• Title/Summary/Keyword: Genetic screening

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Characterising Forages for Ruminant Feeding

  • Dynes, R.A.;Henry, D.A.;Masters, D.G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.1
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    • pp.116-123
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    • 2003
  • Forages are the most important feed resource for ruminants worldwide, whether fed as pastures, forage crops or conserved hay, silage or haylage. There is large variability in the quality of forages so measurement and prediction of feeding value and nutritive value are essential for high levels of production. Within a commercial animal production system, methods of prediction must be inexpensive and rapid. At least 50% of the variation in feeding value of forages is due to variation in voluntary feed intake. Identification of the factors that constrain voluntary feed intake allows these differences to be managed and exploited in forage selection. Constraints to intake have been predicted using combinations of metabolic and physical factors within the animal while simple measurements such as the energy required to shear the plant material are related to constraints to intake with some plant material. Animals respond to both pre- and post-ingestive feedback signals from forages. Pre-ingestive signals may play a role in intake with signals including taste, odour and texture together with learned aversions to nutrients or toxins (post-ingestive feedback signals). The challenge to forage evaluation is identification of the factors which are most important contributors to these feedback signals. Empirical models incorporating chemical composition are also widely used. The models tend to be useful within the ranges of the datasets used in their development but none can claim to have universal application. Mechanistic models are becoming increasingly complex and sophisticated and incorporate both feed characteristics and use of biochemical pathways within the animal. Improvement in utilisation through the deliberate selection of pasture plants for high feeding value appears to have potential and has been poorly exploited. Use of Near Infrared Reflectance Spectroscopy is a simple method that offers significant potential for the preliminary screening of plants with genetic differences in feeding value. Near Infrared Reflectance Spectroscopy will only be as reliable as the calibration sets from which the equations are generated.

Applications of DNA Microarray in Disease Diagnostics

  • Yoo, Seung-Min;Choi, Jong-Hyun;Lee, Sang-Yup;Yoo, Nae-Choon
    • Journal of Microbiology and Biotechnology
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    • v.19 no.7
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    • pp.635-646
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    • 2009
  • Rapid and accurate diagnosis of diseases is very important for appropriate treatment of patients. Recent advances in molecular-level interaction and detection technologies are upgrading the clinical diagnostics by providing new ways of diagnosis, with higher speed and accuracy. In particular, DNA microarrays can be efficiently used in clinical diagnostics which span from discovery of diseaserelevant genes to diagnosis using its biomarkers. Diagnostic DNA microarrays have been used for genotyping and determination of disease-relevant genes or agents causing diseases, mutation analysis, screening of single nucleotide polymorphisms (SNPs), detection of chromosome abnormalities, and global determination of posttranslational modification. The performance of DNA-microarray-based diagnosis is continuously improving by the integration of other tools. Thus, DNA microarrays will play a central role in clinical diagnostics and will become a gold standard method for disease diagnosis. In this paper, various applications of DNA microarrays in disease diagnosis are reviewed. Special effort was made to cover the information disclosed in the patents so that recent trends and missing applications can be revealed.

Enhancement of Lipid Production under Heterotrophic Conditions by Overexpression of an Endogenous bZIP Transcription Factor in Chlorella sp. HS2

  • Lee, Hansol;Shin, Won-Sub;Kim, Young Uk;Jeon, Seungjib;Kim, Minsik;Kang, Nam Kyu;Chang, Yong Keun
    • Journal of Microbiology and Biotechnology
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    • v.30 no.10
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    • pp.1597-1606
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    • 2020
  • Transcription factor engineering to regulate multiple genes has shown promise in the field of microalgae genetic engineering. Here, we report the first use of transcription factor engineering in Chlorella sp. HS2, thought to have potential for producing biofuels and bioproducts. We identified seven endogenous bZIP transcription factors in Chlorella sp. HS2 and named them HSbZIP1 through HSbZIP7. We overexpressed HSbZIP1, a C-type bZIP transcription factor, in Chlorella sp. HS2 with the goal of enhancing lipid production. Phenotype screening under heterotrophic conditions showed that all transformants exhibited increased fatty acid production. In particular, HSbZIP1 37 and 58 showed fatty acid methyl ester (FAME) yields of 859 and 1,052 mg/l, respectively, at day 10 of growth under heterotrophic conditions, and these yields were 74% and 113% higher, respectively, than that of WT. To elucidate the mechanism underlying the improved phenotypes, we identified candidate HSbZIP1-regulated genes via transcription factor binding site analysis. We then selected three genes involved in fatty acid synthesis and investigated mRNA expression levels of the genes by qRT-PCR. The result revealed that the possible HSbZIP1-regulated genes involved in fatty acid synthesis were upregulated in the HSbZIP1 transformants. Taken together, our results demonstrate that HSbZIP1 can be utilized to improve lipid production in Chlorella sp. HS2 under heterotrophic conditions.

