scholarly journals Molecular Genetic Dissection of Complex Immunocompetence Traits in Broilers

Author(s):  
Avigdor Cahaner ◽  
Susan J. Lamont ◽  
E. Dan Heller ◽  
Jossi Hillel

Objectives: (1) Evaluate Immunocompetence-OTL-containing Chromosomal Regions (ICRs), marked by microsatellites or candidate genes, for magnitude of direct effect and for contribution to relationships among multiple immunocompetence, disease-resistance, and growth traits, in order to estimate epistatic and pleiotropic effects and to predict the potential breeding applications of such markers. (2) Evaluate the interaction of the ICRs with genetic backgrounds from multiple sources and of multiple levels of genetic variation, in order to predict the general applicability of molecular genetic markers across widely varied populations. Background: Diseases cause substantial economic losses to animal producers. Emerging pathogens, vaccine failures and intense management systems increase the impact of diseases on animal production. Moreover, zoonotic pathogens are a threat to human food safety when microbiological contamination of animal products occurs. Consumers are increasingly concerned about drug residues and antibiotic- resistant pathogens derived from animal products. The project used contemporary scientific technologies to investigate the genetics of chicken resistance to infectious disease. Genetic enhancement of the innate resistance of chicken populations provides a sustainable and ecologically sound approach to reduce microbial loads in agricultural populations. In turn, animals will be produced more efficiently with less need for drug treatment and will pose less of a potential food-safety hazard. Major achievements, conclusions and implications:. The PI and co-PIs had developed a refined research plan, aiming at the original but more focused objectives, that could be well-accomplished with the reduced awarded support. The successful conduct of that research over the past four years has yielded substantial new information about the genes and genetic markers that are associated with response to two important poultry pathogens, Salmonella enteritidis (SE) and Escherichia coli (EC), about variation of immunocompetence genes in poultry, about relationships of traits of immune response and production, and about interaction of genes with environment and with other genes and genetic background. The current BARD work has generated a base of knowledge and expertise regarding the genetic variation underlying the traits of immunocompetence and disease resistance. In addition, unique genetic resource populations of chickens have been established in the course of the current project, and they are essential for continued projects. The US laboratory has made considerable progress in studies of the genetics of resistance to SE. Microsatellite-marked chromosomal regions and several specific genes were linked to SE vaccine response or bacterial burden and the important phenomenon of gene interaction was identified in this system. In total, these studies demonstrate the role of genetics in SE response, the utility of the existing resource population, and the expertise of the research group in conducting such experiments. The Israeli laboratories had showed that the lines developed by selection for high or low level of antibody (Ab) response to EC differ similarly in Ab response to several other viral and bacterial pathogens, indicating the existence of a genetic control of general capacity of Ab response in young broilers. It was also found that the 10w-Ab line has developed, possibly via compensatory "natural" selection, higher cellular immune response. At the DNA levels, markers supposedly linked to immune response were identified, as well as SNP in the MHC, a candidate gene responsible for genetic differences in immunocompetence of chickens.

2015 ◽  
Vol 54 (03) ◽  
pp. 94-100 ◽  
Author(s):  
P. B. Musholt ◽  
T. J. Musholt

SummaryAim: Thyroid nodules > 1 cm are observed in about 12% of unselected adult employees aged 18–65 years screened by ultrasound scan (40). While intensive ultrasound screening leads to early detection of thyroid diseases, the determination of benign or malignant behaviour remains uncertain and may trigger anxieties in many patients and their physicians. A considerable number of thyroid resections are consecutively performed due to suspicion of malignancy in the detected nodes. Fine needle aspiration biopsy (FNAB) has been recommended for the assessment of thyroid nodules to facilitate detection of thyroid carcinomas but also to rule out malignancy and thereby avoid unnecessary thyroid resections. However, cytology results are dependent on experience of the respective cytologist and unfortunately inconclusive in many cases. Methods: Molecular genetic markers are already used nowadays to enhance sensitivity and specificity of FNAB cytology in some centers in Germany. The most clinically relevant molecular genetic markers as pre-operative diagnostic tools and the clinical implications for the intraoperative and postoperative management were reviewed. Results: Molecular genetic markers predominantly focus on the preoperative detection of thyroid malignancies rather than the exclusion of thyroid carcinomas. While some centers routinely assess FNABs, other centers concentrate on FNABs with cytology results of follicular neoplasia or suspicion of thyroid carcinoma. Predominantly mutations of BRAF, RET/PTC, RAS, and PAX8/PPARγ or expression of miRNAs are analyzed. However, only the detection of BRAF mutations predicts the presence of (papillary) thyroid malignancy with almost 98% probability, indicating necessity of oncologic thyroid resections irrespective of the cytology result. Other genetic alterations are associated with thyroid malignancy with varying frequency and achieve less impact on the clinical management. Conclusion: Molecular genetic analysis of FNABs is increasingly performed in Germany. Standardization, quality controls, and validation of various methods need to be implemented in the near future to be able to compare the results. With increasing knowledge about the impact of genetic alterations on the prognosis of thyroid carcinomas, recommendations have to be defined that may lead to individually optimized treatment strategies.


