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

scholarly journals Gigantic Genomes of Salamanders Indicate Body Temperature, not Genome Size, is the Driver of Global Methylation and 5-Methylcytosine Deamination in Vertebrates

2021 ◽  
Author(s):  
Alexander Nichols Adams ◽  
Robert Daniel Denton ◽  
Rachel Lockridge Mueller
Keyword(s):  
Body Temperature ◽  
Transposable Elements ◽  
Genome Size ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Cpg Methylation ◽  
The Other ◽  
Global Methylation ◽  
Cpg Dinucleotide

Methylation of cytosines at CpG dinucleotide sites silences transposable elements (TEs), sequences that replicate and move throughout genomes. TE abundance drives differences in genome size, but TE silencing variation across genomes of different sizes remains largely unexplored. Salamanders include most of the largest C-values -- 9 to 120 Gb. We measured CpG methylation levels in salamanders with genomes ranging from 2N = ~58 Gb to 4N = ~116 Gb. We compared these levels to results from endo- and ectothermic vertebrates with more typical genomes. Salamander methylation levels are ~90%, higher than all endotherms. However, salamander methylation does not differ from the other ectotherms, despite a ~100-fold difference in nuclear DNA content. Because methylation affects the nucleotide compositional landscape through 5-methylcytosine deamination to thymine, we quantified salamander CpG dinucleotide levels and compared them to other vertebrates. Salamanders have comparable CpG levels to other ectotherms, and ectotherm levels are higher than endotherms. These data show no shift in global methylation at the base of salamanders, despite a dramatic increase in TE load and genome size. This result is reconcilable with previous studies by considering endothermy and ectothermy, which may be more important drivers of methylation in vertebrates than genome size.

scholarly journals THE AGRO-PASTORAL CONFLICTS AND FORAGE SPECIES PRIZED BY CATTLE: CASE OF THE NORTHERN PERIPHERY OF THE MBAM AND DJEREM NATIONAL PARK (ADAMAOUA-CAMEROON)

2021 ◽  
Vol 9 (02) ◽  
pp. 965-985
Author(s):  
Marie Mvu Njoya ◽  
◽  
Ambahe Duplex Rufin ◽  
Keyword(s):  
High Frequency ◽  
National Park ◽  
Low Frequency ◽  
Partial Solution ◽  
The Other ◽  
Survey Method ◽  
Other Hand ◽  
Forage Species ◽  
The One ◽  
The Relationship

In the outskirts of the northern periphery of Mbam and Djerem National Park, agro-pastoral conflicts have become very frequent in recent years. The resulting damage is so surprising that it leaves no one indifferent. Unfortunately, many writings analyze the causes of these agro-pastoral conflicts without, however, dwelling on the fodder resources which constitute not only the staple food of cattle but also one of the primary factors of these antagonisms. To overcome this knowledge gap, the authors adopted the survey method in order to identify, on the one hand, the attributes of agro-pastoral conflicts and the plant species consumed in all seasons by cattle on the northern periphery of the PNMD and, on the other hand, the relationship between these forage species with the frequency of agro-pastoral conflicts according to the protagonists and the seasons. Thus, from field observations and a questionnaire sent to 44 breeders and 103 farmers in four control villages, it results, after processing the data, that the high frequency of conflicts experienced by the farmers in the dry season (35.9 %) and especially by the breeders (70.5%) is due to the location of the forage species prized in this season at the bottom of the valleys where the herds are concentrated and compete. On the other hand, the low frequency of conflicts experienced during the rainy season especially by breeders, except in Mbitom, is more justified by the extension of fodder registers to woody leaves from the start of this season. Finally, the fodder fields of Brachiaria constitute a partial solution to the shortage of pastures even if it sometimes gives rise to new conflicts between herders.

Cytogenetic studies of interspecific hybrids between diploid species of Festuca

1986 ◽  
Vol 28 (6) ◽  
pp. 921-925 ◽  
Author(s):  
W. G. Morgan ◽  
Hugh Thomas ◽  
M. Evans ◽  
M. Borrill
Keyword(s):  
Genome Size ◽  
Chromosome Pairing ◽  
Dna Content ◽  
Interspecific Hybrids ◽  
Parental Species ◽  
Diploid Species ◽  
Chromosome Size ◽  
Cytogenetic Studies ◽  
The Difference

Chromosome pairing in hybrids between diploid species of Festuca is described. The chromosome complements of the species from different taxonomic sections vary in chromosome size and DNA content. In interspecific hybrids involving species of the section Montanae there was a relationship between the difference in DNA content of the parental species and chromosome pairing in the F1 hybrids. The larger the difference between the DNA content of the parental species, the more pronounced the failure of chromosome pairing in the F1 hybrids. Factors other than divergence in genome size were also shown to have an effect on chromosome pairing in other hybrid combinations.Key words: chromosome pairing, DNA content, Festuca, hybrids (interspecific).

