Homoeologous pairing and recombination between the long arms of group 1 chromosomes in wheat × rye hybrids

Genome ◽  
1989 ◽  
Vol 32 (2) ◽  
pp. 293-301 ◽  
Author(s):  
T. Naranjo ◽  
P. Fernández-Rueda ◽  
P. G. Goicoechea ◽  
A. Roca ◽  
R. Giráldez
Keyword(s):  
Banding Pattern ◽  
Homoeologous Pairing ◽  
Parental Type ◽  
C Banding ◽  
Group 1 Chromosomes ◽  
The Relationship ◽  
Double Recombinant ◽  
Group 1 ◽  
Metaphase I

The relationship between homoeologous pairing at metaphase I and recombination at anaphase I between the arms 1AL, 1BL, 1DL, and 1RL was analyzed in ph1b, 5B-deficient, and ph2b wheat × rye hybrids. All four arms could be identified at metaphase I, as well as the arms 1BL and 1RL at anaphase I, by means of C-banding. On the basis of the C-heterochromatin constitution that 1BL and 1RL showed at anaphase I and that association at metaphase I was essentially homoeologous, the following anaphase I chromosome types could be distinguished: parental type, single and double recombinant types between 1BL and 1AL or 1DL, between 1BL and 1RL, and between 1RL and 1AL or 1DL. Recombinant types 1AL – 1DL did not differ from the parental type for the C-banding pattern and was not considered. In the three genotypes, most if not all of 1BL – 1AL, 1BL – 1DL, and 1BL – 1RL metaphase I bonds were chiasmatic. 1RL – 1AL and 1RL – 1DL associations were scarce. Frequencies of one chiasma and two chiasmata for the arm combinations 1BL – 1AL plus 1BL – 1DL, 1BL – 1RL, and 1RL – 1AL plus 1RL – 1DL were estimated. Values decreased in the order ph1b, 5B-deficient, and ph2b hybrids.Key words: C-banding, chiasmata, homoeologues, anaphase I, ph genes.

Genome constitutions of Thinopyrum curvifolium, T. scirpeum, T. distichum, and T. junceum (Triticeae: Gramineae)

Genome ◽  
1993 ◽  
Vol 36 (4) ◽  
pp. 641-651 ◽  
Author(s):  
Zhi-Wu Liu ◽  
Richard R.-C. Wang
Keyword(s):  
Chromosome Pairing ◽  
Banding Pattern ◽  
Triploid Hybrid ◽  
Target Species ◽  
Banding Patterns ◽  
C Banding ◽  
Geographical Separation ◽  
Basic Genome ◽  
Karyotype Analyses ◽  
Metaphase I

The objective of this study is to elucidate genome constitutions of Thinopyrum curvifolium (Lange) D.R. Dewey, T. scirpeum (K. Presl) D.R. Dewey, T. distichum (Thunb.) A. Löve, and T. junceum (L.) A. Löve. Hybrids of T. sartorii (Boiss. &Heidr.) A. Löve with T. scirpeum and T. junceum, as well as the hybrid between T. curvifolium and Pseudoroegneria geniculata ssp. scythica (Nevski) A. Löve, were made and chromosome pairing at metaphase I was studied. The karyotype analyses of mitotic cells stained by aceto-orcein were conducted for both hybrids and the four target species. The Giemsa C-banding following acetocarmine staining was carried out for the above species and the triploid hybrid T. curvifolium × T. bessarabicum (Savul &Rayss) A. Löve. Meiotic data indicate that all target species have two sets of the basic genome J, but they behave like true allopolyploids because of bivalentization. Karyotypes of T. curvifolium and its triploid hybrid with T. bessarabicum indicate that T. curvifolium contains two different versions of the Jb genome, designated as Jb3 and Jb4, rather than two Je genomes as previously believed. Thinopyrum scirpeum and T. elongatum (4x) have similar karyotypes. Both are segmental allotetraploids carrying two forms of the Je genome. Their genome formulae are Je2 Je3 and Je1 Je3, respectively. Thinopyrum distichum has a karyotype similar to T. junceiforme, which has the Jb2 Je2 genome formula. However, the two species differ in C-banding patterns, reflecting their geographical separation. Thinopyrum junceum is a hexaploid with two pairs of Jb2 genomes and one pair of the Je2 genome, and it has a C-banding pattern similar to that of T. junceiforme, which has one pair each of the Jb2 and Je2 genomes.Key words: genome, meiosis, karyotype, C-banding, Triticeae, Thinopyrum.

