• Journal of Animal Reproduction and Biotechnology
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• v.35 no.3
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• pp.279-288
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• 2020

Changes of gonadal morphology and mRNA expression patterns of vitellogenin were investigated in Siberian sturgeon Acipenser baerii (Chondrostei) during its early gonadal maturation period. Early differentiations and morphological transitions of both ovaries and testes appeared to occur actively until the age of 3 years, however from then on, the maturation patterns to full maturity were largely gender-dependent, in which males showed a faster progression of maturation than did females while females experienced a steady-state progress with a lagged interval before entering the final maturation. Expression of vitellogenin mRNAs are closely correlated with transitional patterns of gonadal appearances. In both females and males, hepatic mRNA levels of vitellogenin exponentially increased in the earliest interval (up to 1-year-old). However, in subsequent periods, vitellogenin expression in females continued to increase with age, whereas in males, the expression stabilized at a younger age. Nevertheless, at the age older than or equal to 7-year-old, fully matured individuals showed a quite low level of vitellogenin expression in both females and males. Collectively, results from this study could be useful as a fundamental guideline to address the gonad maturation of this sturgeon species, which is helpful for making practical decisions about farming practices and management for caviar production on local sturgeon farms.

• Development and Reproduction
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• v.17 no.1
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• pp.63-72
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• 2013

A specific inhibitor of RNA polymerase II, ${\alpha}$-amanitin is broadly used to block transcriptional activities in cells. Previous studies showed that ${\alpha}$-amanitin affects in vitro maturation of cumulus-oocyte-complex (COC). In this study, we evaluated the target of ${\alpha}$-amanitin, and whether it affects oocytes or cumulus cells (CCs), or both. We treated ${\alpha}$-amanitin with different time period during in vitro culture of denuded oocytes (DOs) or COCs in comparison, and observed the changes in morphology and maturation status. Although DOs did not show any change in morphology and maturation rates with ${\alpha}$-amanitin treatment, oocytes from COCs were arrested at metaphase I (MI) stage and CCs were more scattered than control groups. To discover causes of meiotic arrest and scattering of CCs, we focused on changes of cumulus expansion, gap junctions, and cellular metabolism which to be the important factors for the successful in vitro maturation of COCs. Expression of genes for cumulus expansion markers (Ptx3, Has2, and Tnfaip6) and gap junctional proteins (Gja1, Gja4, and Gjc1) decreased in ${\alpha}$-amanitin-treated CCs. However, these changes were not observed in oocytes. In addition, expression of genes related to metabolism (Prps1, Rpe, Rpia, Taldo1, and Tkt) decreased in ${\alpha}$-amanitin-treated CCs but not in oocytes. Therefore, we concluded that the transcriptional activities of CCs for supporting suitable transcripts, especially for its metabolic activities and formation of gap junctions among CCs as well as with oocytes, are important for oocytes maturation in COCs.

• Journal of Embryo Transfer
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• v.24 no.2
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• pp.97-104
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• 2009

The objective of this study was to examine the effect of macromolecule in a maturation medium on nuclear maturation, intracellular glutathione (GSH) level of oocytes, and embryonic development after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) in pigs. Immature pig oocytes were cultured in maturation medium that was supplemented with each polyvinyl alcohol (PVA), pig follicular fluid (pFF) or newborn calf serum (NBCS) during the first 22 h and the second 22 h. Oocyte maturation was not influenced by the source of macromolecules during in vitro maturation (IVM). Embryo cleavage and cell number in blastocyst after PA was altered by the source of macromolecule but no difference was observed in blastocyst formation among treatments. Oocytes matured in PVA-PVA medium showed lower rates of oocyte-cell fusion (70.4% vs. 77${\sim}$82%) and embryo cleavage (75% vs. 86${\sim}$90%) after SCNT than those matured in other media but blastocyst formation was not altered (13${\sim}$27%) by different macromolecules. pFF added to IVM medium significantly increased the intracellular GSH level of oocytes compared to PVA and NBCS, particularly when pFF was supplemented during the first 22 h of IVM. Our results demonstrate that source of macromolecule in IVM medium influences developmental competence of oocytes after PA and SCNT, and that pFF supplementation during the early period (first 22 h) of IVM increases intracellular GSH level of oocytes.

