• Genomics & Informatics
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• v.21 no.3
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• pp.39.1-39.15
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• 2023

DNA barcoding without assessing reliability and validity causes taxonomic errors of species identification, which is responsible for disruptions of their conservation and aquaculture industry. Although DNA barcoding facilitates molecular identification and phylogenetic analysis of species, its availability in clariid catfish lineage remains uncertain. In this study, DNA barcoding was developed and validated for clariid catfish. 2,970 barcode sequences from mitochondrial cytochrome c oxidase I (COI) and cytochrome b (Cytb) genes and D-loop sequences were analyzed for 37 clariid catfish species. The highest intraspecific nearest neighbor distances were 85.47%, 98.03%, and 89.10% for COI, Cytb, and D-loop sequences, respectively. This suggests that the Cytb gene is the most appropriate for identifying clariid catfish and can serve as a standard region for DNA barcoding. A positive barcoding gap between interspecific and intraspecific sequence divergence was observed in the Cytb dataset but not in the COI and D-loop datasets. Intraspecific variation was typically less than 4.4%, whereas interspecific variation was generally more than 66.9%. However, a species complex was detected in walking catfish and significant intraspecific sequence divergence was observed in North African catfish. These findings suggest the need to focus on developing a DNA barcoding system for classifying clariid catfish properly and to validate its efficacy for a wider range of clariid catfish. With an enriched database of multiple sequences from a target species and its genus, species identification can be more accurate and biodiversity assessment of the species can be facilitated.

• Genomics & Informatics
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• v.21 no.4
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• pp.47.1-47.12
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• 2023

Silver barb (Barbonymus gonionotus) is among the most economically important freshwater fish species in Thailand. It ranks fourth in economic value and third in production weight for fisheries and culture in Thailand. An XX/XY sex-determination system based on gynogenesis was previously reported for this fish. In this study, the molecular basis underlying the sex-determination system was further investigated. Genome-wide single-nucleotide polymorphism data were generated for 32 captive-bred silver barb individuals, previously scored by phenotypic sex, to identify sex-linked regions associated with sex determination. Sixty-three male-linked loci, indicating putative XY chromosomes, were identified. Male-specific loci were not observed, which indicates that the putative Y chromosome is young and the sex determination region is cryptic. A homology search revealed that most male-linked loci were homologous to the Mariner/Tc1 and Gypsy transposable elements and are probably the remnants of an initial accumulation of repeats on the Y chromosome from the early stages of sex chromosome differentiation. This research provides convincing insights into the mechanism of sex determination and reveals the potential sex determination regions in silver barb. The study provides the basic data necessary for increasing the commercial value of silver barbs through genetic improvements.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.49-53
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• 2001

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.213-218
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• 2001

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.227-231
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• 2001

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.185-190
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• 2001

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.195-199
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• 2001

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.243-247
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• 2001

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.208-212
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• 2001

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.4
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• pp.194-200
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• 2013

In this study, an exhaust filter unit for removing bad smells is designed and manufactured to understand the characteristics, damages, and effects on humans and animals of bad smell substances in laboratory animal breeding facilities. Using the exhaust filter unit, a deodorization performance test using ammonia gas, as a typical bad smell in an animal breeding room, was carried out for three types of activated and impregnated charcoal filters. The experimental results showed that the pressure loss of the HEPA and carbon filter was increased with flow rate and that the average deodorization performance for the case where an impregnated carbon filter was installed was a maximum value of between 93 and 96%, with various fractional flow rates ranging from 1,500 to $3,500m^3/h$ in a laboratory animal breeding room. The experimental results will also be used for the design and manufacture of a practical and efficient exhaust filter unit to cope with bad smell problems in animal breeding facilities.