共查询到20条相似文献，搜索用时 500 毫秒
1.
2.
鸡胚法氏囊的组织发育 总被引：7，自引：0，他引：7
本试验通过对孵化至１３－２１日龄的鸡胚法氏囊进行组织学的连续性动态观察,较为详细地描述了早日龄鸡胚法氏囊的组织学分化发育过程。实验结果显示,直至出壳胶鸡胚法氏囊尚未形成较完整的能组织起 体液免疫促进作用的组织基础结构,其完善的形态结构需在后天环境中分化和发育。 相似文献
3.
鸡胚免疫器官组织学发育过程观察 总被引：3，自引：0，他引：3
通过对孵化至12-21日龄鸡胚的免疫器官胸腺、脾及腔上囊进行组织学连续性观察，较为详细地描述了鸡胚免疫器官的组织发育过程。观察结果显示，胸腺的组织结构发育和形成较早，自12日龄起胸腺就已形成原始的胸腺小叶；虽然脾在12日龄时就已初具轮廓，但脾直到18日龄才开始隐约形成形态可辨的红髓和白髓；腔上囊淋巴滤泡自鸡胚发育到17日龄时即渐趋明显，但完整的滤泡皮质和髓质结构在出壳前仍然处于分化成熟阶段。 相似文献
4.
《黑龙江畜牧兽医》2015,(11)
为了研究敖汉细毛羊毛囊的组织结构与形态发育过程,进而为解析细毛羊毛囊发育的分子调控机制奠定组织学基础,试验采用组织学和显微观测的方法,分析敖汉细毛羊胎龄为第90,120天的胎儿,及出生后1天和1个月时的羔羊体侧部皮肤的组织学特性。结果表明:在胎龄90天时,体侧的初级毛囊可见次级毛囊毛芽;胎龄120天时,部分毛囊发生角质化,初级毛囊周围可见成对的皮脂腺及之间的汗腺导管和竖毛肌;出生后1天时和出生1个月时,大部分毛囊都已形成角质化毛干,皮脂腺、汗腺、竖毛肌等进一步发育成熟。与胎龄120天时相比,出生后1个月时的毛囊纤维直径显著增大(P0.05)。出生后1个月和出生后1天时次级毛囊纤维直径差异不显著(P0.05)。 相似文献
5.
6.
7.
8.
9.
[目的]了解成年绒山羊次级毛囊组织形态的周期性变化过程,为研究绒山羊绒毛生长的分子调控机理奠定组织学基础.[方法]制作内蒙古绒山羊1年周期内每个月的皮肤组织切片,染色后显微镜下观察照相.[结果]成年绒山羊次级毛囊形态在1年中呈周期性变化,在兴盛期、退行期和休止期的形态各不相同.从4月份开始,次级毛囊外根鞘细胞向下分裂延伸,开始了毛囊的重建;8-9月毛囊完成重建,毛囊结构完整;10月毛球细胞停止分裂,毛乳头萎缩,大量细胞程序化死亡,毛根上移,毛囊进入退行期;12月毛囊根部上升到皮脂腺附近不再变化;翌年1-3月毛囊的形态基本没有变化.[结论]了解了成年绒山羊次级毛囊1年内形态的周期性变化过程,为绒山羊绒毛相关领域的研究提供一定的借鉴. 相似文献
10.
《中国畜牧杂志》2015,(17)
本实验旨在探究敖汉细毛羊毛囊的组织结构与形态发生过程,为细毛羊毛囊发育的分子调控机制研究奠定组织学基础。分别采集胎龄第90、120天的胎儿及出生后1 d和30 d的羔羊体侧部(多毛区)和腹股沟部(少毛区)皮肤组织,制作纵、横切片并显微观察。结果表明:敖汉细毛羊毛囊结构包括结缔组织鞘、外根鞘、内根鞘、毛干和毛球部;在胎龄90 d时,体侧部初级毛囊可见皮脂腺原细胞及次级毛囊毛芽,在胎龄120 d时,毛囊形成角质化毛干并穿出体表,再分化次级毛囊发生;出生后1 d和30 d时,穿出体表毛干进一步增多,体侧部初级毛囊密度,在胎龄120 d时低于胎龄90 d时(P0.01),出生后1 d时低于胎龄120 d时(P0.05),次级毛囊密度,在胎龄120 d时高于胎龄90 d时(P0.01),出生后1 d时低于胎龄120 d时(P0.01),出生后1 d和30 d时差异不显著(P0.05),S/P比值,在胎龄120 d时高于胎龄90 d时(P0.01),生后30 d时高于出生后1 d时(P0.01),对腹股沟部皮肤分析显示,其毛囊密度很低。结果可为了解细毛羊毛囊形态结构变化及筛选与毛密度相关的差异基因提供参考依据。 相似文献
11.
