共查询到20条相似文献,搜索用时 31 毫秒
1.
M. Daniela Candia Carnevali Francesco Bonasoro Roberto Invernizzi Elisa Lucca Ulrich Welsch Michael C. Thorndyke 《Cell and tissue research》1996,285(2):341-352
Crinoid echinoderms can completely and rapidly regenerate arms lost following self-induced or traumatic amputation. Arm regeneration
in these animals therefore provides a valuable experimental model for studying all aspects of regenerative processes, particularly
with respect to the nervous system and its specific contribution to regenerative phenomena. Taking into account the primary
role of the nervous system in regeneration in other invertebrates, we have investigated the specific involvement of neural
factors, viz. the monoamine neurotransmitters dopamine and serotonin, in arm regeneration of Antedon mediterranea. In the present work, the presence of classical monoamines has been revealed by employing specific immunocytochemical and
histofluorescence tests in association with biochemical detection by means of high pressure liquid chromatography. The distribution
pattern of these neurohumoral molecules at standard regenerative stages has been compared with that of normal non-regenerating
arms. Results indicate that both dopamine and serotonin dramatically change in both their distribution and concentration during
the repair and regenerative processes. Their remarkably enhanced pattern during regeneration and widespread presence at the
level of both nervous and non-nervous tissues indicates that they are important neural growth-promoting factors in crinoid
arm regeneration.
Received: 18 December 1995 / Accepted: 23 February 1996 相似文献
2.
Patruno M Smertenko A Candia Carnevali MD Bonasoro F Beesley PW Thorndyke MC 《Proceedings. Biological sciences / The Royal Society》2002,269(1502):1741-1747
The phylum Echinodermata is well known for its extensive regenerative capabilities. Although there are substantial data now available that describe the histological and cellular bases of this phenomenon, little is known about the regulatory molecules involved. Here, we use an immunochemical approach to explore the potential role played by putative members of the transforming growth factor-beta (TGF-beta) family of secreted proteins in the arm regeneration process of the crinoid Antedon mediterranea. We show that a TGF-beta-like molecule is present in normal and regenerating arms both in a propeptide form and in a mature form. During regeneration, the expression of the mature form is increased and appears to be accompanied by the appearance of an additional isoform. Immunocytochemistry indicates that TGF-beta-like molecules are normally present in the nervous tissue and are specifically localized in both neural elements and non-neural migratory cells, mainly at the level of the brachial nerve. This pattern increases during regeneration, when the blastemal cells show a particularly striking expression of this molecule. Our data indicate that a TGF-beta-like molecule (or molecules) is normally present in the adult nervous tissues of A. mediterranea and is upregulated significantly during regeneration. We suggest that it can play an important part in the regenerative process. 相似文献
3.
Factors influencing the regeneration capacity of oilseed rape and cauliflower in transformation experiments 总被引:2,自引:0,他引:2
The efficiency ofAgrobacterium-based transformation technique in oilseed rape and cauliflower was influenced by cultivar specificity, donor plant age and explant type. Marked differences in demands for plant hormone contents in the regeneration medium were recorded already among different types of nontransformed explants. The highest regeneration capacity was recorded with stem and leaf segments isolated from one-month-old aseptically grown plants. The regeneration was markedly species-dependent. Regeneration of transformed plants from stem segments and thin layers isolated from field-grown oilseed rape plants (at the most 2% of regenerating explants) and from oilseed rape hypocotyls (0.8% of regenerating explants) and cauliflower (1.2% of explant regenerated transformed shoots) was achieved after disarmedAgrobacterium treatment. Hypersensitive reaction of explants could be prevented by using prolongedin vitro precultivation and delayed application of the selective agent. 相似文献
4.
Cytokinins, donor plants and their time in vitro as well as basal media were investigated for their influence on shoot regenerative capacity of American elm (Ulmus americana L.) leaves. Leaves excised from six 2-year-old seedlings formed adventitious shoots when placed on Driver and Kuniyuki Walnut (DKW) medium supplemented with 7.5, 15 or 22.5 M of benzyladenine (BA) or thidiazuron (TDZ). Thidiazuron induced significantly higher regeneration percentages on elm leaves than BA, regardless of concentration used. Donor plant also affected the efficiency of shoot regeneration, with certain seedlings having 1.5 to 7 times more explants forming shoots as compared to other seedlings tested. By subculture 15, the average number of shoots per regenerating explant increased at least 3-fold for leaves on media with BA or TDZ for the one donor plant that survived continued subculturing. Leaf explants from donor plants with the highest regenerative capacity had a higher percentage of shoot formation on DKW than MS medium. Explants from productive donor plants should be placed on DKW medium supplemented with TDZ to improve shoot regeneration efficiency from American elm leaves. 相似文献
5.
