Chromatin Configurations in the Ferret Germinal Vesicle that Reflect Developmental Competence for In Vitro Maturation     

X Sun  Z Li  Y Yi  W Ding  J Chen  JF Engelhardt  GH Leno 《Reproduction in domestic animals》2009,44(2):320-325

In several mammalian species, the configuration of germinal vesicle (GV) chromatin correlates with the developmental competence of oocytes. Yet, no study has been published on the configuration of GV chromatin in ferret, nor is it known whether a specific configuration predicts meiotic competence in this species, in spite of the potential importance of ferret cloning to the study of human disease and to species conservation efforts. Here, we report on an analysis of the chromatin configuration in ferret GV oocytes and on how they correlate with meiotic development. Three distinct configurations were identified based on the degree of chromatin condensation: (1) fibrillar chromatin (FC), featuring strands of intertwined chromatin occupying most of the visible GV region; (2) intermediate condensed chromatin (ICC), characterized by dense, irregular chromatin masses throughout the GV; and (3) condensed chromatin (CC), which is highly compact and centered around the nucleolus. We also found that chromatin configuration was related to the extent of association with cumulus cells in cumulus–oocyte complexes; CC-configured oocytes were most often surrounded by a compact cumulus layer and also a compact corona but FC-configured oocytes were associated with neither. In addition, increasing chromatin condensation corresponded to an increase in oocyte diameter. Finally, following in vitro culture, significantly more CC-configured oocytes underwent maturation to meiotic metaphase II than did FC- or ICC-configured oocytes. We conclude that, in ferret, chromatin condensation is related to the sequential achievement of meiotic competencies during oocyte growth and differentiation, and thus can be used as a predictor of competence.  相似文献   

动物疫苗及其合理使用（一）   总被引：2，自引：0，他引：2  

罗满林  邵定勇  裴仉福  陈瑞爱 《中国兽药杂志》2009,43(6):55-58

疫苗接种是预防动物传染病发生的重要举措。依据免疫学理论,疫苗作为抗原,通过激发动物机体免疫系统,产生特异的体液免疫和细胞免疫,从而获得针对某种疾病的特异性免疫。疫苗一般分为细菌疫苗、病毒疫苗和类毒素疫苗等。用于防病治病的各种疫苗、菌苗又是特殊的生物药品,与普通化学药品具有完全不同的成分、功能和特性,疫苗中含有多种蛋白质（除细菌或病毒外,有的还含有保护剂、鸡胚尿囊液或细胞培养液）,它们均适合许多病原体的生长,有些制品还是活的微生物,一旦污染后果不堪设想。疫苗在保存、运输和使用时有其特别要求。如果方法不当,不但会使活性物质失活,起不到免疫防病作用;而且还可能适得其反,引发动物新的疾病,造成重大损失。  相似文献   

Greenhouse gas flux from cropland and restored wetlands in the Prairie Pothole Region     

Robert A. Gleason  Brian A. Tangen  Ned H. Euliss Jr. 《Soil biology & biochemistry》2009,41(12):2501-3389

It has been well documented that restored wetlands in the Prairie Pothole Region of North America do store carbon. However, the net benefit of carbon sequestration in wetlands in terms of a reduction in global warming forcing has often been questioned because of potentially greater emissions of greenhouse gases (GHGs) such as nitrous oxide (N₂O) and methane (CH₄). We compared gas emissions (N₂O, CH₄, carbon dioxide [CO₂]) and soil moisture and temperature from eight cropland and eight restored grassland wetlands in the Prairie Pothole Region from May to October, 2003, to better understand the atmospheric carbon mitigation potential of restored wetlands. Results show that carbon dioxide contributed the most (90%) to net-GHG flux, followed by CH₄ (9%) and N₂O (1%). Fluxes of N₂O, CH₄, CO₂, and their combined global warming potential (CO₂ equivalents) did not significantly differ between cropland and grassland wetlands. The seasonal pattern in flux was similar in cropland and grassland wetlands with peak emissions of N₂O and CH₄ occurring when soil water-filled pore space (WFPS) was 40-60% and >60%, respectively; negative CH₄ fluxes were observed when WFPS approached 40%. Negative CH₄ fluxes from grassland wetlands occurred earlier in the season and were more pronounced than those from cropland sites because WFPS declined more rapidly in grassland wetlands; this decline was likely due to higher infiltration and evapotranspiration rates associated with grasslands. Our results suggest that restoring cropland wetlands does not result in greater emissions of N₂O and CH₄, and therefore would not offset potential soil carbon sequestration. These findings, however, are limited to a small sample of seasonal wetlands with relatively short hydroperiods. A more comprehensive assessment of the GHG mitigation potential of restored wetlands should include a diversity of wetland types and land-use practices and consider the impact of variable climatic cycles that affect wetland hydrology.  相似文献   

