• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.582-590
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• 2018

Although there are many studies of the effect of climate change on the breeding phenology and community diversity of amphibians, the studies of variations in reproductive population size of individual species according to climate change are still lacking. We examined the effect of climate change on the reproductive population size of Rana huanrenensis and Hynobius leechii, which bred in mountain valleys, by surveying the reproductive population of the two species between 2005 and 2012 and analyzing the correlation between the variation of the outdoor population and the surrounding climate change factors, obtained from a meteorological observatory located at 5.6 km from the study site. The size of the reproductive population of the two species commonly fluctuated with aan pproximately 3.5-year cycle. That of H. leechii, in particular, decreased significantly over eight years. The air temperature tended to more closely relate with the reproductive population size of R. huanrenensis as was the case of the precipitation with that of H. leechii. The yearly mean highest temperature and spring mean temperature variation consistently decreased over the eight years, and the latter was related with the significantly decreased size of H. leechii reproductive population. These results showed that recent climate change directly could affect the reproductive population size of amphibians, particularly H. leechii, which breeds in mountain valleys.

• Journal of Forest and Environmental Science
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• v.39 no.2
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• pp.73-80
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• 2023

Little is known of the life history of Garcinia kola; the objective of this study, therefore, was to assess the fruiting age and tree size of the species in a coastal humid tropical climate plantation condition. A total 103 trees were used in the study viz; 80 ten-year-old trees at reproductive maturity onset and 13 thirty-year-old trees with several cycles of reproduction that constitute two independent variables. Data collected were age of onset of flowering and size at reproductive maturity onset. Relative size at reproductive maturity onset (RSOM) was estimated as size at reproductive maturity onset (SOM) divided by asymptotic maximal size (AMS). Data analysis was conducted using pairwise t-test and principal component analysis (PCA). Reproductive maturity onset (flowering) was recorded in the ten-year-old stand eight (8) years after planting. Mean size at reproductive maturity onset (SOM) was height 5.32±1.7 m, dbh 0.11±0.03 m, total number of branches was 29.6±7.3, crown depth 5.24±1.05 m, crown diameter was 4.78±0.7 m, branch diameter 0.098±0.01 m, leaf length 0.13±0.02 m, leaf breadth 0.37±0.01 m, twig length 0.35±0.11 m and leaf per twig 6±0.84 and asymptotic maximal size (AMS) was height 19.85±0.76 m, dbh 0.95±0.09 m, total number of branches 62±5, crown depth 18.83±0.7 m, crown diameter 12.5±1.64 m, branch diameter 0.5±1.6 m, leaf length 0.16±0.023 m, leaf breadth 0.45±0.12 m, twig length 0.37±0.11 m and leaf per twig 19±7.5. Pairwise t-test analysis showed there was significant differences between SOM and AMS in all growth factors except leaf length, leaf breadth, and twig length. Highest relative size at reproductive maturity onset (RSOM) was recorded in leaf length 0.82, twig length 0.82, and leaf breadth 0.80, while, the lowest was branch diameter 0.11. Four components out of the total of eleven were extracted to explain the relationship in RSOM: Principal component one (PC1) explained 37.23%; PC2 26.4%, PC3 22.73%, and PC4 13.64%.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.60-60
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• 2003

Embryonic stem (ES) cells have property of self-renewal and can differentiate into the cells of all three primary germ layers. Recently, many growth factors, alteration of culture condition and gene modifications have been used to differentiate mouse and human ES cells into specific cell types. This study was performed to evaluate the differentiation protocol for human ES cells to the endodermal lineage cells. Human ES cells (Miz-hESl ) were cultured on STO feeder layer mitotically inactivated with mitemycin C, and embryoid bodies (EBs) were formed by suspension culture. Differentiation protocol of EBs consisted of three steps: stage I, culture of EBs for 6 days with ITSFn medium; stage II, culture of stage I cells for 8 days with N2 medium ; stage III, culture of stage II cells for 22 days with N2 medium. mRNA levels of the endodermal lineage differentiation genes were analyzed by semi- quantitative RT-PCR. The Oct-4 expression, a marker of the pluripotent state, was detected in undifferentiated human ES cells but progressively decreased after EBs formation. Differentiating human ES cells expressed marker genes of endodermal differentiation and pancreatic islet cells. GATA4, a-fetoprotein, Glut-2, and Ngn3 were expressed in all stages. However, albumin and insulin were expressed in only stage III cells. The human ES cells can be differentiated into endodermal lineage cells by multiple step culture system using various supplements. We are developing the more effective protocols for guided differentiation of human ES cells.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.5
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• pp.722-731
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• 2020