Cristiano Di Benedetto Lorenzo Parma Alice Barbaglio Michela Sugni Francesco Bonasoro Maria Daniela Candia Carnevali 《Cell and tissue research》2014,358(1):189-201
Among echinoderms, crinoids are well known for their remarkable regenerative potential. Regeneration depends mainly on progenitor cells (undifferentiated or differentiated), which migrate and proliferate in the lesion site. The crucial role of the “progenitor” elements involved in the regenerative processes, in terms of cell recruitment, sources, and fate, is a central problem in view of its topical interest and biological implications. The spectacular regenerative potential of crinoids is used to replace lost internal and external organs. In particular, the process of arm regeneration in the feather star Antedon mediterranea is the regeneration model most extensively explored to date. We have addressed the morphological and functional characterization of the cell phenotypes responsible for the arm regenerative processes by using an in vitro approach. This represents the first successful attempt to culture cells involved in crinoid regeneration. A comparison of these results with others from previous in vivo investigations confirms the diverse cell types contributing to regeneration and underscores their involvement in migration, proliferation, and dedifferentiation processes. 相似文献
6.
Sugni M Manno V Barbaglio A Mozzi D Bonasoro F Tremolada P Candia Carnevali MD 《Cell biology and toxicology》2008,24(6):573-586
Echinoderms are valuable test species in marine ecotoxicology and offer a wide range of biological processes appropriate for
this approach. Regenerating echinoderms can be regarded as amenable experimental models for testing the effects of exposure
to contaminants, particularly endocrine disrupter compounds (EDCs). As regeneration is a typical developmental process, physiologically
regulated by humoral mechanisms, it is highly susceptible to the action of pseudo-hormonal contaminants which appear to be
obvious candidates for exerting deleterious actions. In our laboratory experiments, selected EDCs suspected for their antiandrogenic
action (p,p′-DDE and cyproterone acetate) were tested at low concentrations on regenerating specimens of the crinoid Antedon mediterranea. An integrated approach which combines exposure experiments and different morphological analyses was employed; the obtained
results suggest an overall pattern of plausible endocrine disruption in the exposed samples, showing that processes such as
regenerative growth, histogenesis, and differentiation are affected by the exposure to the selected compounds. These results
confirm that (1) regenerative phenomena of echinoderms can be considered valuable alternative models to assess the effects
of exposure to exogenous substances such as EDCs, and (2) these compounds significantly interfere with fundamental processes
of developmental physiology (proliferation, differentiation, etc…) plausibly via endocrine alterations. In terms of future
prospects, taking into account the increasing need to propose animal models different from vertebrates, echinoderms represent
a group on which ecotoxicological studies should be encouraged and specifically addressed. 相似文献
7.
Anna Chiara Maria Biressi Ting Zou Samuel Dupont Carl Dahlberg Cristiano Di Benedetto Francesco Bonasoro Michael Thorndyke Maria Daniela Candia Carnevali 《Zoomorphology》2010,129(1):1-19
All species of the Ophiuroidea have exceptional regenerative capabilities; in particular, they can replace arms lost following
traumatic or self-induced amputation. In order to reconstruct this complex phenomenon, we studied arm regeneration in two
different ophiuroids, Ophioderma longicaudum (Retzius, 1805) and Amphiura filiformis O. F. Müller, 1776, which are quite distantly related. These species present contrasting regeneration and differentiation
rates and differ in several ecological traits. The aim of this paper is to interpret the primary sequence of morphogenetic
and histogenetic events leading to the complete reconstruction of a new arm, comparing the arm regenerative processes of these
two ophiuroid species with those described in crinoids. Arm regeneration in ophiuroids is considered an epimorphic process
in which new structures develop from a typical blastema formed from an accumulation of presumptive undifferentiated cells.
Our results showed that although very different in some respects such as, for instance, the regeneration rate (0.17 mm/week
for O. longicaudum and 0.99 mm/week for A. filiformis), morphogenetic and histogenetic aspects are surprisingly similar in both species. The regenerative process presents similar
characteristics and follows a developmental scheme which can be subdivided into four phases: a repair phase, an early regenerative
phase, an intermediate regenerative phase and an advanced regenerative phase. In terms of histogenesis, the regenerative events
involve the development of new structures from migratory pluripotent cells, which proliferate actively, in addition in both
cases there is a significant contribution from dedifferentiated cells, in particular dedifferentiating myocytes, although
to varying extents. This evidence confirms the plasticity of the regenerative phenomenon in echinoderms, which can apparently
follow different pathways in terms of growth and morphogenesis, but nevertheless involve both epimorphic and morphallactic
contributions at the cellular level. 相似文献
8.
