scholarly journals The Genetic Basis for Salivary Gland Barriers to Arboviral Transmission

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 73
Author(s):  
Irma Sanchez-Vargas ◽  
Ken E. Olson ◽  
William C. Black
Keyword(s):  
Salivary Gland ◽  
Genetic Factors ◽  
Virus Transmission ◽  
Virus Titer ◽  
Gene Interaction ◽  
Narrow Sense Heritability ◽  
Sib Families ◽  
Genetic Contributions ◽  
Arboviral Transmission ◽  
Virus Strains

Arthropod-borne viruses (arboviruses) infect mosquito salivary glands and then escape to saliva prior to virus transmission. Arbovirus transmission from mosquitoes can be modulated by salivary gland infection barriers (SGIBs) and salivary gland escape barriers (SGEBs). We determined the influence of SGIBs and SGEBs by estimating the quantitative genetic contributions of Aedes aegypti half-sib families (Mapastepec, Mexico) infected with three dengue 2 (DENV2), two chikungunya (CHIKV), and two Zika (ZIKV) genotypes. We determined virus titer per salivary gland and saliva at seven days post-infection and virus prevalence in the half-sib population. CHIKV or ZIKV genotypes did not present SGIB, whereas DENV2 genotypes showed low rates of SGIB. However, virus titer and prevalence due to additive genetic factors in the half-sib family displayed a significant narrow-sense heritability (h2) for SGIB in two of the three DENV2 genotypes and one CHIKV and one ZIKV genotype. SGEBs were detected in all seven virus strains: 60–88% of DENV2 and 48–62% of CHIKV or ZIKV genotype infections. SGEB h2 was significant for all CHIKV or ZIKV genotypes but not for any of the DENV2 genotypes. SGIBs and SGEBs exhibited classical gene-by-gene interaction dynamics and are influenced by genetic factors in the mosquito and the virus.

scholarly journals Recent Findings Unravel Genes and Genetic Factors Underlying Leptosphaeria maculans Resistance in Brassica napus and Its Relatives

2020 ◽  
Vol 22 (1) ◽  
pp. 313
Author(s):  
Aldrin Y. Cantila ◽  
Nur Shuhadah Mohd Saad ◽  
Junrey C. Amas ◽  
David Edwards ◽  
Jacqueline Batley
Keyword(s):  
Brassica Napus ◽  
Genetic Factors ◽  
Quantitative Resistance ◽  
Genetic Resistance ◽  
Leptosphaeria Maculans ◽  
Gene Interaction ◽  
R Gene ◽  
R Genes ◽  
Blackleg Resistance ◽  
Avr Gene

Among the Brassica oilseeds, canola (Brassica napus) is the most economically significant globally. However, its production can be limited by blackleg disease, caused by the fungal pathogen Lepstosphaeria maculans. The deployment of resistance genes has been implemented as one of the key strategies to manage the disease. Genetic resistance against blackleg comes in two forms: qualitative resistance, controlled by a single, major resistance gene (R gene), and quantitative resistance (QR), controlled by numerous, small effect loci. R-gene-mediated blackleg resistance has been extensively studied, wherein several genomic regions harbouring R genes against L. maculans have been identified and three of these genes were cloned. These studies advance our understanding of the mechanism of R gene and pathogen avirulence (Avr) gene interaction. Notably, these studies revealed a more complex interaction than originally thought. Advances in genomics help unravel these complexities, providing insights into the genes and genetic factors towards improving blackleg resistance. Here, we aim to discuss the existing R-gene-mediated resistance, make a summary of candidate R genes against the disease, and emphasise the role of players involved in the pathogenicity and resistance. The comprehensive result will allow breeders to improve resistance to L. maculans, thereby increasing yield.

scholarly journals Genetic factors explain a significant part of associations between adolescent well-being and the social environment

2021 ◽  
Author(s):  
Margot P. van de Weijer ◽  
Dirk H. M. Pelt ◽  
Catharina E. M. van Beijsterveldt ◽  
Gonneke Willemsen ◽  
Meike Bartels
Keyword(s):  
Family Conflict ◽  
Generalized Estimating Equations ◽  
Leisure Time ◽  
Genetic Factors ◽  
Well Being ◽  
Causal Association ◽  
Difference Scores ◽  
The Social ◽  
Time Variables ◽  
Genetic Contributions

