Design of vectors for transgene expression: The use of genomic comparative approaches     

Montoliu L  Roy R  Regales L  García-Díaz A 《Comparative immunology, microbiology and infectious diseases》2009,32(2):81-90

The design of transgenes has always been limited by the extent of available information on the endogenous locus whose expression pattern had to be replicated. Those genes whose expression domain had not been entirely documented resulted, usually, in transgenes with an unpredictable expression patterns and suboptimal performance in transgenic animals. The use of genomic comparative approaches, highlighting evolutionary conserved homologous DNA sequences, helps to identify crucial regulatory elements that are associated to a given expression domain. The inclusion of these conserved regulatory sequences in transgenic constructs would normally result in optimal expression levels of transgenes in recipient animals. The use of artificial chromosome-type transgenes usually ensures the inclusion of these preserved regulatory elements that are required for the faithful expression of the gene. These constructs could also contain insulators, a subset of regulatory sequences whose application is being addressed in transgenesis. Therefore, the generation of transgenic animals with genomic-type constructs is the recommended approach to achieve optimal transgene expression, according to the expected pattern of the corresponding endogenous locus.  相似文献   

Plasma progesterone, oestradiol-17β and total oestrogen profiles in relation to oestrous behaviour during induced ovulation in Murrah buffalo heifers     

Roy KS  Prakash BS 《Journal of animal physiology and animal nutrition》2009,93(4):486-495

The objectives of this study were to establish the characteristics of oestrous behaviour in Ovsynch (induction of ovulation through administration of GnRH-PGF2-GnRH in a systemic manner on 0, seventh and ninth day respectively) and Ovsynch plus Norprolac (Quinagolide hydrochloride – an inhibitor of prolactin secretion) treated Murrah buffalo heifers and to determine the relationships between this behaviour and the plasma concentrations of oestradiol-17β (E2), total oestrogen, and progesterone. Oestrus was detected by visual observations of oestrus signs, per rectal examination of genitalia and bull parading thrice a day during treatment period. Among all the symptoms, it was observed that bull mounting of heifers in oestrus was highest. Examination of genital tracts per rectum revealed that the cervix was relaxed, uterus was turgid and ovaries had palpable follicle in animals with oestrus. The peak concentrations of E2 (10.81 ± 0.62 pg/ml) and total oestrogen (17.11 ± 1.21 pg/ml) occurred at 9.45 ± 0.85 and 9.64 ± 0.93 h after second GnRH administration, respectively, in Ovsynch treated animals. However, the peak levels of E2 (20.02 ± 2.87 pg/ml) and total oestrogen (32.71 ± 3.15 pg/ml) occurred at 10.18 ± 0.50 and 10.36 ± 0.75 h after second GnRH administration, respectively, in Ovsynch plus Norprolac treated animals. Plasma progesterone concentration was basal (0.20 ± 0.001 ng/ml) during the peri-oestrus period. The plasma progesterone concentration was the lowest on the day of oestrus and increased to register a peak on day 13 ± 2 of the cycle. Oestrous behaviour was positively correlated with the peak concentration of E2 (p < 0.001) and total oestrogen (p < 0.001) during the peri-oestrus period. Inhibition of prolactin by Norprolac administration significantly increased the concentration of E2 and total oestrogen during oestrus in buffaloes in comparison to those recorded in animals subjected to Ovsynch protocol alone. In conclusion, our results suggest that the peak concentrations of E2 and total oestrogen and mean level of E2 and total oestrogen during the peri-oestrus period are the important factors contributing the behavioural manifestation of oestrus in buffalo cows.  相似文献   

Adenosquamous Carcinoma of the Trachea in a Domestic Ferret (Mustela putorius furo)     

Olivia A. Petritz  Natalie Antinoff  Catherine Pfent  Wayne Corapi  Roy R. Pool  Michelle Fabiani  Sue Chen 《Journal of Exotic Pet Medicine》2013,22(3):287-292

A 4-year-old, castrated, male domestic ferret (Mustela putorius furo) was evaluated for a possible upper respiratory tract infection and wheezing for approximately 3 weeks. Supportive care for a suspected upper respiratory tract infection was initiated; however, the patient became progressively more dyspneic over the next 48 hours. A possible tracheal mass was identified upon thoracic radiographic imaging of the ferret. Tracheoscopy and a computed tomography scan of the neck and thorax confirmed the presence of a tracheal mass approximately 3 cm from the larynx obstructing 80% of the tracheal lumen. Rather than pursuing surgical resection, the owners elected humane euthanasia. An adenosquamous carcinoma of the trachea was diagnosed after histologic analysis. This tumor type has been diagnosed in the lungs of ferrets that were experimentally exposed to carcinogens found in cigarette smoke; however, there are no previous reports of this or any other tumor type associated with the ferret trachea. A tracheal mass causing a partial upper airway obstruction should be considered within the differential disease diagnosis list when a ferret is presented with dyspnea.  相似文献   

l‐Arabinose Release from Arabinoxylan and Arabinogalactan Under Potential Gastric Acidities     

Pingyi Zhang  Qian Zhang  Roy L. Whistler 《Cereal Chemistry》2003,80(3):252-254

Arabinofuranosyl groups are present in many hemicelluloses as single or multiple units attached to the main xylan or galactan chain where they are sensitive to acid hydrolysis. Under acidic conditions of the human stomach, up to 10% of the L‐arabinose is released from the hemicellulose of corn hull, larch wood, and banana peel hemicellulose.  相似文献   

Habitat partitioning among three predatory fish in a temperate reservoir     

Samuel Westrelin  Julien Cucherousset  Romain Roy  Laurence Tissot  Frdric Santoul  Christine Argillier 《Ecology of Freshwater Fish》2022,31(1):129-142

The diversity of predatory species plays a key role in ecosystem functioning but our understanding of the mechanisms underlying their coexistence is limited, particularly in freshwater ecosystems. Northern pike Esox lucius, European perch Perca fluviatilis and pikeperch Sander lucioperca are three widespread predatory species in European lakes, where they often coexist. As potential competitors, we hypothesised that partitioning habitat is a determinant of species coexistence. This was tested by quantifying the variability of their habitat use in tracking adult individuals in the Bariousses reservoir (France, 86.6 ha, mean depth 7.1 m). Specifically, we investigated their distribution along the littoral–pelagic and depth axes along the daily cycle and across seasons. From littoral to pelagic waters were first found pike, then perch and finally pikeperch. Pike was the closest to the surface while pikeperch was the deepest. This general pattern was, however, variable across seasons with the three species located in the upper layer in summer during reservoir stratification. Individuals were more evenly distributed along the littoral–pelagic axis and closer to the bottom when water was mixing (autumn, winter). In summer, perch used more intensively in the pelagic zone during the daytime. Other species did not show any diel change of habitats. Our results highlighted that species coexistence is associated with habitat partitioning among these three predators, with perch showing a more variable behaviour regarding habitat characteristics. Now more than ever, in the context of global change which modifies habitats, it is of crucial importance to understand the coexistence mechanisms of species that shape ecosystems.  相似文献