Beatrice A. Were Samuel Gudu Augustino O. Onkware Anders S. Carlsson Margareta Welander 《Plant Cell, Tissue and Organ Culture》2006,85(2):235-239
The goal of this study was to develop an efficient regeneration protocol to be used for genetic transformation of sesame. Published regeneration methods using benzyladenine (BA) and 1-naphthalene acetic acid (NAA) were unsuccessful for the cultivars used herein. Experiments were carried out using cotyledon and hypocotyl explants from the cultivar Mtwara-2. Later the optimised culture conditions were used to investigate the regeneration response of different genotypes. There was significant interaction between hormone treatments and macronutrients for shoot and root regeneration. Results also showed that shoot regeneration was significantly influenced by explant type. Shoots were only obtained from cotyledons whereas both cotyledons and hypocotyls could produce roots. Modified Murashige and Skoog (MS) medium with N6 macronutrients resulted in twice the shoot regeneration frequency obtained with ½MS macronutrients in the presence of thidiazuron (TDZ). The shoot regeneration frequency was significantly reduced when BA was used in place of TDZ. On shoot regeneration medium containing BA and NAA, only roots were formed. Replacing NAA with indole-3-acetic acid (IAA) greatly improved the regeneration of shoots. The optimum growth regulator combination for shoot regeneration was 20 μM TDZ together with 2.5 μM IAA, which gave a frequency of 63% and 4.4 shoots per regenerating explant for the best cultivar Ex-El. Genotypic differences were significant both for the number of explants regenerating shoots and the number of shoots produced per regenerating explant. 相似文献
9.
Summary Effects of genotype and explant orientation on shoot regeneration from cotyledonary explants of tomato were studied using
10 commercially important cultivars. The explant orientation affected shoot regeneration in all the tested genotypes. Cotyledons
placed in abaxial (lower surface facing down) orientation consistently produced better shoot regenerative response and produced
greater numbers and taller shoots compared to those inoculated in adaxial (upper surface facing down) orientation. Genotypic
variation in terms of shoot regeneration response, number of shoots, and shoot height was apparent. Wounding of cotyledonary
explants increased shoot regeneration response. However, shoot height was much lower in shoots regenerated from wounded explants
compared to those that originated from intact cotyledons. Shoots produced from wounded cotyledons were abnormal in their form
and structure. 相似文献
10.
Effects of X-irradiation on adventitious bud regeneration from in vitro leaf explants of Rosa hybrida 总被引:2,自引:0,他引:2
Ibrahim Rusli Mondelaers Wim Debergh Pierre C. 《Plant Cell, Tissue and Organ Culture》1998,54(1):37-44
The effectiveness of X-radiation on regeneration of adventitious buds on in vitro leaf explants of three Rosa hybrida L. genotypes
was studied. In vitro leaflet explants of roses produced adventitious buds when cultured in the dark for 1 week on Murashige
and Skoog (MS) induction medium containing 6.8 μM thidiazuron (TDZ) + 0.49 μM indole-3-butyric acid (IBA) and subsequently
transferred to MS regeneration medium containing 2.2 μM benzyladenine (BA) + 0.049 μM IBA in the presence of reduced light,
at 15 μmol m-2 s-1 photosynthetically active radiation (PAR). Analysis of radiosensitivity by irradiating leaf explants with
increasing doses of X-rays between 25 and 100 Gray (Gy) resulted in a decreasing rate of leaf explants regenerating buds from
47% to 0% respectively. The lethal dose for 50% of the regenerating explants (LD50) in all the three genotypes was estimated to be 25 Gy at a dose rate 2 Gy/s. For the main experiment, doses of 5 and 15 Gy
were selected and variations were observed between genotypes. Clone RUI 317 had the highest rate of adventitious bud regeneration,
with 83.6% (2.5 buds/explant) at 5 Gy and 64% (1.8 buds/explant) at 15 Gy, compared to 89% (3.4 buds/explant) with the untreated
control. Significant differences in the percentage of bud regeneration of the three genotypes were only observed at 15 Gy
in comparison to the control and the number of buds formed per regenerating explant varied between 1 to 4.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
11.
Summary The first case of true hexapody among the Octopoda, resulting from bilateral agenesis of one arm pair, is described for a malePteroctopus tetracirrhus. A case of decapody, with uniform development of all arms, is also reported for the first time for a maleOctopus briareus. Both conditions apparently result from developmental anomalies of the embryonic arm anlagen. A survey of other anomalous conditions relating to arm development and regeneration within the Cephalopoda is provided. A possible relationship of polyfurcation of arm tips in the Octopoda with regenerative processes in amphibian limbs leading to similar conditions is suggested. 相似文献
12.