2017 ◽  
Vol 17 (1) ◽  
pp. 59-88 ◽  
Author(s):  
Amani Al-Dawood

Abstract Small ruminants (sheep and goats) play a predominant role in the economy of million people, and have provided meat, milk, skin, wool and fiber for centuries. Animals undergo various kinds of stressors, i.e. physical, nutritional, chemical, psychological and heat stress (HS). Among all, HS is the most concerning at present in the ever-changing climatic scenario. Climate change is the most serious long-term challenge faced by small ruminants’ owners worldwide. HS results in decreased growth, reproduction, production, milk quantity and quality, as well as natural immunity, making animals more vulnerable to diseases, and even death. Thus, HS results in great economic losses, emphasizing the necessity to objectively assess animal welfare. The increasing demand for animal products paralleled by the frequent hot climate is a serious threat for the agriculture sector. The ability of sheep and goats to cope with HS without harming their welfare and productive performance has been often overrated. To date, little attention has been paid to comprehensive detailed data on the adverse effect of HS on sheep and goats. Therefore, this review discusses in detail the sheep and goats’ behavioral, physiological, molecular/cellular, hematological, biochemical and immunological responses under HS conditions. In addition, this review also presents the adverse effects of HS on reproduction and fertility, milk quantity and quality, feed intake, and water consumption of sheep and goats. Finally, this review suggests various methods for HS alleviation. In conclusion, HS impairs productivity and well-being in sheep and goats. The improved understanding of the impact of HS on small ruminants will help in developing management techniques to alleviate HS and highlighting the need for future researches on HS in sheep and goats.


2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Joseph B Dube ◽  
Christopher T Johansen ◽  
John Robinson ◽  
Joan Lindsay ◽  
Vladimir Hachinski ◽  
...  

Introduction: “Cognitive impairment, no dementia” (CIND) is a prodromal stage of cognitive decline which marks the onset of dementia and is due most commonly to 1) Alzheimer disease (AD) or 2) vascular dysfunction. In order to assess the genetic component of CIND susceptibility, we investigated cardiovascular disease (CVD) and AD-associated genetic variation in CIND patients, hypothesizing that the genetic variation affecting CVD and AD susceptibility is also associated with CIND susceptibility. Methods: Our study cohort was taken from the Canadian Study of Health and Aging (CSHA) and was comprised of patients >65 years old with CIND (n=274) and matched normal controls (n=301). We genotyped ∼200,000 CVD-related SNPs using the Cardio-Metabochip genotyping array (Illumina). We also genotyped a panel of the top 11 AD-associated single nucleotide polymorphisms (SNPs) and APOE isotype. We tested for association between CIND status and genotypes using a logistic regression model adjusted for appropriate covariates. Genetic risk scores (GRSs) evaluated associations between CIND status and the accumulation of multiple genetic markers. Results: From our Cardio-Metabochip analysis, we identified 5 novel CIND susceptibility loci, with rs16901621 in FLJ22536 as our most significantly associated SNP (P=1.05E-06, OR=2.51, 95%CI=1.73-3.63). APOE ε4 isotype was modestly associated with CIND status (P<0.05), while AD SNP risk alleles were not associated (P>0.1). Conclusion: Using a high-throughput CVD microarray, we found novel genetic markers for CIND approaching genome-wide levels of significance. In contrast, known genetic markers for AD, such as APOE ε4 showed only modest associations in this cohort. Follow-up of variants in a CSHA replication cohort (n=370) is currently underway.


Author(s):  
Mahesh S. Dashyal M. P. Basavarajappa ◽  
G. Manjunath D. P. Prakash ◽  
Sayeed Wajeed R. Mulla Anita Rajkumar Ghandhe

Bacterial blight in pomegranate is a major disease caused by Xanthomonas axonopodis pv. punicae, which has resulted in significant economic losses in terms of both quality and quantity. The ineffectiveness of most chemicals in controlling this disease has shifted grower attention to the quest for a new molecule and hence the use of plant growth regulators and signaling molecules is a novel approach to control the disease as well as improving quality and quantity attributes of pomegranate. Hence, the aim of present study was to determine the impact of plant hormones like ethylene, jasmonic acid and salicylic acid on bacterial blight of pomegranate. Among different hormones applied, ethrel application shown maximum disease severity (33.2%) and salicylic acid shown lowest disease severity (15.08%) under greenhouse condition.


