Displaying publications 201 - 220 of 248 in total

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  1. Estrous cycle based on blood progesterone profiles and changes in vulvar appearance of Malayan tapirs (Tapirus indicus)
    Kusuda S, Ikoma M, Morikaku K, Koizumi J, Kawaguchi Y, Kobayashi K, et al.
    J. Reprod. Dev., 2007 Dec;53(6):1283-9.
    PMID: 17965541
    The progesterone (P(4)) profiles and macroscopic vulvar changes of female Malayan tapirs were investigated in order to understand their fundamental reproductive physiology and to search for visual indicators of estrus. Blood was collected once or twice a week from seven female Malayan tapirs kept at four zoos. Serum or plasma P(4) concentrations were determined by radioimmunoassay. The P(4) concentrations changed cyclically throughout the years, and a total of 56 cycles was confirmed in the seven females. The length of the estrous cycle based on the P(4) profiles was 43.6+/-2.0 days; however, this mean includes great variation in length, from 21 to 84 days. Mucous discharge from the vulva and vulvar swelling were seen when the P(4) concentrations were low before the beginning of a rise in most cases. In conclusion, captive female Malayan tapirs have variations of approximately 1 to 3 months in estrous cycle length, and visual changes in the vulva are helpful in estimating estrus in female Malayan tapirs.
    Matched MeSH terms: Breeding
  2. Fulltext Heritability and genetic advance among chili pepper genotypes for heat tolerance and morphophysiological characteristics
    Usman MG, Rafii MY, Ismail MR, Malek MA, Abdul Latif M
    ScientificWorldJournal, 2014;2014:308042.
    PMID: 25478590 DOI: 10.1155/2014/308042
    High temperature tolerance is an important component of adaptation to arid and semiarid cropping environment in chili pepper. Two experiments were carried out to study the genetic variability among chili pepper for heat tolerance and morphophysiological traits and to estimate heritability and genetic advance expected from selection. There was a highly significant variation among the genotypes in response to high temperature (CMT), photosynthesis rate, plant height, disease incidence, fruit length, fruit weight, number of fruits, and yield per plant. At 5% selection intensity, high genetic advance as percent of the mean (>20%) was observed for CMT, photosynthesis rate, fruit length, fruit weight, number of fruits, and yield per plant. Similarly, high heritability (>60%) was also observed indicating the substantial effect of additive gene more than the environmental effect. Yield per plant showed strong to moderately positive correlations (r = 0.23-0.56) at phenotypic level while at genotypic level correlation coefficient ranged from 0.16 to 0.72 for CMT, plant height, fruit length, and number of fruits. Cluster analysis revealed eight groups and Group VIII recorded the highest CMT and yield. Group IV recorded 13 genotypes while Groups II, VII, and VIII recorded one each. The results showed that the availability of genetic variance could be useful for exploitation through selection for further breeding purposes.
    Matched MeSH terms: Breeding
  3. Fulltext The deadly ebola threat in the midst of an overwhelming dengue epidemic
    Besari AM, Md Noor SS, Lee YY
    Malays J Med Sci, 2014 Nov-Dec;21(6):9-13.
    PMID: 25897277 MyJurnal
    The recent death tolls and morbidities associated with two deadly viral haemorrhagic fevers (VHFs), i.e., Ebola and dengue, are simply shocking. By the end of August 2014, 65 672 people were afflicted with dengue fever (DF) in Malaysia, with 9505 from Kelantan, and there were 128 reported deaths. More astounding are the death tolls associated with Ebola: 3091 deaths from 6574 reported cases so far. It is not difficult to imagine the potential disaster if Ebola spreads beyond Africa. VHFs are characterised by an acute onset of fever, vascular disruption and a rapid progression to shock and death. The revised World Health Organization (WHO) 2012 classification (dengue with and without warning signs and severe dengue) is more clinically relevant and allows more streamlined admission. With good administrative support and public health and governmental efforts, the dengue epidemic in Malaysia is now more contained. However, there should be no laxity with the imminent lethal Ebola threat. Human-to-human transmission is an important mechanism for the spread of Ebola, and this calls for strict precautions regarding contact with any suspected cases. In contrast, the control and elimination of dengue would require successful control of the vectors and their breeding sites.