Epidemioclinical Feature of Early-Onset Colorectal Cancer at-Risk for Lynch Syndrome in Central Iran

  • Zeinalian, Mehrdad;Hashemzadeh-Chaleshtori, Morteza;Akbarpour, Mohammad Javad;Emami, Mohammad Hassan
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.11
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    • pp.4647-4652
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    • 2015
  • Background: Colorectal cancer (CRC) is becoming one of the most complicated challenges of human health, particularly in developing countries like Iran. In this paper, we try to characterize CRC cases diagnosed < age 50 at-risk for Lynch syndrome within central Iran. Materials and Methods: We designed a descriptive retrospective study to screen all registered CRC patients within 2000-2013 in Poursina Hakim Research Center (PHRC), a referral gastroenterology clinic in central Iran, based on being early-onset (age at diagnosis ${\leq}50years$) and Amsterdam II criteria. We calculated frequencies and percentages by SPSS 19 software to describe clinical and family history characteristics of patients with early-onset CRC. Results: Overall 1,659 CRC patients were included in our study of which 413 (24.9%) were ${\leq}50years$ at diagnosis. Of 219/413 successful calls 67 persons (30.6%) were reported deceased. Family history was positive for 72/219 probands (32.9%) and 53 families (24.2%) were identified as familial colorectal cancer (FCC), with a history of at-least three affected members with any type of cancer in the family, of which 85% fulfilled the Amsterdam II Criteria as hereditary non-polyposis colorectal cancer (HNPCC) families (45/219 or 20.5%). Finally, 14 families were excluded due to proband tumor tissues being unavailable or unwillingness for incorporation. The most common HNPCC-associated extracolonic-cancer among both males and females of the families was stomach, at respectively 31.8 and 32.7 percent. The most common tumor locations among the 31 probands were rectum (32.3%), sigmoid (29.0%), and ascending colon (12.9%). Conclusions: Given the high prevalence of FCC (~1/4 of early-onset Iranian CRC patients), it is necessary to establish a comprehensive cancer genetic counseling and systematic screening program for early detection and to improve cancer prognosis among high risk families.

Functional PstI/RsaI Polymorphisms in the CYP2E1 Gene among South Indian Populations

  • Lakkakula, Saikrishna;Maram, Rajasekhar;Munirajan, Arasambattu Kannan;Pathapati, Ram Mohan;Visweswara, Subrahmanyam Bhattaram;Lakkakula, Bhaskar V.K.S.
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.179-182
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    • 2013
  • Human cytochrome P4502E1 (CYP2E1) is a well-conserved xenobiotic-metabolizing enzyme expressed in liver, kidney, nasal mucosa, brain, lung, and other tissues. CYP2E1 is inducible by ethanol, acetone, and other low-molecular weight substrates and may mediate development of chemically-mediated cancers. CYP2E1 polymorphisms alter the transcriptional activity of the gene. This study was conducted in order to investigate the allele frequency variation in different populations of Andhra Pradesh. Two hundred and twelve subjects belonging to six populations were studied. Genotype and allele frequency were assessed through TaqMan allelic discrimination (rs6413419) and polymerase chain reaction-sequencing (-1295G>C and -1055C>T) after DNA isolation from peripheral leukocytes. The data were compared with other available world populations. The SNP rs6413419 is monomorphic in the present study, -1295G>C and -1055C>T are less polymorphic and followed Hardy-Weinberg equilibrium in all the populations studied. The -1295G>C and -1055C>T frequencies were similar and acted as surrogates in all the populations. Analysis of HapMap populations data revealed no significant LD between these markers in all the populations. Low frequency of $CYP2E1^*c2$ could be useful in the understanding of south Indian population gene composition, alcohol metabolism, and alcoholic liver disease development. However, screening of additional populations and further association studies are necessary. The heterogeneity of Indian population as evidenced by the different distribution of $CYP2E1^*c2$ may help in understanding the population genetic and evolutionary aspects of this gene.

