Spermatogonial stem cells are self-renewal and differentiate into sperm in post-pubertal mammals. There exists a balance between the self-renewal and differentiation in the testes. Spermatogonial stem cells make up only 0.03% of testicular cells in adult mice. These cells maintain sperm production by differentiating after puberty. Therefore, analyzing the expression of genes associated with spermatogenesis is critical for understanding differentiation. The present study aimed to establish the postnatal period of cells in relation to spermatogenesis. To study the expression of differentiated and undifferentiated marker genes in enriched spermatogonial stem cells, in vitro culture was performed and cells from pup (6–8-day-old) and adult (4-months-old) testicular tissues were isolated. As a result, undifferentiated genes, Pax7, Plzf, GFRa1, Etv5 and Bcl6b , were highly increased in cultured spermaotogonial stem cells compared with pup and adult testicular cells. On the other hands, differentiated gene, c-kit was highly increased in adult testicular cells, Also Stra8 gene was highly increased in pup and adult testicular cells. This study provides a better understanding of spermatogenesis-associated gene expression during postnatal periods.

A high-cholesterol diet can reduce male fertility. However, it is not known whether a high-cholesterol diet can regulate the expression of genes involved in sperm maturation and sperm fertilizing ability. Quercetin, a natural product, is known to have cytoprotective effects by regulating lipid metabolism in various cell types. This study aimed to confirm the expression of genes involved in sperm maturation in the testes of mice fed a high-cholesterol diet and to determine whether quercetin can reverse the genetic regulation of cholesterol. Mice were divided into groups fed a normal chow diet and a high-cholesterol diet. Mice fed the high-cholesterol diet were dose-dependently supplemented with quercetin for 6 weeks. Investigations using quantitative PCR and in situ hybridization revealed that the high-cholesterol diet alters the expression of genes associated with sperm maturation in the testes of mice, and this was reversed with the supplementation of quercetin. In addition, the high-cholesterol diet regulated the expression of genes related to lipid metabolism in the liver of mice. Under a high-cholesterol diet, quercetin can improve male fertility by regulating the expression of genes involved in sperm maturation.

Abstract - Global decline in wildlife mammals has been accelerated during past decades. Especially the conservation the wild life mammals in polar areas, is urgent. In an effort to understand the reproduction of the seals dwelling in the polar area, sperm

본 연구는 New Zealand White 수토끼에서 춘기발동 기간 동안에 혈청내 IGF-I(insulin-like growth factor-I)과 GH(growth hormone) 수준의 변화, 정자 형성에 따른 정소내 세포 구성 변화 및 이들 측정치들 간에 관계를 조사하기 위하여 실시되었다. 주령과 관련된 정소내 세포의 DNA 함량 변화 조사를 위하여 10~28주령 수토끼 정소 조직의 fine-needle biopsy를 flow cytometry(FCM)로 분석하였다. 생체중은 12~20주령 때 크게 증가되었고(P<0.05), 28주령 체중은 3.4kg이었다. 혈청 IGF-I 수준(451.3ng/mL)은 20주령에서 가장 높았으며(P<0.05), 그 후 낮은 수준으로 유지되었다. 혈청 GH 수준은 183.3pg/mL으로 다른 주령 때보다 현저히 높았으며(P<0.05), 상승시기가 IGF-I보다는 다소 빨랐다. 정소 조직세포 중 1C-세포의 상대적 비율은 18주령 때 48.2%로 16주령보다 크게 상승되었고(P<0.05), 주령 증가와 더불어 68%로 증가되었다. 2C-세포 비율은 18주령 때 26.8%로 16주령의 54.3%보다 현저히 낮았다(P<0.05). 4C-세포 비율은 18주령 때 9.9%를 제외하고 2~6%를 유지하였다. 이상 결과에서 토끼는 춘기 발동 개시가 약 18주령에 일어나고 이 기간 중 IGF-I과 GH 수준의 변화가 나이 또는 체성장과 관계가 있었으며 그 영향이 정자 형성과 관련이 있음을 알 수 있었다. Fine-needle biopsy와 연계된 FCM은 춘기 발동 개시와 관련된 정자의 형성 과정을 평가하는데 매우 정확한 방법임을 확인할 수 있었다.

플라스틱 제품의 가소제로 널리 사용되며, 최근 내분비 교란물질로 알려져 있는 di-(2-ethylhexyl)phthalate(DEHP)를 흰쥐에 15일 동안 구강 투여(1g/kg/day, 2g/kg/day, 3g/kg/day)한 후, 정자형성과정에 연관된 정소의 기능과 구조에 미치는 영향을 조사하였다. DEHP 처리군에서는 대조군에 비하여 체중 증가율이 감소하였을 뿐만 아니라 정소의 무게도 감소하였다. 또한 세정관의 직경이 고농도군으로 갈수록 작아지는

The ultrastructures of germ cells and the functions of Leydig cells and Sertoli cells during spermatogenesis in male Kareius bicoloratus (Pleuronectidae) were investigated by electron microscope observation. Each of the well-developed Leydig cells during active maturation division and before spermiation contained an ovoid vesicular nucleus, a number of smooth endoplasmic reticula, well-developed tubular or vesicular mitochondrial cristae, and several lipid droplets in the cytoplasm. It is assumed that Leydig cells are typical steroidogenic cells showing cytological characteristics associated with male steroidogenesis. No cyclic structural changes in the Leydig cells were observed through the year. However, although no clear evidence of steroidogenesis or of any transfer of nutrients from the Sertoli cells to spermatogenic cells was observed, cyclic structural changes in the Sertoli cells were observed over the year. During the period of undischarged germ cell degeneration after spermiation, the Sertoli cells evidenced a lysosomal system associated with phagocytic function in the seminiferous lobules. In this study, the Sertoli cells function in phagocytosis and the resorption of products originating from degenerating spermatids and spermatozoa after spermiation. The spermatozoon lacks an acrosome, as have been shown in all teleost fish spermatozoa. The flagellum or sperm tail of this species evidences the typical 9+2 array of microtubules.

