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Fulltext Recent Strategies for Detection and Improvement of Brown Planthopper Resistance Genes in Rice: A Review

Sani Haliru B, Rafii MY, Mazlan N, Ramlee SI, Muhammad I, Silas Akos I, et al.

Plants (Basel), 2020 Sep 14;9(9).
PMID: 32937908 DOI: 10.3390/plants9091202

Brown planthopper (BPH; Nilaparvata lugens Stal) is considered the main rice insect pest in Asia. Several BPH-resistant varieties of rice have been bred previously and released for large-scale production in various rice-growing regions. However, the frequent surfacing of new BPH biotypes necessitates the evolution of new rice varieties that have a wide genetic base to overcome BPH attacks. Nowadays, with the introduction of molecular approaches in varietal development, it is possible to combine multiple genes from diverse sources into a single genetic background for durable resistance. At present, above 37 BPH-resistant genes/polygenes have been detected from wild species and indica varieties, which are situated on chromosomes 1, 3, 4, 6, 7, 8, 9, 10, 11 and 12. Five BPH gene clusters have been identified from chromosomes 3, 4, 6, and 12. In addition, eight BPH-resistant genes have been successfully cloned. It is hoped that many more resistance genes will be explored through screening of additional domesticated and undomesticated species in due course.

Matched MeSH terms: Genetic Background
Fulltext Identification of two novel mutations, PSEN1 E280K and PRNP G127S, in a Malaysian family

Ch'ng GS, An SS, Bae SO, Bagyinszky E, Kim S

Neuropsychiatr Dis Treat, 2015;11:2315-22.
PMID: 26396515 DOI: 10.2147/NDT.S86334

Alzheimer's disease (AD) is the most common form of dementia, which can be categorized into two main forms: early onset AD and late onset AD. The genetic background of early onset AD is well understood, and three genes, the APP, PSEN1, and PSEN2 have been identified as causative genes. In the current study, we tested three siblings from Malaysia who were diagnosed with early onset dementia, as well as their available family members. The family history was positive as their deceased father was similarly affected. Patients were tested for mutations in APP, PSEN1, PSEN2, and PRNP. A novel variant, E280K, was discovered in exon 8 of PSEN1 in the three siblings. In silico analyses with SIFT, SNAP, and PolyPhen2 prediction tools and three-dimensional modeling were performed, and the results suggested that the mutation is probably a pathogenic variant. Two additional pathogenic mutations were previously been described for codon 280, E280A, and E280G, which could support the importance of the E280 residue in the PS1 protein contributing to the pathogenic nature of E280K. Additional ten family members were screened for the E280K mutation, and all of them were negative. Six of them presented with a variety of neuropsychiatric symptoms, including learning disabilities, epilepsy, and schizophrenia, while four family members were asymptomatic. A novel PRNP G127S mutation was found in a step-niece of the three siblings harboring the PSEN1 E280K mutation. In silico predictions for PRNP G127S mutation suggested that this might be possibly a damaging variant. Additional studies to characterize PRNP G127S would be necessary to further understand the effects of this mutation.

Matched MeSH terms: Genetic Background
A cross-sectional study on the total lipid content of milk from Malaysian mothers of fullterm infants

Shaik Alaudeen, Nor Muslim, Kamarul Faridah, Hamid Arshat

Malaysian Journal of Child Health, 1997;9(1):66-72.
MyJurnal

Milk lipids play an important role in the early nutrition of an infant's life. A study was undertaken to investigate the total lipid content of milk obtained from urban, exclusively breastfeeding Malaysian mothers offill term infants. Results from approximately 600 samples analysed using a commercial kit [MerckotestO] , showed that the total lipid concentration was lowest in colostrum [1.9 + 0.1 g/dl J, however this value increased gradually with days of lactation and attained a maximum concentration of 3.1 ± 0.1 g/dl during the mature milk stage. This agrees with results from other studies that the total lipid content is indeed influenced by the stage of lactation. The effect of socioeconomic factors such as income and parity on the milk lipids was also investi-gated and the results revealed that the above factors had no significant influence on the total lipid content of Malaysian mother 's milk obtained during all three stages of lactation studied [colostrum, transitional and mature milk] . However; ethnicity showed significant influence during the mature but not in the early [colostrum and transitional] stage of lactation. This however, is not filly explained by this study. As a whole, this study suggests that the human breast, through a mechanism that is ill understood, maintains cm optimal level of total lipid in milk despite their differing cultural and genetic background. It is hoped that such scientific evidence will instil more confidence among breastfeeding mothers in this fast developing cosmopolitan nation.

