discussed. Key words: B chromosomes, spermiogenesis, insect cytogenetics.

Antifúngicos poliénicos. Mecanismo de acción y aplicaciones

2020 ◽  
Vol 63 (2) ◽  
pp. 7-17
Author(s):  
Evelyn Rivera-Toledo ◽  
Alan Uriel Jiménez-Delgadillo ◽  
Patricia Manzano-Gayosso
Keyword(s):  
Antifungal Activity ◽  
Key Words ◽  
Secondary Metabolism ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Fungal Infections ◽  
Variable Number ◽  
Therapeutic Failure ◽  
Morbidity And Mortality ◽  
Clinical Use

The first compounds with specific antifungal activity were identified in the middle of the last century as a product of the secondary metabolism of bacteria of the order Actinomycetales, and their clinical use significantly diminished the morbidity and mortality associated with severe fungal infections. Many of such biosynthetic compounds are characterized by a chemical polygenic structure, with a variable number of carbon-carbon double bonds. Currently, besides polygenic antimycotics, there are other antifungal agents, such as the azole compounds, that have less toxicity in patients; however, cases of therapeutic failure with such compounds have been documented, therefore, the use of polygenics is still the best alternative in such cases. This review presents data about the properties and applications of antifungal-polygenic compounds using amphotericin B as a model. Key words: Amphotericin B; antifungal polyenes; ergosterol

Features of obstetric and perinatal pathology at women with an undifferentiated dysplasia of connecting tissue

2017 ◽  
pp. 96-98
Author(s):  
A.L. Kostiuk ◽  
Keyword(s):  
Pregnant Women ◽  
Key Words ◽  
High Frequency ◽  
Clinical Laboratory ◽  
Perinatal Pathology

The objective: to study features of obstetric and perinitalny pathology at women with undifferentiated dysplasia of a connecting tissue. Patients and methods. 100 patients with clinical-laboratory signs of an undifferentiated dysplasia of connecting tissue are surveyed. On the basis of the received results of the patient were divided into two groups: the main – 50 women (expression of і6 points) whom regarded as patients with the expressed undifferentiated dysplasia of connecting tissue, and group of comparison – 50 women (expression <6 points) whom regarded as patients without the expressed undifferentiated dysplasia of connecting tissue. Results. Results of the conducted researches testify to the high frequency of obstetric and perinatal pathology at pregnant women with clinical-laboratory and functional signs of an undifferentiated dysplasia of connecting tissue. Conclusion. The received results are the basis for algorithm improvement the diagnostical and treatment-and-prophylactic actions at women with an undifferentiated dysplasia of connecting tissue. Key words: undifferentiated dysplasia of connecting tissue, obstetric and perinatal pathology.

Features of professional disease of women–medical workers

2017 ◽  
pp. 70-71
Author(s):  
A.S. Shelygin ◽  
Keyword(s):  
Key Words ◽  
Functional Assessment ◽  
High Frequency ◽  
Clinical Laboratory ◽  
State Of Health ◽  
Case Rate ◽  
Working Out ◽  
Doctors And Nurses

The objective: an assessment of a professional case rate of women–medical workers. Patients and methods. The complex clinical-laboratory and functional assessment of a state of health, including genesial, at 100 women of doctors of various specialties and at 100 women of average medical workers is carried out. Results. Results of the spent researches testifies to high frequency of professional disease of medical workers of a various link – doctors and nurses. Conclusion. The received results are necessary for considering by working out of algorithm of diagnostic and treatment-and-prophylactic actions. Key words: medical workers, professional disease.

High frequency of neurexin 1β signal peptide structural variants in patients with autism

2006 ◽  
Vol 409 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Jinong Feng ◽  
Richard Schroer ◽  
Jin Yan ◽  
Wenjia Song ◽  
Chunmei Yang ◽  
...  
Keyword(s):  
Signal Peptide ◽  
High Frequency ◽  
Structural Variants

Structural hybridity and supernumerary chromosomes in a diploid Tradescantia hirsuticaulis

1975 ◽  
Vol 53 (5) ◽  
pp. 456-465 ◽  
Author(s):  
C. C. Chinnappa
Keyword(s):  
Reciprocal Translocation ◽  
Cytological Study ◽  
B Chromosomes ◽  
The Other ◽  
Meiotic Pairing ◽  
Structural Hybridity ◽  
Supernumerary Chromosomes

Cytological study of a diploid (2n = 12) population of Tradescantia hirsuticaulis Small from Stone Mountain, Georgia, revealed striking variation in four plants growing in a cluster, indicating that they constitute different genotypes. The occurrence of B chromosomes, fragments, and aneusomaty in the plants is associated with structural hybridity in the chromosomes. Two plants were homozygotes with simple meiotic pairing, one was heterozygous for a reciprocal translocation, and the other was a heterozygote for two interchanges as well as for inversions. The behavior and the origin of B chromosomes, fragments, and structural hybridity are discussed.

