• Korean Journal of Ecology and Environment
• /
• v.51 no.2
• /
• pp.168-173
• /
• 2018

Mauremys reevesii is a Korean endemic turtle, and designed as an endangered species and national monument in South Korea. Recently, the population of the species has been dramatically declining because of habitat destruction, pollution and illegal capture. Moreover, small population size, difficulty of securing individuals, and lack of research are factors that impede the effective management of the species. In this study, we tested the effect of individual breeding and feeding on the seven juveniles of M. reevesii. Our results showed individual breeding and feeding were guaranteed the effective growth and development. Noticeable growth was confirmed in both body weight and carapace length. Moreover, the size difference among the individuals appeared at the start of this study decreased at the end of this study. Artificial breeding during the wither season was not caused disorders on the growth, behavior and morphology. This individual breeding may lead to effective growth and development, and it will be a way to increase the survival rate when the juveniles released into the wild.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.10
• /
• pp.1485-1489
• /
• 2007

Achaete-scute like 2 (ASCL2) gene encodes a member of the basic helix-loop-helix transcription factor which is essential for the maintenance of proliferating trophoblasts during placental development. ASCL2 gene preferentially expresses the maternal allele in the mouse. However, it escapes genomic imprinting in the human. In this study, the complete open reading frame consisting of 193 amino acids of ASCL2 gene was obtained. Sequence analysis indicated that a C-G mutation existed in the 3' region between Meishan and Large White pigs. The polymorphism was used to determine the monoallelic or biallelic expression with RT-PCR-RFLP in pigs of Large $White{\times}Meishan$ $F_1$ hybrids. Imprinting analysis indicated that the ASCL2 gene expression was biallelic in all the tested tissues (heart, liver, spleen, lung, kidney, stomach, small intestine, skeletal muscle, fat, uterus, ovary and pituitary). PCR-RFLP was used to detect the polymorphism in 270 pigs of the "$Large\;White{\times}Meishan$" $F_2$ resource population. The statistical results showed highly significant associations of the genotypes and fat meat percentage (FMP), lean meat percentage (LMP) and ratio of lean to fat (RLF) (p<0.01), and significant associations of the genotypes and loin eye area (LEA) and internal fat rate (IFR) (p<0.05).

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.10
• /
• pp.1363-1367
• /
• 2005

A pedigree file of 4,738 records of a purebred flock of Muzaffarnagari sheep, maintained at Central Institute for Research on Goats (CIRG), Makhdoom, for a period of 24 years (1978 to 2001) was used to calculate inbreeding coefficients. The lambtraits studied were birth, 3, 6, 9 and 12 months weights as well as 6 and 12 months fleece yields. The lambs' and ewes' inbreeding coefficients ranged from 0 to 26.4% and 0 to 25%, respectively. The average inbreeding coefficient of lambs was higher than that of ewes in all periods as expected in a closed flock. Fluctuations in lamb and ewe inbreeding were observed in the periods under study. The percentages of animals in the higher inbred categories varied somewhat but generally were relatively constant. The mean rate of inbreeding was 0.63% per generation. The effective population size of the flock was 79.1. On average, an increase of 1% individual inbreeding significantly (p<0.05) reduced weights at birth by 0.010 kg, at 3 month by 0.048 kg, at 6 month by 0.075 kg, at 9 month by 0.129 kg and at 12 month by 0.112 kg. Ewes' inbreeding had non-significant effects on body weight at all ages. Effects of both lambs' and ewes' inbreeding had negative but non-significant effects on fleece weights at 6 and 12 months of age. Thus, inbreeding depression in lambs significantly reduced body weights from birth to 12 months of age but had a negligible effect on fleece yields.

