鹌鹑早期原始生殖细胞迁移和聚集规律的研究

本研究旨在观察鹌鹑早期原始生殖细胞的迁移和聚集规律,为分离PGCs,并将其应用于转基因技术提供依据。运用QH1单抗标记特异性的识别鹌鹑的PGCs,检测早期各个阶段PGCs的分布和数量。研究表明:鹌鹑的原始生殖细胞(PGCs)起源于胚盘暗区,而后逐渐迁移至明区、生殖新月区。孵化27h,已有少量PGCs分布于明区的血管中。到孵化36h时,有大量的PGCs聚集在明区血管网中,左右两侧都有。孵化45h时,从头部到脐肠系膜PGCs均有散在和聚团分布,并主要聚集在头部间充质的血管中。PGCs在各个时期的数量存在差异,有2个增殖高峰期,即原条期(孵化6h)和十体节期(孵化36h)。QH1单抗可鉴定早至未孵化期的鹌鹑原始生殖细胞,PGCs在早期胚盘中是随机散在分布的,而且具有2个增殖高峰期。     

哺乳动物PGCs用于胚胎干细胞培养的研究

本文综述了哺乳动物原始生殖细胞（PGCs）的研究进展；归纳了影响用PGCs分离胚胎干培养的因素。阐述了在PGCs用于胚胎干细胞培养研究中存在的问题及应用前景。     

鸡胚胎生殖嵴中原始生殖细胞的分离培养研究

在鸡胚孵化的 19期以Ficoll密度梯度离心和酶解离两种方法分离生殖嵴中的原始生殖细胞 (PGCs)。探索在生殖嵴中PGCs分离、培养的适宜方法 ,以获得较多数量 ,较高活力的PGCs作介导生产转基因鸡。在倒置显微镜下进行形态观察 ,台盼兰染色比较存活时间 ,PAS特异染色法识别鉴定PGCs。结果表明两种分离方法均能分离到一定数量的PGCs细胞。与Ficoll密度梯度离心法相比 ,酶解离法分离到的PGCs的相对数量较多 ,存活时间较长 ,是一种较可行的分离方法。在鸡胚孵化的第 19期 ,PGCs大量聚集在肢体后端的生殖嵴原基处 ,此时的生殖嵴大小已达一定程度 ,分离其中的PGCs操作简便 ,有较强的可操作性 ;提取出的PGCs为转基因鸡的生产提供了介导材料     

五指山近交猪胚胎生殖细胞(EG)嵌合体在我国移植产仔

采集25~28日龄的五指山小型猪(WZSP)胚胎原始生殖嵴细胞(PGCs),用于 WZSP生殖细胞(EG)建系培养技术研究。研究发现:以DMEM含15%胎牛血清、0 1 mol/L巯基乙醇等为基础培养液,分别添加生长因子20 ng/mL LIF、40 ng/mL hSCF、20 ng/mL hbFGF,以STO为饲养层,进行 EG培养建系,WZSP 3 d 可出现克隆,其克隆具有出现早,生长数量多,增殖快,成熟亦早,传代率高的特点。培养 7~10 d需传代或冷冻保存。EG类细胞冷冻、解冻后尚可复苏,并传至11代。若基础培养液不添加生长因子,培养 6~10 d后亦可出现 EG克隆细胞株,但其克隆具有出现晚、数量少、增殖慢等特点。研究中还发现25~26日龄的WZSP胚胎的原始生殖嵴小、不易观察、PGCs分离较困难; 27 ~ 28 日龄的 WZSP 胚胎的原始生殖嵴体积大、易观察、便于分离并可获得多量的PGCs。同时对PGCs进行了形态学、体外分化、AKP染色鉴定等研究。2002 年 9-12 月,在中国农业科学院畜牧研究所五指山猪保种场先后从22头超排处理的大白猪供体中,于配种后(当天为 0 d)5 5~7 d实施手术法获得252枚可用胚。将123枚胚胎显微注射WZSP的EG细胞,每枚注射5~15个细胞,与未注射的 103 枚混合分别移植给9头受体,平均每头受体移植胚胎25 11±5 11枚、含注射 EG细胞胚胎 13 67±3 57 枚,其中 7 头分别     