Cytogenetics of two interspecific synthetic hybrids of the grasshopper genus Euchorthippus

Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 909-912 ◽  
Author(s):  
J. L. Santos ◽  
P. Arana ◽  
N. Henriques-Gil
Keyword(s):  
Parental Species ◽  
The Other ◽  
Meiotic Pairing ◽  
Banding Patterns ◽  
Hybrid Individual ◽  
C Banding ◽  
Isolating Mechanisms ◽  
Synthetic Hybrids ◽  
The Cross ◽  
Homoeologous Chromosomes

The spermatogenesis of two synthetic hybrid individuals of the grasshopper genus Euchorthippus was studied by C-banding methods. One resulted from the cross Euchorthippus pulvinatus ♂ × Euchorthippus chopardi ♀ (p/c), whereas the other one was produced in the cross E. chopardi ♂ × E. pulvinatus ♀ (c/p). The two parental sets of chromosomes were always recognized according to their different C-banding patterns. Chiasma frequency was decreased in both hybrids when compared with the parental species, this decrease being more accentuated in the hybrid individual c/p, where univalents at metaphase I were frequent. Chiasmata were formed between homoeologous chromosomes, and only two multivalent associations were observed. Polyploid spermatids and some micronuclei were a common feature in both hybrids. It is suggested that C-heterochromatin differences do not play any important role in the speciation process: genie differences between parental genomes are probably more important.Key words: synthetic hybrid, Euchorthippus, C-heterochromatin, meiotic pairing, reproductive isolating mechanisms.

scholarly journals Genome size expansion and the relationship between nuclear DNA content and spore size in the Asplenium monanthes fern complex (Aspleniaceae)

2013 ◽  
Vol 13 (1) ◽  
pp. 219 ◽  
Author(s):  
Robert J Dyer ◽  
Jaume Pellicer ◽  
Vincent Savolainen ◽  
Ilia J Leitch ◽  
Harald Schneider
Keyword(s):  
Genome Size ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Spore Size ◽  
The Relationship

scholarly journals Dolphin-Inspired Target Detection for Sonar and Radar

2015 ◽  
Vol 39 (3) ◽  
pp. 319-332 ◽  
Author(s):  
Timothy Leighton ◽  
Paul White
Keyword(s):  
Target Detection ◽  
High Frequency ◽  
Laboratory Tests ◽  
Biological Process ◽  
Breaking Waves ◽  
The Other ◽  
Humpback Whales ◽  
Biological Processes ◽  
Methane Seeps ◽  
The Relationship

Abstract Gas bubbles in the ocean are produced by breaking waves, rainfall, methane seeps, exsolution, and a range of biological processes including decomposition, photosynthesis, respiration and digestion. However one biological process that produces particularly dense clouds of large bubbles, is bubble netting. This is practiced by several species of cetacean. Given their propensity to use acoustics, and the powerful acoustical attenuation and scattering that bubbles can cause, the relationship between sound and bub-ble nets is intriguing. It has been postulated that humpback whales produce ‘walls of sound’ at audio frequencies in their bubble nets, trapping prey. Dolphins, on the other hand, use high frequency acous-tics for echolocation. This begs the question of whether, in producing bubble nets, they are generating echolocation clutter that potentially helps prey avoid detection (as their bubble nets would do with man-made sonar), or whether they have developed sonar techniques to detect prey within such bubble nets and distinguish it from clutter. Possible sonar schemes that could detect targets in bubble clouds are proposed, and shown to work both in the laboratory and at sea. Following this, similar radar schemes are proposed for the detection of buried explosives and catastrophe victims, and successful laboratory tests are undertaken.

Nucleotypic effects without nuclei: Genome size and erythrocyte size in mammals

Genome ◽  
2000 ◽  
Vol 43 (5) ◽  
pp. 895-901 ◽  
Author(s):  
T Ryan Gregory
Keyword(s):  
Blood Cell ◽  
Metabolic Rate ◽  
Key Words ◽  
Genome Size ◽  
Cell Morphology ◽  
Red Blood Cell ◽  
Dna Content ◽  
C Value ◽  
Blood Cell Morphology ◽  
The Relationship

Previously reported haploid genome sizes (C-values) and erythrocyte sizes (measured as mean dry diameters) were compared for 67 species of mammals representing 31 families and 16 orders. Measurements on erythrocytes of four species of bats were also included in the study. Erythrocyte size was significantly positively correlated with genome size at each of the specific, generic, familial, and ordinal levels, with the relationship becoming much stronger following the exclusion of the order Artiodactyla, a group unique among mammals in terms of red blood cell morphology. Physiologically, these results are relevant in light of the known relationship between C-value and mass-corrected metabolic rate in homeotherms. In evolutionary terms, they provide insights into the constraints on genome expansion among mammals and are therefore of interest in attempts to solve the long-standing C-value enigma (also known as the C-value paradox).Key words: cell size, C-value paradox, DNA content, evolution, genome size.

