• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.229-233
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• 1999

The possibility for long-term preservation of Larix leptolepis embryogenic tissue was tested in this study. Higher relative increase of the tissue fresh weight was observed when embryogenic tissue was pretreated for 24 hrs in a medium containing 0.4 M sorbitol or 20% polyethyleneglycol with cooling rate of -0.33$^{\circ}C$/min. The fast cooling rate of -0.5$^{\circ}C$ and -1.$0^{\circ}C$/min appeared to be less effective in regrowth of tissues from cryopreservation. No DNA variants have been observed by PCR analysis among the embryogenic tissues recovered after 1-, 7-, and 28-day-cryopreservation. The post-thaw embryogenic tissue gave rise to mature somatic embryos which developed into plants.

• Korean Journal of Breeding Science
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• v.40 no.1
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• pp.15-21
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• 2008

It was previously pointed out that mutation is the ultimate source of variation. Adequate variation is needed for plant breeding if there is a limitation in natural genetic resources. When the ionizing radiation has been known to cause chromosomal and genomic alternations, it is widely used for inducing mutagenesis. The electron beam as an ionizing radiation is the principal physical mutagens that induces mutation and effectively used in plant breeding. Since dose-response relationships of electron beam in plant species are rarely known, we investigated the seed germination rate and early seedling growth of irradiated seeds of creeping bentgrass (Agrostis palustris Huds., cv Penn-A1) with various electron beam irradiating conditions (1, 1.3, 2 MeV at both 0.03 mA and 0.06 mA with dose of 100 Gy (Gray) and 0.03, 1, 1.3, 2 MeV at 0.03 mA with dose of 200 Gy, respectively) using electron accelerator at Korea Atomic Energy Research Institute. The growth parameters in terms of shoot length, primary root length, and secondary root length showed similar response between 0.06 / 1 (mA / MeV) at 100 Gy and 0.03 / 0.3 (mA / MeV) at 200 Gy. Bentgrass seed germination was mainly affected by the intensity of irradiated dose (Gray). Germination rate was lowered as the irradiated dose increased. On the other hand, early seedling growth was mainly governed not by the dose of radiation but by voltage.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.1
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• pp.65-68
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• 2001

A new silkworm variety, Chunsujam, for spring rearing season is F$_1$ hybrid between Japanese race Jam145 bred by 8459/8711 and Chinese race Jam146 by 8544/M8626. Jam145, Japanese parent of the Chunsujam, showed high GCA in pupation rate and Jam146, Chinese parent, showed high GCA in pupation rate and single cocoon weight. In the local adaptability test performed at 8 local areas in spring of 1999, Chunsujam was 5% higher in larval weight, 3% in single cocoon weight, and 4% in cocoon yield from 10,000 of the 3rd molted larvae, respectively, than the check variety Baegokjam.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.8
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• pp.1062-1066
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• 2001

Studies were carried out on forty young bulls of the Hariana breed (around 18 months of age) selected on the basis of their dam's milk yield at the animal farm of CCS HAU, Hisar during the period 1993-1999. Since animals showed variation in capacity to work over prolonged periods, they were subjected to regimes of carting without load and with 8 qtls. of load for three hours. The study revealed that maximum change took place in the pulse rate, followed by respiration rate and rectal temperature. The mean fatigue score for pulling an empty cart ranged between 1.66 to 2.20 after two hours work, and 2.36 to 2.73 after three hours work. For a cart loaded with 8 qtls., the corresponding ranges were 2.90 to 3.36 and 3.40 to 4.10, respectively. These results indicated that the animals under experiment had the capacity to pull moderate load (8 qtls.) for about two hours without showing any serious effect on the ability to recover and soon to work again.

• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.2
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• pp.67-73
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• 2013

Antheraea mylitta Drury is basically a crossbreeding species, as such it seems to be potentially a good material for the exploitation of heterosis. In the present study F1 hybrid of wild ecorace Laria (L) and semi-domestic Daba (D) was raised and evaluated for various quantitative traits and biochemical parameters during larval stage. Improved fecundity ($+18{\pm}1.8%$ and higher egg hatching rate ($+10.96{\pm}1.3%$) was recorded in the F1hybrid ($L{\times}D$). Biochemical parameters studied in the hemolymph, midgut and fatbody of the larva showed significantly higher (P<0.05) total proteins and carbohydrate concentration besides digestive enzyme activity. Correspondingly SDS-PAGE revealed more number of protein bands in the hemolymph sample of F1s, ranging between 29 kDa to 66 kDa compared to parental lines. The present study demonstrates the positive heterosis effect in the F1 hybrid of Laria ${\times}$ Daba. Biochemical analysis indicates that, there is possibilities of exploitation of hybrids with specific parents targeted for desirable commercial traits (silk yield and fecundity). Moreover, most of these biochemical parameters can be used as markers to analyze the genetic improvement in the tasar silkworms.

