• The Korean Journal of Malacology
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• v.30 no.3
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• pp.211-218
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• 2014

Spermatid differentiations during spermiogenesis and sperm ultrastructures in male Mercenaria stimpsoni were investigated by transmission electron microscopic observations. In the early stage of the spermatid during spermiogenesis, a few granules and a proacrosomal granule, which is formed by the Golgi complex, become a proacrosomal vesicle. Consequently, it becomes an acrosome by way of the process of acrosome formation. The morphologies of the sperm nucleus type and the acrosome of this species have a curved cylindrical type and cap shape, respectively. The spermatozoon is approximately $48-51{\mu}m$ in length including a curved cylinderical sperm nucleus (about $4.18{\mu}m$ long), an acrosome (about $0.52{\mu}m$ in length) and tail flagellum ($42-45{\mu}m$ long). As some ultrastructural characteristics of the acrosomal vesicle, the peripheral parts of two basal rings show electron opaque part (region), while the apex part of the acrosome shows electron lucent part (region). These charateristics of the sperm belong to the family Veneridae in the subclass Heterodonta, unlike a characteristic of the subclass Pteriomorphia showing all part of the acrosome being composed of electron opaque part (region). Therefore, it is easy to distinguish the families or the subclasses by the acrosome structures. Exceptionally, In particular, a cylinder-like nucleus of the sperm is curved (the angle of the nucleus is about $80^{\circ}$), as seen in some species of Veneridae (range from $0^{\circ}$ to $80^{\circ}$). The number of mitochondria in the midpiece of the sperm of this species are four, as one of common characteristics appeared in most species except for a few species in Veneridae in the subclass Heterodonta. Cross-sectioned axoneme of the sperm tail flagellum shows a 9+2 structure.

• Development and Reproduction
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• v.18 no.3
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• pp.179-186
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• 2014

Characteristics of the developmental stages of spermatids during spermiogenesis and phylogenetic classicfication of the species using sperm ultrastructures in male Crassostrea ariakensis were investigated by transmission electron microscope observations. The morphology of the spermatozoon of this species has a primitive type and is similar to those of Ostreidae. Ultrastructures of mature sperms are composed of broad, modified cap-shaped acrosomal vesicle and an axial rod in subacrosomal materials on an oval nucleus, four spherical mitochondria in the sperm midpiece, and satellite fibres which appear near the distal centriole. The axoneme of the sperm tail shows a 9+2 structure. Accordingly, the ultrastructural characteristics of mature sperm of C. ariakensis resemble to those of other investigated ostreids in Ostreidae in the subclass Pteriomorphia. In this study, particularly, two transverse bands (stripes) appear at the anterior region of the acrosomal vesicle of this species, unlike two or three transverse bands (stripes) in C. gigas. It is assumed that differences in this acrosomal substructure are associated with the inability of fertilization between the genus Crassostrea and other genus species in Ostreidae. Therefore, we can use sperm ultrastructures and morphologies in the resolution of taxonomic relationships within the Ostreidae in the subclass Pteriomorphia. These spermatozoa, which contain several ultrastructures such as acrosomal vesicle, an axial rod in the sperm head part and four mitochondria and satellite fibres in the sperm midpiece, belong to the family Ostreidae in the subclass Pteriomorphia.

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.113-118
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• 2001

The objective of this study was to investigate the effects of $\alpha$-tocopherol and selenium on the boar semen characteristics. Semen volume and pH values were not different among treatments. However sperm concerntration, total number of sperm and sperm mortility were significantly(P＜0.05) increased comparing to the control group and sperm abnormality was significantly(P＜0.05) decreased comparing to the control group. Also, sperm mortility by storage day was significantly(P＜0.05) increased comparing to the control group. The results from this experiment indicate that dietary $\alpha$-tocopherol and selenium can affect boar semen characteristics.

• Korean Journal of Animal Reproduction
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• v.25 no.1
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• pp.79-84
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• 2001

This study was carried out to investigate the effects of spring (March~May) and summer (June~August) influencing semen characteristics, frozen-thawed sperm viability and serum testosterone concentration in Duroc boars. Results of this study were as follows: 1. There were no significant differences in the semen volume, pH and sperm concentration of Duroc boars between spring and summer. 2. Sperm motility and normal acrosome of raw semen in Duroc boars did not differ significantly between spring and summer. However, motility and normal acrosome of frozen-thawed sperm were higher in spring season than in summer season(P＜0.05). 3. Serum testosterone concentrations in Duroc boars were 2.15 ng/$m\ell$ in spring and 0.65 ng/$m\ell$ in summer. Serum testosterone concentrations in spring were higher thin those in summer (P＜0.05). 4. In conclusion, when serum testosterone concentrations in Duroc boars were higher, frozen-thawed sperm viability were higher.