Objective: Two experiments were conducted using 28 healthy multiparous sows to evaluate the oxidative stress status and reproductive performance of sows during gestation and lactation under different thermal environments. Methods: Fourteen multiparous sows were used in Exp. 1 under a high thermal environment, and the other 14 multiparous sows were used in Exp. 2 under a moderate thermal environment. In both experiments, reproductive performances of sows were recorded. Plasma samples were collected on d 35, 60, 90, and 109 of gestation, and d 1 and 18 of lactation for malondialdehyde, protein carbonyls, 8-hydroxy-deoxyguanosine, immunoglobulin g (IgG), and IgM analysis. Results: For sows in Exp. 1, plasma malondialdehyde concentration on d 109 of gestation tended to be greater (p<0.05) than it on d 18 of lactation. Plasma concentration of protein carbonyl on d 109 of gestation was the greatest (p<0.05) compared with all the other days. Plasma concentrations of 8-hydroxy-deoxyguanosine on d 109 of gestation was greater (p<0.05) than d 18 of lactation in Exp. 1. For sows in Exp. 2, there was no difference of malondialdehyde and protein carbonyl concentration during gestation and lactation. In both Exp. 1 and 2, litter size and litter weight were found to be negatively correlated with oxidative stress indicators. Conclusion: Sows under a high thermal environment had increased oxidative stress during late gestation indicating that increased oxidative damage to lipid, protein, and DNA could be one of the contributing factors for reduced reproductive performance of sows in this environment. This study indicates the importance of providing a moderate thermal environment to gestating and lactating sows to minimize the increase of oxidative stress during late gestation which can impair reproductive outcomes.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.3
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• pp.191-198
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• 2010

Uterine myomas are heterogeneous tumors in composition, size, location, and number; variation in any of these factors could possibly alter the effect on a woman's fertility status. The effect of myomas on fertility has been the subject of many studies. However, a definitive answer is still missing. The location and size of the myomas are the two parameters that influence the success of a future pregnancy. Subserosal myomas seem to have little effect on reproductive outcome. Myomas that compress the uterine cavity with an intramural portion and submucosal myomas significantly reduce pregnancy rates, and should be removed before assisted reproductive techniques are performed. Patients with intramural myomas also may have a poorer reproductive outcome, but the lacks of quality evaluations make this conclusion tenuous at best. Removal of myomas with an intra-cavitary component seems to be of benefit. However there are as yet no data to support myomectomy in the treatment of intramural myomas to improve fertility outcomes. Treatment modality for myomas located at intramural sites should be determined according to clinical status of the patient and doctor's experience.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.2
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• pp.113-120
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• 2022