    Matched MeSH terms: Breeding
  4. Differential expression of the HvCslF6 gene late in grain development may explain quantitative differences in (1,3;1,4)-β-glucan concentration in barley
    Wong SC, Shirley NJ, Little A, Khoo KH, Schwerdt J, Fincher GB, et al.
    Molecular breeding : new strategies in plant improvement, 2015 01 20;35:20.
    PMID: 25620877
    The cellulose synthase-like gene HvCslF6, which is essential for (1,3;1,4)-β-glucan biosynthesis in barley, collocates with quantitative trait loci (QTL) for grain (1,3;1,4)-β-glucan concentration in several populations, including CDC Bold × TR251. Here, an alanine-to-threonine substitution (caused by the only non-synonymous difference between the CDC Bold and TR251 HvCslF6 alleles) was mapped to a position within HvCSLF6 that seems unlikely to affect enzyme stability or function. Consistent with this, transient expression of full-length HvCslF6 cDNAs from CDC Bold and TR251 in Nicotianabenthamiana led to accumulation of similar amounts of (1,3;1,4)-β-glucan accumulation. Monitoring of HvCslF6 transcripts throughout grain development revealed a significant difference late in grain development (more than 30 days after pollination), with TR251 [the parent with higher grain (1,3;1,4)-β-glucan] exhibiting higher transcript levels than CDC Bold. A similar difference was observed between Beka and Logan, the parents of another population in which a QTL had been mapped in the HvCslF6 region. Sequencing of a putative promoter region of HvCslF6 revealed numerous polymorphisms between CDC Bold and TR251, but none between Beka and Logan. While the results of this work indicate that naturally occurring quantitative differences in (1,3;1,4)-β-glucan accumulation may be due to cis-regulated differences in HvCslF6 expression, these could not be attributed to any specific DNA sequence polymorphism. Nevertheless, information on HvCslF6 sequence polymorphism was used to develop molecular markers that could be used in barley breeding to select for the desired [low or high (1,3;1,4)-β-glucan] allele of the QTL.
    Matched MeSH terms: Breeding
  5. Fulltext Design and characterization of a 52K SNP chip for goats
    Tosser-Klopp G, Bardou P, Bouchez O, Cabau C, Crooijmans R, Dong Y, et al.
    PLoS One, 2014;9(1):e86227.
    PMID: 24465974 DOI: 10.1371/journal.pone.0086227
    The success of Genome Wide Association Studies in the discovery of sequence variation linked to complex traits in humans has increased interest in high throughput SNP genotyping assays in livestock species. Primary goals are QTL detection and genomic selection. The purpose here was design of a 50-60,000 SNP chip for goats. The success of a moderate density SNP assay depends on reliable bioinformatic SNP detection procedures, the technological success rate of the SNP design, even spacing of SNPs on the genome and selection of Minor Allele Frequencies (MAF) suitable to use in diverse breeds. Through the federation of three SNP discovery projects consolidated as the International Goat Genome Consortium, we have identified approximately twelve million high quality SNP variants in the goat genome stored in a database together with their biological and technical characteristics. These SNPs were identified within and between six breeds (meat, milk and mixed): Alpine, Boer, Creole, Katjang, Saanen and Savanna, comprising a total of 97 animals. Whole genome and Reduced Representation Library sequences were aligned on >10 kb scaffolds of the de novo goat genome assembly. The 60,000 selected SNPs, evenly spaced on the goat genome, were submitted for oligo manufacturing (Illumina, Inc) and published in dbSNP along with flanking sequences and map position on goat assemblies (i.e. scaffolds and pseudo-chromosomes), sheep genome V2 and cattle UMD3.1 assembly. Ten breeds were then used to validate the SNP content and 52,295 loci could be successfully genotyped and used to generate a final cluster file. The combined strategy of using mainly whole genome Next Generation Sequencing and mapping on a contig genome assembly, complemented with Illumina design tools proved to be efficient in producing this GoatSNP50 chip. Advances in use of molecular markers are expected to accelerate goat genomic studies in coming years.