Ascospore abortion in crosses of Cochliobolus heterostrophus heterozygous for the virulence locus Tox1

Genome ◽  
1988 ◽  
Vol 30 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Charlotte R. Bronson
Keyword(s):  
Key Words ◽  
Reciprocal Translocation ◽  
High Frequency ◽  
Chromosome Rearrangement ◽  
Cochliobolus Heterostrophus ◽  
Bipolaris Maydis ◽  
Field Isolates

Crosses heterozygous for the virulence locus Tox1 show a high frequency of nonrandom ascospore abortion, in addition to a high frequency of random abortion seen in homozygous crosses. In crosses among closely related laboratory strains, the frequency of asci with eight mature, viable spores dropped from 35–47% of asci with mature spores in crosses homozygous for Tox1 to 3–17% in heterozygous crosses. Segregation for alternate alleles of Tox1 was 2:2 in 98% of asci with four viable spores. Patterns of abortion in crosses involving field isolates were similar to the patterns in crosses among laboratory strains. No recombinants between Tox1 and the abortion-inducing factor were detected among 112 progeny of laboratory strains. The results suggest that race T (TOX1) and race O (tox1) strains of C. heterostrophus differ by a chromosome rearrangement, possibly a reciprocal translocation, with a breakpoint at or near Tox1.Key words: fertility, T-toxin, Cochliobolus heterostrophus, Helminthosporium maydis, Bipolaris maydis, Drechslera maydis, chromosome rearrangement, reciprocal translocation.

Male germ line polysomy in the grasshopper Chorthippus binotatus: extra chromosomes are not transmitted

Genome ◽  
1990 ◽  
Vol 33 (3) ◽  
pp. 384-388 ◽  
Author(s):  
M. Talavera ◽  
M. D. López-Leon ◽  
J. Cabrero ◽  
J. P. M. Camacho
Keyword(s):  
Natural Population ◽  
Sierra Nevada ◽  
Germ Line ◽  
Male Parent ◽  
Male Germ Line ◽  
Controlled Crosses

Some males of the grasshopper Chorthippus binotatus from a natural population in Sierra Nevada (Granada, Spain) were found to be polysomic mosaics for the presence of extra chromosomes (E) in a high proportion of testicular follicles. Transmission analysis of these chromosomes was performed in 21 controlled crosses, 2 of which involved a polysomic parent. While most spermatozoa produced by polysomic males carried E chromosomes, these chromosomes were not transmitted to the progeny, since all 22 embryos descended from a polysomic male parent lacked them.Key words: transmission, polysomy, grasshopper, Chorthippus binotatus.

Karyotype, C-banding, chromosomal location of active nucleolar organizing regions, and B-chromosomes in Lasius niger (Hymenoptera, Formicidae)

Genome ◽  
1990 ◽  
Vol 33 (2) ◽  
pp. 267-272 ◽  
Author(s):  
T. Palomeque ◽  
E. Chica ◽  
R. Díaz de la Guardia
Keyword(s):  
Germ Cells ◽  
Chromosomal Location ◽  
Ganglion Cells ◽  
Cerebral Ganglion ◽  
B Chromosomes ◽  
Lasius Niger ◽  
Nucleolar Organizing Regions ◽  
Nucleolar Organizing Region ◽  
C Banding ◽  
Numerical Variation

The karyotype of Lasius niger (n = 15) was analysed using C-banding and observation of nucleolar organizing region (NOR) sites. C-banding showed the existence of heterochromatin in the paracentromeric regions of all chromosomes. Two sites with primary NORs were found in chromosomes 6 and 8. Chromosome 13 showed a secondary NOR. In both cases, the NORs were located in the paracentromeric region. B-chromosomes were found in male and female germ cells. They exhibited intra- and inter-individual numerical variation. No B-chromosomes were observed in somatic cells (cerebral ganglion cells) of all castes. The Bs are telocentric, small, and clearly distinguishable from the regular members of the complement. They show positive heteropycnosis in meiotic prophase and they are highly C-band positive. The activity of NORs does not change when Bs are present. Several aspects of the behaviour of these Bs are examined.Key words: C-bands, nucleolar organizing region (primary), nucleolar oganizing region (secondary), B-chromosomes, Formicidae.

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