• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.357-364
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• 2000

Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$ -subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$-subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t631 or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632~653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agoinst-occupied receptors ~2- and ~17- fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.

• Development and Reproduction
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• v.10 no.3
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• pp.159-168
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• 2006

Rodents and many other mammals have two chemosensory systems that mediate responses to pheromones, the main and accessory olfactory system, MOS and AOS, respectively. The chemosensory neurons associated with the MOS are located in the main olfactory epithelium, while those associated with the AOS are located in the vomeronasal organ(VNO). Pheromonal odorants access the lumen of the VNO via canals in the roof of the mouth, and are largely thought to be nonvolatile. The main pheromone receptor proteins consist of two superfamilies, V1Rs and V2Rs, that are structurally distinct and unrelated to the olfactory receptors expressed in the main olfactory epithelium. These two type of receptors are seven transmembrane domain G-protein coupled proteins(V1R with $G_{{\alpha}i2}$, V2R with $G_{0\;{\alpha}}$). V2Rs are co-expressed with nonclassical MHC Ib genes(M10 and other 8 M1 family proteins). Other important molecular component of VNO neuron is a TrpC2, a cation channel protein of transient receptor potential(TRP) family and thought to have a crucial role in signal transduction. There are four types of pheromones in mammalian chemical communication - primers, signalers, modulators and releasers. Responses to these chemosignals can vary substantially within and between individuals. This variability can stem from the modulating effects of steroid hormones and/or non-steroid factors such as neurotransmitters on olfactory processing. Such modulation frequently augments or facilitates the effects that prevailing social and environmental conditions have on the reproductive axis. The best example is the pregnancy block effect(Bruce effect), caused by testosterone-dependent major urinary proteins(MUPs) in male mouse urine. Intriguingly, mouse GnRH neurons receive pheromone signals from both odor and pheromone relays in the brain and may also receive common odor signals. Though it is quite controversial, recent studies reveal a complex interplay between reproduction and other functions in which GnRH neurons appear to integrate information from multiple sources and modulate a variety of brain functions.

• Development and Reproduction
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• v.11 no.1
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• pp.49-54
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• 2007

Ethane 1,2-dimethane sulfonate(EDS), a toxin which specifically kills Leydig cells(LC), has been widely used to prepare the reversible testosterone(T) depletion rat model. In the present study, we monitored the gene expression profiles of pituitary gonadotropins, LH and FSH, up to 7 weeks after EDS injection. Adult male Sprague-Dawley rats($300{\sim}350\;g$ B.W.) were injected with a single dose of EDS(75 mg/kg i.p.) and sacrificed on weeks 0, 1, 2, 3, 4, 5, 6 and 7. Total RNAs were purified from each pituitary, and the message levels of common alpha subunit($C{\alpha}$) of pituitary glycoprotein hormones, LH beta subunit($LH{\beta}$), FSH beta subunit($FSH{\beta}$) and GnRH receptor(GnRH-R) were evaluated by semi-quantitative RT-PCRs. The message levels of $C{\alpha}$ increased sharply during weeks 1-4, then return to the control level on week 5. The mRNA levels of $LH{\beta}$ were elevated after week 2, reached the peak at week 4, then declined to the control level after week 5. The message levels of $FSH{\beta}$ were elevated after week 2, reached the peak at week 3, then declined to the nadir at week 5. Similarly, the mRNA levels of GnRH-R were elevated after week 2, reached the peak at week 3, then gradually declined to the control level after week 5. The present study indicated that EDS treatment could induce reversible alterations in the transcriptional activities of gonadotropin subunits and GnRH-R in the anterior pituitary from male rats. EDS injection model might be useful to understand the mechanism of hormonal regulation of hypothalamus- pituitary neuroendocrine axis in male rats.