• The Korean Journal of Malacology
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• v.27 no.3
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• pp.273-282
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• 2011

The ultrastructural characteristics of germ cells during spermatogenesis and mature sperm morphology in male Pinctada martensii were investigated by transmission electron microscope observation. The morphologies of the sperm nucleus and the acrosome of this species are the oval shape and cone shape, respectively. Spermatozoa are approximately $47-50{\mu}m$ in length including a sperm nucleus (about $1.24{\mu}m$ in length), an acrosome (about $0.60{\mu}m$ in length), and tail flagellum (about $45-47{\mu}m$). The axoneme of the sperm tail shows a 9+2 structure. In P. martensii in Pteriidae, a special substructure showing a thick and wide triangular shape which is composed of electron-dense opaque material (occupied about 50% of all, the upper part of the acrosomal vesicle), appeared in the upper region (part) of the acrosomal vesicle, while the lower region (part) of the acrosomal vesicle is composed of electron-lucent material. Thus, this special structure, which exist in the upper part of the acrosomal vesicle in P. martensii, is somewhat different from those of other subacrosomal vesicle in other families in subacrosomal vesicles. Therefore, we assume that the existence of a special substructure showing a thick and wide triangular shape in the acrosomal vesicle of the spermatozoon can be used as a key characteristic for identification of P. martensii or other species in Pteriidae in subclass Pteriomorphia. The number of mitochondria in the midpiece of the sperm of this species are five (exceptionally sometimes four), as one of common characteristics appear the same number of mitochondria in the same families of superfamilyies. This species in Pteriidae does not contain the axial rod and satellite fibres which appear in the species in Ostreidae in subclass Pteriomorphia. These characteristics can be used for the taxonomic analysis of the family or superfamily levels as a systematic key or tools.

• Reproductive and Developmental Biology
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• v.28 no.4
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• pp.261-265
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• 2004

The present study was conducted to assess sperm characteristics in miniature-pig. The semen samples were transported to the laboratory at 17℃ within 3 hours after collection. The extended semen was stored at 17℃, and sperm quality was evaluated at 0, 1, 3, 5 and 7 days after storage. The semen volume of miniature-pig (62±22㎖) was significantly (p<0.05) lower than that of Duroc (155±25㎖) and Yorkshire (154±23㎖). Significant differences were also observed in sperm concentrations. During 3 days of storage, sperm viability did not differ among miniature-pig, Duroc and Yorkshire. However, the viability was significantly (p<0.05) lower in miniature-pig than in Duroc and Yorkshire semen after Day 3 of storage. In abnormality, acrosome intactness and intensity, there were no differences among miniature-pig, Duroc and Yorkshire semen. On the other hand, the viability of frozen-thawed sperm in miniature-pig was significantly (p<0.05) lower than in that of Duroc and Yorkshire. This study also examined CTC patterns in frozen-thawed spermatozoa. The rates of AR pattern were higher in miniature-pig than in Duroc and Yorkshire. However, no difference was found in F, B and AR patterns. The results of present study suggest that further research is necessary to develop of semen extender and freezing methods to improve sperm quality in miniature-pig.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1561-1565
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• 2006

The objective of this study was to investigate the anti-oxidative effects of taurine on sperm characteristics for in vitro storage of boar semen. Semen was randomly divided into 10 groups in conical tubes and treated with different concentrations of taurine (25-100 mM) with or without $250{\mu}M$ $H_2O_2$. The percentage of motile spermatozoa in taurine groups after 6 and 9 h were significantly higher at >94% and 87%, respectively, compared to the control group ($85.1{\pm}0.5$ and $72.4{\pm}0.3$, p<0.05). The sperm motility in taurine with $H_2O_2$ after 6 h incubation was slightly decreased compared to the taurine alone treatment, but after 9 and 12 h incubation % sperm motility dropped sharply in taurine with $H_2O_2$ ($75.3{\pm}0.3$ and $69.6{\pm}2.9$, p<0.05). For 3, 9 and 12 h incubation, sperm viability in the control was lower than in taurine groups, irrespective of taurine concentration. In eosin Y and nigrosin staining (ENS), the sperm survival rates (%) for 6 h incubation were significantly higher in 25 mM ($76.0{\pm}0.6$) and 50 mM taurine groups ($78.0{\pm}0.7$), respectively. Sperm survival rates for 9 and 12 h incubation were higher in taurine groups (${\geq}48%$ in 9 h and ${\geq}42%$ in 12 h) compared to controls ($43.0{\pm}2.1$ and $31.0{\pm}0.6$, respectively). In the hyoosmotic swelling test (HOST), sperm membrane integrity was similar to the results of sperm survival. These experiments indicate that supplementation of taurine to the semen extender can increase the sperm characteristics(motility, viability, survival and membrane integrity).

