Statistical analysis of chromosome distribution to the poles in interspecific hybrids with variable chromosome pairing

A probability distribution of chromosome separation to the poles was developed to test the randomness of movement of univalents in asynaptic material where a variable amount of meiotic pairing occurs. Two tables were calculated, one for 24 chromosomes which can be used for any even number equal or less than 24, and the other for 19 chromosomes which can be used for any odd number equal or less than 19.Three Nicotiana hybrids, namely N. glutinosa × N. otophora, N. glutinosa, N. sylvestris, and N. tabacum × N. glutinosa, and one polyhaploid were investigated. All hybrids had a tendency towards an equal distribution of unpaired chromosomes to the poles. The polyhaploid N. tabacum (with a substituted N. plumbaginifolia chromosome) had an opposite tendency, i.e. towards a flatter distribution than expected from random distribution of univalents. A short discussion of the problem is given.

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Differences in meiotic pairing induction between the A genomes of Triticum boeoticum Boiss. and T. urartu Tum. using diploid species of the subtribe Triticineae as analysers

Genome ◽

10.1139/g87-153 ◽

1987 ◽

Vol 29 (6) ◽

pp. 891-893 ◽

Cited By ~ 2

Author(s):

H. Lucas ◽

J. Jahier

Keyword(s):

Interspecific Hybrids ◽

Diploid Species ◽

Distinct Species ◽

The Other ◽

Meiotic Behaviour ◽

Meiotic Pairing ◽

Haynaldia Villosa ◽

Pollen Mother Cells ◽

Triticum Boeoticum ◽

Mother Cells

The number of associations between chromosome arms in the pollen mother cells of the hybrid Triticum boeoticum × T. urartu is similar to that in the pollen mother cells of the parental accessions. The latter two species were crossed with the following diploid species: T. tauschii, T. comosum, T. umbellulatum, and Haynaldia villosa. The meiotic behaviour of the hybrids showed that the chromosomes of T. urartu share more homology with the diploid Triticum species than do those of T. boeoticum. On the other hand, there is more pairing in the hybrid T. boeoticum × H. villosa than in T. urartu × H. villosa. These results confirm that T. boeoticum and T. urartu are distinct species. Key words: Triticineae, interspecific hybrids, meiotic behaviour, speciation.

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Meiosis in interspecific Hordeum hybrids. I. Diploid combinations

Canadian Journal of Genetics and Cytology ◽

10.1139/g86-077 ◽

1986 ◽

Vol 28 (4) ◽

pp. 525-535 ◽

Cited By ~ 109

Author(s):

Roland Von Bothmer ◽

Jan Flink ◽

Thomas Landström

Keyword(s):

Interspecific Hybrids ◽

Genomic Structure ◽

Genetic Regulation ◽

The Other ◽

South American ◽

Meiotic Pairing ◽

Hordeum Bulbosum ◽

High Affinity ◽

Hordeum Species ◽

Pairing Behaviour

The meiotic pairing behaviour of 39 new interspecific combinations between diploid Hordeum species are reported. On the basis of this data, four "basic genomes" are probably present in the genus. Hordeum bulbosum and H. vulgare have the same genome (I); H. marinum ("X") and H. murinum ("Y") each have one distinct genome. All other diploid taxa have either the same or a somewhat modified form of genome H. In this latter group of diploids, the South American taxa together with H. pusillum and H. intercedens in North America constitue a homogeneous group with respect to genomic structure, which differs somewhat from that found in the other Asiatic and North American species. Hordeum roshevitzii from Central Asia is unique, showing high affinity to both the Asiatic and to the American taxa. Evidence suggesting genetic regulation of chromosome pairing (both pairing promoting and pairing reducing) was obtained from a number of the diploid hybrids.Key words: Hordeum, interspecific hybrids, meiosis, diploids.

