• Development and Reproduction
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• v.15 no.3
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• pp.239-247
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• 2011

Spermatogenesis and taxonomic values of mature sperm morphology of in male Septifer (Mytilisepta) virgatus were investigated by transmission electron microscope observations. The morphologies of the sperm nucleus and the acrosome of this species are the cylinder shape and cone shape, respectively. Spermatozoa are approximately 45-50 ${\mu}m$ in length including a sperm nucleus (about 1.26 ${\mu}m$ long), an acrosome (about 0.99 ${\mu}m$ long), and tail flagellum (about 45-47 ${\mu}m$). Several electron-dense proacrosomal vesicles become later the definitive acrosomal vesicle by the fusion of several Golgi-derived vesicles. The acrosome of this species has two regions of differing electron density: there is a thin, outer electron-dense opaque region (part) at the anterior end, behind which is a thicker, more electron-lucent region (part). In genus Septifer in Mytilidae, an axial rod does not find and also a mid-central line hole does not appear in the sperm nucleus. However, in genus Mytilus in Mytilidae, in subclass Pteriomorphia, an axial rod and a mid-central line hole appeared in the sperm nucleus. These morphological differences of the acrosome and sperm nucleus between the genuses Septifer and Mytilus can be used for phylogenetic and taxonomic analyses as a taxonomic key or a significant tool. The number of mitochondria in the midpiece of the sperm of this species are five, as seen in subclass Pteriomorphia.

• The Korean Journal of Malacology
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• v.26 no.3
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• pp.235-244
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• 2010

Ultrastructural characteristics of the testis and spermatogenesis of Crassostrea gigas were investigated by Transmission and Scanning Electron microscope observations. The testis is a diffuse organ consisting of branching acini containing differentiating germ cells in a variety of stages. The acinus is surrounded by an intermitent layer of myoepithelial cells andis divided into subcompartments that are partially separated by pleomorphic accessory cells which remain in close contact with germ cells until late stages of development. these accessory cells contain a large quantity of glycogen particles and lipid droplets in the cytoplasm. Therefore, it is assumed that they are involved in the supplying of the nutrients for germ cell development, while any phenomena associated with phagocytosis of undischarged, residual sperms by lysosomes could be find in the cytoplasm of the accessory cells. The morphology of the spermatozoon has a primitive type and is similar to those of other bivalves. Mature spermatozoa consist of broad, cap-shaped acrosomal vesicle, subacrosomal material (containing axial rod embedded in a granular matrix), a oval nucleus showing deeply invaginated anteriorly, two triplet substructure centrioles surrounded by four spherical mitochondria, and satelite fibres appear to the distal centriole and plasma membrane. Spermatozoa of C. gigas resemble to those of other investigated ostreids. In particular, the anterior region of the acrosomal vesicle is transversely banded. 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 morphology in the resolution of taxonomic relationships within the Ostreidea. The spermatozoon is approximately $42-47{\mu}m$ in length including an oval sperm nucleus (about $0.91{\mu}m$ in length), an acrosome (about $0.42{\mu}m$ in length) and tail flagellum ($40-45{\mu}m$). The axoneme of the sperm tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail shows a 9 + 2 structure. These morphological charateristics of acrosomal vesicle belong to the family Ostreidae in the subclass Pteriomorphia.

• Journal of Embryo Transfer
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• v.16 no.2
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• pp.139-144
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• 2001

This study was carried out to investigate the effects of the bull, sperm type and sperm pretreatment on the pronuclear formation and in vitro development after injection of spermatozoa into in vitro matured bovine oocytes. 1. Spermatozoa derived room four bulls(A, B, C and D) were used for ICSI. The male pronuclear formation and developmental rates were 73.9∼87.0% and 33.3∼60.9%, respectively. 2. The effects of sperm type were examined. Male pronuclear formation rates by using fresh-and frozen-sperm, tail-cutting and tail-scoring sperm were 82.0%. 78.0%. 42.2% and 51.1% (p<0.05) while development rates were 56.0%. 42.0%, 17.8% and 22.2%, respectively. Fresh sperm achived a high mail pronuclear- and development rates than those of other groups. 3. Cheroical pretreatments were tested and compared. When sperm were pretreated with heparin, BFF(bovine follicula fluid), His, Ca Ionophore(I) and I + caffeine, mate pronuclear formation and developmental rates were 66.7∼82.2% and 33.3∼60.6%. respectively. and these values of treatment of I + caffeine were higher than that of other methods. 4. The male pronuclear formation and developmental rates of oocytes obtained by ICSI treated with or without zona pellucida were 80.0%. 72.0% and 46.0%, 36.0%, respectively.