The effect of vascular endothelial growth factor on in vitro embryonic heart development in rats 总被引：5，自引：0，他引：5
In vitro effects of vascular endothelial growth factor (VEGF) on heart development and total embryonic growth were investigated in 84 rat embryos (obtained from nine pregnant females) at 9.5 days of gestation that were cultured in whole rat serum (WRS), in <30 kDa + >50 kDa serum fractions [retenate (R)], and in R + VEGF. After 24-h culture, the embryos from each group were harvested and divided into two groups. One group was analysed morphologically and biochemically to obtain embryo protein content, the second group was serially sectioned and examined by light microscopy. Morphological score, embryo protein content, somite number and crown-rump length of embryos indicated that embryos cultured in R had significant embryonic retardation, whereas the addition of VEGF to R increased embryonic growth and development. The morphological scores for WRS, R and R + VEGF were 57.7 +/- 0.87, 46.6 +/- 1.90 and 52.1 +/- 0.97, somite numbers were 26.5 +/- 0.47, 20.1 +/- 0.63 and 24.4 +/- 0.46, crown-rump lengths were 3 +/- 0.07, 2.4 +/- 0.06 and 2.7 +/- 0.06 mm, and embryo protein contents were 160.5 +/- 7.41, 98.2 +/- 4.81 and 141.1 +/- 10.96 mug per embryo, respectively. The results of histological examination of heart development were similar. The hearts of embryos grown in R were unseptated and tubular. The atrioventricular endocardial cushions were incompletely developed. The addition of VEGF to R improved heart development. There were no gross morphological differences in the cardiac development between embryos grown in WRS and R + VEGF. In both groups, development of the muscular interventricular septum had begun. Development of the atrioventricular cushions was also similar in both groups and had caused narrowing of the atrioventricular canals, but the atrial septation was not observed. 相似文献
12.
13.
试验选取健康且体重一致、12周龄的红腹锦鸡15只,随机分为5个处理,每个处理设3个重复,每个重复1只,试验期为12周,分别饲喂蛋白质水平不同的5种试验日粮(A组16.78%,B组17.76%,C组18.75%,D组19.75%,E组20.67%)。结果表明:23同龄时,在能量水平为12.14 MJ/kg、蛋白质水平为18.75%时,育成期红腹锦鸡体重最大,为511.63 g,与其他各组差异显著(P0.05)。蛋白质水平为19.75%时,育成期红腹锦鸡的体型发育最佳。 相似文献
14.
15.
Everaert N Willemsen H De Smit L Witters A De Baerdemaeker J Decuypere E Bruggeman V 《British poultry science》2008,49(5):574-582
1. This research focused on the embryonic development of broiler and layer embryos. 2. Egg, embryo and yolk weights were measured and partial pressure of gases in the air cell and blood were analysed at several embryonic ages. The static stiffness of the eggshell was measured before the start of incubation and at embryonic day (ED) 18 to register the change in shell strength. Times of internal pipping (IP), external pipping (EP) and hatch were recorded. Plasma corticosterone, triiodothyronine and thyroxine concentrations were determined. 3. Relative egg weight loss was higher in layer eggs. Before ED16, layer embryos showed a slower development which was reflected in lower (relative) embryo weight, lower air cell and blood pCO(2) and higher air cell O(2). From ED16 onwards, relative growth rate accelerated in the layer strain; as a consequence the difference in relative yolk-free chick weight at hatch had disappeared between strains. 4. Differences in physiological events necessary for hatching (thyroid hormones, corticosterone, air cell pCO(2)) are most probably responsible for the observed differences in timing of pipping and hatching events between layer and broilers. 相似文献
16.
The development of methods to produce embryos in vitro in the horse has been delayed compared with other domestic species. Oocytes can be collected from excised ovaries or from the small or preovulatory follicles of live mares. Intracytoplasmic sperm injection is the only reliable method to fertilize equine oocytes in vitro. Intracytoplasmic sperm injection-produced embryos can be transferred into the oviducts of recipient mares or cultured to the morula or blastocyst stage of development for nonsurgical embryo transfers into recipients' uteri. Embryos cultured in vitro have some morphological differences compared with embryos collected from the mares' uteri. Most notably, the embryonic capsule does not form in culture, and the zona pellucida fails to expand completely. However, embryo produced in vitro can result in viable pregnancies and healthy offspring. 相似文献
17.