An Evaluation of the Relationship between Retinal Nerve Fiber Thickness, Cochlear Nerve Thickness, the Level of Tinnitus, and Hearing Loss in Unilateral Tinnitus Patients

2021 ◽  
pp. 1-8
Author(s):  
Mustafa Avcu ◽  
Mehmet Metin ◽  
Raşit Kılıç ◽  
Muhammed Alpaslan
Keyword(s):  
Hearing Loss ◽  
Nerve Fiber ◽  
Normal Hearing ◽  
Cochlear Nerve ◽  
Significant Difference ◽  
The Relationship ◽  
Fiber Thickness ◽  
Moderate Hearing Loss ◽  
Group 1 ◽  
Retinal Nerve Fiber

Background: In this study, optic coherence tomography (OCT) examination was performed to check whether there was any interaction between ophthalmic axonal structures in unilateral tinnitus patients, and the relationship between optic nerve thickness and cochlear nerve thickness was evaluated. Objective: The aim of the study was to evaluate the relatioship between hearing loss, tinnitus, and nerve thicknesses. Study Design: Prospective study. Setting: Tertiary referral university hospital. Patients: The study included 88 patients with unilateral tinnitus, for which no organic cause could be found in physical examination, psychiatric evaluation, or with imaging methods. Study groups were formed of the tinnitus side and control groups were formed of the healthy side as follows: Group 1 (Non-tinnitus side normal hearing values – n = 30), Group 2 (non-tinnitus side minimal hearing loss – n = 27), Group 3 (non-tinnitus side moderate hearing loss – n = 31), Group 4 (tinnitus side normal hearing values – n = 25), Group 5 (tinnitus side minimal hearing loss – n = 25), and Group 6 (tinnitus side moderate hearing loss – n = 38). Intervention: Retinal nerve fiber layer (RNFL) thickness was evaluated with OCT, and the cochlear nerve cross-sectional area was evaluated with MRI. Main Outcome Measures: RNFL measurements were taken with OCT from the subfoveal area (RNFL-SF) and 1.5 mm temporal to the fovea (RNFL-T µm) and nasal (RNFL-N µm) sectors. On MRI, 3 measurements were taken along the nerve from the cerebellopontine angle as far as the internal auditory canal, and the mean value of these 3 measurements was calculated. Results: When the groups were evaluated in respect of cochlear nerve thickness, a significant difference was seen between Group 1 and both the groups with hearing loss and the tinnitus groups. In the subgroup analysis, a statistically significant difference was determined between Group 1 and Groups 3, 4, 5, and 6 (p = 0.013, p = 0.003, p < 0.001, and p < 0.001, respectively). When the groups were evaluated in respect of the RNFL-SF (µm), RNFL-T (µm), and RNFL-N (µm) values, the differences were determined to be statistically significant (p < 0.001 for all). In the correlation analysis, a negative correlation was determined between hearing loss and cochlear nerve diameter (r: −0.184, p = 0.014), and RNFL-N (r: −0.272, p < 0.001) and between tinnitus and cochlear nerve diameter (r: −0.536, p < 0.001), and RNFL-T (r: −0.222, p < 0.009). Conclusion: The study results clearly showed a relationship between cochlear nerve fiber thickness and hearing loss and the severity of tinnitus in cases with unilateral tinnitus and that there could be neurodegenerative factors in the disease etiology. A similar relationship seen with the RNFL supports the study hypothesis.

The Relationship between Serum Ferritin Levels and 5-Year All-Cause Mortality in Hemodialysis Patients

2021 ◽  
pp. 1-7
Author(s):  
Emre Erdem ◽  
Ahmet Karatas ◽  
Tevfik Ecder
Keyword(s):  
Serum Ferritin ◽  
Hemodialysis Patients ◽  
Rank Test ◽  
Significant Difference ◽  
All Cause Mortality ◽  
Group 3 ◽  
Group 2 ◽  
The Relationship ◽  
Group 1