Noninvasive prenatal test for the pregnancy with Turner syndrome mosaicism 45, X/47, XXX: A case report

  • Kim, Ji Hye;Lee, Gun Ho;Cha, Dong Hyun;Cho, Eun-Hae;Jung, Yong Wook
    • Journal of Genetic Medicine
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    • v.12 no.2
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    • pp.118-122
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    • 2015
  • Noninvasive prenatal test (NIPT) is a novel screening method for the diagnosis of fetal chromosomal aneuploidies. NIPT is based on technology that detects cell-free fetal DNA in maternal plasma and analyzes it with massively parallel sequencing technology to determine whether the fetus is at risk of trisomy 21, trisomy 18, trisomy 13 or sex chromosome abnormalities (SCAs). NIPT has been reported to have sensitivity of 99% and a false positive rate of less than 1% for detecting trisomy 21 and trisomy 18. Although extension of the application of NIPT to other SCAs has been attempted, there are concerns in extending NIPT to SCAs because of maternal or fetal mosaicism, undetected maternal SCAs, and multiple pregnancies. Recently, we assessed a pregnancy with the rare Turner syndrome mosaicism 45, X/47, XXX, which was reported as 45, X with NIPT. We present the case here and briefly review the current literatures on NIPT in testing for fetal monosomy X. To the best of our knowledge, this is the first report of the 45, X/47, XXX mosaicism in Korea to be reported as 45, X by NIPT with whole genome sequencing. This case report will provide valuable information for counseling women who want to undergo NIPT.

Screening of Ecotoxicant Responsive Genes and Expression Analysis of Benzo[a]pyrene-exposed Rockfish (Sebastes schlgeli)

  • Yum, Seung-Shic;Woo, Seon-Ock;Lee, Taek-Kyun
    • Molecular & Cellular Toxicology
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    • v.2 no.2
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    • pp.114-119
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    • 2006
  • Benzo[a]pyrene is a representative ecotoxicant in marine environment and a model compound of polycyclic aromatic hydrocarbons, which has an ability to bioaccumulate in aquatic organisms. This study aimed to identify molecular biomarkers suitable for assessing environmental pollution using a microarray technique. We examined the effects of benzo[a]pyrene on gene expressions in the rockfish, Sebastes schlegeli. We constructed the subtractive cDNA library with hepatic RNA from benzo[a]pyrene-exposed and non-exposed control fish. From the library 10,000 candidate clones were selected randomly and cDNA microarray was constructed. We determined benzo[a]pyrene-responsive genes using a high-density microarray. Statistical analysis showed that approximately 400 genes are significantly induced or reduced by benzo[a]pyrene treatment ($2\;{\mu}m$). Especially gene expression changes of 4 candidate clones among the up- or down-regulated genes were investigated in 6, 12 and 24 hr BaP-exposed fish groups. Many methods have been developed to monitor marine environmental status, which depend on quantifying the levels of the toxic components in polluted seawater or on ecological accessing, such as species diversity or richness. However, those methods could not provide information on physiological or genetic changes induced by such environmental stresses. Comparing with the conventional methods, these data will propose that benzo[a]pyrene-responsive genes can be useful for biological risk assessment of polycyclic aromatic hydrocarbons on marine organism at molecular level.

Pathogenic variant in NLRP7 (19q13.42) associated with recurrent gestational trophoblastic disease: Data from early embryo development observed during in vitro fertilization

