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Jae-Seong Lee,
Ryeo-Ok Kim,
Jae-Sung Rhee,
Jeonghoon Han,
Dae-Sik Hwang,
Beom-Soon Choi, Chang Joo Lee,
Yong-Dal Yoon,
Jong-Sung Lim,
Young-Mi Lee,
Gyung Soo Park,
Atsushi Hagiwara,
Ik-Young Choi
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ABSTRACT: The monogonont rotifer, Brachionus ibericus (S type), is considered to be a promising model species for developmental biology, evolution, and environmental genomics.
In an attempt to accelerate the molecular understanding of B. ibericus, we sequenced 680.5Mb of genomic DNA using the genome sequencer GS-FLX-Titanium. We obtained 2,062,621 reads (average read
length 329.9bp) and 145,418 contigs (total contigs length 125.7Mb) after excluding small reads (less than 200bp) from the
assembly, and finally obtained 10,133 unigenes (E value≤9.00E−04) after non-redundant (NR) BLAST search. In this article, we summarize the genomic DNA sequences of B. ibericus and discuss their potential use in the study of reproductive biology, endocrinology, environmental genomics, and ecotoxicological
studies, and for providing insight into the genetic basis of mechanisms such as egg formation, antioxidant stress defense,
and xenobiotic metabolism.
KeywordsMongonont rotifer-
Brachionus ibericus
-GS-FLX-Titanium-Genomic DNA-Unigene
Hydrobiologia 04/2012; 662(1):65-75. · 1.78 Impact Factor
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ABSTRACT: Endocrine disrupting chemicals (EDCs) have been a major concern in the normal reproduction and development of aquatic organisms. In the teleost, steroid hormones are synthesized via the steroidogenesis pathway, and play a key physiological role in the regulation of gonadal sex differentiation. The protogynous hermaphroditic fish, Kryptolebias marmoratus is the only vertebrate capable of reproducing through internal self-fertilization. To uncover the effect of bisphenol A (BPA) on sex differentiation genes on transcription, we investigated the expression patterns of several sex differentiation-related genes such as dax1, dmrt1, mis, sf1, figlα, StAR and wt1 after BPA exposure with controls (E2 and TMX). In response to 17β-estradiol (E2) exposure, a testis-specific gene, dmrt1 mRNA was down-regulated in the gonad of the secondary male but the expression of the female-specific gene, dax1 mRNA was significantly elevated in the brain and gonad. A high level of StAR mRNA was detected in the brain and gonad of both hermaphrodite and secondary males, suggesting that the elevated expression of dax1 and StAR genes would be involved in E2 exposure. As expected, upon BPA exposure, the dmrt1 and MIS mRNA level decreased in both hermaphrodite and secondary males, while the female-specific gene, figlα mRNA level increased in the gonad of both genders. BPA showed an opposite mode of action on the expression of dax1 (induction, P>0.05) and sf1 mRNA (inhibition, P>0.05) in the brain and gonad against both genders. The sensitivity of dax1 to BPA on expression was relatively high in the secondary male. The wt1 mRNA was up-regulated in most tissues except in the liver of BPA-exposed secondary males. Regarding the time course study, the figlα mRNA level increased at 6 h after BPA exposure. In addition, BPA elevated the expression of StAR, dax1, and wt1 mRNA but repressed sf1 mRNA. In this paper, we demonstrated that BPA may modulate the expression of sex differentiation and steroidogenesis pathway genes, and this finding would provide a better understanding on the modulation of transcription upon BPA exposure in steroidogenesis and sex differentiation in the hermaphroditic fish, K. marmoratus.