AbstractSocio-environmental factors play an important role in adolescent well-being, but potential genetic contributions to these associations are rarely assessed. To address this gap in the literature, associations between well-being and family conflict and functioning, number of friends, friendship importance and satisfaction, and leisure time variables were studied in N =  ~ 4700 twin pairs from the Netherlands Twin Register, us ing generalized estimating equations and twin-difference scores. When twin-difference scores indicated a role for genetic factors, we used bivariate genetic models to quantify genetic and environmental contributions to these associations. We identify significant associations between well-being and family functioning, family conflict, different leisure time activities, number of friends, and satisfaction with friendships. Additionally, we find evidence for large (73–91%) genetic influence on the associations between well-being and family conflict and functioning, leisure time sport/scouting clubs, and satisfaction with friendships. Finally, findings support the hypothesis of a causal association between well-being and family conflict and functioning. These findings have important implications for research into the social correlates of well-being in adolescence, as not taking genetic factors into account leads to overestimations of the influence of identified correlates and consequently to recommendations of these correlates as intervention targets.

scholarly journals Environmental and Genetic Contributions to Indicators of Oral Malodor in Twins

2011 ◽  
Vol 14 (6) ◽  
pp. 568-572 ◽  
Author(s):  
Walter A. Bretz ◽  
Aaron Biesbrock ◽  
Patricia M. Corby ◽  
Andrea L. Corby ◽  
Walter G. Bretz ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Genetic Factors ◽  
Sulfur Compounds ◽  
Exhaled Breath ◽  
Tongue Coating ◽  
Oral Malodor ◽  
Volatile Sulfur Compounds ◽  
Item Questionnaire ◽  
Genetic And Environmental Factors ◽  
Genetic Contributions

This study aimed to: (1) determine concordance rates of self-reported and subjectively determined indicators of oral malodor in twins; (2) determine the relative contributions of genetic and environmental factors to levels of volatile sulfur compounds (VSCs) in intraoral and exhaled breath. Fifty-one twin pairs participated in the study. Measurements of VSCs were obtained by a halimeter. The presence of tongue coatings was determined and twins filled out a 32-item questionnaire on oral malodor indicators independently of one another. Estimates of heritability (h2) for halimeter measurements were computed by SOLAR. The concordance rates for the presence of tongue coating among identical and fraternal twins were 67% and 11%, respectively. In the 10 most informative items, 70% exhibited higher concordance rates for identical than for fraternal twins. Of particular interest were the differences in concordance rates for dry mouth, sinus infection and unusual sweating. The h2 for intra-oral breath was 0.28 ± 0.17 (NS), whereas the h2 for exhaled breath was 0.50 ± 0.20 (p = .0207). The concordance rates of tongue coatings and malodor indicators were higher in identical twins than in fraternal twins. Intraoral breath VSC values were primarily attributable to environmental factors, whereas exhaled breath VSC values were partially explained by genetic factors.

GENETIC SOURCES OF RESISTANCE TO BLACKBIRD PREDATION IN SUNFLOWER

1986 ◽  
Vol 66 (1) ◽  
pp. 19-23 ◽  
Author(s):  
DAN E. PARFITT ◽  
GREGORY J. FOX
Keyword(s):  
Agelaius Phoeniceus ◽  
Narrow Sense ◽  
Sources Of Resistance ◽  
Bird Predation ◽  
Narrow Sense Heritability ◽  
The Third ◽  
Naturally Occurring ◽  
Xanthocephalus Xanthocephalus ◽  
Sib Families ◽  
Highly Correlated

Fifty-one sunflower (Helianthus annuus L.) inbreds were grown at three environments (locations) in North Dakota. Inbreds at two locations were subjected to naturally occurring bird predation by redwinged blackbirds (Agelaius phoeniceus L.) and yellowheaded blackbirds (Xanthocephalus xanthocephalus Bonaparte). The third sunflower plot was surrounded by a cage into which redwinged blackbirds were introduced. Bird damage was estimated as percent achenes removed from individual sunflower heads. Significant differences among environments were observed (P < 0.01). However, genotype performance among environments was highly correlated (P < 0.01). Half sib progeny from 36 of these inbreds were grown along with their maternal inbred parents to estimate narrow sense heritability (h2NS) of resistance to bird predation. Estimates of h2NS obtained by parent offspring regression and by covariance among half-sib families were h2NS = 0.69 and h2NS = 0.66, respectively. These estimates indicate a 67% level of heritability for resistance to bird predation, and suggest that it should be possible to develop sunflower lines with improved resistance.Key words: Sunflower, bird feeding, redwinged blackbird, yellowheaded blackbird

scholarly journals Heritability of Morphological Traits in Apple Early-ripening Full-sib and Half-sib Offspring and Its Potential Use for Assisted Selection