<b><i>Introduction:</i></b> The effect of high serum ferritin levels on long-term mortality in hemodialysis patients is unknown. The relationship between serum ferritin levels and 5-year all-cause mortality in hemodialysis patients was investigated in this study. <b><i>Methods:</i></b> A total of 173 prevalent hemodialysis patients were included in this study. The patients were followed for up to 5 years and divided into 3 groups according to time-averaged serum ferritin levels (group 1: serum ferritin &#x3c;800 ng/mL, group 2: serum ferritin 800–1,500 ng/mL, and group 3: serum ferritin &#x3e;1,500 ng/mL). Along with the serum ferritin levels, other clinical and laboratory variables that may affect mortality were also included in the Cox proportional-hazards regression analysis. <b><i>Results:</i></b> Eighty-one (47%) patients died during the 5-year follow-up period. The median follow-up time was 38 (17.5–60) months. The 5-year survival rates of groups 1, 2, and 3 were 44, 64, and 27%, respectively. In group 3, the survival was lower than in groups 1 and 2 (log-rank test, <i>p</i> = 0.002). In group 1, the mortality was significantly lower than in group 3 (HR [95% CI]: 0.16 [0.05–0.49]; <i>p</i> = 0.001). In group 2, the mortality was also lower than in group 3 (HR [95% CI]: 0.32 [0.12–0.88]; <i>p</i> = 0.026). No significant difference in mortality between groups 1 and 2 was found (HR [95% CI]: 0.49 [0.23–1.04]; <i>p</i> = 0.063). <b><i>Conclusion:</i></b> Time-averaged serum ferritin levels &#x3e;1,500 ng/mL in hemodialysis patients are associated with an increased 5-year all-cause mortality risk.

scholarly journals Identification and Physical Localization of Useful Genes and Markers to a Major Gene-Rich Region on Wheat Group1SChromosomes

Genetics ◽  
2001 ◽  
Vol 157 (4) ◽  
pp. 1735-1747 ◽  
Author(s):  
Devinder Sandhu ◽  
Julie A Champoux ◽  
Svetlana N Bondareva ◽  
Kulvinder S Gill
Keyword(s):  
Dna Analysis ◽  
Major Gene ◽  
Rflp Markers ◽  
Rich Region ◽  
Wheat Group ◽  
Marker Loci ◽  
Group 1 Chromosomes ◽  
Gene Rich Region ◽  
Homeologous Group ◽  
Group 1

AbstractThe short arm of Triticeae homeologous group 1 chromosomes is known to contain many agronomically important genes. The objectives of this study were to physically localize gene-containing regions of the group 1 short arm, enrich these regions with markers, and study the distribution of genes and recombination. We focused on the major gene-rich region (“1S0.8 region”) and identified 75 useful genes along with 93 RFLP markers by comparing 35 different maps of Poaceae species. The RFLP markers were tested by gel blot DNA analysis of wheat group 1 nullisomic-tetrasomic lines, ditelosomic lines, and four single-break deletion lines for chromosome arm 1BS. Seventy-three of the 93 markers mapped to group 1 and detected 91 loci on chromosome 1B. Fifty-one of these markers mapped to two major gene-rich regions physically encompassing 14% of the short arm. Forty-one marker loci mapped to the 1S0.8 region and 10 to 1S0.5 region. Two cDNA markers mapped in the centromeric region and the remaining 24 loci were on the long arm. About 82% of short arm recombination was observed in the 1S0.8 region and 17% in the 1S0.5 region. Less than 1% recombination was observed for the remaining 85% of the physical arm length.

Rye C-banding patterns and meiotic stability of hexaploid triticale (× Triticosecale) selections differing in kernel shriveling

Genome ◽  
1990 ◽  
Vol 33 (5) ◽  
pp. 686-689 ◽  
Author(s):  
Charles M. Papa ◽  
R. Morris ◽  
J. W. Schmidt
Keyword(s):  
Secale Cereale ◽  
Chromosome Banding ◽  
Agronomic Performance ◽  
Hexaploid Triticale ◽  
Kernel Development ◽  
Banding Patterns ◽  
C Banding ◽  
Meiotic Stability ◽  
Metaphase I

Two winter hexaploid triticale populations derived from the same cross were selected on the basis of grain appearance and agronomic performance. The five lines from 84LT402 showed more kernel shriveling than the four lines from 84LT401. The derived lines were analyzed for aneuploid frequencies, rye chromosome banding patterns, and meiotic stability to detect associations with kernel development. The aneuploid frequencies were 16% in 84LT401 and 18% in 84LT402. C-banding showed that both selection groups had all the rye chromosomes except 2R. The two groups had similar telomeric patterns but differed in the long-arm interstitial patterns of 4R and 5R. Compared with lines from 84LT402, those from 84LT401 had significantly fewer univalents and rod bivalents, and more paired arms at metaphase I; fewer laggards and bridges at anaphase I; and a higher frequency of normal tetrads. There were no significant differences among lines within each group for any meiotic character. Since there were no differences within or between groups in telomeric banding patterns, the differences in kernel shriveling and meiotic stability might be due to genotypic factors and (or) differences in the interstitial patterns of 4R and 5R. By selecting plump grains, lines with improved kernel characteristics along with improved meiotic stability are obtainable.Key words: triticale, meiotic stability, C-banding, Secale cereale, heterochromatin.

