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1.
山西五台山地区褐马鸡的再引入   总被引:12,自引:0,他引:12  
Brown eared-pheasant Crossoptilon mantchuricum is endemic to China, and mainly occurs in Luliang Mountains of Shanxi, Xiaowntai of Hebei and Huanglong of Shaanxi. Reintroduction of Brown eared pheasant was carried out from April to December in 2000. According to the criterions of release site selection in Guidelines for Reintroductions of IUCN, and habitat selection of Brown eared pheasant, Kuantan forestry in Wutaishan Mountains of Shanxi Province was selected as the release site. Of the 8 released individuals, 5 wild individuals were captured in winter in Luyashan Nature Reserve of Shanxi Province, and 3 were offsprings of captive-reared individuals. Transmitters were attached when the 8 individuals were released. Overall, 6 individuals survived for at least 1 month, and the longest time for survival was 155 days, except that one was confirmed as having been killed by a raptor on the second day and one was lost on the eighth day after release. All moved away from the release site after release and established stable home ranges in different sites after 10 days, respectively. In early May, the individuals again dispersed to establish new home ranges. The wandering distance and days of the captive individuals were longer and the home range size were larger than that of the wild birds,which resulted from the weak adaptability to new habitat for the captive individuals, such as recognizing and fetching food. For wild individuals, the second wandering distance was longer than the first. We believe the difference was related to looking for partners. After wandering, individuals established stable home ranges in different sites [Acta Zoologica Sinica 50 (1): 126-132, 2004].  相似文献   

2.
The ultrastructure of the mature egg and fertilization in the fern Ceratopteris thafictroides (L.) Brongn. were observed by transmission electron microscopy. The results revealed that the mature egg possesses an obvious egg membrane at the periphery of the egg. Furthermore, a fertilization pore was identified in the upper egg membrane of the mature egg. The structure of the pore is described for the first time. The fertilization experiment indicated that spermatozoids crowd into the cavity above the egg through the neck canal of the archegonium; however, only one of these can penetrate into the egg through the fertilization pore. Immediately on penetration of the spermatozoid, the egg begins to shrink. The volume of the fertilized egg decreases to almost one-half that of the unfertilized egg. As a result, the protoplasm of the fertilized egg becomes dense and opaque, which may lead to a situation where the organelles of both the egg and the fertilizing spermatozoid become indistinguishable. Simultaneously, abundant vesicles containing concentric membranes or opaque materials appear near the fertilization pore in the cytoplasm of the fertilized egg. These vesicles are considered to act as a barrier that prevents polyspermy. The present study provides a new insight into the ultrastructure of the mature egg and the cytological mechanism of fertilization in ferns.  相似文献   

3.
Li H Q  Lian Z M  Chen C G  Wu S B 《农业工程》2009,29(5):302-306
A study on the seasonal changes in the ranging area of Brown-eared pheasant and its affecting factors was conducted in the Huanglongshan Nature Reserve, Huanglong County, Shaanxi Province, China, from March 2006 to January 2007. Forty used sites and forty random plots were selected along 8–9 transects crossing the study area. Fifteen factors related to the changes of altitude were measured in each site. The results showed that the altitude of home range of Brown-eared pheasant varied with seasons: the highest home range was found in summer, and the lowest one was found in winter, while the home range in autumn was higher than that in spring. According to the frequency of occurrences of Brown-eared pheasant in different seasons, we found that its home range occurred mainly at an altitude below 1400 m in spring, above 1500 m in summer, between 1200 m and 1500 m in autumn and below 1300 m in winter. The possible reason that Brown-eared pheasants preferred to live at lower altitude in spring was to have access to water sources and the abundance of food, correlated to the slope locations, number of trees and number of shrubs; in summer, they tended to appear at highest altitude, and the average height of shrubs, average height of grasses, sheltering class and distance to edge of woods, and human disturbance were affecting factors; in autumn, they appeared at higher altitude which was correlated with the covers of trees, shrubs and grasses, and ultimately related to the abundance of food; in winter, they lived at lowest altitude, which was correlated to the distance from the edge of woods, cover of trees and sheltering class, and ultimately related to the abundance of food and shelter.  相似文献   