Matched MeSH terms: Genetic Background
Application of molecular markers in Malaysian fisheries genetic resources

Tan, Soon Guan, Bhassu, Subha, Rosly Hassan

Buletin Persatuan Genetik Malaysia, 2005;11(2):0-0.
MyJurnal

The Malaysian fish production is about 1.5 million metric tonnes and 86.9% of this comes from the marine sector and 13.1% from the inland sector. This included fish production by capture and culture. (DOF, 2002). Fisheries genetic resources need to have a value in terms of economic, ecological and social uses and they need to characterized. This is the mandate to FAO and it is also necessary for fisheries management and aquaculture development. The vast aquatic diversity that exists in Malaysia consist of numerous taxa of marine and freshwater fishes, crustaceans, mollusks, plants and animals. These figures could be an underestimate to the actual figure. The levels of genetic diversity includes ecosystems, communities, population, genotypes and individual genes. A knowledge of the genetic background of a species and its population structure is essential for its management, breeding and conservation programmes in fisheries. Problems like how to choose the right candidates for breeding, identifiying and monitoring lines, families and individuals, monitoring and control of inbreeding, inheritance of simple traits and genetic improvement through selection for favourable gene and gene combinations can potentially be answered through the use of molecular markers in the management of fisheries genetic resources.

Matched MeSH terms: Genetic Background
Fulltext Maternal ancestry analyses of red tilapia strains based on D-loop sequences of seven tilapia populations

Jiang B, Fu J, Dong Z, Fang M, Zhu W, Wang L

PeerJ, 2019;7:e7007.
PMID: 31179190 DOI: 10.7717/peerj.7007

Background: Many tilapia species or varieties have been widely introduced and have become an economically important food fish in China. Information on the genetic backgrounds of these populations is deficient and requires more research, especially for red tilapia strains.
Methods: In the present study, displacement loop (D-loop) sequences were used to evaluate the genetic relationship and diversity of seven tilapia populations that are widely cultured in China; this was done specifically to speculate on the maternal ancestry of red tilapia strains. Three red tilapia varieties of Oreochromis ssp., Taiwan (TW), Israel (IL), and Malaysia (MY) strains and other populations, including O. aureus (AR), O. niloticus (NL), O. mossambicus (MS), and the GIFT strain of O. niloticus, were collected and analyzed in this study.
Results: A total of 146 polymorphic sites and 32 haplotypes of D-loop sequences were detected among 332 fish and four major haplotypes were shared among the populations. The TW and NL populations had a greater number of haplotypes (20 and 8, respectively). The haplotype diversity (Hd) and nucleotide diversity (π) of each population ranged from 0.234 to 0.826, and 0 to 0.060, respectively. The significant positive Tajima's D value of neutral test were detected in the NL, IL, and MY populations (P 0.05). The nearest K2P genetic distance (D = 0.014) was detected between the MS and TW populations, whereas, the farthest (D = 0.101) was found between the GIFT and AR populations. The results from the molecular variance analysis (AMOVA) showed that there was an extremely significant genetic variation observed among the populations (P

Matched MeSH terms: Genetic Background
The effect of immune status, age and genetic background on induction of oral tolerance to Actinomyces viscosus in mice

Sosroseno W, Herminajeng E, Bird P

Biomed Pharmacother, 2015 Mar;70:294-8.
PMID: 25776514 DOI: 10.1016/j.biopha.2014.12.039

The aim of the present study was to determine the effect of immune status, age and genetic background on the induction of oral tolerance to Actinomyces viscosus. Suppression of delayed type hypersensitivity (DTH) response and antigen-specific serum antibody levels could be induced in DBA/2 mice intragastrically and systemically immunized with A. viscocus, suggesting the induction of oral tolerance. In contrast, this immune suppression could be abrogated if the animals had been systemically immunized prior to the induction of oral tolerance with the same bacterium. Long-term systemic immunization prior to intragastric immunization with A. viscocus suppressed DTH response only. Cell transfer of this group of animals also suppressed DTH response in the donors, indicating the action of suppressor cells for inhibition of DTH response. Furthermore, oral tolerance to A. viscocus failed to occur in mice aged at 3 days and 1, 2, 4, 6 and 36 weeks old. Mice bearing H-2(d) haplotype were the most susceptible to oral tolerization, followed by H-2(b) and H-2(k). Therefore, the results of the presence study suggest that the induction of oral tolerance to A. viscosus in mice may be dependence on the immune status and genetic background but not age.