• The Korean Journal of Malacology
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• v.26 no.1
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• pp.51-62
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• 2010

The ultrastructures of germ cells and the accessory cells during spermatogenesis and mature sperm ultrastructure in male Gomphina veneriformis, which was collected on the coastal waters of Yangyang, East Sea of Korea, were investigated by transmission electron microscope observations. The morphology of the spermatozoon has a primitive type and is similar to those of other bivalves in that it contains a short midpiece with four mitochondria surrounding the centrioles. Accessory cells are observed to be connected to adjacent germ cells, they contain a large quantity of glycogen particles and lipid droplets in the cytoplasm. Therefore, it is assumed that they are involved in the supplying of the nutrients for germ cell development, while any phenomena associated with phagocytosis of undischarged, residual sperms by lysosomes in the cytoplasm of the accessory cells after spawning was not observed in this study. The morphologies of the sperm nucleus type and the acrosome shape of this species have a cylindrical and modified long cone shape, respectively. In particular, the axial filaments in the lumen of the acrosome, and subacrosomal granular materials are observed in the subacrosomal space between the anterior nuclear fossa and the beginning part of axial filaments in the acrosome. The spermatozoon is approximately $50-55{\mu}m$ in length including a long sperm nucleus (about $7.80{\mu}m$ in length), an acrosome (about $1.13{\mu}m$ in length) and tail flagellum ($40-45{\mu}m$). The axoneme of the sperm tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail shows a 9+2 structure. Some charateristics of sperm morphology of this species in the family Veneridae are (1) acrosomal morphology, (2) the number of mitochondria in the midpiece of the sperm,. The axial filament appears in the acrosome as one of characteristics seen in several species of the family Veneridae in the subclass heterodonta, unlikely the subclass pteriomorphia containing axial rod instead of the axial filament. As some characteristics of the acrosome structures, 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 belong to the family Veneridae in the subclass heterodonta, unlikely 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. The number of mitochondria in the midpiece of the sperm of this species are four, as one of common characteristics appeared in most species in the family Veneridae.

• Development and Reproduction
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• v.13 no.2
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• pp.115-122
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• 2009

Spermatogenesis and ultrastructural characteristics of sperm of brackish water diploid Corbicula japonica were investigated by electron microscope observations. Based on the cytological studies, the spermatozoon of this species (brackish water diploid) C japonica is approximately 55 ${\mu}m$ in length. The sperm head (about 12 ${\mu}m$ long) is elongated and tapers with a slight curve. Sperm nucleus is about 7.90 ${\mu}m$ long, and the acrosome is about 2.70 ${\mu}m$ long: The morphologies of the sperm nucleus type and the acrosome shape of this species are a long arrow-like type and long cone-like shape, respectively. The sperm head of this species (external fertilization, dioecious and oviparous species) is partially modified from that of the primitive type, as seen in triploid Corbicula species (internal fertilization, hermaphrodite and ovoviparous species), reported by some authors. However, this species produces uniflagellate spermatozoa, unlike freshwater triploid hermaphroditic clams being possessed of partially modified biflagellate spermatozoa. Diploid C japonica is similar to those of other bivalves being possessed of a short midpiece containing four mitochondria surrounding the centrioles. The axoneme of the sperm tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail shows a 9+2 structure, and from uniflagellate sperm cross sectioned, in particular, wing-like axonernal lateral fins are observed, as seen in external fertilization fishes.

• Applied Microscopy
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• v.33 no.4
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• pp.267-274
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• 2003

The ultrastructures of spermatogenesis and sperm in Xiphophorus maculatus, ovoviviparous fish were investigated by electronmicroscopy The testis of Xiphophorus maculatus contained numerous testicular sacs, and spermatogenesis was synchronized in these testicular sac. In the case of spermatogonium, the nucleus was comparatively large ellipsoidal, and the nucleolus and mitochondria showed a marked development. The size of primary spermatocyte was smaller than that of spermatogonia, and that of secondary spermatocyte was smaller than that of primary spermatocyte. The chromatin of spermatocyte was highly condensed according to their development. The nucleus with electron-dense was round shape. In spermiogenesis, flagella started to be formed and chromatin was more condensed. The mitochondria were rearranged along the tail. The sperm was formed by loss of cytoplasm. The head of mature sperm was long cone shape and had not acrosome. The microtubules of flagella were arranged 9+2 structure. Also, the sperm has a loop-like structure at the end of a tail.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1160-1168
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• 2018