    Matched MeSH terms: Breeding
  6. Fulltext A review of maturation diets for mud crab genus Scylla broodstock: Present research, problems and future perspective
    Azra MN, Ikhwanuddin M
    Saudi J Biol Sci, 2016 Mar;23(2):257-67.
    PMID: 26981008 DOI: 10.1016/j.sjbs.2015.03.011
    Study of broodstock maturation diets is important in order to increase the quality of berried females, which indirectly improve the larval quantity in the hatchery production of cultured species. This paper reviewed the studies on the maturation diets for mud crab broodstock, genus Scylla and compared independently to identify their effect on reproductive performance and larval quality. The broodstock is usually caught from the wild and held in the spawning or maturation tank for further use of hatchery seed production. Mud crab broodstock was fed either natural diet, artificial diet or mixed diet. Trash fishes were commonly used as a natural feed for mud crab broodstock; meanwhile artificial diets are from formulated fish meal and various kinds of feed. The results indicated that mud crab broodstock has a high dietary requirement for lipids, fatty acids and protein which are to be used during the maturation and breeding processes. However, the natural diet produce better larval quality compared to the artificial diet. The mixed diet is the better diet which resulted in better reproductive performances such as growth, survival, fecundity and maturation processes. This review also discusses the problems in the previous studies for the potential future research to develop very high quality and cost-effective formulated diet for the enhancement of broodstock and seed production technology. Information from this review can be useful in developing a better quality of crustacean broodstock's diet for commercial hatchery production.
    Matched MeSH terms: Breeding
  7. Breeding habitat preference of preimaginal black flies (Diptera: Simuliidae) in Peninsular Malaysia
    Ya'cob Z, Takaoka H, Pramual P, Low VL, Sofian-Azirun M
    Acta Trop, 2016 Jan;153:57-63.
    PMID: 26476394 DOI: 10.1016/j.actatropica.2015.10.007
    To investigate the breeding habitat preference of black flies, a comprehensive black fly survey was conducted for the first time in Peninsular Malaysia. Preimaginal black flies (pupae and larvae) were collected manually from 180 stream points encompassing northern, southern, central and east coast of the Peninsular Malaysia. A total of 47 black fly species were recorded in this study. The predominant species were Simulium trangense (36.7%) and Simulium angulistylum (33.3%). Relatively common species were Simulium cheongi (29.4%), Simulium tani (25.6%), Simulium nobile (16.2%), Simulium sheilae (14.5%) and Simulium bishopi (10.6%). Principal Component Analysis (PCA) of all stream variables revealed four PCs that accounted for 69.3% of the total intersite variance. Regression analysis revealed that high species richness is associated with larger, deeper, faster and higher discharge streams with larger streambed particles, more riparian vegetation and low pH (F=22.7, d.f.=1, 173; P<0.001). Relationship between species occurrence of seven common species (present in >10% of the sampling sites) was assessed. Forward logistic regression analysis indicated that four species were significantly related to the stream variables. S. nobile and S. tani prefer large, fast flowing streams with higher pH, large streambed particles and riparian trees. S. bishopi was commonly found at high elevation with cooler stream, low conductivity, higher conductivity and more riparian trees. In contrast, S. sheilae was negatively correlated with PC-2, thus, this species commonly found at low elevation, warmer stream with low conductivity and less riparian trees. The results of this study are consistent with previous studies from other geographic regions, which indicated that both physical and chemical stream conditions are the key factors for black fly ecology.
    Matched MeSH terms: Breeding
  8. In vitro fermentative capacity of swine large intestine: comparison between native Lantang and commercial Duroc breeds
    Cheng PH, Liang JB, Wu YB, Wang Y, Tufarelli V, Laudadio V, et al.