Ultrastructural characteristics of the germ cells and accessory cells in testis during spermatogenesis and taxonomic values of mature sperm morphology of Ruditapes philippinarum were investigated by the transmission electron microscope and scanning electron microscope observations. The testis is the diffuse organ that consists of branching acini containing developing germ cells and accessory cells associated with spermatogenesis. The morphology of the spermatozoon is of the primitive type and is somewhat different to those of other bivalves. The morphologies of the sperm nucleus type and the acrosome shape of this species have a cylinderical type and a modified cone shape, respectively. As some ultrastructural characteristics of the acrosomal vesicle, the peripheral parts of two basal rings show electron opaque part, while the apex part of the acrosome shows electron lucent part. These characteristics of 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. In particular, a cylinder-like nucleus of the sperm is curved. The spermatozoon is approximately 48-51 μm in length, including a long acrosome (about 2.40 μm in length), a curved sperm nucleus (about 3.40 μm in length), and a tail flagellum. The axoneme of the sperm tail shows a 9+2 structure.

The ultrastructural characteristics of germ cell differentiations during spermatogenesis and mature sperm morphology in male () were evaluated via transmission electron microscopic observation. The accessory cells, which contained a large quantity of glycogen particles and lipid droplets in the cytoplasm, are assumed to be involved in nutrient supply for germ cell development. Morphologically, the sperm nucleus and acrosome of this species are ovoid and conical in shape, respectively. The acrosomal vesicle, which is formed by two kinds of electron-dense or lucent materials, appears from the base to the tip: a thick and slender elliptical line, which is composed of electron-dense opaque material, appears along the outer part (region) of the acrosomal vesicle from the base to the tip, whereas the inner part (region) of the acrosomal vesicle is composed of electron-lucent material in the acrosomal vesicle. Two special characteristics, which are found in the acrosomal vesicle of A. () in Pinnidae (subclass Pteriomorphia), can be employed for phylogenetic and taxonomic analyses as a taxonomic key or a significant tool. The spermatozoa were approximately in length, including a sperm nucleus (about in length), an acrosome (about in length), and a tail flagellum (about ). The axoneme of the sperm tail evidences a 9+2 structure.

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 in length including a sperm nucleus (about 1.26 long), an acrosome (about 0.99 long), and tail flagellum (about 45-47 ). 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.

본 연구는 수컷 살조개 Protothaca (Notochione) yessoensis의 정자 형성 과정 중 생식세포들의 분화와 성숙정자의 미세구조 특징에 관한 몇 가지 특징을 투과전자현미경 관찰에 의해 조사하였다. 본 종의 정자형태는 원시형(primitive type)으로, 이매패강, 이치아강(Heterodonta)에 속하는 다른 종들과 유사하다. 생식세포에 인접하여 연결되어 있는 보조세포들은 생식세포들의 발달을 위해 영양공급에 관여한다. 본 종의 정자의 핵형은 긴 원통형이며 첨체의 형태는 모자모양이다. 정자는 길이가 대략 46～50 ㎛이며, 길다란 정핵(길이 약 2.44 ㎛)과, 첨체(길이 0.45 ㎛), 그리고 미부 편모(약 42～46 ㎛)로 이루어져 있다. 미부 편모의 악소님(axoneme)은 9+2 구조를 나타낸다. 첨체소포의 특징으로써 basal ring의 기저부 위에서 측면부위는 전자밀도가 불투명한 부위를 나타내나, 첨체소포의 앞쪽 정단부위는 전자밀도가 비교적 투명한 부위로 나타나는 특징을 보인다. 이것이 이치아강에 속하는 백합과와 또 다른 여러 과들에 속하는 종들의 정자들이 갖는 첨체소포의 공통특징이다. 따라서 이치아강이 갖는 이들 첨체소포가 갖는 공통특징은 분류의 key 또는 중요한 도구로써 계통․분류를 위해 사용될 수 있다. 정자 중편에 있는 미토콘드리아 수는 4개로 이치아강 내에서 백합과의 3종을 제외한 모든 종들과 다른 과들의 종들에서 공통으로 나타나고 있는데, 예외로, 개조개, 백합, 가무락조개 만은 중편의 미토콘드리아가 5개로 이루어져 있다. 미토콘드리아 수는 과나 또는 상과 수준에서 종들의 분류학적 분석을 할 경우, 분류 key 또는 중요한 도구로 사용될 수 있다.

We investigated the androgenic effects of 11-ketotestosterone (11-KT) on gonadal sex reversal and spermatogenesis in honeycomb grouper Epinephelus merra by method of gonadal biopsy. 11-KT was injected intramuscularly at a concentration of 1 and body weight. The proportion of cross sectional area of the gonad occupied by each germ cell type was measured and compared pre- and post-injection group. During the sex change phase, the distribution ratio of oocytes was decreased in all fish of 11-KT treatment group while the distribution ratio of spermatocytes was increased than pre-injection group. In male phase, all fish of 11-KT treatment group shown the increased distribution ratio of spermatocytes, but the distribution ratio of spermatozoa was decreased than pre-injection group. The present results suggest that 11-KT can stimulate degeneration of oocytes, proliferation of spermatocytes and spermiation in honeycomb grouper.