野生日本鸣鹑与家鹌鹑及其杂交后代的行为规律研究

将微山湖野生日本鸣鹑与家鹌鹑杂交F2代按1公∶5母进行分组,采用秒表单位记时法观察鹌鹑的行为,并引用同期亲本和F1代的相同资料,对鸣叫、打斗和交配行为频次进行比较。结果表明:①杂交F2代鹌鹑鸣叫行为比家鹑低,除10∶00～11∶00外,其余时间段均存在显著差异(P<0.05);在14∶00～15∶00与野生日本鸣鹑存在显著差异(P<0.05);在14∶00～16∶00杂交F1代有显著差异(P<0.05);②杂交F2代鹌鹑打斗行为除16∶00～17∶00外与家鹑及杂交F1代无显著差异;③杂交F2代鹌鹑交配行为除16∶00～18∶00外与家鹑及杂交F1代均有显著差异(P<0.05)。     

家鹑与野生日本鸣鹑群体微卫星DNA标记的遗传学分析

选择10个微卫星标记位点，合成引物对微山湖野生日本鸣鹑和家鹌鹑各40只进行PCR扩增，变性聚丙烯酰胺凝胶电泳检测分型，并对其品种内和品种间的遗传变异进行群体遗传学分析，从分子水平上揭示这两个鹌鹁群体的遗传结构关系、亲缘关系和遗传分化程度，为鹌鹑的遗传资源研究提供新资料。     

Effects of Reticuloendotheliosis Virus on the Viability and Reproductive Performance of Japanese Quail

The effects of reticuloendotheliosis virus (REV) infection were studied using an experimental model in Japanese quail during 2 consecutive generations. The REV used in this study (APC-566) was isolated from Attwater's prairie chickens (Tympanuchus cupido attwateri). Tumors were induced by APC-566 as early as 6 wk of age. Mortality was significantly higher in groups of quail with a higher frequency of REV infection. Egg production, hatchability, and fertility rates decreased in infected quail as compared with uninfected control quail. The BW of infected quail were significantly reduced at 8 wk of age in the first generation of infected quail (breeders) and at 3 and 6 wk of age in the second generation (quail broilers) compared with uninfected quail.     

A Growth Performance and Nonlinear Growth Curve Functions of Large- and Normal-Sized Japanese Quail (Coturnix japonica)

This study aimed to evaluate the differences between the growth patterns of large- and normal-sized Japanese quail strains and their F₁ progeny, by fitting their growth parameter values to five nonlinear regression growth models (Weibull, Logistic, Gompertz, Richards, and Brody). The Richards model presented the best fit for both sexes of the large-sized quail strain, whereas the Gompertz model presented the best fit for both sexes of the normal-sized quail strain, based on goodness-of-fit criteria (higher adjusted R² and lower Akaike and Bayesian information criteria). Both sexes of F₁ birds derived from the cross between normal-sized females and large-sized males were best fitted by the Richards model. In contrast, growth parameters of the F₁ birds derived from the cross between large-sized females and normal-sized males were best fitted to the Gompertz model. The data could be fitted nearly as well to the Weibull and Logistic models as to the Richards and Gompertz models. The Brody model presented the poorest fit for the growth parameter values. The results indicated that the Richards and Gompertz models could best describe the growth characteristics of both large- and normal-sized quails. Moreover, the observed growth pattern of the F₁ birds was likely inherited from the male parental strain. To the best of our knowledge, this is the first study comparing the growth curves of the reciprocal F₁ generations with their parental strains in quails.     