W.-L. Teng 《Plant cell reports》1999,18(5):363-368
In vitro culture of Venus fly-trap (Dionaea muscipula) was initiated using flower stalk explants. Activated charcoal was required for bud initiation, but omitted in the subculture
of regenerated plantlets. Regenerated plants were subsequently used as explant source for investigations concerning effects
of source of tissue, etiolation, orientation and illumination of leaf explants on plant regeneration. Etiolation of source
plantlets increased the rate of regeneration from explants and decreased explant failure. Generally, adventitious buds developed
at the adaxial side and proximal end of an explant. However, when explants were incubated in the dark, 20–30% of bud initiation
occurred at the distal end. The site of shoot regeneration on a leaf explant was affected by both illumination and orientation
of explants. Placing an explant adaxial side up resulted in the highest rate of regeneration. The most effective condition
for plantlet regeneration was found with etiolated petioles incubated with the adaxial side facing the light.
Received: 18 March 1998 / Revision received: 12 August 1998 / Accepted: 7 September 1998 相似文献
13.
Jedediah Tressler Francis Maddox Eli Goodwin Zhuobin Zhang Nathan J. Tublitz 《Invertebrate neuroscience : IN》2014,14(1):37-49
To provide quantitative information on arm regeneration in cuttlefish, the regenerating arms of two cuttlefish species, Sepia officinalis and Sepia pharaonis, were observed at regular intervals after surgical amputation. The third right arm of each individual was amputated to ~10–20 % starting length. Arm length, suction cup number, presence of chromatophores, and behavioral measures were collected every 2–3 days over a 39-day period and compared to the contralateral control arm. By day 39, the regenerating arm reached a mean 95.5 ± 0.3 % of the control for S. officinalis and 94.9 ± 1.3 % for S. pharaonis. The process of regeneration was divided into five separate stages based on macroscopic morphological events: Stage I (days 0–3 was marked by a frayed leading edge; Stage II (days 4–15) by a smooth hemispherical leading edge; Stage III (days 16–20) by the appearance of a growth bud; Stage IV (days 21–24) by the emergence of an elongated tip; and Stage V (days 25–39) by a tapering of the elongated tip matching the other intact arms. Behavioral deficiencies in swimming, body postures during social communication, and food manipulation were observed immediately after arm amputation and throughout Stages I and II, returning to normal by Stage III. New chromatophores and suction cups in the regenerating arm were observed as early as Stage II and by Stage IV suction cup number equaled that of control arms. New chromatophores were used in the generation of complex body patterns by Stage V. These results show that both species of cuttlefish are capable of fully regenerating lost arms, that the regeneration process is predictable and consistent within and across species, and provide the first quantified data on the rate of arm lengthening and suction cup addition during regeneration. 相似文献
14.
The incidence of arm regeneration, effects of arm regeneration on non-regenerating body components and rate of arm regeneration were examined under field conditions. Approximately 60% of Luidia clathrata found in the upper portion of Tampa Bay, Florida were regenerating one or more arms. Individuals with two arms amputated at the disk edge took 380 days to regenerate completely. Both arms of an individual regenerated at the same rate. Length of regenerating arms initially increased faster than dry mass. No difference was found between non-regenerating and regenerating individuals for the dry mass of the body wall, pyloric caeca, and gonad of a non-regenerating arm. The absolute masses of the gonad and pyloric caeca were low through out the year possibly indicating a low food environment. Based on the rate of regeneration, arm loss just prior to the reproductive season may reduce the reproductive potential of this species. 相似文献
15.
Juliana A. Fernando Maria Lúcia C. Vieira Silvia R. Machado Beatriz Appezzato-da-Glória 《Plant Cell, Tissue and Organ Culture》2007,91(1):37-44
We present evidences that ultrastructural electron microscope findings are valuable ways to understand the in vitro regeneration
process, in particular in the yellow passion fruit. Shoot-regeneration was induced in hypocotyl and leaf-derived explants
using 4.44 μM BAP, and the entire organogenic process was analyzed using conventional histology, scanning and transmission
electronic microscopy. Both direct and indirect regeneration modes were observed in hypocotyl explants, but only direct regeneration
occurred in leaf-derived cultures. In the direct pathway from both explant types, meristemoids developed into globular structures,
here called protuberances. The peripheral meristematic layers of the protuberances displayed ultrastructural characteristics
indicative of a high metabolic activity, and only these cells originated shoots and leaf primordia, the latter being frequent
when leaf explants were used. Moreover, the peripheral cells of the protuberances derived from leaf explants lost adhesion
during the culture, diminishing the regeneration rates. We recommend the use of hypocotyls as a source of explant to obtain
shoots as well as a genetic transformation system for the yellow passion fruit. However, the direct pathway is preferred because
a type of amitosis occurred in the peripheral cells of hypocotyl-derived calli, which has the potential to result in genetic
instability of the regenerating plants/tissue. 相似文献
16.