• The Korean Journal of Food And Nutrition
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• v.25 no.1
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• pp.57-63
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• 2012

This paper analyzes phenolic compounds, carbon isotopes, and sugar components of whiskys based on the maturation period. For this, the paper considers a total of 40 whiskys(mainly imports) distributed in Korea. It is important to analyze the presence phenolic compounds(e.g., furfural, syringaldehyde, vanillin, syringic acid, and vanillic acid) because these are found only in whiskys ripened in oak. The results indicate that the total content of phenolic compounds increased with the increase in the storage period regardless of the type of whisky. In terms of vanillin/syringaldehyde(V/S), Scotch whiskys had 0.4~0.5; American whiskies, 0.30~0.34; and Canadian whiskies, 0.31~0.33. In terms of Scotch whiskys, Macallan had 0.25~0.34, making it unique among Scotch whiskys. In terms of the ratio of carbon isotopes, there were clear differences between malt Scotch whiskys, blended Scotch grain whiskys, American whiskys, and Canadian whiskys: -23.4~ -24.3, -16.8~-21.0, -11.0~-11.5 and -9.5~13.9, respectively. In addition, malt Scotch whiskys contained 40~230 $mg/{\ell}$ of fructose; blended Scotch whiskys, 20~120 $mg/{\ell}$; American whiskys, 50~70 $mg/{\ell}$; and Canadian whiskys, 20~100 $mg/{\ell}$, demonstrating that the fructose content of single-malt whiskys was twice the average fructose content. On the other hand, malt Scotch whiskys contained 30~170 $mg/{\ell}$ of glucose; blended Scotch whiskys, 20~120 $mg/{\ell}$; American whiskys, 20~30 $mg/{\ell}$; and Canadian whiskys, 10~110 $mg/{\ell}$, demonstrating that the glucose content of single-malt whiskys exceeded the average glucose content. This study's results can be used as a database of classification for whiskys based on the fermentation of raw ingredients and the period of maturation for distinguishing between different types of whiskys. In addition, the results can facilitate the verification of genuine whiskys by allowing for the identification of different types of whiskys based on the period of maturation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.745-751
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• 2015

The ecological characteristics of Silvetia siliquosa, an endangered brown alga, were investigated from January to December 2013 in Jindo, South Korea. The S. siliquosa population formed widespread patches on natural rock. Receptacles were observed from March to August when seawater temperatures ranged from 8-26℃. A maturation peak was detected in June, when seawater temperatures were 23.4℃. After embryo release, the alga bleached and only the discoidal holdfast remained after August. Developmental initiation of the thallus occurred at temperatures above 8℃, and receptacle formation required approximately 196 degree-days. This is the first study to examine a S. siliquosa population throughout the entire year in a natural habitat.

• Korean Journal of Food Science and Technology
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• v.19 no.1
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• pp.69-74
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• 1987

These studies were conducted to investigate the changes in carbohydrate properties of the endosperm during the stages of maturity. Original moisture continued to decrease while 1,000-kernel weight and test weight increased steadily in all varieties with maturation. Starch content of the endosperm increased continuously by 35 to 40 days after heading. The B-type starch granules synthesis of the the early mature variety, Chokwang, was depressed at the later stages of development. Amylose and amylopectin components of starch both increased as the kernel matured, and amylose-amylopectin ratio also increased during the same period. Amount of pentosan per kernel basis increased throughout the maturation period. Amylograph break-down had a highly negative coefficient correlation with starch and pentosan content of endosperm. Results indicated that wheat maturation was characterized by an increase in the starch and pentosan content of the kernel.

• Development and Reproduction
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• v.24 no.4
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• pp.287-296
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• 2020

The absence of functional estrogen receptor α (Esr1) results in an overgrowth of the epididymal fat, as observed in estrogen receptor α knockout (ERαKO) mouse. The present research was aimed to evaluate expression of various molecules associated with adipocyte differentiation and maturation in the epididymal fat of ERαKO mouse at several postnatal ages by using quantitative real-time polymerase chain reaction. The highest transcript levels of all molecules were detected at 12 months of postnatal age, except leptin which the mRNA level was increased at 5 months of age and was unchanged until 12 months of age. The expression levels of CCAAT enhancer binding protein (Cebp) alpha, androgen receptor, and lipoprotein lipase were decreased at 5 months of age but increased at about 8 months of age. The mRNA levels of Cebp gamma and sterol regulatory element binding transcription factor 1 remained steady until 8 months of age. Continuous increases of transcript levels during postnatal period were found in Cebp beta, estrogen receptor (ER) beta, fatty acid binding protein 4, and delta like non-canonical Notch ligand 1. The increases of peroxisome proliferator-activated receptor gamma and adiponectin mRNA levels were detected as early as 8 months of age. The levels of fatty acid synthase and resistin transcript at 5 and 8 months of age were lower than that at 2 months of age. These findings show the aberrant expression patterns of genes related to adipocyte differentiation and maturation in the postnatal epididymal fat pad by the disruption of ER alpha function.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.328-335
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• 2009

