Dong-Kee Jeong

Evaluation of body growth and immunity-related differentially expressed genes through deep RNA sequencing in the piglets of Jeju native pig and Berkshire

This study was carried out with the objective to investigate the differentially expressed genes (DEGs) between Jeju native pig (JNP) and Berkshire piglets. The RNA-Seq technique was used to investigate the transcriptomes in the fat, liver and longissimus dorsi muscle from these two breeds. Paired-end reads of the sequences that passed the quality filters were aligned to the Sus scrofa genome using tophat2 (v2.0.2). In this study, 65% of muscle, 20% of fat and 54% of liver genes showed higher expression in the piglets of JNP than in Berkshire. Gene Ontology and signaling pathways showed that immune response and lipid metabolisms were commonly enriched pathways in all three tissues. It was found that the genes pertaining to body growth and immune system are significantly (P < 0.01) more highly expressed in Berkshire piglets. DEGs explored between the piglets of the two breeds might influence the identification of the genetic markers for further breed improvement programs. Our findings provide a new perspective for understanding and identifying candidate genes that are involved in various biological functions. Moreover, transcriptome analysis makes it easier to understand the differences between genetic mechanisms of breeds.

Comparative Transcriptomic Analyses by RNA-seq to Elucidate Differentially Expressed Genes in the Muscle of Korean Thoroughbred Horses

The athletic abilities of the horse serve as a valuable model to understand the physiology and molecular mechanisms of adaptive responses to exercise. We analyzed differentially expressed genes in triceps brachii muscle tissues collected from Eonjena Taeyang and Jigusang Seryeok Thoroughbred horses and their co-expression networks in a large-scale RNA-sequence dataset comparing expression before and after exercise. High-quality horse transcriptome data were generated, with over 22 million 90-bp pair-end reads. By comparing the annotations, we found that MYH3, MPZ, and PDE8B genes in Eonjena Taeyang and PDE8B and KIF18A genes in Jigusang Seryeok were upregulated before exercise. Notably further, we observed that PPP1R27, NDUFA3, TNC, and ANK1 in Eonjena Taeyang and HIF1A, BDNF, ADRB2, OBSCN, and PER3 in Jigusang Seryeok have shown upregulation at the postexercise period. This investigation suggested that genes responsible for metabolism and oxidative phosphorylations associated with endurance and resistance exercise were highly expressed, whereas genes encoding structural proteins were generally suppressed. The expression profile of racehorses at pre- and postexercise will provide credible reference for further studies on biological effects such as responses to stress and adaption of other Thoroughbred horse, which might be useful for selective breeding for improvement of traits in commercial production.

Characterization and cardiac differentiation of chicken spermatogonial stem cells.

Spermatogonial stem cells (SSCs), a unique population of germline stem cells in adult testis, have the capability to self-renew and produce daughter cells destined to differentiate into spermatozoa throughout the life of the bird. Chicken SSCs were successfully isolated from testicular cells and subsequent analysis was performed to identify pluripotent cells by investigation with cytochemical reagents including Periodic acid-Schiff (PAS), alkaline phosphatase (AP), and antibodies to germline cell specific (DAZL or VASA) and stage-specific embryonic antigens (Oct4, SSEA1, SSEA3, SSEA4, TRA-1-60, and TRA-1-81). Results confirmed these as germline cells with the expression of DAZL (Deleted in Azoospermia-Like) and VASA genes in isolated cells. Immunochemistry results showed that multipotent germline stem cells (mGSCs) expressed these gene markers related to embryonic stem cells (ESCs) and could spontaneously differentiate into three embryonic germ (EG) layers in vitro. The mGSC-derived cardiomyocytes expressed cardiac-specific markers such as sarcomeric alpha actinin, alpha-cardiac actinin; conexin-43, the major protein of gap junctions which are thought to have an important role in the synchronized contraction of the heart and in embryonic development; and cardiac troponin T, the tropomyosin binding subunit of the troponin complex which regulates muscle contraction. Furthermore, reverse transcription polymerase chain reaction (RT-PCR) results indicated that the genes related to cardiac transcription factors were expressed following differentiation. Results of the present study strongly contribute to the information related to the ability of chicken mGSCs to differentiate into cells such as contraction cardiomyocytes similar to ESCs and may provide a new source of cardiomyocytes for basic research and potential therapeutic application in various cardiac degenerative diseases of birds and other animals.

Efficacious rat model displays non-toxic effect with Korean beechwood creosote: a possible antibiotic substitute

Wood creosote, an herbal anti-diarrheal and a mixture of major volatile compounds, was tested for its non-toxicological effects, using a rat model, with the objective to use the creosote as an antibiotic substitute. A total of 30 Sprague-Dawley rats were studied to form five groups with 6 rats each. Korea beechwood creosote was supplemented into three test groups with 0.03 g/kg, 0.07 g/kg and 0.1 g/kg body weight/day without antibiotic support, along with a positive control of Apramycin sulphate (at 0.5% of the daily feed) and a negative control. Korean beechwood creosote supplementation showed no negative effect on the body weight gain in comparison to the negative and the positive control groups and the feed conversion ratio was also comparable with that of the control groups. The clinical pathology parameters studied were also under the umbrella of normal range, including liver specific enzymes, blood glucose, total protein, blood urea nitrogen (BUN), which indicated no toxic effect of creosote at the given doses. The non-hepatotoxic effect was also confirmed using hepatic damage specific molecular markers like Tim-p1, Tim-p2 and Tgf-β1. The results suggested that Korean beechwood may be used as antibiotic substitute in weanling pigs feed without any toxic effect on the body. Although the antimicrobial properties of creosote were not absolutely similar to those of apramycin sulphate, they were comparable.

Production of Antibody Against E. coli E68 and H28 in Egg Yolk from Laying Hens

1) Antibodies are used for preventing several infectious diseases in food animals. Though, antibiotics can deal with infection however, their widespread usage may cause developments of resistance and can also get transferred to humans through animal products. Therefore, production of antibodies against infectious agents in the egg yolk could be an interesting alternative. The present study was conducted with a focus on producing the antibody against Escherichia coli E68 and H28 in egg yolk of laying hens, which are believed to be a cause for diarrhea and beriberi in piglets. The result received from the experiment were promising and have shown efficiency of antibody production in the range of 2-7.3% in the groups which are infected with E68 only and the one which was infected with both strains. The outcome of present research has revealed the potentiality of egg yolk in production of antibody for laying hens, could open a new approach for production of antibodies to manage diarrhea and beriberi. (