G Antunes A Chaveiro P Santos A Marques HS Jin F Moreira da Silva 《Reproduction in domestic animals》2010,45(1):26-32
The correlation between apoptosis and early bovine embryonic loss is still not fully elucidated. In the present study, the relationship between the arrest of bovine embryos at the different stages of development and apoptosis was evaluated. We used embryos 7 days after in vitro maturation and fertilization, and morphologic and biochemical apoptotic analyses were performed by using a phase contrast microscope and by the terminal transferase dUTP nick end‐labelling respectively. For the statistic, the apoptotic cell ratio (ACR) was determined as the percentage of apoptotic cells per embryo. To evaluate the relation between ACR and fragmentation pattern, embryos were divided into five groups, groups I–V. To assess the relation between ACR and cytoplasmatic fragmentation, embryos were divided into three groups, according to the fragmentation percentage (<5%; 5–15% and >15%). Of the total 139 embryos included, 65 arrested at 2–8 cells; 14 arrested at 9–16 cells; 18 compacted morula and 42 were non‐arrested blastocysts. The average number of embryonic fragmentation at different stages of the development, 2–8 cells, 9–16 cells, compacted morula and blastocyst, was 16.0 ± 1.5, 28.7 ± 4.4, 4.4 ± 2.4 and 1 ± 0.3 respectively. The embryos at the stage of arrested 9–16 cells and compacted morula had higher ACR than those at the blastocyst stage, excluding the stage of 2–8 cells (the genome is not yet active). The correlation detected between embryonic development and ACR was 0.92 (p < 0.01). It was observed that embryos possessing high fragmentation showed the higher ACR value (r = 0.98, p < 0.05). Comparing the results between fragmentation percentage and ACR, it was observed that the embryos with higher percentage of fragmentation corresponded to higher ACR (r = 0.97, p < 0.01). These results clearly demonstrated that bovine embryonic arrest at different stages of development is correlated with the apoptotic mechanisms. 相似文献
18.
E. Unur H. Ulger N. Ekinci M. Hac&#;aliogullar &#; T. Ertekin E. Kilic 《Anatomia, histologia, embryologia》2009,38(4):241-245
In this study, we aimed at the in vitro effects of anti-fibroblast growth factor-2 (anti-FGF-2 or anti-bFGF) on embryo culture in rats. In vitro effects of anti-bFGF on total embryonic development were investigated in 40 rat embryos (which were divided into four groups) (obtained from five pregnant females) at 9.5 days of gestation that were cultured in whole rat serum (WRS), and in WRS+ 2.5, 5, and 10 μg/ml anti-bFGF. After 48 h of culturing, the embryos from each group were harvested to be analysed morphologically according to a morphological scoring system and biochemically to obtain the embryo protein content. The morphological score, embryo protein content, somite number and crown-rump length of embryos indicated that embryos cultured in WRS+ anti-bFGF had significant embryonic retardation. Mean morphological scores for the embryos grown in WRS, in the presence of 2.5, 5 and 10 μg anti-FGF-2 were 61.4 ± 1.64, 46.3 ± 8.42, 27 ± 2.58 and13.6 ± 0.96 respectively. These results suggest that bFGF is very important for normal embryonic development and rat anti-bFGF neutralizes bFGF effect. 相似文献
19.
本试验旨在研究胚胎期大鼠性腺生长与分化的情况。选取12.5~15.5 dpc SD大鼠胚胎为研究对象,运用PCR技术进行大鼠胚胎性别鉴定,采用H-E技术对大鼠性腺分化形态进行观察。结果表明:12.5 d的鼠胚肾管已经开始形成,生殖嵴已经建立,此时仍无明显的性别分化形态;13.5 d的鼠胚开始出现性别分化的迹象,雄性的原始性索开始形成,雌性性腺分化比雄性稍晚,此期仍不易辨别出典型的卵巢特征结构;14.5 d的鼠胚性腺形态初步成型,此期性别明显分化,雄性的原始性索开始分化为实心原始生精小管,雌性胚胎中性腺分为两层,初步形成卵巢特征;15.5 d的鼠胚,雄性胚胎性腺中已经具有明显的曲精小管的雏形,雌性胚胎卵巢特征也开始明显。大鼠胚胎性腺从13.5 d胚龄时开始分化,15.5 d胚龄性腺特征明显。 相似文献