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Meiosis in interspecific Hordeum hybrids. IV. Tetraploid (4x × 4x) hybrids

Genome ◽

10.1139/g88-080 ◽

1988 ◽

Vol 30 (4) ◽

pp. 479-485 ◽

Cited By ~ 35

Author(s):

Roland von Bothmer ◽

Jan Flink ◽

Tomas Landström

Keyword(s):

Interspecific Hybrids ◽

Genetic Regulation ◽

The Other ◽

Meiotic Pairing ◽

Genomic Constitution ◽

Hordeum Species ◽

Hordeum Brevisubulatum ◽

Pairing Behaviour

The meiotic pairing behaviour of 31 interspecific combinations of tetraploid Hordeum species are reported. The autoploid H. bulbosum with the II genomic constitution has no homology to the other species. The constitution of tetraploid H. murinum is not clear, but it is not homologous to other tetraploids. Hordeum marinum is a probable autoploid (XX) but with a very strong genetic regulation of pairing. The X genome is possibly found in H. secalinum and H. capense, both of which also possess the H genome in several diploids. Hordeum fuegianum, H. tetraploidum, H. jubatum, H. brachyantherum, and H. roshevitzii are segmental alloploids all with the same two partly homoeologous genomes. Hordeum depressum is probably a segmental alloploid with the H genome and with a very strong pairing regulation. Hordeum brevisubulatum is a pure autoploid with two homologous H genomes.Key words: Hordeum, interspecific hybrids, meiosis, tetraploids.

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Interspecific hybridizations in the Elymus semicostatus group (Poaceae)

Genome ◽

10.1139/g93-118 ◽

1993 ◽

Vol 36 (5) ◽

pp. 899-905 ◽

Cited By ~ 9

Author(s):

Björn Salomon

Keyword(s):

Interspecific Hybridization ◽

Interspecific Hybrids ◽

The Other ◽

Morphological Data ◽

Meiotic Pairing ◽

Subgroup Ii

Meiotic pairing in 16 interspecific hybrids in the genus Elymus is reported. The hybrids were made among seven species in the Elymus semicostatus group, viz., E. semicostatus, E. validus (subgroup I), E. abolinii (subgroup II), E. fedtschenkoi, E. nevskii, E. praeruptus (subgroup III), and E. panormitanus (subgroup IV). All species are tetraploid (2n = 4x = 28) and possess the SY genomes. Meiotic pairing was distinctly higher in hybrids made within subgroups than between subgroups, but the genomes in E. panormitanus have differentiated from those in the other species. These results generally support the subdivision of the E. semicostatus group based on morphological data but also indicate that the subgroups are more distantly related than previously believed, and that the group may be nonmonophyletic.Key words: meiotic pairing, interspecific hybridization, relationships, Triticeae, Poaceae.

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Autonomously Replicating Macronuclear DNA Pieces Are the Physical Basis of Genetic Coassortment Groups in Tetrahymena thermophila

Genetics ◽

10.1093/genetics/155.3.1119 ◽

2000 ◽

Vol 155 (3) ◽

pp. 1119-1125

Author(s):

Laura Wong ◽

Lana Klionsky ◽

Steve Wickert ◽

Virginia Merriam ◽

Eduardo Orias ◽

...

Keyword(s):

Random Distribution ◽

Tetrahymena Thermophila ◽

Physical Basis ◽

The Other ◽

Site Specific ◽

Phenotypic Assortment ◽

Somatic Genome

Abstract The macronucleus of the ciliate Tetrahymena thermophila contains a fragmented somatic genome consisting of several hundred identifiable chromosome pieces. These pieces are generated by site-specific fragmentation of the germline chromosomes and most of them are represented at an average of 45 copies per macronucleus. In the course of successive divisions of an initially heterozygous macronucleus, the random distribution of alleles of loci carried on these copies eventually generates macronuclei that are pure for one allele or the other. This phenomenon is called phenotypic assortment. We have previously reported the existence of loci that assort together (coassort) and hypothesized that these loci reside on the same macronuclear piece. The work reported here provides new, rigorous genetic support for the hypothesis that macronuclear autonomously replicating chromosome pieces are the physical basis of coassortment groups. Thus, coassortment allows the mapping of the somatic genome by purely genetic means. The data also strongly suggest that the random distribution of alleles in the Tetrahymena macronucleus is due to the random distribution of the MAC chromosome pieces that carry them.