HortScience ◽  
2012 ◽  
Vol 47 (3) ◽  
pp. 328-333 ◽  
Author(s):  
Hassan Hajnajari ◽  
Bahaeddin Chashnidel ◽  
Kourosh Vahdati ◽  
Mohsen Ebrahimi ◽  
Alireza Nabipour ◽  
...  
Keyword(s):  
Morphological Traits ◽  
High Efficiency ◽  
Chlorophyll Concentration ◽  
Leaf Length ◽  
Breeding Program ◽  
Seedling Height ◽  
Early Screening ◽  
Narrow Sense Heritability ◽  
Early Ripening ◽  
Sib Families

To select the superior parents for the breeding program we oriented to produce new early-ripening cultivars, we evaluated more than 60 productive and vegetative characters in 108 native and imported cultivars grown in national collection for commercial apples located in Karaj, Iran, using an apple descriptor. The germination percentage of 100,000 hybrid seeds was 7% in the first year. In the second year, only 3000 from 7000 seedlings had to pass the final screening. Use of morphological markers as an early selection technique showed high efficiency in the apple breeding program. This study was conducted to determine heritability of certain morphological traits potentially used for selection of fruit early-ripening progenies in apple (Malus ×domestica Borkh.). Morphological traits in 3- and 4-year-old seedlings from 28 half-sib and 16 full-sib families were studied in 2007 and 2008, respectively. Parent–progeny correlations were analyzed using true-to-type progenies and their relative parents, all in the juvenile phase. Significant variations were observed between parental cultivars and half-sib and full-sib progenies for most of the studied traits. Positive correlations were found between seedling height and other morphological characters. A highly significant correlation (r = 0.98) was observed between branch distance along seedling stem and number of branches. The results showed that the heritability varied among the traits, ranging from moderate to high values. A high level of heritability was found in leaf chlorophyll concentration (LCC) and seedling heights in both half-sib and full-sib families. Heritability of half-sib progenies derived from the early-ripening parents was higher than the late-ripening parents. The relatively high heritability estimates for morphological traits, particularly in early-ripening cross combinations, suggested narrow-sense heritability as a criterion for early screening. The progenies of early cultivars exhibited the maximum and minimum heritability for seedling height (0.91) and leaf length (0.56), respectively. Oppositely, in the late-ripening progenies, the maximum and minimum heritability were found in LW and TD traits (0.79 and 0.42), respectively.

ADHD genetics

2018 ◽  
Author(s):  
Kate Langley
Keyword(s):  
Genetic Factors ◽  
Rare Variants ◽  
Association Studies ◽  
Copy Number Variant ◽  
Polygenic Risk Score ◽  
Genome Wide Association Studies ◽  
Clinical Factors ◽  
Genome Wide ◽  
Different Types ◽  
Genetic Contributions

This chapter reviews the evidence suggesting that there is a strong genetic component to ADHD and the efforts to identify the specific genetic factors that might be involved. It discusses the different types of genetic contributions, from common to rare variants, and the evidence that these are involved in the aetiology of the disorder. An overview of the methodological strategies employed, including genome-wide association studies (GWAS), polygenic risk score, and copy number variant (CNV) analyses, is undertaken, as well as discussion of the strengths and pitfalls of such work. The contradictory findings in the field and controversies that arise as a result are also explored. Finally, this chapter considers how the heritability of ADHD and specific genetic factors involved need to be examined in the context of clinical factors such as comorbidity and how these factors affect investigations into the genetics of ADHD.

scholarly journals Gene-Drug Interaction in Stroke

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Serena Amici ◽  
Maurizio Paciaroni ◽  
Giancarlo Agnelli ◽  
Valeria Caso
Keyword(s):  
Genetic Basis ◽  
Complex Disease ◽  
Genetic Factors ◽  
Gene Interaction ◽  
Recombinant Tissue Plasminogen Activator ◽  
Cerebrovascular Diseases ◽  
Clinical Approach ◽  
Drug Effectiveness ◽  
Tissue Plasminogen