Aquatic toxicology (Amsterdam, Netherlands) 08/2011; 104(3-4):218-29. · 3.12 Impact Factor
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ABSTRACT: Ovarian follicular degeneration is accelerated by gamma-radiation. To investigate the precise radiation-induced cellular and molecular biological changes in the ovary, prepubertal mice were whole-body irradiated with 6.94 Gy, which is the 30% of the lethal dose of gamma-radiation using a (60)Co source. At 0, 3, 6, 12, and 24 hr after irradiation, ovarian expression of p53 and p21 mRNA and protein were analyzed by reverse-transcription polymerase chain reaction and immunoblotting, respectively. Immunohistochemical localization of p53 and p21 antigens was also carried out. Immunoreactive p53 and p21 were expressed in the nuclei of granulosa cells, but were not detected on the theca. In control mouse ovaries, p21 was weakly expressed on granulosa but not on the theca cells. In gamma-irradiated mouse ovaries, however, immunoreactive p21 proteins were detected in the nuclei of follicular granulosa cells. After irradiation expression of p53 and p21 mRNA and protein was significantly increased compared to beta-actin. Taken together, these observations suggest that p53 and p21 are actively involved in gamma-radiation-induced follicular degeneration in the prepubertal mouse ovary.
Molecular Reproduction and Development 03/2008; 75(2):383-91. · 2.53 Impact Factor
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Jin-Yong Chung,
Ji Young Kim,
Yoon-Jae Kim,
Sun Ju Jung,
Ji-Eun Park,
Seung Gee Lee,
Jin Tac Kim,
Seunghoon Oh, Chang Joo Lee,
Yong-Dal Yoon,
Young Hyun Yoo,
Jong-Min Kim
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ABSTRACT: Leydig cells of the mammalian testis produce testosterone and support spermatogenesis, and thereby their role in male function is fundamental. Although benzo[a]pyrene (B[a]P) has been known to exhibit carcinogenic, apoptogenic, and endocrine-disrupting activities, its potential signaling system in Leydig cells remains to be discovered. In the present study, using the TM3 Leydig cell line and primary Leydig cells, we showed that Leydig cells do not die by exposure to B[a]P and found that an increased level of X chromosome-linked inhibitor of apoptosis protein may be associated with the antiapoptotic process. The Leydig cells were shown to express p53, but its translational level was extremely low. Although a high level of p53 protein was not necessary for apoptosis induced by B[a]P-7,8-diol-9,10-epoxide (a final B[a]P metabolite) in Leydig cells, the apoptosis of primary Leydig cells appears to be p53 independent. This indicates the lack of p53 function in primary Leydig cells. Furthermore, Leydig cells were found to retain insignificant levels of endogenous aryl-hydrocarbon receptor and AhR nuclear transporter proteins in nature. Exposure to B[a]P did not result in a significant increase in aryl-hydrocarbon receptor proteins that are required for CYP1A1 transcription. CYP1A1 expression was present in Leydig cells but at levels insufficient to exhibit its activity. Finally, we have demonstrated that overexpression of CYP1A1 in Leydig cells sensitizes the cells to exhibit its activity in the presence of B[a]P and, thus, induction of apoptosis. Together, these results indicate that the deficiency of CYP1A1 activity might be a decisive condition rendering Leydig cells secure from exogenous polycyclic aromatic hydrocarbons such as B[a]P.
Endocrinology 01/2008; 148(12):6134-44. · 4.46 Impact Factor
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ABSTRACT: Ovarian follicular degeneration is accelerated by γ-radiation. To investigate the precise radiation-induced cellular and molecular biological changes in the ovary, prepubertal mice were whole-body irradiated with 6.94 Gy, which is the 30% of the lethal dose of γ-radiation using a 60Co source. At 0, 3, 6, 12, and 24 hr after irradiation, ovarian expression of p53 and p21 mRNA and protein were analyzed by reverse-transcription polymerase chain reaction and immunoblotting, respectively. Immunohistochemical localization of p53 and p21 antigens was also carried out. Immunoreactive p53 and p21 were expressed in the nuclei of granulosa cells, but were not detected on the theca. In control mouse ovaries, p21 was weakly expressed on granulosa but not on the theca cells. In γ-irradiated mouse ovaries, however, immunoreactive p21 proteins were detected in the nuclei of follicular granulosa cells. After irradiation expression of p53 and p21 mRNA and protein was significantly increased compared to β-actin. Taken together, these observations suggest that p53 and p21 are actively involved in γ-radiation-induced follicular degeneration in the prepubertal mouse ovary. Mol. Reprod. Dev. 75: 383–391, 2008. © 2007 Wiley-Liss, Inc.