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Proposal of an Adaptive Neurofuzzy System to Control Flow Power in Distributed Generation Systems

Complexity ◽

10.1155/2019/1610898 ◽

2019 ◽

Vol 2019 ◽

pp. 1-16 ◽

Cited By ~ 4

Author(s):

Helbert Eduardo Espitia ◽

Iván Machón-González ◽

Hilario López-García ◽

Guzmán Díaz

Keyword(s):

Statistical Analysis ◽

Distributed Generation ◽

Distribution System ◽

Voltage Control ◽

Control Flow ◽

The Other ◽

Charge Variation ◽

Flow Power ◽

Dynamics Identification ◽

Neurofuzzy Systems

Systems of distributed generation have shown to be a remarkable alternative to a rational use of energy. Nevertheless, the proper functioning of them still manifests a range of challenges, including both the adequate energy dispatch depending on the variability of consumption and the interaction between generators. This paper describes the implementation of an adaptive neurofuzzy system for voltage control, regarding the changes observed in the consumption within the distribution system. The proposed design employs two neurofuzzy systems, one for the plant dynamics identification and the other for control purposes. This focus optimizes the controller using the model achieved through the identification of the plant, whose changes are produced by charge variation; consequently, this process is adaptively performed. The results show the performance of the adaptive neurofuzzy system via statistical analysis.

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Was This in Your Statistics Textbook? IV. Frequency Data

Experimental Agriculture ◽

10.1017/s0014479700016392 ◽

1989 ◽

Vol 25 (1) ◽

pp. 11-25

Author(s):

D. J. Finney

Keyword(s):

Statistical Analysis ◽

Contingency Tables ◽

The Other ◽

Frequency Data ◽

Significance Tests ◽

Test Statistic ◽

Jumping To Conclusions ◽

Proper Role ◽

Measure Of Association

SUMMARYObservations that are frequencies rather than measurements often call for special types of statistical analysis. This paper comments on circumstances in which methods for one type of data can sensibly be used for the other. A section on two-way contingency tables emphasizes the proper role of χ2 a test statistic but not a measure of association; it mentions the distinction between one-tail and two-tail significance tests and reminds the reader of dangers. Multiway tables bring new complications, and the problems of interactions when additional classificatory factors are explicit or hidden are discussed at some length. A brief outline attempts to show how probit, logit, and similar techniques are related to the analysis of contingency tables. Finally, three unusual examples are described as illustrations of the care that is needed to avoid jumping to conclusions on how frequency data should be analysed.

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The Effect of Homoeologous Meiotic Pairing in Tetraploid Hordeum bulbosum L. × H. vulgare L. Hybrids on Alien Introgressions in Offspring

Cytogenetic and Genome Research ◽

10.1159/000455141 ◽

2016 ◽

Vol 150 (2) ◽

pp. 139-149 ◽

Cited By ~ 1

Author(s):

Margret Scholz ◽

Galina Pendinen

Keyword(s):