  • Sills, E. Scott;Obregon-Tito, Alexandra J.;Gao, Harry;McWilliams, Thomas K.;Gordon, Anthony T.;Adams, Catharine A.;Slim, Rima
    • Clinical and Experimental Reproductive Medicine
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    • v.44 no.1
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    • pp.40-46
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    • 2017
  • Objective: To describe in vitro development of human embryos derived from an individual with a homozygous pathogenic variant in NLRP7 (19q13.42) and recurrent hydatidiform mole (HM), an autosomal recessive condition thought to occur secondary to an oocyte defect. Methods: A patient with five consecutive HM pregnancies was genomically evaluated via next generation sequencing followed by controlled ovarian hyperstimulation, in vitro fertilization (IVF) with intracytoplasmic sperm injection, embryo culture, and preimplantation genetic screening. Findings in NLRP7 were recorded and embryo culture and biopsy data were tabulated as a function of parental origin for any identified ploidy error. Results: The patient was found to have a pathogenic variant in NLRP7 (c.2810+2T>G) in a homozygous state. Fifteen oocytes were retrieved and 10 embryos were available after fertilization via intracytoplasmic sperm injection. Developmental arrest was noted for all 10 embryos after 144 hours in culture, thus no transfer was possible. These non-viable embryos were evaluated by karyomapping and all were diploid biparental; two were euploid and eight had various aneuploidies all of maternal origin. Conclusion: This is the first report of early human embryo development from a patient with any NLRP7 mutation. The pathogenic variant identified here resulted in global developmental arrest at or before blastocyst stage. Standard IVF should therefore be discouraged for such patients, who instead need to consider oocyte (or embryo) donation with IVF as preferred clinical methods to treat infertility.

Increased Free Circulating DNA Integrity Index as a Serum Biomarker in Patients with Colorectal Carcinoma

  • El-Gayar, Dina;El-Abd, Nevine;Hassan, Noha;Ali, Reem
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.939-944
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    • 2016
  • Background: Cell-free DNA circulating in blood is a candidate biomarker for malignant tumors. Unlike uniformly truncated DNA released from apoptotic non diseased cells, DNA released from necrotic cancer cells varies in size. Objectives: To measure the DNA integrity index in serum and the absolute DNA concentration to assess their clinical utility as potential serum biomarkers for colorectal carcinoma (CRC) compared to CEA and CA19-9. Materials and Methods: Fifty patients with CRC, 10 with benign colonic polyps and 20 healthy sex and age matched volunteers, were investigated by real time PCR of ALU repeats (ALU q-PCR) using two sets of primers (115 and 247 bp) amplifying different lengths of DNA fragments. The DNA integrity index was calculated as the ratio of q-PCR results of ALU 247/ALU 115bp. Results: Serum DNA integrity was statistically significantly higher in CRC patients compared to the benign and control groups (p<0.001). ROC curves for differentiating CRC patients from normal controls and benign groups had areas under curves of 0.90 and 0.85 respectively. Conclusions: The DNA integrity index is superior to the absolute DNA concentration as a potential serum biomarker for screening and diagnosis of CRC. It may also serve as an indicator for monitoring the progression of CRC patients. Combining CEA and CA19-9 with either of the genetic markers studied is better than either of them alone.

DNA Methylation Profiles of Blood Cells Are Distinct between Early-Onset Obese and Control Individuals

  • Rhee, Je-Keun;Lee, Jin-Hee;Yang, Hae Kyung;Kim, Tae-Min;Yoon, Kun-Ho
    • Genomics & Informatics
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    • v.15 no.1
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    • pp.28-37
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    • 2017
  • Obesity is a highly prevalent, chronic disorder that has been increasing in incidence in young patients. Both epigenetic and genetic aberrations may play a role in the pathogenesis of obesity. Therefore, in-depth epigenomic and genomic analyses will advance our understanding of the detailed molecular mechanisms underlying obesity and aid in the selection of potential biomarkers for obesity in youth. Here, we performed microarray-based DNA methylation and gene expression profiling of peripheral white blood cells obtained from six young, obese individuals and six healthy controls. We observed that the hierarchical clustering of DNA methylation, but not gene expression, clearly segregates the obese individuals from the controls, suggesting that the metabolic disturbance that occurs as a result of obesity at a young age may affect the DNA methylation of peripheral blood cells without accompanying transcriptional changes. To examine the genome-wide differences in the DNA methylation profiles of young obese and control individuals, we identified differentially methylated CpG sites and investigated their genomic and epigenomic contexts. The aberrant DNA methylation patterns in obese individuals can be summarized as relative gains and losses of DNA methylation in gene promoters and gene bodies, respectively. We also observed that the CpG islands of obese individuals are more susceptible to DNA methylation compared to controls. Our pilot study suggests that the genome-wide aberrant DNA methylation patterns of obese individuals may advance not only our understanding of the epigenomic pathogenesis but also early screening of obesity in youth.