Effects of age and orientation of the explant on callus induction and de novo shoot regeneration from cotyledonary leaf segments of Jatropha curcas were studied. The callus induction and shoot regeneration capacity of cotyledonary leaf segments were found significantly related to the age of the explants and their orientation in culture medium. The youngest explant, derived from the cotyledonary leaf of germinated seed induced the highest regeneration response as compared to one- and two-week-old explants. A gradient response with age of the explant was observed in percentage of callus induction, shoot regeneration from callus and the number of shoots per regenerating callus. The explants cultured with their abaxial side in medium showed significantly higher regeneration response. The youngest explant was found to be most amenable to Agrobacterium-mediated transformation as compared to older explants. The fact that callus induced from the edges of the explant followed by de novo shoot induction, and strong transient gus expression observed in the edges of the explant are significant for routine Agrobacterium-mediated transformation and generation of stable transgenic plants in J. curcas. 相似文献
17.
《Journal of experimental marine biology and ecology》1987,106(1):1-16
The ophiuroids Ophiomyxa flaccida (Say), Ophionereis reticulata (Say), Ophiocoma wendtii Müller & Troschel, O. echinata (Lamarck), O. pumila Lütken, Ophioderma appressum (Say), O. cinereum Müller & Troschel, and Ophiolepis impressa (Lütken) in back-reef populations in Jamaica were found to differ significantly in the number of arms regenerating. The proportion of arms regenerating varied from 74.4% for Ophionereis reticulata to 28.3% for Ophiolepis impressa. Regeneration rates, hitherto unknown except for Ophiocoma pumila, were determined for all the species for a single arm over a 3-month period. O. wendtii had the highest rate, regenerating 55% of its mean maximum arm length in 3 months, and O. impressa the slowest, regenerating only 23% of its mean maximum arm length in the same time.Injury rates, i.e., the number of arms broken and the total percent loss estimated to have occurred in the month prior to collection, were determined by dating wounds with reference to regeneration rates over 1 month. The species differed significantly in injury rates. O. pumila and O. reticulata suffered the highest levels of injury and O. impressa the least. Injury rates were not simply related to either the palatability to predators or the behaviour of the brittle-stars. 相似文献
18.
19.
Gavin Burns Olga Ortega-Martinez Michael C. Thorndyke Samuel Dupont 《Journal of experimental marine biology and ecology》2011,407(2):315-322
Echinoderms and in particular brittle stars display a remarkable ability to regenerate lost or damaged tissues. They offer an excellent model in which to study regeneration displaying extensive regenerative ability and close relationship to vertebrates providing the opportunity for comparative studies. Previous studies of gene expression during arm regeneration in brittle stars have focused on single genes commonly associated with the regenerative process. In this study we present the first microarray investigation of gene expression during arm regeneration in the brittle star Amphiura filiformis. We show the large-scale gene expression changes associated with the complex process of regeneration with over 50% of the clones measured showing a significant change at some point during the process when compared to non-regenerating arms. Particular attention is paid to genes associated with Hox gene expression regulation, neuronal development and the bone morphogenic protein BMP-1. Our data give an insight into the molecular control required during the various stages of regeneration from the stem cell rich blastema stage through to the highly differentiated regenerate. This work also forms an important basis for future gene expression investigations in this emerging model of limb regeneration. 相似文献
20.
Abstract. We have explored the process by which crinoids increase arm number as they grow. Two hypotheses have been proposed: (1) arm autotomy with subsequent bifurcation and regeneration of a pair of arms, and (2) growth of a pinnule into an additional arm. We have traced the development of Oxycomanthus japonicus for about a year after fertilization and provide the first confirmation that the number of arms increases by autotomy, bifurcation, and subsequent regeneration of a pair of arms. The next such addition tends to occur at some distance from the previous pair. Thus, increase of arm number takes place in such a manner that the density of the arms remains relatively constant, and an efficient filtration fan for feeding is maintained. Although arm autotomy in crinoids has been considered to occur only as a response to physical or chemical disturbance, the present results suggest that autotomy also occurs as a specific, intrinsically programmed event during normal development. 相似文献