    Anim Sci J, 2017 Aug;88(8):1141-1148.
    PMID: 28026141 DOI: 10.1111/asj.12723
    Native Lantang and commercial Duroc pigs were used as animal models to evaluate the differences existing in dietary fiber utilization ability between breeds. Animals were fed the same diet from weaning (4 weeks) to 4 months of age. Neutral detergent fiber (NDF) from wheat bran (as substrate) and fecal samples from the two breeds (as inoculum) were used in an in vitro gas production trial. Results showed that cumulative and maximum gas productions were higher in inocula from Lantang than those from the Duroc breed (P 
    Matched MeSH terms: Breeding*
  9. Fulltext The Use of Genetic and Gene Technologies in Shaping Modern Rapeseed Cultivars (Brassica napus L.)
    Ton LB, Neik TX, Batley J
    Genes (Basel), 2020 09 30;11(10).
    PMID: 33008008 DOI: 10.3390/genes11101161
    Since their domestication, Brassica oilseed species have undergone progressive transformation allied with the development of breeding and molecular technologies. The canola (Brassica napus) crop has rapidly expanded globally in the last 30 years with intensive innovations in canola varieties, providing for a wider range of markets apart from the food industry. The breeding efforts of B. napus, the main source of canola oil and canola meal, have been mainly focused on improving seed yield, oil quality, and meal quality along with disease resistance, abiotic stress tolerance, and herbicide resistance. The revolution in genetics and gene technologies, including genetic mapping, molecular markers, genomic tools, and gene technology, especially gene editing tools, has allowed an understanding of the complex genetic makeup and gene functions in the major bioprocesses of the Brassicales, especially Brassica oil crops. Here, we provide an overview on the contributions of these technologies in improving the major traits of B. napus and discuss their potential use to accomplish new improvement targets.
    Matched MeSH terms: Plant Breeding*
  10. A PCR-based sex determination method for possible application in caprine gender selection by simultaneous amplification of the Sry and Aml-X genes
    Phua AC, Abdullah RB, Mohamed Z
    J. Reprod. Dev., 2003 Aug;49(4):307-11.
    PMID: 14967923
    Sex determination of livestock is performed to achieve the objectives of livestock breeding programmes. Techniques for sex determination have evolved from karyotyping to detecting Y-specific antigens and recently to the polymerase chain reaction (PCR), which appears to be the most sensitive, accurate, rapid and reliable method to date. In this study, a PCR-based sex determination method for potential application in goat breeding programmes was developed. Primers were designed to amplify a portion of the X amelogenin gene (Aml-X) on the X chromosome to give a 300 bp product and Sry gene on the Y chromosome to give a 116 bp product. PCR optimization was performed using DNA template extracted from a whole blood sample of Jermasia goats (German Fawn x Katjang) of both sexes. It was possible to identify the sex chromosomes by amplifying both male- and female-specific genes simultaneously in a duplex reaction with males yielding two bands and females yielding one band. The Aml-X primer set, which served as an internal control primer, did not interfere with amplification of the Y-specific sequence even when a low amount of DNA (1 ng) was used. The duplex reaction subjected to a blind test showed 100% (14/14) concordance, proving its accuracy and reliability. The primer sets used were found to be highly specific and were suitable for gender selection of goats.
    Matched MeSH terms: Breeding/methods
  11. Fulltext Differential metabolite profiles during fruit development in high-yielding oil palm mesocarp
    Teh HF, Neoh BK, Hong MP, Low JY, Ng TL, Ithnin N, et al.
    PLoS One, 2013;8(4):e61344.