Molecular Reproduction and Development 06/2007; 75(2):383 - 391. · 2.53 Impact Factor
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ABSTRACT: Prepubertal mice were whole-body irradiated with a mean lethal dose (LD50) of gamma-radiation using a 60Co source with a total dose of 7.2 Gy and a dose rate of 12.0 cGy/min. At day 0 before the irradiation and at day 1, 2, and 3 after the irradiation, the ovaries were collected and the morphological changes were assessed. The ratios (%) of atretic or polymorphonuclear leukocytes (neutrophil)-infiltrated follicles in the largest cross sections were calculated. In the early atretic follicle of the control mouse ovary, both apoptotic and mitotic cells were observed and occasionally neutrophils were infiltrated into the follicle cavity. However, in the atretic follicles 2 days post-irradiation, numerous cell fragments, apoptotic cells and bodies, and especially, a number of neutrophils were observed. In the non-irradiated control, the ratios of atretic follicles were 58.0+/-8.6 and 27.3+/-11.2 (mean+/-S.E.M.) in antral and preantral follicles, respectively. The ratios of the number of antral and preantral follicles with one or more neutrophils to the total number of atretic follicles were 29.3+/-12.0. At 2 days post-irradiation, the ratios of atretic follicles were increased to 94.0+/-3.4 and 86.9+/-7.6 in antral and preantral follicles, respectively. The ratios of neutrophil-containing follicles among the atretic one were increased to 65.9+/-11.5 and 57.8+/-15.4 at 2 and 3 days after the irradiation, respectively. Taken together, the present results show that gamma-radiation induces apoptotic and inflammatory degeneration of mouse ovarian follicles. Besides, neutrophils may be involved in the acute atretic degeneration in gamma-irradiated mouse ovarian follicles.
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 11/2005; 578(1-2):247-55. · 2.85 Impact Factor
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ABSTRACT: We isolated mitochondrial DNA from the rayfish Raja porosa by long-polymerase chain reaction (Long-PCR) with conserved primers, and sequenced it by primer walking method using flanking sequences as sequencing primers. R. porosa mitochondrial DNA consists of 16,972 bp and its structural organization is conserved in comparison with other fishes and mammals. Based on the mitochondrial cytochrome b (cyt b) sequence, the phylogenetic position of R. porosa among cartilaginous fishes was inferred using different phylogenetic methods (ML-based quartet puzzling, Neighbor-joining (NJ) and Bayesian approaches). In this paper, we report the characteristics of the R. porosa mitochondrial genome including structural organization, base composition of rRNAs, tRNAs and protein-encoding genes and characteristics of mitochondrial tRNAs. These findings are applicable to comparative mitogenomics of R. porosa with other related taxa.
DNA Sequence 07/2005; 16(3):187-94. · 0.75 Impact Factor
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ABSTRACT: The mechanism of development of the ovarian follicles has been largely unknown. We performed an immunohistochemical (IHC) study to determine the follicular expressions of c-kit, SCF, and inhibin-alpha at different developmental stages in mouse ovary. Ovaries were obtained from 14 and 16 days post coitum and 2, 7, and 21 days post partum (dpp) mice. IHC for c-kit, SCF, and inhibin-alpha was carried out. c-Kit and SCF were expressed on oogonia regardless of the developmental stage. Immunoreactive c-kit and SCF antigens were expressed on oocytes of primordial and primary follicles of neonate mouse ovaries. In 21 dpp mouse ovary, the expression of c-kit/SCF in oocytes gradually decreased as the follicles developed. c-Kit/SCF was expressed strongly in oocytes of preantral follicles and weakly in granulosa and thecal cells. Inhibin-alpha was mainly expressed on granulosa cells of preantral and early antral follicles of the 21 dpp mouse ovaries. These findings suggest that the IHC expression of c-kit/SCF proteins is specific in all developmental stages of ovarian follicles and is decreased after the follicle starts to grow. The expression of inhibin-alpha is negatively correlated with the expression of c-kit/SCF in the ovarian follicles in mice.