• The Korean Journal of Ecology
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• v.27 no.6 s.122
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• pp.383-390
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• 2004

This study was conducted in three sites, Si-Hwa Lake, Dongman and Seoman island and Janguyeop island, from march, 1999 to september, 2002. The behaviors of pre-breeding season, territorial behaviors, reproductive ecology, foraging sites and behaviors, and the competition of reproduction and foods between intraspecific or interspecific of Eurasian Oystercatcher (Haematopus ostralegus) were observed in each studying sites. The breeding of Eurasian Oystercatcher started on the middle of April in Si-Hwa Lake and on the middle of May in Dongman and Seoman island and Janguyeop island. For intension of pair bond on pre-breeding season, Eurasian Oystercatcher foraged with pair and behaved male-female chasing flight behavior. The pair foraged with male and female before copulation. If other pairs and individuals approached in feeding site of pair, this pair attacked them with piping calling and intruder chasing flight. If continuos serial behaviors were not observed, the discrimination of male-female chasing flight and intruder chasing flight was difficult. Territorial behaviors classified four types; butterfly flight, calling behavior, chasing behavior, fight behavior. The important foraging sites in Si-Hwa Lake are the land place in Daeboo island, tidal flat of Bangameori, tidal flat a front of a stationary net for catching fishes and tidal flat a front of a view station for bird watching. Eurasian Oystercatcher foraged at tidal flat on low water of the tide and foraged at feeding sites near island on flood tide in Dongman and Seoman island. Eurasian Oystercater in Janguyeop island usually foraged feeding sites near island, because water level was not different between low water of the tide and flood tide. Eurasian Oystercatcher competed on foods of intraspecific and interspecific. They chased for taking foods by force in feeding sites and drove out intruders in feeding sites. The foods interspecific competition happened with Black-tailed Gull (Larus crassirostris). Eurasian Oystercatcher was robbed of foods and attacked by Black-tailed Gull. The individual of food competition with Black-tailed Gull was low foods intake rate comparison with other feeding sites and this individual flied out other feeding sites.

• Development and Reproduction
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• v.8 no.2
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• pp.77-84
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• 2004

The purpose of this experiment was to determine the effects of di(2-ethylhexyl) phthalate(DEHP) on reproductive characteristic, blood hematological and chemical values in mice. The male mice were intraperitoneally injected DEHP in negative control(no treatment), positive control(corn oil, 3ml/kg B.W), 0.5, 1.0 and 10.0mg DEHP/kg B.W and the female mice were injected DEHP in control(corn oil, 3ml/kg B.W), 0.5, 1.0 and 10.0mg DEHP/kg B.W with 5 times for 15 days on 3 days interval. The administration of DEHP in male mice were not affect on body weight, epididymis, vesicular gland and coagulating gland weight. The testis weight were slightly higher in DEHP treatment groups than in control. The semen characteristics(sperm concentration, viability, motility and abnormality) of male mice were not difference in all experimental groups. The RBC, Hb, HT, MCV, MCH, MCHC< PLT, albumin, BUN and total protein of blood hematological and chemical values were not affect the administration of DEHP in mice. The WBC values in 10.0mg DEHP group was slightly difference in all experimental group(P>0.05). The histological evaluation of testis, ovary and affevt the reproductive characteristic, blood hematological and chemical values.

• Korean Journal of Animal Reproduction
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• v.26 no.1
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• pp.17-23
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• 2002