    PMID: 23593468 DOI: 10.1371/journal.pone.0061344
    To better understand lipid biosynthesis in oil palm mesocarp, in particular the differences in gene regulation leading to and including de novo fatty acid biosynthesis, a multi-platform metabolomics technology was used to profile mesocarp metabolites during six critical stages of fruit development in comparatively high- and low-yielding oil palm populations. Significantly higher amino acid levels preceding lipid biosynthesis and nucleosides during lipid biosynthesis were observed in a higher yielding commercial palm population. Levels of metabolites involved in glycolysis revealed interesting divergence of flux towards glycerol-3-phosphate, while carbon utilization differences in the TCA cycle were proven by an increase in malic acid/citric acid ratio. Apart from insights into the regulation of enhanced lipid production in oil palm, these results provide potentially useful metabolite yield markers and genes of interest for use in breeding programmes.
    Matched MeSH terms: Breeding/methods
  12. Fulltext Ornamental exterior versus therapeutic interior of Madagascar periwinkle (Catharanthus roseus): the two faces of a versatile herb
    Nejat N, Valdiani A, Cahill D, Tan YH, Maziah M, Abiri R
    ScientificWorldJournal, 2015;2015:982412.
    PMID: 25667940 DOI: 10.1155/2015/982412
    Catharanthus roseus (L.) known as Madagascar periwinkle (MP) is a legendary medicinal plant mostly because of possessing two invaluable antitumor terpenoid indole alkaloids (TIAs), vincristine and vinblastine. The plant has also high aesthetic value as an evergreen ornamental that yields prolific blooms of splendid colors. The plant possesses yet another unique characteristic as an amiable experimental host for the maintenance of the smallest bacteria found on earth, the phytoplasmas and spiroplasmas, and serves as a model for their study. Botanical information with respect to synonyms, vernacular names, cultivars, floral morphology, and reproduction adds to understanding of the plant while the geography and ecology of periwinkle illustrate the organism's ubiquity. Good agronomic practices ensure generous propagation of healthy plants that serve as a source of bioactive compounds and multitudinous horticultural applications. The correlation between genetic diversity, variants, and TIA production exists. MP is afflicted with a whole range of diseases that have to be properly managed. The ethnobotanical significance of MP is exemplified by its international usage as a traditional remedy for abundant ailments and not only for cancer. TIAs are present only in micro quantities in the plant and are highly poisonous per se rendering a challenge for researchers to increase yield and reduce toxicity.
    Matched MeSH terms: Breeding/methods
  13. Presence of a predator image in potential breeding sites and oviposition responses of a dengue vector
    Dieng H, Satho T, Suradi NFB, Hakim H, Abang F, Aliasan NE, et al.
    Acta Trop, 2017 Dec;176:446-454.
    PMID: 28865898 DOI: 10.1016/j.actatropica.2017.08.033
    In dengue vector control, attempts to minimize or replace the use of pesticides have mostly involved use of predators, but success has been severely impeded by difficulties associated with financial and environmental costs, predator mass production, and persistence in target habitats. Visual deterrents have been used successfully to control animal pests, in some cases in an effort to replace pesticide use. Despite evidence that visual signals are crucial in site choice for egg deposition by dengue vectors, and that female mosquitoes respond to artificial predation, the role of predator intimidation as it affects the oviposition behavior of dengue vectors remains largely unexplored. Here, we examined the oviposition responses of Aedes aegypti exposed to various mosquito predator pictures. Gravid females were presented with equal opportunities to oviposit in two cups with predator images [Toxorhynchites splendens-TXI, Goldfish (Carassius auratus)-small (SFI) and large (LFI) and Tx. splendens+Goldfish-TXFI] and two others without pictures. Differences in egg deposition were examined between sites with and without these images. When given a chance to oviposit in cups with and without TXI, Ae. aegypti females were similarly attracted to both sites. When provided an opportunity to oviposit in cups displaying pictures of fish (SFI or LFI) and blank cups, egg deposition rates were much lower in the fish picture sites. Females showed a preference for blank cups over TXFI for egg deposition. They also equally avoided cups with pictures of fish, regardless of the size of the picture. Our results indicate that the presence of images of goldfish and their association with Tx. larvae significantly reduced egg deposition by Ae. aegypti, and this was not the case with the predatory larvae alone. The observations that the images of natural predators can repel gravid females of a dengue vector provide novel possibilities to develop effective and inexpensive alternative tools to harmful insecticides.