1992 ◽  
Vol 68 (6) ◽  
pp. 709-719 ◽  
Author(s):  
Peng Li ◽  
Jean Bousquet ◽  
John MacKay

Hardwoods are diverse, and they are important components in several forest regions of Canada. Yet low demand from the pulp and paper sector, abundant natural regeneration for several species, and high costs associated with seedling production and plantation establishment have restrained industries and governments from investing intensively into basic biological and genetic research of hardwoods. Recently, new interests have emerged for the utilization and conservation of hardwood species. To devise efficient gene conservation and breeding strategies for hardwoods, knowledge is needed about their genetic structure, genecology, and mating systems. Here we review information on the organization of genetic diversity in the few Canadian hardwood species that have been studied. Results derived from analyses of quantitative characters showed extensive genetic variation among populations and among individuals within populations in all species. Genetic variation among populations was found to be associated with environmental factors, especially for adaptive traits. Levels of genetic diversity were also found high in allozyme genetic markers. The application of molecular genetic markers at the DNA level in monitoring genetic diversity of hardwoods is also discussed. Information available regarding genetic diversity of Canadian hardwoods is insufficient to design efficient gene conservation strategies. Several programs investigating genetic diversity of hardwoods have been initiated in Canada, and should yield urgently needed data.


1994 ◽  
Author(s):  
Susan J. Lamont ◽  
E. Dan Heller ◽  
Avigdor Cahaner

This project utilized two live-animal populations in an integrated research program to identify molecular markers for immune response and disease resistance. The populations each had their foundation from meat-type commercial breeder chicken lines of their respective countries. Investigations effectively used unique availability of resources in each country to study commercial-type environments in Israel and line-crosses with diverse inbred lines in the US. Two bacterial systems were investigated to cover both respiratory and gastrointestinal, and primary and secondary, infections. Individual experimental groups of animals were evaluated for combinations of vaccine antibody levels, response to pathogen challenge, growth parameters, genetic background and molecular markers. The positive association of antibody level with resistance to disease was confirmed. Effectiveness of genetic selection for vaccine antibody response level was demonstrated. Molecular markers, both inside and outside the MHC region, were associated with antibody response and resistance to disease. Markers were shown to have a generalized effect, by association with multiple traits of immune response and disease resistance. The impact of genetic background on marker effect was shown to be important. The overall results demonstrate the effectiveness of selection on vaccine antibody response and the potential of molecular marker-assisted selection to improve efficiency of production of meat-type chickens by reducing genetic susceptibility to disease.


2019 ◽  
Author(s):  
Laura Rohmeier ◽  
Wolfram Petzl ◽  
Mirja Koy ◽  
Tordis Eickhoff ◽  
Alina Hülsebusch ◽  
...  

Abstract Title: In vivo model to study the impact of genetic variation on clinical outcome of mastitis in dairy uniparous cows Background: In dairy herds, mastitis causes detrimental economic losses. Genetic selection offers a sustainable tool to select animals with reduced susceptibility towards postpartum diseases. Studying underlying mechanisms is important to assess the physiological processes that cause differences between selected haplotypes. Therefore, the objective of this study was to establish an in vivo infection model to study the impact of selecting for alternative paternal haplotypes in a particular genomic region on cattle chromosome 18 for mastitis susceptibility under defined conditions in dairy uniparous cows. Results: At the start of pathogen challenge, no significant differences between the favorable (Q) and unfavorable (q) haplotypes were detected. Intramammary infection (IMI) with Staphylococcus aureus 1027 (S. aureus, n = 24, 96 h) or Escherichia coli 1303 (E. coli, n = 12, 24 h) was successfully induced in all uniparous cows. This finding was confirmed by clinical signs of mastitis and repeated recovery of the respective pathogen from milk samples of challenged quarters in each animal. After S. aureus challenge, Q-uniparous cows showed lower somatic cell counts 24 h and 36 h after challenge (P < 0.05), lower bacterial shedding in milk 12 h after challenge (P < 0.01) and a minor decrease in total milk yield 12 h and 24 h after challenge (P < 0.01) compared to q-uniparous cows. Conclusion: An in vivo infection model to study the impact of genetic selection for mastitis susceptibility under defined conditions in dairy uniparous cows was successfully established and revealed significant differences between the two genetically selected haplotype groups. This result might explain their differences in susceptibility towards IMI. These clinical findings form the basis for further in-depth molecular analysis to clarify the underlying genetic mechanisms for mastitis resistance.


2005 ◽  
Vol 166 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Susan E. Meyer ◽  
David L. Nelson ◽  
Suzette Clement ◽  
Jennifer Waters ◽  
Mikel Stevens ◽  
...  

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