Matched MeSH terms: Genetic Background*
Cytochrome P450 genotype-guided drug therapies: An update on current states

Dong AN, Tan BH, Pan Y, Ong CE

Clin Exp Pharmacol Physiol, 2018 10;45(10):991-1001.
PMID: 29858511 DOI: 10.1111/1440-1681.12978

Over the past 2 decades, knowledge of the role and clinical value of pharmacogenetic markers has expanded so that individualized pre-emptive therapy based on genetic background of patients could be within reach for clinical implementation. This is evidenced from the frequent updating of drug labels that incorporates pharmacogenetic information (where compelling data become available) by the regulatory agencies (such as the US FDA), and the periodical publication of guidelines of specific therapeutic recommendations based on the results of pharmacogenetic tests by the pharmacogenetics working groups or consortiums of professional bodies. Clinical relevance of the cytochrome P450 (CYP) polymorphism related to dose, effectiveness and/or toxicity of key drugs are presented in this review, including that of warfarin, clopidogrel, tricyclic antidepressants, and proton pump inhibitors. Prospect for routine clinical application of CYP genotyping before prescribing drugs is still currently unclear due to challenges and barriers associated with availability of well-defined and validated pharmacogenetic studies, the interpretation, result reporting and potential error of genotype testing, involvement of non-genetic factors, and other patient's demographic and disease conditions. Further studies to provide additional supporting clinical data and acceleration of pharmacogenetic testing standards and techniques should help improve the evidence base needed for clinical utility and hence move the implementation of genotype-guided therapy in clinical practice a step closer to reality.

Matched MeSH terms: Genetic Background
Fulltext Identification of Predictive DNA Methylation Biomarkers for Chemotherapy Response in Colorectal Cancer

Baharudin R, Ab Mutalib NS, Othman SN, Sagap I, Rose IM, Mohd Mokhtar N, et al.

Front Pharmacol, 2017;8:47.
PMID: 28243201 DOI: 10.3389/fphar.2017.00047

Resistance to 5-Fluorouracil (5-FU) is a major obstacle to the successful treatment of colorectal cancer (CRC) and posed an increased risk of recurrence. DNA methylation has been suggested as one of the underlying mechanisms for recurrent disease and its contribution to the development of drug resistance remains to be clarified. This study aimed to determine the methylation phenotype in CRC for identification of predictive markers for chemotherapy response. We performed DNA methylation profiling on 43 non-recurrent and five recurrent CRC patients using the Illumina Infinium HumanMethylation450 Beadchip assay. In addition, CRC cells with different genetic backgrounds, response to 5-FU and global methylation levels (HT29 and SW48) were treated with 5-FU and DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-azadC). The singular and combined effects of these two drug classes on cell viability and global methylation profiles were investigated. Our genome-wide methylation study on the clinical specimens showed that recurrent CRCs exhibited higher methylation levels compared to non-recurrent CRCs. We identified 4787 significantly differentially methylated genes (P < 0.05); 3112 genes were hyper- while 1675 genes were hypomethylated in the recurrent group compared to the non-recurrent. Fifty eight and 47 of the significantly hypermethylated and hypomethylated genes have an absolute recurrent/non-recurrent methylation difference of ≥20%. Most of the hypermethylated genes were involved in the MAPK signaling pathway which is a key regulator for apoptosis while the hypomethylated genes were involved in the PI3K-AKT signaling pathway and proliferation process. We also demonstrate that 5-azadC treatment enhanced response to 5-FU which resulted in significant growth inhibition compared to 5-FU alone in hypermethylated cell lines SW48. In conclusion, we found the evidence of five potentially biologically important genes in recurrent CRCs that could possibly serve as a new potential therapeutic targets for patients with chemoresistance. We postulate that aberrant methylation of CCNEI, CCNDBP1, PON3, DDX43, and CHL1 in CRC might be associated with the recurrence of CRC and 5-azadC-mediated restoration of 5-FU sensitivity is mediated at least in part by MAPK signaling pathway.

Matched MeSH terms: Genetic Background