Journal of Histochemistry and Cytochemistry 12/2003; 51(11):1447-58. · 2.72 Impact Factor
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ABSTRACT: Purpose. To investigate the potential effects of pentobarbital and ketamine on serum concentrations of sex hormones, the present
study was performed using pregnant mare serum gonadotropin (PMSG)-primed cyclic female Sprague-Dawley rats.
Methods. Pentobarbital sodium (37 mg·kg−1, i. p.) or ketamine-hydrochloride (229 mg·kg−1, i. m.) was injected 2 and 3 days after PMSG treatment. At 0, 1, 2, 3, 4, and 5 days after PMSG treatment, sera were collected
by cardiac puncture. The serum concentrations of progesterone (P4), testosterone (T), and estradiol-17β (E2) were determined by radioimmunoassay.
Results. The serum concentrations of P4 tended to be lower in both the pentobarbital- and the ketamine-treated groups compared with the control group. Significant
differences were found on days 3 and 4 after pentobarbital and on days, 1, 4, and 5 after ketamine administration. Serum concentrations
of T were also suppressed in both the pentobarbital and the ketamine-treated groups, whereas E2 concentrations decreased only in the ketamine-treated group.
Conclusion. Pentobarbital and ketamine decrease serum sex hormone concentrations in PMSG-primed female rats.
Journal of Anesthesia 09/2000; 14(4):187-190. · 0.83 Impact Factor
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ABSTRACT: This paper presents a new learning method to solve the category
proliferation problem in fuzzy ART. In the conventional learning
methods, both the top-down and bottom-up weight vectors are updated by
the fuzzy AND operation between the input vector and the weight vector
(or template). But in the proposed method, these vectors are differently
updated: the top-down weight vector is updated by the weighted sum of
both its current value and the input vector, and the bottom-up weight
vector is updated by the fuzzy AND operation between its current value
and the newly learned top-down weight vector. The proposed learning
method can prevent the abrupt change of the template and achieve good
noise tolerance in noisy input pattern. Simulation results show that the
proposed learning method effectively resolves the category proliferation
problem without increasing the training epochs in noisy environments
Neural Networks, 1995. Proceedings., IEEE International Conference on; 12/1995
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ABSTRACT: Tissue transglutaminase (tTG) protein begins to accumulate in apoptotic cells and its mRNA is expressed at the onset of apoptotic change. In the present study, we compared tTG expression with the atretic degree of mouse ovarian follicles. The whole-body gamma-irradiated mouse ovaries were collected and immunohistochemistry for tTG and in situ 3'-end labeling (TUNEL) was performed. Based on the identification of atretic follicles with hematoxylin-eosin and TUNEL immunostaining, tTG expression was evaluated and compared between normal (NF) and atretic follicles (AF). The expression of tTG was different among AF depending on the degree of atretic changes. There was a strong association of tTG expression with the follicular apoptotic changes. Among NF, 24% of follicles expressed tTG protein. This value, however, increased up to 66% in atretic follicles. The present results suggest that the follicular expression of tTG is closely related to the degree of follicle atresia. Therefore, the expression of tTG can be used as a useful marker for the identification of atretic follicles in the ovary.
In vivo (Athens, Greece) 17(3):235-8. · 1.17 Impact Factor