scholarly journals Factors associated with rs1801394 of the methionine synthase reductase gene polymorphism in patients with rheumatoid arthritis

2021 ◽  
Vol 15 (3) ◽  
pp. 15-19
Author(s):  
M. Yu. Krylov ◽  
G. I. Gridneva ◽  
Yu. V. Muravyev
Keyword(s):  
Rheumatoid Arthritis ◽  
Clinical Characteristics ◽  
Methionine Synthase ◽  
Nucleotide Polymorphisms ◽  
Allelic Discrimination ◽  
Methionine Synthase Reductase ◽  
Reductase Gene ◽  
Group 2 ◽  
The Relationship ◽  
Group 1

Clinical response to methotrexate (MT) therapy in rheumatoid arthritis (RA) can be predicted on the basis of some single nucleotide polymorphisms (SNPs) of genes, involved in folate metabolism. One of these SNPs is the rs1801394 (A66G) polymorphism of the methionine synthase reductase gene (MTRR). We investigated the association of this polymorphism with the clinical characteristics of RA patients after 6 months of MT therapy. Studies of the relationship between the response to MT therapy and the rs1801394 polymorphism have not been carried out in Russia previously.Objective: to study the possible association of the rs1801394 polymorphism with the clinical characteristics of patients with RA after 6 months of MT therapy.Patients and methods. The study included 60 patients with RA who met the ACR / EULAR criteria (2010) and received≥20 mg MT per week continuously. Based on the EULAR criteria, patients were divided into two groups: group 1 (n=30) with a good (DAS28>1.2) and group 2 (n=30) with an unsatisfactory (DAS28 <1.2) response to MT therapy. Genotyping of the rs1801394 polymorphism was performed by allelic discrimination using real-time polymerase chain reaction.Results and discussion. The frequency distribution of the A66G polymorphism genotypes in both groups was similar, however, in the 2nd group with an unsatisfactory response, there was a tendency towards a higher frequency of the mutant GG genotype (p=0.067). An association of the A66G polymorphism with gender and disease duration was found. In group 1, the AG genotype was more often detected in men than in women (p=0.017). In group 2, the AG genotype was also more common in men (p=0.075). In addition, in this group, carriers of the G allele (genotypes AG and GG) had a longer duration of the disease than carriers of the AA genotype (p=0.003 and p=0.005, respectively).Conclusion. In the present study, the relationship of the studied polymorphism rs1801394 of the MTRR gene with gender and duration of RA disease was established.

scholarly journals GENOME SIZE IN THREE SPECIES OF Glandularia AND THEIR HYBRIDS

2019 ◽  
Vol 30 (2) ◽  
pp. 47-54
Author(s):  
M.R. Ferrari ◽  
E.J. Greizerstein ◽  
L. Poggio
Keyword(s):  
Genome Size ◽  
Dna Content ◽  
High Frequency ◽  
Parental Species ◽  
The Other ◽  
F1 Hybrids ◽  
Homoeologous Pairing ◽  
The Relationship ◽  
Species Being ◽  
Homoeologous Chromosomes

In this work the relationship between genome size of Glandularia species and the meiotic configurations found in their hybrids are discussed. Glandularia incisa (Hook.) Tronc., growing in two localities of Corrientes and Córdoba provinces, Argentina, with different ecological conditions, showed inter-population variability of the 2C-value. The DNA content found in the Corrientes locality (2.41 pg) was higher than that obtained in the Córdoba locality (2.09 pg) which has more stressful environmental conditions than the former. These values are statistically different from those that were found in Glandularia pulchella (Sweet) Tronc. from Corrientes (1.43 pg) and in Glandularia perakii Cov. et Schn from Córdoba (1.47 pg). The DNA content of the diploid F1 hybrids, G. pulchella × G. incisa and G. perakii × G. incisa, differed statistically from the DNA content of the parental species, being intermediate between them. Differences in the frequency of pairing of homoeologous chromosomes were observed in the hybrids; these differences cannot be explained by differences in genome size since hybrids with similar DNA content differ significantly in their meiotic behavior. On the other hand, the differences in the DNA content between the parental species justify the presence of a high frequency of heteromorphic open and closed bivalents and univalents with different size in the hybrids. Key words: Intra-specific DNA content variability, homoeologous pairing, heteromorphic bivalents

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