Effect of Anserine and Carnosine on Sperm Motility in the Japanese Quail

Sperm motility is considered as one of the most important traits for successful fertilization, but the motility of an ejaculated sperm decreases with time when stored as liquid. It is reported that seminal plasma serves as a nutrient rich medium for sperm and plays an important role in sperm motility and its fertilization ability. Several studies have reported that imidazole dipeptides such as anserine and carnosine affect sperm motility and its fertilization ability in mammals. In this study, we report the presence of anserine and carnosine in the male reproductive tract of the Japanese quail. Abundant levels of anserine (44.46 µM) and carnosine (41.75 µM) were detected in the testicular fluid and seminal plasma respectively using the amino acid analyzer; however, seminal plasma solely contained carnosine. When the ejaculates were incubated with anserine or carnosine, we found that both the dipeptides improve sperm motility parameters such as straight line velocity, curvilinear velocity, average path velocity and amplitude of lateral head displacement after in vitro sperm storage at 15°C. These results indicate that imidazole dipeptides are present in the male reproductive tract and may improve sperm quality during in vitro sperm storage in the liquid states.     

山羊原始生殖细胞分离与培养的影响因素

以本地白山羊胎儿的生殖嵴为试验材料,从原始生殖细胞(primordial germ cells,PGCs)中分离培养得到胚胎生殖细胞(embryonic germ cells,EGCs),对其进行体外培养和鉴定等。胎儿生殖嵴在室温(25℃)下消化15 min,使用0.125%胰酶+0.02%EDTA比0.25%胰酶+0.04%EDTA效果好,差异显著(P<0.05);挑取集落法和胰酶消化法均能将PGCs传至第2代,两种方法差异不显著(P>0.05);以GEF为饲养层,在培养液中添加不同浓度和种类的细胞因子:①LIF:10 ng/mL;②LIF:20 ng/mL;③LIF(10 ng/mL)+SCF(10 ng/mL);④LIF(20 ng/mL)+SCF(20 ng/mL)。4种情况对于原代集落形成率的影响差异不显著(P>0.05),均能得到传至第2代的EGCs;研究不同胎龄胎儿分离培养PGCs的效果,结果发现4例冠臀长小于15 mm的胎儿仅观察到一个原代集落,6例大于30 mm的胎儿没有观察到原代集落。     

猪原始生殖嵴细胞(PGCs)建系因素的研究

从五指山猪(WSZP)近交系第8～13代培育群中，先后选用21头5～10月龄青年母猪，分别于授精后25～30d采集胎儿106个，进行原始生殖嵴(PGCs)细胞分离、培养等建系技术研究。以DMEM F10(1:1)为基础培养液，按添加或不添加生长因子，将培养液分为A、B、C3种，并以STO细胞作饲养层，在38℃、5.0％CO2和湿润的气相中进行培养建系。结果获得胚胎生殖嵴细胞(EG)细胞系6个细胞株，其中1个EG细胞株传至11代、2个传至5代、1个传至4代、2个传至3代冻存。并进行了AKP染色、体外分化、冷冻-解冻复苏和嵌合体制作等鉴定研究。研究发现：不同胚龄对EG细胞建系具有一定影响，不同培养液对EG细胞建系效果不同，STO细胞饲养层的质量是建株、传代、冷冻-解冻复苏的关键因素之一。EG细胞系的初步建立，为今后筛选进入种系的EG细胞系、实施体外基因操作提供了可能。     

鸡胚原始生殖细胞的冷冻保存和体外培养

采用Ficoll密度梯度离心,提取第19期(孵化72h)鸡受精蛋性腺中的原始生殖细胞(primordialgermcells,PGCs),用不同的冷冻保护液对PGCs采用提纯后直接冷冻保存和在培养体系中培养24h后再进行冷冻保存,7d后复苏,用台盼蓝染色检测其存活率,并用PAS染色对冷冻后的PGCs进行特异性鉴定。复苏后的PGCs在培养体系中培养5d后,更换为培养体系继续培养,进行体外分化试验。结果如下分离后直接进行冷冻保存的PGCs复苏后存活率最高为(85.93±1.24)%;复苏后的PGCs在培养体系中培养48h后进行了PAS染色鉴定,结果PGCs呈PAS阳性(细胞核不着色,细胞质呈红色),表明PGCs的染色特性没有因冷冻保存和体外培养而发生改变;复苏后的PGCs在培养体系中培养可形成细胞克隆,当把PGCs更换到培养体系培养5d后,PGCs克隆有的仍保持克隆状态,但体积缩小,克隆中细胞排列紧密,颜色较深,有的克隆由鸟巢状变为不规则形,且在克隆周围形成类神经细胞样细胞。而经体外培养后再进行冷冻保存的PGCs,复苏后存活率最高为(42.26±1.36)%。     