The importance of trifluoromethyl pyridines in crop protection          下载免费PDF全文

Adam Burriss  Andrew JF Edmunds  Daniel Emery  Roger G Hall  Olivier Jacob  Jürgen Schaetzer 《Pest management science》2018,74(6):1228-1238

The pyridine ring, substituted by a trifluoromethyl substituent has been successfully incorporated into molecules with useful biological properties. During the period 1990 to September 2017, 14 crop protection products bearing a trifluoromethyl pyridine have been commercialized or proposed for an ISO common name, covering fungicides, herbicides, insecticides and nematicides. Chemical processes have been developed to provide trifluoromethyl pyridine intermediates, from non‐fluorinated pyridine starting materials, at scale and with affordable costs of goods. These attractive starting materials were readily adopted by research chemists, and elaborated through simple chemical modifications into new active ingredients. In a second approach, substituted trifluoromethyl pyridine rings have been constructed from acyclic, trifluoromethyl starting materials, which again has served to identify new active ingredients. Molecular matched pair analysis reveals subtle, yet important differences in physicochemical and agronomic properties of trifluoromethyl pyridines compared with the phenyl analogues. This review focuses on the past 27 years, seeking to identify reasons behind the success of such research programmes, and inspire the search for new crop protection chemicals containing the trifluoromethyl pyridine ring. © 2017 Society of Chemical Industry  相似文献   

Abortion in goats by Caprine alphaherpesvirus 1 in Spain          下载免费PDF全文

J Gonzalez  G Passantino  A Esnal  N Cuesta  JA García Vera  L Mechelli  A Saez  JF García Marín  M Tempesta 《Reproduction in domestic animals》2017,52(6):1093-1096

An abortion outbreak occurred in a goat herd of Murciano‐Granadina breed in Almeria Region in Spain where 80 pregnant females aborted. All bacteriological and parasitological examinations resulted negative, whereas virological investigations and real‐time PCR assay showed the presence of Caprine alphaherpesvirus 1 DNA in the pathological specimens from aborted foetuses. Nucleotide sequence analysis revealed that the DNA was highly close related to the Swiss strain E‐CH (99.7%) and a little less extent to the Italian BA.1 strain (99.4%). Histopathological examination revealed multifocal, well‐circumscribed, 50‐ to 200‐μm‐diameter foci of coagulative necrosis in the liver, lungs and kidneys of three foetuses. In the periphery of the necrosis, there were frequently epithelial cells with the chromatin emarginated by large, round, amphophilic intranuclear viral inclusion bodies. The source of the infection in the herd could not clearly find out even some hypothesis were formulated. This seems to be the first report of an abortion outbreak due to Caprine alphaherpesvirus 1 in a goat herd in Spain.  相似文献   

Effects of GnRH,a progesterone‐releasing device,and energy balance on an oestrus synchronisation program in anoestrous dairy cows          下载免费PDF全文

SK Sahu  JF Cockrem  TJ Parkinson  RA Laven 《Australian veterinary journal》2017,95(8):281-288

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Follicular Dynamics,Interval to Ovulation and Fertility After AI in Short‐Term Progesterone and PGF2α Oestrous Synchronization Protocol in Sheep     

JF Cox  R Allende  E Lara  A Leiva  T Díaz  J Dorado  F Saravia 《Reproduction in domestic animals》2012,47(6):946-951