• Molecules and Cells
• /
• v.38 no.4
• /
• pp.304-311
• /
• 2015

Most follicles in the mammalian ovary undergo atresia. Granulosa cell apoptosis is a hallmark of follicle atresia. Our previous study using a microRNA (miRNA) microarray showed that the let-7 microRNA family was differentially expressed during follicular atresia. However, whether the let-7 miRNA family members are related to porcine (Sus scrofa) ovary follicular apoptosis is unclear. In the current study, real-time quantitative polymerase chain reaction showed that the expression levels of let-7 family members in follicles and granulosa cells were similar to our microarray data, in which miRNAs let-7a, let-7b, let-7c, and let-7i were significantly decreased in early atretic and progressively atretic porcine ovary follicles compared with healthy follicles, while let-7g was highly expressed during follicle atresia. Furthermore, flow cytometric analysis and Hoechst33342 staining demonstrated that let-7g increased the apoptotic rate of cultured granulosa cells. In addition, let-7 target genes were predicted and annotated by TargetScan, PicTar, gene ontology and Kyoto encyclopedia of genes and genomes pathways. Our data provide new insight into the association between the let-7 miRNA family in granulosa cell programmed death.

• Journal of Ecology and Environment
• /
• v.30 no.2
• /
• pp.121-126
• /
• 2007

We monitored gold-spotted pond frog (Rana chosenica) populations near the Korea National University of Education in Chungbuk, Korea, from 19 May to 8 August, 2006 to examine the spatial distribution of populations in local areas and to investigate patterns of migration of adult gold-spotted pond frogs from terrestrial hibernation sites to breeding sites, We captured individuals from the largest population using a drift fence with 22 pitfall traps surrounding the breeding site. A total of 22 individuals (19 males and 3 females) were captured between 23 May and 15 June. No peak in breeding migration was detected, but the onset of the breeding migration may correspond with increased humidity. Male body weights were negatively correlated with sampling dates. Seven of 22 individuals were captured at the 4th pitfall trap, which was placed between two culverts. The capture rate per pitfall trap was higher in traps close to the rice field banks (1.44, traps $1{\sim}9$) than in traps facing hilly land (0.33, traps $13{\sim}18$). Comparative data from the Korean frog (Rana coreana), a sympatric species in the study area, were also collected and compared with those of the gold-spotted pond frog.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.39 no.1
• /
• pp.14-21
• /
• 2019

Genome editing by CRISPR/Cas9, a third-generation gene scissor in molecular breeding at the genome level, is attracting much attention as one of the breeding techniques of the future. In this study, genetic and phenotypic analysis was used to examine the responsiveness of the Bakokjam variety of the silkworm Bombyx mori to molecular breeding using CRISPR/Cas9 in editing the white egg 2 (w-2) gene. The nucleotide sequence of the w-2 gene was analyzed and three different guide RNAs (gRNA) were prepared. The synthesized gRNA was combined with Cas9 protein and then analyzed by T7 endonuclease I after introduction into the Bm-N silkworm cell line. To edit the silkworm gene, W1N and W2P gRNA and Cas9 complexes were microinjected into silkworm embryos. Based on the results of microinjection, the hatching rate was 16-24% and the incidence of mutation was 33-37%. The gene mutation was verified in the heterozygous F1 generation, but no phenotypic change was observed. In F2 homozygotes generated by F1 self-crosses, a mutant phenotype was observed. These results suggest that silkworm molecular breeding using the CRISPR/Cas9 system is possible and will be a very effective way to shorten the time required than the traditional breeding process.

• Animal Bioscience
• /
• v.35 no.12
• /
• pp.1839-1849
• /
• 2022

Objective: The study aims to uncover the genetic diversity and unique genetic structure of the Min pig conserved population, divide the nucleus conservation population, and construct the molecular pedigree. Methods: We used KPS Porcine Breeding Chip v1 50K for SNP detection of 94 samples (31♂, 63♀) in the Min pig conserved population from Lanxi breeding Farm. Results: The polymorphic marker ratio (PN), the observed heterozygosity (Ho), and the expected heterozygosity (He) were 0.663, 0.335, and 0.330, respectively. The pedigree-based inbreeding coefficients (F_PED) was significantly different from those estimated from runs of homozygosity (F_ROH) and single nucleotide polymorphism (F_SNP) based on genome. The Pearson correlation coefficient between F_ROH and F_SNP was significant (p<0.05). The effective population content (Ne) showed a continuously decreasing trend. The rate of decline was the slowest from 200 to 50 generations ago (r = 0.95), then accelerated slightly from 50 to 5 generations ago (1.40

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.38 no.1
• /
• pp.44-52
• /
• 2018