Stroke is the third cause of mortality and one of most frequent causes of long-term neurological disability, as well as a complex disease that results from the interaction of environmental and genetic factors. The focus on genetics has produced a large number of studies with the objective of revealing the genetic basis of cerebrovascular diseases. Furthermore, pharmacogenetic research has investigated the relation between genetic variability and drug effectiveness/toxicity. This review will examine the implications of pharmacogenetics of stroke; data on antihypertensives, statins, antiplatelets, anticoagulants, and recombinant tissue plasminogen activator will be illustrated. Several polymorphisms have been studied and some have been associated with positive drug-gene interaction on stroke, but the superiority of the genotype-guided approach over the clinical approach has not been proved yet; for this reason, it is not routinely recommended.

scholarly journals Genetic Regulation of Polerovirus and Luteovirus Transmission in the Aphid Schizaphis graminum

2006 ◽  
Vol 96 (8) ◽  
pp. 828-837 ◽  
Author(s):  
M. E. Burrows ◽  
M. C. Caillaud ◽  
D. M. Smith ◽  
E. C. Benson ◽  
F. E. Gildow ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Barley Yellow Dwarf Virus ◽  
Major Gene ◽  
Genetic Regulation ◽  
Virus Transmission ◽  
Schizaphis Graminum ◽  
Yellow Dwarf ◽  
Dwarf Virus ◽  
Barley Yellow Dwarf ◽  
Yellow Dwarf Virus

Sexual forms of two genotypes of the aphid Schizaphis graminum, one a vector, the other a nonvector of two viruses that cause barley yellow dwarf disease (Barley yellow dwarf virus [BYDV]-SGV, luteovirus and Cereal yellow dwarf virus-RPV, polerovirus), were mated to generate F1 and F2 populations. Segregation of the transmission phenotype for both viruses in the F1 and F2 populations indicated that the transmission phenotype is under genetic control and that the parents are heterozygous for genes involved in transmission. The ability to transmit both viruses was correlated within the F1 and F2 populations, suggesting that a major gene or linked genes regulate the transmission. However, individual hybrid genotypes differed significantly in their ability to transmit each virus, indicating that in addition to a major gene, minor genes can affect the transmission of each virus independently. Gut and salivary gland associated transmission barriers were identified in the nonvector parent and some progeny, while other progeny possessed only a gut barrier or a salivary gland barrier. Hemolymph factors do not appear to be involved in determining the transmission phenotype. These results provide direct evidence that aphid transmission of luteoviruses is genetically regulated in the insect and that the tissue-specific barriers to virus transmission are not genetically linked.

scholarly journals Estimating Fetal and Maternal Genetic Contributions to Premature Birth From Multiparous Pregnancy Histories of Twins Using MCMC and Maximum-Likelihood Approaches

2009 ◽  
Vol 12 (4) ◽  
pp. 333-342 ◽  
Author(s):  
Timothy P. York ◽  
Jerome F. Strauss ◽  
Michael C. Neale ◽  
Lindon J. Eaves
Keyword(s):  
Preterm Birth ◽  
Maximum Likelihood ◽  
Genetic Factors ◽  
Covariance Structures ◽  
Mcmc Methods ◽  
Binary Outcome ◽  
Likelihood Methods ◽  
Maximum Likelihood Methods ◽  
Complex Models ◽  
Genetic Contributions

AbstractThe analysis of genetic and environmental contributions to preterm birth is not straightforward in family studies, as etiology could involve both maternal and fetal genes. Markov Chain Monte Carlo (MCMC) methods are presented as a flexible approach for defining user-specified covariance structures to handle multiple random effects and hierarchical dependencies inherent in children of twin (COT) studies of pregnancy outcomes. The proposed method is easily modified to allow for the study of gestational age as a continuous trait and as a binary outcome reflecting the presence or absence of preterm birth. Estimation of fetal and maternal genetic factors and the effect of the environment are demonstrated using MCMC methods implemented in WinBUGS and maximum likelihood methods in a Virginia COT sample comprising 7,061 births. In summary, although the contribution of maternal and fetal genetic factors was supported using both outcomes, additional births and/or extended relationships are required to precisely estimate both genetic effects simultaneously. We anticipate the flexibility of MCMC methods to handle increasingly complex models to be of particular relevance for the study of birth outcomes.

Sign in / Sign up

Export Citation Format

Share Document