4.
A study on the seasonal changes in the ranging area of Brown-eared pheasant and its affecting factors was conducted in the Huanglongshan Nature Reserve, Huanglong County, Shaanxi Province, China, from March 2006 to January 2007. Forty used sites and forty random plots were selected along 8–9 transects crossing the study area. Fifteen factors related to the changes of altitude were measured in each site. The results showed that the altitude of home range of Brown-eared pheasant varied with seasons: the highest home range was found in summer, and the lowest one was found in winter, while the home range in autumn was higher than that in spring. According to the frequency of occurrences of Brown-eared pheasant in different seasons, we found that its home range occurred mainly at an altitude below 1400 m in spring, above 1500 m in summer, between 1200 m and 1500 m in autumn and below 1300 m in winter. The possible reason that Brown-eared pheasants preferred to live at lower altitude in spring was to have access to water sources and the abundance of food, correlated to the slope locations, number of trees and number of shrubs; in summer, they tended to appear at highest altitude, and the average height of shrubs, average height of grasses, sheltering class and distance to edge of woods, and human disturbance were affecting factors; in autumn, they appeared at higher altitude which was correlated with the covers of trees, shrubs and grasses, and ultimately related to the abundance of food; in winter, they lived at lowest altitude, which was correlated to the distance from the edge of woods, cover of trees and sheltering class, and ultimately related to the abundance of food and shelter.  相似文献   

5.
In order to understand the composition and quantitative variation of ecdysteriods in the adults and eggs of Opogona sacchari (Bojer), an invasive alien pest, we analyzed the ecdysteroid composition and titers in the adult and egg of this pest. On day 4 after eclosion, the titer of ecdysteriods in the male adult was 0.080 ng/adult, much lower than 5.978 ng/adult in the female adult. During the development of ovaries, the titer of ecdysteriods was low on the first two days, and high in the late period, with the peak (10.48 ng/ovary) appearing on day 3. During the development of eggs, the titer of ecdysteriods was about 0.010 ng/egg from day 1 to day 3, and then decreased to 0.006 ng/egg on day 4. In both adults and eggs, three main components of ecdysteriods were found by identification of HPLC/RIA. They were 20-hydroxyecdysone, 26-hydroxyecdysone, and an unidentified component.  相似文献   

6.
Qi H  Pei D 《Cell research》2007,17(7):578-580
The developmental process from a fertilized egg to agrown adult is programmed with remarkable accuracy.While the genetic information of the fertilized egg and itsdescendent somatic cells are the same, it is the selectiveexpressions of the same genome that give rise to the 200or so different cell types in an adult. The differentiatedstates of these adult cells are maintained epigenetically,presumably through the modification of chromatins and theassociated histones. In higher mammals, it was thought thatthe differentiation process is irreversible until the successfulcloning of Dolly [1]. By transferring a nucleus from a fullydifferentiated cell in the mammary gland, Wilmut and col-leagues were able to generate an exact replica of a highermammal, the Doily [1]. This work not only demonstratedthat the genome of differentiated cells can be reprogrammedinto an embryonic state and then to resume a full-fledgeddevelopmental process to generate a normal adult, but alsorejuvenated the field of animal cloning. The prospect thata somatic cell from a patient may be reprogrammed to the  相似文献   

7.
Laboratory bioassays were conducted to determine the effect of food source on the survival of Tribolium castaneum Herbst, Oryzaephilus surinamensis L. and Rhyzopertha dominica F., after exposure to five diatomaceous earth (DE) formulations: Protect-It, Insecto, Perma-GuardTM, Dryacide and SilicoSec. Adults of these species were exposed to DEs at the rate of 0.5 mg/cm^2 for 1 day on filter paper inside plastic Petri dishes. After exposure, the initial mortality was counted and live individuals of the three species were held for a week in glass vials containing 50 mg wheat flour, rice and whole wheat, respectively. In the second experiment, after 1 day exposure to DEs, beetles were transferred to Petri dishes without food and held for a week to determine if the presence of food source would decrease the mortality of beetles. Experiments were carried out at 27℃ and 55% RH in the dark. The initial mortality in both of the experiments reached 100% for the three species exposed to Protect-It and in the case ofR. dominica and O. surinamensis exposed to Dryacide. In contrast, low level of mortality (〈 10%) was observed for T. castaneum exposed to Perma-GuardTM and Insecto. The mortality after the post-treatment period on food was decreased for the three species exposed to Perma-GuardTM and in the case of T. castaneum and R. dominica exposed to Insecto and SilicoSec. Adults of O. surinamensis were the most susceptible followed by R. dominica and 100% adult mortality was obtained, whereas T. castaneum were the least susceptible beetles to DEs. Protect-It and Dryacide were the most efficient DE formulations and can be used effectively in a stored grain integrated pest management program.  相似文献   