This experiment was conducted at Suwon, Korea from 2013 to 2015. The objective of this study was to establish the optimum seeding rate, and to clarify the nitrogen fertilizer level for rye seed production in central and north area of Korea. We used Korean rye cultivar 'Gogu' for this test. We employed a split-plot design with three replications. The main plots were designed by three seeding levels (3, 5 and $7kg\;10a^{-1}$), but other sub-plots were randomly seeded. The plots were treated with three different nitrogen fertilizer levels (3, 6 and $9kg\;10a^{-1}$). The percentage of productive tiller, number of grain per spike, fertility rate, 1 liter weight, and 1000-grain weight decreased as seeding rate increased from $3kg\;10a^{-1}$ to $7kg\;10a^{-1}$, whereas the number of spike per $m^2$ increased. Therefore the grain yields of rye had less of an effect by increasing seeding rate. There was an increase in number of spike per $m^2$, number of grain per spike, and fertility rate as nitrogen fertilizer level increased from $3kg\;10a^{-1}$ to $9kg\;10a^{-1}$, but grain yields significantly not affected by the interaction of seeding rate ${\times}$ nitrogen fertilizer levels. However, the best seeding rate and nitrogen fertilizer level for rye seed production were 5 kg and $5{\sim}6kg\;10a^{-1}$, respectively, considering seed and fertilizer reduction and the prevention of pollution by excess fertilization.

• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.2
• /
• pp.261-266
• /
• 1992

Yearling replacement heifers were used in a two-year study at the Fort Stanton Experimental Ranch near Capitan, New Mexico, USA to compare frequency (once versus three times weekly) of feeding a cottonseed cake supplement. The study involved periods of 130 days (January 4 through May 14) in 1985, and 146 days (December 4 through April 29) in 1986. In each year, supplemental periods were just before the breeding season (natural breeding in multiple-sire groups) that lasted for 75 days during first year and 60 days during second year. During the first year, all (83) heifers (Angus $\times$ Hereford) were supplemented at a level equivalent to 45 kg/head daily and during second year, all (69) heifers (Angus $\times$ Hereford, Hereford) were fed at a level equivalent to .68 kg/head daily. In the first year, heifers were sorted by initial weight into two replications, i.e., those weighing under 223 kg were placed in replicate 1 and those weighing over 223 kg were placed in replicate 2. During the second year, heifers were sorted by breed into two replications, i.e., Angus $\times$ Hereford heifers were placed in replicate 1 and Hereford heifers in replicate 2. Each year, half of the heifers in each replication were supplemented once weekly and the other half three time weekly. Weight gains of heifers were similar for the two treatments over both years of study. During the first year, weight gains for heifers supplemented once or thrice weekly (.23 vs .21 kg daily, respectively) did not differ (p>.05) and the same trend for the second year (.15 vs .16 kg daily, respectively) was observed. Similarly, breeding performance was consistent with weight gains and no difference (p>.05) between treatments was observed either year. Lower conception rates during the second tear of study (92 vs 72% for years 1 and 2, respectively) were due mainly to involvement of Hereford heifers that had an average weight of 232 kg at the start of breeding season and conception rate of 54% (averaged across both supplemental treatments). Based on the combined results of both trials, frequency of supplementation did not affect growth rate of yearling heifers nor did it influence their subsequent conception rate.

• Korean Journal of Environment and Ecology
• /
• v.22 no.1
• /
• pp.59-65
• /
• 2008

This study is mainly focused on the mating of 9 couples of Eagle Owl Bubo bubo habitating in Paju, Ganghwa Island, Icheon, Sihwa Lake, Chungju. For this study, from 2005 to 2007, regular filming and mornitoring for the breeding ecology and copulation behavior of 9 couples of Eagle Owl in the nest and near area had been done. Clutches ranged in size from one to four eggs but averaged 2.27 eggs(n=15), hatching success rate was 71 %(n=34) and fledgling success rate was 83%(n=23). Through the filming and mornitoring, it was found that Eagle Owl continued to copulate each other even after hatching and kept its copulation until the chicks left their nest($7\sim8$ weeks after hatching). This copulation behaviour without fertilization seems to be done for confirming, maintaining and strengthening of pair-bond by the necessity of both male and female, and to aim at stable breeding of their chicks.