The study was aimed to assess the influence that short‐term progesterone treatments have on follicular dynamics, oestrus and ovulation in sheep. The treatment was tested thereafter in a field trial to assess its fertility after AI with fresh semen. In a first experiment, 12 ewes without CL were grouped to receive a new (n = 6) or used CIDR (n = 6) for 7 days and blood samples were obtained to follow plasma progesterone profiles. In a second experiment, 39 cycling ewes were synchronized by a 7‐day P4+PGF2α protocol using a new (n = 20) or a 7‐day used CIDR (n = 19). Half of both groups received 400 IU eCG and half remained untreated as controls. Ultrasound ovarian examination and oestrous detection were used to compare follicular dynamics, oestrus and ovulation in both groups. In a third experiment, 288 ewes in 3 farms were synchronized by the short‐term P4+PGF2α+eCG protocol and ewes were AI with fresh semen 24 h after oestrous detection. Lambing performance was used to test the fertility of the treatment. In Experiment 1, ewes with new inserts presented higher P4 concentration than ewes with used inserts throughout the sampling period (p < 0.05) and exhibited a P4 peak at days 1‐2 of the treatment that was not observed in ewes with used inserts. In Experiment 2, ewes treated with new and used inserts show similar ovarian and behavioral traits (p > 0.10). However, ewes treated with eCG show shorter interval to oestrus (p = 0.004) and tend to have larger mature CL (p = 0.06). In Experiment 3, oestrous presentation and lambing performance after AI with fresh semen was considered normal compared to published results. Results suggest that the oestrous synchronization protocol based on P4+PGF2α allows little control of follicular dynamics without compromising fertility after AI with fresh semen provided that eCG is added at the end of the treatment.  相似文献   

Administration of hCG 5 days after Breeding and Reproductive Performance in Nulliparous Dairy Goats     

JF Fonseca  CAA Torres 《Reproduction in domestic animals》2005,40(6):495-499

The objective of this study was to investigate the effect of hCG administration 5 days after breeding on plasma progesterone (P4) concentration and reproductive performance of oestrous-induced nulliparous dairy goats. A total of 59 nulliparous goats (36 Alpine and 23 Saanen) received intravaginal sponges with 60 mg medroxyprogesterone acetate for 9 days plus 200 IU equine chorionic gonadotrophin (eCG) and 22.5 microg d-cloprostenol 24 h before sponge removal. After detection of oestrus (day of oestrus = day 0) and breeding, 49 females were randomly assigned, according to the breed, into two treatments (T1 and T2). In T1 (n = 25) and T2 (n = 24), animals received intramuscular injection of 1 ml of saline solution (control) or 250 IU hCG, respectively, 5 days after breeding. Plasma P4 concentration (ng/ml) was determined from blood sampled on days 0, 5, 7, 13, 17, 21, 28 and 45 after breeding. Animals were scanned by transrectal ultrasound (5 MHz probe) on days 35 and 70 after breeding for detection of pregnancy. Plasma P4 concentration did not differ (p > 0.05) between treatments in all days, but it was increased (p < 0.05) in Saanen than in Alpine goats from days 13 to 45. Pregnancy and parturition rates, litter size and gestation period were similar (p > 0.05) to treatments and breeds. Results of this study indicate that human chorionic gonadotrophin (hCG) administration 5 days after breeding did not significantly alter reproductive performance in dairy nulliparous goats and that plasma P4 differed between Saanen and Alpine goats.  相似文献   

Ivermectin toxicosis in a neonatal foal   总被引：1，自引：0，他引：1  

LM GODBER †  FJ DERKSEN  JF WILLIAMS†  B. MAHMOUD§ 《Australian veterinary journal》1995,72(5):191-192

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Colour‐Doppler ultrasound imaging as a laparoscopy substitute to count corpora lutea in superovulated sheep          下载免费PDF全文

PHN Pinto  GM Bragança  MFA Balaro  EKN Arashiro  GB dos Santos  GN de Souza  JMG Souza‐Fabjan  JF Da Fonseca  FZ Brandão 《Reproduction in domestic animals》2018,53(1):266-269

This study evaluated colour‐Doppler ultrasound imaging (UI) as a substitute for laparoscopy to count the corpora lutea (CL) in superovulated sheep. Twenty‐five Santa Ines ewes were superovulated three times at 21‐day intervals. Corpora lutea were counted by colour‐Doppler UI (CL_DOPPLER) 6 days after each superovulation and confirmed by laparoscopy (CL_LAP) 12 hr later. The mean number of CL was similar for both techniques (2.1 ± 2.5 vs. 2.1 ± 2.7 for CL_DOPPLER and CL_LAP, respectively) with a significant positive correlation (r = .94; r²=.89). Colour‐Doppler UI effectively evaluated the ovarian response in superovulated ewes and efficiently identified animals that did not respond to superovulation.  相似文献