The present study was carried out to investigate the effects of the maturation media such as a modified TCM-199 (mTCM-199) medium, modified Waymouth MB 752/1 (mWaymouth MB 752/1) medium or NCSU-23 medium on penetrability of pig oocytes by liquid boar sperm. Oocytes (30~40) were transferred into each well of a Nunc 4-well multidish containing 0.5 $m\ell$ maturation medium. When immature pig oocytes were cultured in mTCM-199, mWaymouth MB 752/1 and NCSU-23 maturation media for 44 h in 5% $CO_2$, in air at 38.5$^{\circ}C$, the germinal vesicle breakdown (CVBD) rates of the oocytes were 95.6, 94.1 and 94.9%, respectively, and the maturation rates (metaphase II) of oocytes were 92.5, 90.1 and 91.1%, respectively. No differences were observed among the maturation media. The spermrich portion of ejaculates with greater than 90% motile sperm were used in the experiment. The semen was cooled 22 to 24$^{\circ}C$ over 2 h period. The semen was diluted with Beltsville Thawing Solution (BTS) extender at room temperature to give 2$\times$10$^{8}$ sperm/$m\ell$ in 100 $m\ell$ plastic bottle. Liquid boar semen of 30 $m\ell$ in 100 $m\ell$ plastic bottle was kept at 17$^{\circ}C$ for 5 days. The sperm with greater than 70% motility after day 5 of storage were used for in-vitro fertilization (IVF). After 44 h maturation of immature oocytes, cumulus cells were removed and oocytes (30~40) coincubated far 6 h in 0.5 $m\ell$ mTCM-199 and mTBM fertilization media with 2$\times$1061$m\ell$ sperm concentration. At 6 h after IVF, oocytes were transferred into 0.5 $m\ell$ mTCM-199 and NCSU-23 culture media for further culture 6 or 42 h. Sperm penetration, polyspermy and male pronuclear formation of oocytes at 12 h after IVF, and developmental ability of oocytes at 48 h after IVF were evaluated. The oocytes in combination with NCSU-23 medium for maturation and mTBM medium for IVF increased male pronuclear formation (48.0%) compared to those in combination with mTCM-199 media for maturation and IVF, and mWaymouth MB 752il medium for maturation and mTCM-199 medium far IVF. The rates of cleaved embryos (2~4 cell stage) at 48 h after IVF were 24.1% in combination with mTCM-199 media for maturation, IVF and culture, 43.6% in combination with mWaymouth MB 75211 medium fur maturation and mTCM-199 media for IVF and culture, and 71.2% in combination with NCSU-23 medium for maturation, mTBM medium for IVF and NCSU-23 medium for culture. In conclusion, we found out the oocytes matured in vitro were fertilized by liquid boar sperm stored in BTS extender at 17$^{\circ}C$ for 5 days. We recommend the simple defined NCSU-23 medium for nuclear maturation, mTBM medium and liquid boar sperm for IVF, and NCSU-23 medium for embryo culture.

• Korean Journal of Animal Reproduction
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• v.23 no.2
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• pp.105-111
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• 1999

The effects of exogenous spleen cells on the progesterone and insulin like-growth factor-I (IGF-I) secretions in luteal cells were studied by using in vitro luteal cell culture system in the Hanwoo luteal cells. The corpora lutea(CL) were collected and pooled from the Korean native cattle(Hanwoo) ovaries from a local slaughter house. After enzymatic dissociation, combined large and small luteal cells(LLC and SLC)(1.0$\times$10$^{6}$ cells/$m\ell$) were incubated in D-MEM media containing antibiotics and 10% FCS. Spleen cells (1.0$\times$10$^{6}$ cells/$m\ell$) obtained from castrated adult male Hanwoo were added to luteal cells and co-cultured for 24 h in the absence or presence of luteinizing hormone (LH) (100 ng). Progesterone contents from luteal tissues were increased at CL-3 stage during each stage of estrous cycle. Progesterone secretion from luteal cell culture by the presence of LH (100 ng/$m\ell$) was positively stimulated compared with control. However, progesterone secretion was not changed by the addition of 5, 10 and 20% of spleen cells in the absence of LH. Co-culture of luteal cells with 10% of spleen cells in the presence of LH(l00ng/$m\ell$) significantly. enhanced after 24 h of culture. IGF-Isecretion from in vitro luteal cells co-culture by the addition of spleen cells (5%, 10% and 20%) was not significantly effected. Besides, in the presence of LH (100ng/$m\ell$), IGF-Isecretions from luteal cells by addition of spleen cells were higher than control media. However, LH alone significantly increased IGF-I secretion at 24 h of culture. These data provide the demonstrate that spleen cells can enhance LH action so as to stimulate progesterone secretion from Hanwoo luteal cells but have no effect to stimulate IGF-I secretion.