This study was undertaken to investigate the influence of exposure and removal of four different cryoprotectants (CPAs) on the ATP content of cumulus cell-enclosed (COs) and cumulus cell-denuded (DOs) immature porcine oocytes. The in vitro nuclear maturation of the COs, exposed to and removed from the CPAs was also assessed. Both COs and DOs were exposed to 1.5 M concentrations of each CPA (ethylene glycol (EG); propylene glycol (PG); dimethyl-sulfoxide (DMSO); and glycerol (G)) for durations of 5, 15, and 30 minutes at room temperature ($23.5{\pm}1.5^{\circ}C$), and immersed in physiological saline supplemented with 20% (v/v) fetal bovine serum for 5 minutes ($39^{\circ}C$) to remove each CPA. Before, during and after exposure to each CPA, the ATP content of both the COs and the DOs was measured. After removal from each CPA an aliquot of the COs was matured for 44${\pm}$2 h, and their nuclear maturation rates were measured up to the metaphase stage of the second meiotic division (the M-II stage). The maturation rates up to the M-II stage were not significantly different between all the groups that were exposed to each CPA for 5 minutes. For 15 and 30 minute exposures, the maturation rates of the COs exposed to PG, DMSO and EG were almost the same as those of the control groups; however, the rates of G group exposed for 15 and 30 minutes were significantly lower (p<0.05) than the control group. These groups were also found to have a decrease in the ATP content of COs and DOs during and after exposure for the same periods (p<0.05). In addition, although the ATP contents of the COs after exposure to EG for any period were the same as the controls, the ATP content of the DOs exposed to EG for any period were significantly lower (p<0.05) than those of the controls. When the ATP content of the COs and DOs of each CPA were compared, the DOs exposed to PG were found to have a significantly greater level (p<0.05) than DOs exposed to G for any duration. In addition, the ATP content of DOs exposed to PG for 30 min and removal was also higher (p<0.05) than when exposed to DMSO for the same period. These findings indicate that PG may be a useful CPA for the cryopreservation of immature porcine oocytes.

• Development and Reproduction
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• v.13 no.1
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• pp.35-41
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• 2009

In the present study, we investigated the effects of rearing condition during the winter period on artificial maturation and reproduction of cultured female eel, Anguilla japonica. The female eel was adapted by combination of environmental conditions (seawater/low temperature, $10^{\circ}C$; seawater/high temperature, $20^{\circ}C$; freshwater/low temperature, $10^{\circ}C$; freshwater/high temperature, $20^{\circ}C$) during 8 weeks of the winter period. Then, the female eel cultivated by different conditions during the winter were transferred to seawater at $20^{\circ}C$ for induction of artificial maturation by salmon pituitary extraction (SPE) injection. The results shown that gonadosomatic index (GSI) and plasma levels of estradiol-$17{\beta}$ (E2) were significantly higher in female eel were reared in seawater than in freshwater, and were the highest at eel adapted by seawater/low temperature. Also, reproduction coefficient were higher in seawater/low temperature than in the other groups. These results will provide valuable information for elevation of the artificial maturation and reproduction coefficient in the cultured female eel.

• Reproductive and Developmental Biology
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• v.33 no.3
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• pp.125-131
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• 2009

The aim of this study is to investigate the effect of porcine epididymal fluid (pEF) on in vitro-maturation and subsequent fertilization of porcine follicular oocytes. Porcine cumulus-oocytes complexes retrieved from antral follicles were cultured in tissue culture medium (TCM)-l99 supplemented with pEF of different concentrations. At 48 h after culture, development of oocytes to germinal vesicle (GV) breakdown, metaphase I, anaphase-telophase I, and metaphase II were examined Significant (p<0.05) increase in the proportion of oocytes developed to MII stage was observed in oocytes cultured in pEF-containing TCM-l99 than in oocytes cultured in pEF-free TCM-199 (46.2% vs 16.7%), which was a dose-dependent manner. Subsequently, the proportion of monospermic fertilization were significantly (p<0.05) increased in oocytes cultured in the TCM supplemented with pEF than those cultured in pEF-free TCM-199 (51.0% vs 24.1%). In the second series of experiment, the percentage of MII oocytes was significantly (p<0.05) increased after exposure of oocytes to pEF during the first 22 h period of culture than after exposure of oocytes to pEF during the next 24 h of culture, while no significant difference in the percentage of monospermy was observed. The results of this study demonstrate that pEF contains at least enhancing component(s) for nuclear maturation.