    Matched MeSH terms: Breeding
  14. Fulltext Maize Dwarf Mosaic Virus: From Genome to Disease Management
    Kannan M, Ismail I, Bunawan H
    Viruses, 2018 09 13;10(9).
    PMID: 30217014 DOI: 10.3390/v10090492
    Maize dwarf mosaic virus (MDMV) is a serious maize pathogen, epidemic worldwide, and one of the most common virus diseases for monocotyledonous plants, causing up to 70% loss in corn yield globally since 1960. MDMV belongs to the genus Potyvirus (Potyviridae) and was first identified in 1964 in Illinois in corn and Johnsongrass. MDMV is a single stranded positive sense RNA virus and is transmitted in a non-persistent manner by several aphid species. MDMV is amongst the most important virus diseases in maize worldwide. This review will discuss its genome, transmission, symptomatology, diagnosis and management. Particular emphasis will be given to the current state of knowledge on the diagnosis and control of MDMV, due to its importance in reducing the impact of maize dwarf mosaic disease, to produce an enhanced quality and quantity of maize.
    Matched MeSH terms: Plant Breeding
  15. Identification and expression profiling of genes governing lignin biosynthesis in Casuarina equisetifolia L
    Vikashini B, Shanthi A, Ghosh Dasgupta M
    Gene, 2018 Nov 15;676:37-46.
    PMID: 30201104 DOI: 10.1016/j.gene.2018.07.012
    Casuarina equisetifolia L. is an important multi-purpose, fast growing and widely planted tree species native to tropical and subtropical coastlines of Australia, Southeast Asia, Malaysia, Melanesia, Polynesia and New Caledonia. It is a nitrogen-fixing tree mainly used for charcoal making, construction poles, landscaping, timber, pulp, firewood, windbreaks, shelterbelts, soil erosion and sand dune stabilization. Casuarina wood is presently used for paper and pulp production. Raw material with reduced lignin is highly preferred to increase the pulp yield. Hence, understanding the molecular regulation of wood formation in this tree species is vital for selecting industrially suitable phenotypes for breeding programs. The lignin biosynthetic pathway has been extensively studied in tree species like Eucalypts, poplars, pines, Picea, Betula and Acacia sp. However, studies on wood formation at molecular level is presently lacking in casuarinas. Hence, in the present study, the transcriptome of the developing secondary tissues of 15 years old Casuarina equiseitfolia subsp. equisetifolia was sequenced, de novo assembled, annotated and mapped to functional pathways. Transcriptome sequencing generated a total of 26,985 transcripts mapped to 31 pathways. Mining of the annotated data identified nine genes involved in lignin biosynthesis pathway and relative expression of the transcripts in four tissues including scale-like leaves, needle-like brachlets, wood and root were documented. The expression of CeCCR1 and CeF5H were found to be significantly high in wood tissues, while maximum expression of CeHCT was documented in stem. Additionally, CeTUBA and CeH2A were identified as the most stable reference transcript for normalization of qRT-PCR data in C. equisetifolia. The present study is the first wood genomic resource in C. equisetifolia, which will be valuable for functional genomics research in this genus.
    Matched MeSH terms: Plant Breeding
  16. Fulltext Development of High-Density SNP Markers and Their Application in Evaluating Genetic Diversity and Population Structure in Elaeis guineensis
    Xia W, Luo T, Zhang W, Mason AS, Huang D, Huang X, et al.
    Front Plant Sci, 2019;10:130.