8.
Ultrastructure of Oogenesis in Dryopteris crassirhizoma Nakai   总被引:1,自引:0,他引:1  
The ultrastructure ofoogenesis in Dryopteris crassirhizoma Nakai has been investigated using transmission electron microscopy. The nucleus in the young egg is rounded with an uneven outline. As it develops, it becomes amoeboid and extends nuclear protrusions that are not only sac-like nuclear evaginations like those often seen in the oogenesis of other ferns, but also mushroom-like and finger-like, with an opening at their end allowing the nucleolus material to flow out from the openings. This has not been observed previously. The nuclear protrusions differ from Dryopterisfilix-mas (L.) Schott. in the absence of sheets of nuclear membrane in the form of a closed ring. As the egg matures, the nucleus transforms into a tuber-like structure with a smooth surface, lying transversely in the egg cell. In the immature egg, vesicles almost encircle the nucleus twice and are most remarkable. In the maturing egg, the vesicles are distributed at the periphery, except for at the top of the egg, and affect the formation of the separation cavity and extra egg membrane. Simultaneously, vesicles from the venter canal cell move to the egg and take part in the formation of separation cavity and extra egg membrane. In the mature egg, a large number of small vesicles containing fragments of lamellae or osmiophilic material emerge from the cytoplasm. The origin of these vesicles is obscure. Irregular plastids containing a cylindrical starch grain dedifferentiated progressively.Mitochondria seem to have been undeveloped during the process, but return to normal at later stages of oogenesis. There is a high frequency of ribosomes in the mature egg. Microtubules, rarely seen in the eggs of D.filix-mas (L.) Schott. and Pteridium aquilinum (L.) Kuhn, have been observed inside the plasmalemma of the maturing egg in D. crassirhizoma.  相似文献   

9.
 Exposure to high altitude causes loss of body mass and alterations in metabolic processes, especially carbohydrate and protein metabolism. The present study was conducted to elucidate the role of glutamine synthetase, glutaminase and glycogen synthetase under conditions of chronic intermittent hypoxia. Four groups, each consisting of 12 male albino rats (Wistar strain), were exposed to a simulated altitude of 7620 m in a hypobaric chamber for 6 h per day for 1, 7, 14 and 21 days, respectively. Blood haemoglobin, blood glucose, protein levels in the liver, muscle and plasma, glycogen content, and glutaminase, glutamine synthetase and glycogen synthetase activities in liver and muscle were determined in all groups of exposed and in a group of unexposed animals. Food intake and changes in body mass were also monitored. There was a significant reduction in body mass (28–30%) in hypoxia-exposed groups as compared to controls, with a corresponding decrease in food intake. There was rise in blood haemoglobin and plasma protein in response to acclimatisation. Over a three-fold increase in liver glycogen content was observed following 1 day of hypoxic exposure (4.76±0.78 mg·g−1 wet tissue in normal unexposed rats; 15.82±2.30 mg·g−1 wet tissue in rats exposed to hypoxia for 1 day). This returned to normal in later stages of exposure. However, there was no change in glycogen synthetase activity except for a decrease in the 21-days hypoxia-exposed group. There was a slight increase in muscle glycogen content in the 1-day exposed group which declined significantly by 56.5, 50.6 and 42% following 7, 14, and 21 days of exposure, respectively. Muscle glycogen synthetase activity was also decreased following 21 days of exposure. There was an increase in glutaminase activity in the liver and muscle in the 7-, 14- and 21-day exposed groups. Glutamine synthetase activity was higher in the liver in 7- and 14-day exposed groups; this returned to normal following 21 days of exposure. Glutamine synthetase activity in muscle was significantly higher in the 14-day exposed group (4.32 μmol γ-glutamyl hydroxamate formed·g protein−1·min−1) in comparison to normal (1.53 μmol γ-glutamyl hydroxamate formed·g protein−1·min−1); this parameter had decreased by 40% following 21 days of exposure. These results suggest that since no dramatic changes in the levels of protein were observed in the muscle and liver, there is an alteration in glutaminase and glutamine synthetase activity in order to maintain nitrogen metabolism in the initial phase of hypoxic exposure. Received: 30 March 1998 / Revised: 18 November 1998 / Accepted: 25 November 1998  相似文献   

10.
We demonstrated the simple and effective production of transgenic chickens, in which the enhanced green fluorescence protein (EGFP) was expressed by using third-generation self-inactive HIV-based lentiviral vectors. In our experiments, lentiviruses were injected into 204 fertilized eggs, from which 30 (15%) chickens were hatched. The exogenous gene was detected in the genomes of 16 out of 30 (53%) chickens. The green fluorescence signal was observed directly in various body parts, and was particularly significant in the testes. The transgenes were also found in the offspring of these chickens. The results indicate that HIV-based lentiviral vectors can be used to generate transgenic birds economically and effectively [ Current Zoology 55 (5): 383 - 387,2009].  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

16.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

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Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.  相似文献   

19.
正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases  相似文献   

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