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1417-1425
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• 2014

The selection of morphologically normal spermatozoa is critical to obtain high breeding performances in boar breeding farms and artificial insemination (AI) centers. Parameters for the selection of semen mainly include total sperm motility, concentration, and morphology. However, these primary parameters are often not reliable for discriminating between normal and abnormal, non-fertilizable spermatozoa. The present study was designed to compare the motion characteristics, fertilization ability using in vitro fertilization (IVF), and acrosome formation of the semen from boars having low (boar number 2012) and normal (boar number 2004 and 2023) breeding performances. The ultimate goal was to identify additional simple and easy criteria for the selection of normal sperm. There was no significant difference between boar 2004 and boar 2023 sperm total motility in computer assisted sperm analysis. However, boar number 2012 semen presented a significantly reduced population of rapid moving spermatozoa and an increased population of slow moving spermatozoa compared to boar numbers 2004 and 2023. Analysis of detailed motion characteristics revealed that sperm from boar number 2012 had significantly reduced motility in progressiveness, average path velocity, straight-line velocity (VSL), curvilinear velocity (VCL), straightness, and linearity. The assessment of the fertilizing ability by IVF also showed that sperm from boar number 2012 showed a fertility rate of 3.4%, whereas sperm from boar number 2023 had a fertility rate of 75.45%. Interestingly, most of the sperm nuclei were found on the peripheral area of the oocytes, suggesting that the sperm from boar number 2012 lacked penetration ability into the oocyte zonapellucida. The acrosome formation analysis using Pisum sativum agglutinin staining demonstrated that the sperm from boar number 2012 had a defect in acrosome formation. Consequently, primary parameters for selecting semen before AI such as motility are not sufficient to select normal and fertilizable spermatozoa. In conclusion, the present study suggests that the acrosome staining and detailed motion characteristics such as progressiveness, VCL, and VSL should be included in determining semen quality together with primary parameters for successful AI and high breeding performance in the swine industry.

• Journal of Embryo Transfer
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• v.27 no.1
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• pp.45-50
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• 2012

The objective of this study is to estimate the effect of adding TES to LEY and FGE freezing extender for the sperm viability, acrosomal morphology and DNA fragmentation from miniature pig sperm, we evaluated sperm characteristics in TFGE, TLE and LEY with various thawing condition ($37^{\circ}C$ for 20 sec, 45 sec and $75^{\circ}C$ for 5 sec, respectively), and in different concentration of glycerol at 1%, 1.5%, 3%. The sperm viability and normal acrosome intact(NAI) in TFGE (Viability : $60.3{\pm}2.4$, NAI : $58.6{\pm}2.2%$), TLE ($61.3{\pm}2.4$, $62.2{\pm}2.2%$) extender significantly(p<0.05) increased than that in LEY ($50.2{\pm}2.4$, $54.5{\pm}2.2%$) extender thawed at $75^{\circ}C$ for 5 sec. According to the results from glycerol concentration, the viability and NAI of miniature pig sperm in 1.5% glycerol TLE ($66.1{\pm}3.2$, $66.2{\pm}1.0%$) was highest among the experimental groups. In accordance with this, DNA fragmentation rates was the lowest in TLE ($43.3{\pm}0.5%$) while that in LEY ($63.5{\pm}2.3%$) is the highest. Therefore, these results suggest that TLE extender method for freezing- thawing of miniature pig sperm increased the viability after thawing.

• Reproductive and Developmental Biology
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• v.40 no.1
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• pp.1-5
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• 2016

This study investigated the effects of L-carnitine (LC) and nicotinic acid (NA) on sperm viability during liquid storage at $18^{\circ}C$ in miniature pigs. $10{\mu}M$ LC and 30 mM NA, combined LC and NA (LN) were treated in fresh semen for 3, 7, and 10 days. In results, sperm survival increased in NA- and LN-treated semen on 7 and 10 days (p<0.05), mitochondrial integrity of live sperm increased in LN-treated semen on 7 days (p<0.05), but not NA-treated semen. In addition, we examined the acrosome reaction of sperm in miniature pigs. LC and NA did not influence on acrosome reaction of boar sperm. In conclusion, LC and NA effectively maintained the viability and quality of sperm during long-term storage in miniature pigs, suggesting that the combined LN may be useful for improving the semen extender for long-term liquid storage in pigs.