Objective: This study was conducted to compare morphological defects, viability, motility (MOT), fertility (F), and hatchability (H) in four Korean native chicken breeds (KNCBs), and to evaluate whether defective segments of spermatozoa are associated with MOT, F, and H. Methods: Four KNCBs, including Korean Ogye (KO), Hwangbong (HB), Hyunin Black (HH), and Hoengseong Yakdak (HY) were used. White Leghorn (WL) was used as a control. Nine cocks from each breed were randomly assigned into three groups. Semen was collected by abdominal massage method. Eosin-nigrosin staining method was used to identify live-dead spermatozoa. Different segments and specific morphological defects of spermatozoa were identified using 4', 6-diamidino-2-phenylidole and MitoTracker Red CMXRos. F and H rates were evaluated following artificial insemination (AI). Results: KO had the highest MOT rate compared to HY. Viable normal sperm rates of KO and HH were high and comparable with WL. HY spermatozoa had the highest viable abnormal sperm (VAS) or morphological defect rate followed by HB. Likewise, HB spermatozoa had the highest dead sperm (dead) rate compared to KO, HY, and WL. Bent, coiled, detached, broken, and knotted were common identified specific morphological defects for all breeds. Most morphological defects were at the head and tail in all breeds. VAS showed strong negative correlation with MOT (r = -0.697) and F (r = -0.609). Similarly, defective tail was negatively correlated with MOT (r = -0.587), F (r = -0.797), and H (r = -0.448). The F and H rates of KO and WL were comparable. Conclusion: These data indicate that most identified specific morphological defects are at the head and tail. VAS and defective tail were associated with poor motility, F, and H. KNCBs showed more morphological defects than WL. Finally, these results will facilitate successful AI and semen cryopreservation.

• 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.

• Applied Microscopy
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• v.44 no.1
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• pp.1-7
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• 2014

The spermatogenesis of Siamese fighting fish, Betta splendens, belongs to Osphronemidae was investigated by light and electron microscopic observations. In primary spermatocyte stage, the nucleus was comparatively large ellipsoidal, and mitochondria showed a marked development in cytoplasm. In secondary spermatocyte stage, the germ cells were smaller than that of primary spermatocytes. The nucleus was a spherical shape and intercellular space was formed between germ cells. In spermatid stage, the early spermatids were not much different from a secondary spermatocyte. But, the chromatin condensation was occurred from the outside to the inside. The nucleus was more condensed. Intracellular space was larger than early spermatid. The mitochondria were rearranged in a middle piece, and occupied about half of the head part in early sperm. In sperm stage, the head of mature sperm was a spherical shape and had no acrosome. The flagellum was showed the typical 9+2 array of microtubules. Also, the tail of sperm had no lateral fins and outer coarse fibers. These ultrastructural characteristics can be used in classification of species.

• Development and Reproduction
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• v.23 no.1
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• pp.11-19
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• 2019

The study was conducted to investigate the effects of alpha-linolenic acid (ALA) combined with bovine serum albumin (BSA) or methyl-beta-cyclodextrin (MBCD) on plasma and acrosomal membrane damages, mitochondrial activity, morphological abnormality, motility, and oxidative stress in frozen-thawed boar sperm. In previous our study, 3 ng/mL ALA had been shown protective effect during freezing process of boar sperm. Therefore, we used 3 ng/mL ALA in present study and ALA was combined with same molar ratio of BSA or MBCD (ALA+BSA and ALA+MBCD, respectively). To confirm the effect of two carrier proteins, same volume of BSA and MBCD without ALA were added during cryopreservation. Membrane damage, mitochondrial activity, reactive oxygen species (ROS) and lipid peroxidation (LPO) levels were measured using flow cytometry, and movement of sperm tail as motility parameter and morphological abnormality were observed under light microscope. In results, all of sperm parameters were enhanced by ALA combined with BSA or MBCD compared to control groups (p<0.05). Mitochondrial activity, morphological abnormality, ROS and LPO levels in ALA+BSA or MBCD groups were no significant difference compared with ALA, BSA and MBCD treatment groups. On the other hand, plasma and acrosomal membrane intact, and sperm motility in ALA+MBCD group were higher than single treatment groups (p<0.05), whereas ALA+BSA did not differ. Our findings indicate that carrier proteins such as BSA and MBCD could improve the effect of ALA during cryopreservation of boar sperm, and treatment of ALA with carrier proteins enhance membrane integrity, mitochondrial activity through reduction of ROS-induced LPO.