鸡胚原始生殖细胞诱导分化为神经元样细胞的研究

原始生殖细胞（Primordial Germ Cells：PGCs）是指能够发育为性细胞的前体细胞,可作为胚胎干细胞（ES）分离与克隆的一种新型材料,其形态、表面标志、体内外分化潜能及体外培养条件均类似于胚胎干细胞.体外培养过程中,在培养液中加入一定的诱导分化剂,PGCs细胞将发生定向分化.长期以来神经系统损伤和神经退行性病变是临床上难以解决的问题,由于原始生殖细胞具有发育全能性,可以在体外通过对其进行定向诱导,得到特定类型的细胞,这将使原始生殖细胞成为今后细胞替代疗法和组织器官移植的来源.本试验采用不同的诱导剂对PGCs进行诱导,以探讨PGCs细胞向神经细胞分化的适宜条件.     

泰山螭霖鱼原始生殖细胞的发生及性腺分化规律的研究

通过光镜、电镜及PAS法对泰山螭霖鱼原始生殖细胞的发生、迁移及性腺分化规律进行了研究。结果表明,原始生殖细胞最早出现于受精后11 h的原肠早期;6日龄,生殖嵴形成;20日龄,原始生殖细胞迁移到生殖嵴中,与生殖嵴共同组成原始性腺;60日龄,原始性腺开始分化。卵巢的分化时间早于精巢。电镜下观察到泰山螭霖鱼原始生殖细胞核膜附近有生殖质存在。原始生殖细胞的PAS反应呈阳性。     

Immunolocalization of sex steroid receptors in the epididymis and ductus deferens of immature and mature Japanese Quail, Coturnix Japonica

The goal of this study was to determine whether in the Japanese quail the male genital tract contains receptors for progesterone, androgen and estrogen (PR, AR and ER, respectively), which have significant roles in reproductive functions, and whether their localization changes during sexual maturation. The epididymis and ductus deferens (middle and ampulla regions) of immature (approximately 30-day-old) and mature male Japanese quail were collected and frozen sections of them were immunostained for PR, AR and ER. The immunoreaction products for AR and PR were found in the nuclei of epithelial cells in the efferent ductules, epididymal duct, and the middle and ampulla regions of the ductus deferens of mature and immature birds. In the mature birds, the epithelial cells of the efferent ductules, epididymal duct, and the middle and ampulla regions of the ductus deferens were positive for ER, although some of the cells in the ductus deferens were negative. The epithelial cells of the ductules in the epididymis stained positive for ER, but the immunoreactions were negligible in the ductus deferens of immature birds. These results suggest that the epididymis and ductus deferens in quail possesses PR, AR and ER receptors. Each receptor is expressed before sexual maturation, although enhancement of ER expression may occur during maturation.     

Production of germ-line chimeras by the transfer of cryopreserved gonadal germ cells collected from 7- and 9-day-old chick embryos

Gonadal germ cells (GGC) were collected from the gonads of 7‐ or 9‐day‐old White Leghorn chick embryos and suspended in freezing medium containing 10% dimethylsulfoxide (DMSO). The cell suspension was frozen at ?1°C/min. until the temperature reached ?80°C. Then, the cells were immersed in liquid nitrogen at ?196°C and stored for 3–4 months. Approximately 50 frozen/thawed GGC were injected into the dorsal aorta of each 2‐day‐old Rhode Island Red (RIR) embryo, from which blood was drawn before germ‐cell injection. The injected embryos were incubated until they hatched and the chicks were raised until sexually mature. On reaching sexual maturity, a progeny test was performed by mating recipient chicks with normal RIR of the opposite sex. Progenies were obtained from male germ cell recipients that were injected with germ cells collected from 7‐ and 9‐day‐old embryos. The results demonstrated that frozen/thawed GGC collected from 7‐ or 9‐day‐old fertilized eggs can be used to produce male germ‐line chimeras.