    PMID: 30809240 DOI: 10.3389/fpls.2019.00130
    High-density single nucleotide polymorphisms (SNPs) are used as highly favored makers to analyze genetic diversity and population structure, to construct high-density genetic maps and provide genotypes for genome-wide association analysis. In order to develop genome-wide SNP markers in oil palm (Elaeis guineensis), single locus amplified fragment sequencing (SLAF-seq) technology was performed in a diversity panel of 200 oil palm individuals and 1,261,501 SNPs were identified with minor allele frequency > 0.05 and integrity > 1. Among them, only 17.81% can be mapped within the genic region and the remaining was located into the intergenic region. A positive correlation was detected between the distribution of SNP markers and retrotransposons [transposable elements (TEs)]. Population structure analysis showed that the 200 individuals of oil palm can be divided into five subgroups based on cross-validation errors. However, the subpopulations divided for the 200 oil palm individuals based on the SNP markers were not accurately related to their geographical origins and 80 oil palm individuals from Malaysia showed highest genetic diversity. In addition, the physical distance of linkage disequilibrium (LD) decay in the analyzed oil palm population was 14.516 kb when r2 = 0.1. The LD decay distances for different chromosomes varied from 3.324 (chromosome 15) to 19.983 kb (chromosome 7). Our research provides genome-wide SNPs for future targeted breeding in palm oil.
    Matched MeSH terms: Breeding
  17. Fulltext Dengue prevention practices and their associated factors among wet market in Hilir Perak District, Malaysia
    Nur Intan Kartiniewatie Kamaruddin, Salmiah Md Said, Hayati Kadir @ Shahar, Lim Poh Ying
    Malaysian Journal of Medicine and Health Sciences, 2019;15(104):46-46.
    MyJurnal
    Introduction: Wet markets are predisposed to Aedes breeding due to nature of daily activities that involve frequent water storage and usage of water collecting containers. Large numbers of visitors patronising wet markets could cause rapid spread of dengue infection. This study aimed to determine the level of dengue prevention practices among wet market traders in Hilir Perak District and their associated socioecological factors. Methods: A cross sectional study using stratified sampling method was conducted where 246 wet market traders were interviewed to collect data on dengue prevention practices (prevention of Aedes mosquitoes breeding and prevention of mosquito bites), and so-cioecological factors. Chi square test and logistic regression modelling were performed to identify socioecological factors associated with dengue prevention practices. Results: Response rate for this study was 88.9%. Majority of the respondents were male, above 40 years old, had secondary education and above, had monthly income of above MYR2000, were owner of the shop lots, was or had ever married and sold fish, vegetable or groceries products. Most of the respondents had high level of dengue prevention practices (78%). Those who were owner of shop lots, had high perceived susceptibility, high family support, and high perceived dengue prevention and control laws and reg-ulations were predicted to have high level of dengue prevention practices. Conclusion: Level of dengue prevention practices is determined not only by individual factors, but also other factors from relationship to societal level which must also be considered in planning or evaluating current dengue control programmes.
    Matched MeSH terms: Breeding
  18. Fulltext Sex determination in the GIFT strain of tilapia is controlled by a locus in linkage group 23
    Taslima K, Wehner S, Taggart JB, de Verdal H, Benzie JAH, Bekaert M, et al.
    BMC Genet, 2020 04 29;21(1):49.
    PMID: 32349678 DOI: 10.1186/s12863-020-00853-3
    BACKGROUND: Tilapias (Family Cichlidae) are the second most important group of aquaculture species in the world. They have been the subject of much research on sex determination due to problems caused by early maturation in culture and their complex sex-determining systems. Different sex-determining loci (linkage group 1, 20 and 23) have been detected in various tilapia stocks. The 'genetically improved farmed tilapia' (GIFT) stock, founded from multiple Nile tilapia (Oreochromis niloticus) populations, with some likely to have been introgressed with O. mossambicus, is a key resource for tilapia aquaculture. The sex-determining mechanism in the GIFT stock was unknown, but potentially complicated due to its multiple origins.