Sperm cryopreservation is a fundamental process for the long-term conservation of livestock genetic resources. Yet, the packaging method has been shown, among other factors, to affect the frozen-thawed (FT) sperm quality. This study aimed to develop a new mini-straw for sperm cryopreservation. In addition, the kinematic patterns, viability, acrosome integrity, and mitochondrial membrane potential (MMP) of boar spermatozoa frozen in the developed 0.25 mL straw, 0.25 mL (minitube, Germany), or 0.5 mL (IMV technologies, France) straws were assessed. Post-thaw kinematic parameters were not different (experiment 1: total motility (33.89%, 32.42%), progressive motility (19.13%, 19.09%), curvilinear velocity (42.32, 42.86), and average path velocity (33.40, 33.62) for minitube and the developed straws, respectively. Further, the viability (38.56%, 34.03%), acrosome integrity (53.38%, 48.88%), MMP (42.32%, 36.71%) of spermatozoa frozen using both straw were not differ statistically (p > 0.05). In experiment two, the quality parameters for semen frozen in the developed straw were compared with the 0.5 mL IMV straw. The total motility (41.26%, 39.1%), progressive motility (24.62%, 23.25%), curvilinear velocity (46.44, 48.25), and average path velocity (37.98, 39.12), respectively, for IMV and the developed straw, did not differ statistically. Additionally, there was no significant difference in the viability (39.60%, 33.17%), acrosome integrity (46.23%, 43.23%), and MMP (39.66, 32.51) for IMV and the developed straw, respectively. These results validate the safety and efficiency of the developed straw and highlight its great potential for clinical application. Moreover, both 0.25 mL and 0.5 mL straws fit the present protocol for cryopreservation of boar spermatozoa.

• Clinical and Experimental Reproductive Medicine
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• v.50 no.3
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• pp.185-191
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• 2023

Objective: Although intracytoplasmic sperm injection (ICSI) is a way to deal with in vitro fertilization failure, 3% of couples still experience repeated fertilization failure after attempted ICSI, despite having sperm within normal parameters. These patients are a challenging group whose sperm cannot fertilize the egg during ICSI. Unfortunately, no test can predict the risk of fertilization failure. Phospholipase C zeta (PLCζ) and transition nuclear proteins (TNPs) are essential factors for chromatin packaging during sperm maturation. This study aimed to assess PLCζ1 and TNP1 expression in the sperm of patients with fertilization failure and the correlations among the DNA fragmentation index, PLCζ1 and TNP1 gene and protein expression, and the risk of fertilization failure. Methods: In this study, 12 infertile couples with low fertilization rates (<25%) and complete failure of fertilization in their prior ICSI cycles despite normal sperm parameters were chosen as the case group. Fifteen individuals who underwent ICSI for the first time served as the control group. After sperm analysis and DNA fragmentation assays, quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blot analyses were performed to compare the gene and protein expression of PLCζ and TNP1 in both groups. Results: DNA fragmentation was significantly higher in the fertilization failure group. The qRT-PCR and Western blot results demonstrated significantly lower PLCζ and TNP1 gene and protein expression in these patients than in controls. Conclusion: The present study showed that fertilization failure in normozoospermic men was probably due to deficient DNA packaging and expression of TNP1.

• Journal of Animal Reproduction and Biotechnology
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• v.39 no.2
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• pp.121-130
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• 2024

Background: This study focused on reproductive traits in Hanwoo cattle, specifically the environmental factors affecting gestation length and birth weight. Methods: The records of 1,540 cows calved at the Hanwoo Research Institute from 2015 to 2023 were examined. This study analyzed two populations, line-breeding Hanwoo (LBH) and general Hanwoo (GH), with all cows undergoing estrus synchronization and artificial insemination. The R software was used to compare the differences between the two populations and analyze the environmental factors affecting each trait. Results: The results showed that the average gestation length for LBH was 283.28 ± 5.93 days, which was significantly shorter than that of the GH, which had an average of 285.63 ± 6.21 days (p < 0.001). The average birth weight of LBH calves was 25.10 ± 3.69 kg, significantly lighter than GH calves, which weighed 27.26 ± 4.11 kg on average (p < 0.001). Analysis of environmental factors revealed significant differences in the gestation length of LBH based on dam parity, year, and season of calving. However, no significant differences were observed based on calf sex. For LBH, birth weight showed significant differences based on dam parity, year of calving, and sex of the calf, but not the season of calving. In GH, gestation length varied with dam parity and calving season, but not with calving year or calf sex. The GH birth weight showed differences based on dam parity, year of calving, and calf sex, but not the season of calving. Conclusions: Reproductive traits in the Hanwoo cattle industry are economically vital but are heavily influenced by environmental factors due to their low heritability. An accurate evaluation of the genetic potential of these traits requires an analysis of the environmental factors affecting them. The results of this study serve as foundational data for predicting the potential for genetic improvement in the gestation length and birth weight of Hanwoo cattle.

