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1.
LAURA K. SNOOK 《Botanical journal of the Linnean Society. Linnean Society of London》1996,122(1):35-46
Recent debate on whether or not mahogany ( Swietenia macrophylla King) is threatened by the international timber trade has focused on the breadth of its range and estimates of the remaining stock of mahogany trees. These data are inadequate to reveal the status of mahogany populations, both because they are incomplete in areal extent and because they do not reveal population parameters such as the existence or density of young trees smaller than commercial size. However, there is sufficient information on the regeneration ecology of mahogany to indicate that under natural conditions this species regenerates in essentially even-aged stands after catastrophic disturbances destroy many or most trees, and, in the case of fires and flooding, saplings and seedlings as well. Adult mahoganies tend to survive these events, and regenerate by shedding seed onto the resulting gaps or clearings. This ecological strategy makes mahogany vulnerable to logging, first because juvenile mahoganies are not found in the understorey, and secondly because logging operations shortcircuit mahogany regeneration processes by selectively removing almost all mahogany seed sources while leaving standing competing vegetation of other species. Listing of mahogany in CITES Appendix II could provide both a mechanism to fill in gaps in information and an incentive to change current practices in favour of silvicultural management to provide for regeneration of this valuable timber species in forests subjected to logging. 相似文献
2.
Kateryna Raykova Melina V. Jones Hwa Huang Paul F. Hoffman Michael Levy 《Journal of visualized experiments : JoVE》2015,(99)
The rat optic nerve is a useful model for stem cell regeneration research. Direct injection into the rat optic nerve allows delivery into the central nervous system in a minimally-invasive surgery without bone removal. This technique describes an approach to visualization and direct injection of the optic nerve following minor fascial dissection from the orbital ridge, using a conjunctival traction suture to gently pull the eye down and out. Representative examples of an injected optic nerve show successful injection of dyed beads. 相似文献
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《Developmental cell》2023,58(8):660-676.e7
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Harry J. Wichers Marien P. Harkes Randy R. J. Arroo 《Plant Cell, Tissue and Organ Culture》1990,23(2):93-100
The 5-methoxypodophyllotoxin contents of plants, cell cultures and regenerated plants of Linum flavum are compared. It is demonstrated that cell cultures are able to produce amounts of 5-methoxypodophyllotoxin that are comparable to the concentration in fully differentiated plants. The production of 5-methoxy-podophyllotoxin depends on the hormonal balance of the growth medium. The use of 2,4-dichlorophenoxyacetic acid as the growth regulator is favourable for 5-methoxypodophyllotoxin production when compared to naphthylacetic acid. The 5-methoxypodophyllotoxin accumulation appears to be positively related to the internal cell volume. 相似文献
7.
An explant culture system is described that allows examination of axonal growth from the tonically and phasically active motoneurons of the abdominal nerve cord of the crayfish. In this preparation, growth occurs from the cut end of the axon while the remainder of the motoneuron is undisturbed. In vitro growth from the branches of the third roots, which contain the axons from the tonic and phasic motoneurons of abdominal ganglia one through four, was verified as axonal by retrograde labeling of axons and neuronal somata within the nerve cord. Growth from the axons of phasic and tonic cells was observed as early as 24 h after plating and continued for an additional 7–10 days. The morphology and growth rates of the motor terminals differed between the tonic and phasic axons. The phasic axons grew significantly faster and branched more often than did the tonic motor axons. These differences in growth may be related to differences in motoneuron size or, may result from differences in electrical activity. Tonic motoneurons show spontaneous impulse activity for up to 6 days in culture, whereas phasic motoneurons show no spontaneous impulse activity. In addition, the differences in growth may be related to the morphological differences in tonic and phasic motor terminals observed in situ. © 1993 John Wiley & Sons, Inc. 相似文献
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Ross A. Robinson Samuel C. Griffiths Lieke L. van de Haar Tomas Malinauskas Eljo Y. van Battum Pavol Zelina Rebekka A. Schwab Dimple Karia Lina Malinauskaite Sara Brignani Marleen H. van den Munkhof Özge Düdükcü Anna A. De Ruiter Dianne M.A. Van den Heuvel Benjamin Bishop Jonathan Elegheert A. Radu Aricescu R. Jeroen Pasterkamp Christian Siebold 《Cell》2021,184(8):2103-2120.e31
10.
Mamta Singhvi Dipti Joshi Shalaka Gaikaiwari Digambar V. Gokhale 《Indian journal of microbiology》2010,50(1):97-100
Method for production and regeneration of Lactobacillus delbrueckii protoplasts are described. The protoplasts were obtained by treatment with a mixture of lysozyme and mutanolysin in protoplast
buffer at pH 6.5 with different osmotic stabilizers. The protoplasts were regenerated on deMan, Rogosa and Sharpe (MRS) with
various osmotic stabilizers. Maximum protoplast formation was obtained in protoplast buffer with sucrose as an osmotic stabilizer
using a combination of lysozyme (1 mg/ml) and mutanolysin (10 μg/ml). Maximum protoplast regeneration was obtained on MRS
medium with sucrose (0.5 M) as an osmotic stabilizer. The regeneration medium was also applicable to other species of lactobacilli
as well. This is, to our knowledge, the first report on protoplast formation and efficient regeneration in case of L. delbrueckii. 相似文献