Interspecific Hybrids ◽

In Situ Hybridisation ◽

Basic Material ◽

Meiotic Pairing ◽

Hordeum Bulbosum ◽

Homoeologous Pairing ◽

Introgression Breeding ◽

The Individual ◽

Pairing Behaviour

The pairing behaviour of the individual chromosome arms of Hordeum vulgare (Hv) with their homoeologous arms of H. bulbosum (Hb) at metaphase I of meiosis in tetraploid Hb × Hv hybrids and the frequencies of recombined Hv chromosome arms in selfed offspring were studied on differentially visualized chromosomes after fluorescent in situ hybridisation. The frequencies of paired Hv-Hb arms in the F2 and F3 hybrids were correlated with the frequencies of recombined Hv chromosomes in progenies. Self-generation of hybrids, the number of Hv and Hb chromosomes, and the number of recombined Hv chromosomes of the hybrids strongly influenced the Hv-Hb pairing frequency in meiosis. Within the offspring of F2 and F3 hybrids both Hv plants and hybrids were detected. In contrast, all progenies of the F4 hybrid were hybrids which exhibited centromere misdivisions. The highest frequencies of homoeologous pairing in hybrids and most recombinants were obtained for the barley chromosome 1HL. Recombinants for 4HL, 5HS, 6HS, and 7HS were rarely found. Meiotic pairing and recombinants involving chromosome 1HS were never observed. The results of this study demonstrate that fertile tetraploid interspecific hybrids with a high intergenomic pairing at meiosis are valuable basic material for introgression breeding in barley.

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Changes in Nutrient Levels of Lake Water Stored at 4 °C

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f84-113 ◽

1984 ◽

Vol 41 (6) ◽

pp. 985-988 ◽

Cited By ~ 3

Author(s):

A. H. El-Shaarawi ◽

M. A. Neilson

Keyword(s):

Statistical Analysis ◽

Lake Water ◽

Water Samples ◽

Soluble Reactive Phosphorus ◽

Lake Ontario ◽

The Other ◽

Nutrient Levels ◽

Glass Bottles ◽

Reactive Phosphorus

Water samples were collected on Lake Ontario during April and November, filtered (0.45 μm), and immediately analyzed onboard ship for the nutrients soluble reactive phosphorus, nitrate-plus-nitrite, and ammonia. Replicates were stored in glass bottles at 4 °C and reanalyzed within 8 d. Statistical analysis showed that soluble reactive phosphorus decreased by 11 and 13% and nitrate-plus-nitrite by 7 and 6%, whereas ammonia increased by 75% on one cruise and decreased by 37% on the other.

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Hypermobility and sports injury

BMJ Open Sport & Exercise Medicine ◽

10.1136/bmjsem-2018-000366 ◽

2018 ◽

Vol 4 (1) ◽

pp. e000366 ◽

Cited By ~ 2

Author(s):

Joseph Alexander Nathan ◽

Kevin Davies ◽

Ian Swaine

Keyword(s):

Statistical Analysis ◽

Sports Injury ◽

The Other ◽

Anecdotal Evidence ◽

Demographic Information ◽

Cross Sectional Survey ◽

Cross Sectional ◽

Exact Test ◽

Joint Dislocation ◽

Ligament Sprain

ObjectiveTo determine whether there is an association between hypermobility and sports injury.MethodsA quantitative observational approach using a cross-sectional survey was adopted. Individuals were identified as hypermobile or not. All participants were asked to complete two questionnaires: one asking demographic information and the other injury-specific. Fisher’s exact test was used for statistical analysis.Results114 individuals participated in the study, 62 women and 52 men. 26% of the participants were hypermobile. There was no significant association between hypermobility and sports injury (p=0.66). There was a significant increase in joint and ligament sprain among the non-hypermobile (NH) group covering all sports (p=0.03). Joint dislocation was found exclusively among hypermobile individuals. The duration of injury in hypermobile individuals was higher than NH. The use of oral painkillers or anti-inflammatories in the semiprofessional group was greater than the general population.ConclusionHypermobility is relatively common among individuals, and there is a lot of anecdotal evidence associating it with increased rates of injuries. This project finds that NH individuals are more likely to sustain a ligament or joint sprain in sports. This is due to increased joint laxity and flexibility preventing injury. There were important limitations to this study which will be addressed in further work. These include assessing for pauciarticular hypermobility and focusing on one sport to investigate its association with sports injury in those who are hypermobile or not. It would also be important to focus on one specific joint, assessing its flexibility and association with injury.

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