• Korean Journal of Animal Reproduction
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• v.25 no.3
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• pp.207-217
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• 2001

Diagnosis and treatment of major reproductive failures were carried out for 836 dairy cows of 12 farms in Kimje area from May 1999 to May 2000. Reproductive failures were classified into four categories: uterine diseases, ovarian diseases, combination of uterine and ovarian diseases, and anestrus with corpus luteum (CL), based on the diagnosis by both rectal palpation and ultrasonography (SA 600, Medison, 5.OMHz transducer). 1. Of 102 cows examined, 15 cows were diagnosed as pregnant. Cows with real reproductive failures were therefore 87 cows and the rate of reproductive failures far all the cows of 12 farms was 10.4% (87/836). 2. Of 57 cows with reproductive failures, the cows with uterine diseases were 33 heads (37.9%), with ovarian diseases: 30 heads (34.5%), with combination form: 16 heads (18.4%), and with anestrus with CL: 8 heads (9.2%). 3. Of 87 cows with reproductive failures, 7 cows were slaughtered and 80 cows were treated by hormone or douche. The cows expressed estrus were 74 cows (92.5%, 74/80 heads) and 56 cows were pregnant (70.0%, 56/80 heads) following treatment. 4. The reproductive failures tended to be increased as the period proceeded from 30 days (2.3%, 2/87 heads) to over 120 days (56.3%, 49/87 heads) after parturition. 5. Associated other diseases to reproductive failures were foot diseases(5 cows), joint diseases (5 heads), urovagina (6 heads), and rectovaginal fistula (2 cows) and the rate of occurrence of associated diseases was 20.7% (18/87 heads). 6. No reproductive record was used in 7 farms of 12 farms and 5 farms had no play ground or not used for the cows. These results indicated that diagnosis fur reproductive failures by rectal palpation along with ultrasonography was more accurate than the conventional rectal palpation and brought better result of treatment for major types of reproductive failures. It was also indicated that non-uses of reproductive record and play ground were also important factors in occurrence of reproductive failures.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.1
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• pp.57-66
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• 2002

Objective : This study was designed to investigate the interrelationship and clinical usefulness of sperm morphology by strict criteria (SM), acrosome reaction following ionophore challenge test (ARIC) and sperm penetration assay (SPA) using zona-free hamster ova as prognostic factors in in vitro fertilization. Materials and Methods: Semen samples were provided by 83 patients undergoing IVF. We first evaluated the differences between normal fertilization group and poor fertilization group on three andrologic tests. Secondly, we analyzed the relationship between the three andrologic tests and in vitro fertilization on IVF settings. Finally, we evaluated the effectiveness of the three andrologic tests as the prognostic indicators for fertilizing ability. Results: The fertilization rate of all men in the poor fertilization group was less than 30%; but there was no evidence that this poor fertilization was due to oocyte defects. The results of three andrologic tests were significatly higher in normal fertilization group. Fertilization rate (%) in vitro was highly correlated (p<0.001) with % normal sperm by SM, ARIC value (%), and SPA result. By using Receiver-Operator-Characteristic curve (ROC), we evaluated the effectiveness of these three tests. The sensitivity and specificity of SM, ARIC test and SPA in predicting fertilization potential in IVF setting were 76% and 75%, 84% and 90%, and 76% and 95%, respectively. Conclusion: Our data suggest that the three andrologic tests can be reliable tools as prognostic factors of sperm fertilizing ability. Among these test, ARIC test and SPA gave more accurate information on fertilizing capacity. ARIC test was shown to have a predictive value for fertilizing ability comparable to that of SPA that appears to be a simple and cost-effective addition to current andrology laboratory. Combined application of these three tests may give more information on predicting sperm fertilizing capacity.