Reliability of the Minimum Masking Level as Outcome Variable in Tinnitus Clinical Research

2020 ◽  
Vol 29 (3) ◽  
pp. 429-435
Author(s):  
Patricia C. Mancini ◽  
Richard S. Tyler ◽  
Hyung Jin Jun ◽  
Tang-Chuan Wang ◽  
Helena Ji ◽  
...  
Keyword(s):  
Standard Deviation ◽  
High Frequency ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Outcome Variable ◽  
Reliable Estimate ◽  
Moderate Correlation ◽  
Trained Subjects ◽  
The Relationship ◽  
Minimum Intensity

Purpose The minimum masking level (MML) is the minimum intensity of a stimulus required to just totally mask the tinnitus. Treatments aimed at reducing the tinnitus itself should attempt to measure the magnitude of the tinnitus. The objective of this study was to evaluate the reliability of the MML. Method Sample consisted of 59 tinnitus patients who reported stable tinnitus. We obtained MML measures on two visits, separated by about 2–3 weeks. We used two noise types: speech-shaped noise and high-frequency emphasis noise. We also investigated the relationship between the MML and tinnitus loudness estimates and the Tinnitus Handicap Questionnaire (THQ). Results There were differences across the different noise types. The within-session standard deviation averaged across subjects varied between 1.3 and 1.8 dB. Across the two sessions, the Pearson correlation coefficients, range was r = .84. There was a weak relationship between the dB SL MML and loudness, and between the MML and the THQ. A moderate correlation ( r = .44) was found between the THQ and loudness estimates. Conclusions We conclude that the dB SL MML can be a reliable estimate of tinnitus magnitude, with expected standard deviations in trained subjects of about 1.5 dB. It appears that the dB SL MML and loudness estimates are not closely related.

Comparison of In-the-Ear and Over-the-Ear Hearing Aid Fittings

1986 ◽  
Vol 51 (4) ◽  
pp. 362-369 ◽  
Author(s):  
Donna M. Risberg ◽  
Robyn M. Cox
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Comparative Evaluation ◽  
Speech Intelligibility ◽  
Hearing Aid ◽  
Hearing Aid Fitting ◽  
The Difference ◽  
Functional Gain ◽  
The Relationship

A custom in-the-ear (ITE) hearing aid fitting was compared to two over-the-ear (OTE) hearing aid fittings for each of 9 subjects with mild to moderately severe hearing losses. Speech intelligibility via the three instruments was compared using the Speech Intelligibility Rating (SIR) test. The relationship between functional gain and coupler gain was compared for the ITE and the higher rated OTE instruments. The difference in input received at the microphone locations of the two types of hearing aids was measured for 10 different subjects and compared to the functional gain data. It was concluded that (a) for persons with mild to moderately severe hearing losses, appropriately adjusted custom ITE fittings typically yield speech intelligibility that is equal to the better OTE fitting identified in a comparative evaluation; and (b) gain prescriptions for ITE hearing aids should be adjusted to account for the high-frequency emphasis associated with in-the-concha microphone placement.

The Relationship Between Suicidal Thinking and Dating Violence in a Sample of Adolescent Abortion Patients

Crisis ◽  
2011 ◽  
Vol 32 (5) ◽  
pp. 246-253 ◽  
Author(s):  
Gretchen E. Ely ◽  
William R. Nugent ◽  
Julie Cerel ◽  
Mholi Vimbba
Keyword(s):  
Unintended Pregnancy ◽  
Dating Violence ◽  
Young Women ◽  
Psychosocial Problems ◽  
The Other ◽  
Assessment Scale ◽  
Adolescent Dating Violence ◽  
Adolescent Relationships ◽  
Suicidal Thinking ◽  
The Relationship

Background: The relationship between suicidal thinking and adolescent dating violence has not been previously explored in a sample of adolescent abortion patients. Aims: This paper highlights a study where the relationship between dating violence and severity of suicidal thinking was examined in a sample of 120 young women ages 14–21 seeking to terminate an unintended pregnancy. Methods: The Multidimensional Adolescent Assessment Scale and the Conflict in Adolescent Relationships Scale was used to gather information about psychosocial problems and dating violence so that the relationship between the two problems could be examined, while controlling for the other psychosocial problems. Results: The results suggest that dating violence was related to severity of suicidal thinking, and that the magnitude of this relationship was moderated by the severity of problems with aggression. Conclusions: Specifically, as the severity of participant’s general problems with aggression increased, the magnitude of the relationship between dating violence and severity of suicidal thinking increased. Limitations of the study and implications for practice are discussed.

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