    RESULTS: A bulk segregant analysis (BSA) version of double-digest restriction-site associated DNA sequencing (BSA-ddRADseq) was developed and used to detect and position sex-linked single nucleotide polymorphism (SNP) markers in 19 families from the GIFT strain breeding nucleus and two Stirling families as controls (a single XY locus had been previously mapped to LG1 in the latter). About 1500 SNPs per family were detected across the genome. Phenotypic sex in Stirling families showed strong association with LG1, whereas only SNPs located in LG23 showed clear association with sex in the majority of the GIFT families. No other genomic regions linked to sex determination were apparent. This region was validated using a series of LG23-specific DNA markers (five SNPs with highest association to sex from this study, the LG23 sex-associated microsatellite UNH898 and ARO172, and the recently isolated amhy marker for individual fish (n = 284).

    CONCLUSIONS: Perhaps surprisingly given its multiple origins, sex determination in the GIFT strain breeding nucleus was associated only with a locus in LG23. BSA-ddRADseq allowed cost-effective analysis of multiple families, strengthening this conclusion. This technique has potential to be applied to other complex traits. The sex-linked SNP markers identified will be useful for potential marker-assisted selection (MAS) to control sex-ratio in GIFT tilapia to suppress unwanted reproduction during growout.

    Matched MeSH terms: Breeding
  19. Fulltext Arctic-adapted dogs emerged at the Pleistocene-Holocene transition
    Sinding MS, Gopalakrishnan S, Ramos-Madrigal J, de Manuel M, Pitulko VV, Kuderna L, et al.
    Science, 2020 06 26;368(6498):1495-1499.
    PMID: 32587022 DOI: 10.1126/science.aaz8599
    Although sled dogs are one of the most specialized groups of dogs, their origin and evolution has received much less attention than many other dog groups. We applied a genomic approach to investigate their spatiotemporal emergence by sequencing the genomes of 10 modern Greenland sled dogs, an ~9500-year-old Siberian dog associated with archaeological evidence for sled technology, and an ~33,000-year-old Siberian wolf. We found noteworthy genetic similarity between the ancient dog and modern sled dogs. We detected gene flow from Pleistocene Siberian wolves, but not modern American wolves, to present-day sled dogs. The results indicate that the major ancestry of modern sled dogs traces back to Siberia, where sled dog-specific haplotypes of genes that potentially relate to Arctic adaptation were established by 9500 years ago.
    Matched MeSH terms: Selective Breeding
  20. Genetic Diversity of Xanthomonas oryzae pv. oryzae in Asia
    Adhikari TB, Cruz C, Zhang Q, Nelson RJ, Skinner DZ, Mew TW, et al.
    Appl Environ Microbiol, 1995 Mar;61(3):966-71.
    PMID: 16534980
    Restriction fragment length polymorphism and virulence analyses were used to evaluate the population structure of Xanthomonas oryzae pv. oryzae, the rice bacterial blight pathogen, from several rice-growing countries in Asia. Two DNA sequences from X. oryzae pv. oryzae, IS1112, an insertion sequence, and avrXa10, a member of a family of avirulence genes, were used as probes to analyze the genomes of 308 strains of X. oryzae pv. oryzae collected from China, India, Indonesia, Korea, Malaysia, Nepal, and the Philippines. On the basis of the consensus of three clustering statistics, the collection formed five clusters. Genetic distances within the five clusters ranged from 0.16 to 0.51, and distances between clusters ranged from 0.48 to 0.64. Three of the five clusters consisted of strains from a single country. Strains within two clusters, however, were found in more than one country, suggesting patterns of movement of the pathogen. The pathotype of X. oryzae pv. oryzae was determined for 226 strains by inoculating five rice differential cultivars. More than one pathotype was associated with each cluster; however, some pathotypes were associated with only one cluster. Most strains from South Asia (Nepal and India) were virulent to cultivars containing the bacterial blight resistance gene xa-5, while most strains from other countries were avirulent to xa-5. The regional differentiation of clusters of X. oryzae pv. oryzae in Asia and the association of some pathotypes of X. oryzae pv. oryzae with single clusters suggested that strategies that target regional resistance breeding and gene deployment are feasible.
    Matched MeSH terms: Breeding
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