• Animal cells and systems
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• v.15 no.1
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• pp.85-90
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• 2011

In 2001, we conducted a study to assess the effects of differential arrival times and nest-site selection on reproductive performance in a mixed-species heronry consisting of six species in Taeseong-ri, Chungbuk, Korea. We recorded the arrival dates, nest heights, clutch sizes, and brood sizes after 15-20 days of the age of the birds' chicks. The grey herons and cattle egrets arrived first and last, respectively, on the colony site. In the homogenous vegetation structure of the breeding site, the pitch pine trees (Pinus rigida) were mainly used for building nests on 48 of the 50 pine trees (96%). The breeding species vertically stratifies the nest sites according to their body size, except for the cattle egrets and black-crowned night herons that nested at sites higher than those predicted from their body size. The mean nest success rates of the six species under study were positively correlated with the mean nest heights. Our findings suggest that aggressive interspecific interactions among neighbors influence nest-site selection to enhance breeding success.

• Journal of Ecology and Environment
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• v.29 no.1
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• pp.35-39
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• 2006

During the breeding seasons in 2002 and 2003, the influences of vegetation cover on breeding processes of Black-tailed Gulls (Laurs crassirostris) were studied on Hongdo Island. We checked dutch sizes, calculated hatching success and survival rates on day 15 and a vegetation cover, There was significant positive relationship between vegetation cover and hatching success, and survival on day 15. In order to analyze the relationship, sample nests were categorized as 'exposed' and 'covered' nests, and the breeding processes at each nest were compared. Hatching success and survival on day 15 in covered nests were significantly higher than ones in exposed nests. However, in clutch size, there was no significant difference. The rate of the hatching and survival failure was different amongst the categorized nests. The primary cause of hatching failure in covered and exposed nests was 'disappeared', and the primary causes of survival failure on day 15 were 'disappeared' and 'killed by adults'. The failure in exposed nests was significantly larger than that of covered nests. In the breeding of Black-tailed Gulls on Hongdo Island, vegetation cover influenced the survival of eggs and chicks as the cover provided shelter against predators and extreme weather.

• Animal Bioscience
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• v.35 no.11
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• pp.1635-1648
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• 2022

Thermal stress due to extreme changes in the thermal environment is a critical issue in cattle production. Many previous findings have shown a decrease in feed intake, milk yield, growth rate, and reproductive efficiency of cattle when subjected to thermal stress. Therefore, selecting thermo-tolerant animals is the primary goal of the efficiency of breeding programs to reduce those adverse impacts. The recent advances in molecular genetics have provided significant breeding advantages that allow the identification of molecular markers in both beef and dairy cattle breeding, including marker-assisted selection (MAS) as a tool in selecting superior thermo-tolerant animals. Single-nucleotide polymorphisms (SNPs), which can be detected by DNA sequencing, are desirable DNA markers for MAS due to their abundance in the genome's coding and non-coding regions. Many SNPs in some genes (e.g., HSP70, HSP90, HSF1, EIF2AK4, HSBP1, HSPB8, HSPB7, MYO1A, and ATP1A1) in various breeds of cattle have been analyzed to play key roles in many cellular activities during thermal stress and protecting cells against stress, making them potential candidate genes for molecular markers of thermotolerance. This review highlights the associations of SNPs within these genes with thermotolerance traits (e.g., blood biochemistry and physiological responses) and suggests their potential use as MAS in thermotolerant cattle breeding.

• Journal of Animal Science and Technology
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• v.64 no.2
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• pp.235-246
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• 2022

In this study, we used more reliable experimental materials and methods to detect the effects of osteopontin (OPN) on boar sperm in vitro capacitation, acrosome reaction, and fertilization efficiency. We reorganized and obtained the OPN protein of the porcine source. Immunofluorescence and Western blot show the localization and expression of the OPN protein before and after sperm capacitation. To determine whether OPN can affect sperm during sperm capacitation, we examined cyclic adenosine monophosphate (cAMP) concentrations after sperm capacitation, and the results showed that OPN significantly increased the cAMP concentration in sperm (p < 0.05). Flow cytometry showed that 0.1 ㎍/mL OPN-treated sperm had better acrosome reaction ability. In vitro fertilization (IVF) showed that 0.1 ㎍/mL OPN significantly increased the rate of embryo division. In conclusion, this study found that 0.1 ㎍/mL porcine OPN protein can significantly improve porcine capacitated sperm motility, cAMP concentration after capacitation sperm, acrosome reaction ability, and embryo division during IVF and provides new clues to explore the mechanism of OPN's function on sperm.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.9
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• pp.1229-1233
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• 2006

To find the candidate genes concerned with ovulation rate of sheep, Differential Display Reverse Transcription Polymerase Chain Reaction was employed to find the differently expressed cDNA controlling ovulation in the Small Tail Han sheep of polyembryony and in Tan sheep of single birth. Twenty-four primer pairs of three anchored primers and eight arbitrary primers were assembled to amplify the specialized bands from these sheep. Positive cross tests were applied to optimize the ascertainable PCR conditions in which different special bands can be identified by silver strain in one PCR tube. After eliminating the false positive PCR products by Northern hybridization, 24 differential display bands were acquired from the ovary in the Small Tail Han sheep. These EST bands were sequenced and 18 different ESTs were found in which five ESTs had several copies and 13 ESTs had only one copy. Comparing these ESTs with homologous sequences by BLAST in the GenBank, there were six ESTs with known open reading frame (ORF) and function, three ESTs with known ORF and no function, and 9 ESTs without homologous sequence. These ESTs partly represent several genes such as NOS2, tensin, TCRA, CDKN1A, ESR1 and ACTB which express especially in Small Tail Han sheep.