• Korean Journal of Animal Reproduction
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• v.5 no.1
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• pp.64-72
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• 1981

This experiment was carried out to study on changing phases of the concentrations of serum testosterone and metabolites in the various grwoing stages of male pigs. The eight males were used to obtain serial blood samples at a, pp.oximately 20kg body weight intervals from birth to 130kg body weight. The blood samples were taken from the jugular veins and serum was stored at -20$^{\circ}C$ until assay. Testosterone concentrations in the serum were analyzed by radioimmunoassay. The result obtained are as follows: 1. Serum testosterone concentrations were elevated at birth and were reached a maximum level between 50 and 70kg body weight, which was when sexual maturity was reached. 2. Calcium values did not vary a, pp.eciably with body weight, and ranged from 9.6${\pm}$0.6 to 11.9${\pm}$0.8mg/100$m\ell$. Potassium and sodium concentrations ranged from 38.5${\pm}$2.9 and 233.9${\pm}$2.1mg/100$m\ell$ to 64.2${\pm}$6.5 and 269.1${\pm}$9.5mg/100$m\ell$, respectively. Magnesium values dro, pp.d at birth and then rose to peak at 15kg of body weight. Iron concentrations was 0.12${\pm}$0.02mg/100$m\ell$ at birth, rose to 0.20${\pm}$0.04mg/100$m\ell$ at 15kg of body weight and then gradually increased to 0.29${\pm}$0.04mg/100$m\ell$ at 30kg of body weight. Serum zinc concentrations rose from a low of 56${\pm}$3.3mg/100$m\ell$ at birth to a high of 83.3${\pm}$3.4mcg/100$m\ell$ at 15kg of body weight. Co, pp.r values rose from a low of 25${\pm}$2.5mcg/100$m\ell$ at birth to a high of 183${\pm}$4.3mcg/100$m\ell$ at 15kg of body weight. 3. Serum cholesterol concenrtration did not vary a, pp.eciably with body weight, and ranged from 90.5${\pm}$6.0mg/100$m\ell$ to 95.0${\pm}$6.3mg/100$m\ell$. Glucose concentrations ranged from 80.5${\pm}$1.2mg/100$m\ell$ to 108.7${\pm}$8.4mg/100$m\ell$. Serum total protein rose from alow of 2.7${\pm}$0.8mg/100$m\ell$ at birth to a rapidly high of 4.3${\pm}$0.1mg/100$m\ell$ at 15kg of body weight and then gradually increased to 7.3${\pm}$0.4mg/100$m\ell$ at 130kg of body weight. Serum albumin values ranged from 0.5${\pm}$0.1$m\ell$ to 3.0${\pm}$0.3mg/100$m\ell$. 4. The total concentrations of essential/nonessential amino acid were 944.7mg/100$m\ell$ and 934.4mg/100$m\ell$ at birth, respectively. The values of essential/nonessential amino acid gradually rose from a low level at birth to a high level at 130kg of body weight. The total concentrations of essential/non-essential amino acid ratios remained from birth to 130kg of body weight.

• Proceedings of the KSAR Conference
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• 2000.10a
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• pp.10-12
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• 2000

Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$-subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$ -subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was. efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to consist of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t63I or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632-653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agonist-occupied receptors ~2- and ~17-fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.

• Korean journal of applied entomology
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• v.24 no.1 s.62
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• pp.15-18
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• 1985

Studies were made on the morphology and life cycle of the mite, Pyemotes tritici $Lagr{\acute{e}}z$-Fossot & $Montagn{\acute{e}}$ (Trombidiformes; Pyemotidea) ,parasitic on larvae of cigarette beetle, Lasioderma serricorne F., which is one of the most serious pests of stored tobacco, cigar, and cigarette in Korea. One generation time was $20.9{\pm}0.7$ days out of which $9.5{\pm}0.3$ days were spent for feeding and $10.3{\pm}0.8$ days for reproduction of progenies. A female of this insect-parasitic mite produced $56.7{\pm}6.9$ progenies during her reproduction period. The body size of a newly-laid male or female was $280{\mu}m$ long and $85{\mu}m$ wide. As female of this mite sucked on, their abdomen grew larger and larger to reach $825{\mu}m$ in width and $0.346mm^3$ in volume after $9{\sim}10$ days. By sucking the humor of a host, the abdomen of a female mite became almost a global shape in two days. The increase rate of abdominal width was the biggest on the second or the third day of feeding while the volume of abdomen reached to the largest on $6{\sim}8$ days after feeding. The largest number of the daily young produced on 4-th day after a female began to reproduce.