Polarized inhibitory control of differentiation in the early chick embryo, studied <i>in Vitro</i>

Katoh, Arthur

doi:10.1002/jmor.1051080306

Cited by 12 publications

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References 17 publications

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“…1958BRAVERMAN. , 1961CLARKE and MCCALLION, 1959;KATOH, 1961) Gewebe induzieren konnen (homoiogenetische induktion), daB aber die Gewebe eher eine induzierende als eine hemmende Wirkung ausuben konnen. Nach WADDINGTON ist es richtiger anzunehmen, daB ,,differentiation is usually an ,autocata!iytic process', the substance produced by one type of differentiation tending to encourage rather than to inhibit the same type of development" (1957, p. 193 In anderen Versuchen wurde festgestellt, daB nicht nur das Zerebralganglion, sondern auch die Nervenstamme eine hemmende Wirkung ausiiben konnen.…”

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Beiträge Zum Problem Einer “Morphogene‐tischen Hemmung” an Hand Experimen‐teller Befunde Be1 Der Regeneration Von Planarien

Török¹,

Törö²

1962

Embryologia

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FRAGESTELLUNGIn der experimentellen Erforschung der morphogenetischen Prozesse trat in der letzten Zeit das Problem der Hemmung immer mehr in den Vordergrund, und die Zahl der Hypothesen, die sich auf die entwicklungsgeschichtliche Bedeutung der morphogenetischen Hemmung beziehen, nimmt stkindig zu. Vorlaufig gibt es noch verhaltnismai3ig wenige experimentelle Befunde (im Vergleich z. B. mit der Erforschung der Induktion), und auch die Discussion der Theorien ist noch bei weitem nicht abgeschlossen. Trotzdem ist es schon heute offensichtlich, daB die organ-bzw. gewebespezifischen Hemmungen in der normalen Morphogenese eine ebenso wichtige Rolle spielen wie die entgegengesetzt gerichteten Induktionsvorgiinge. Die normale Morphogenese, gleichgultig ob es sich nun um eine Embryogenese oder eine Regeneration handle, ist ein organisierter Komplex einander entgegengesetzter Teilvorgkinge, dessen harmonisch-normaler Charakter gerade durch den ihm innewohnenden Antagonismus gesichert wird.

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“…Gehirnextrakt verhindert die Diff erenzierung des embryonalen Nervensystems usw. BRAVERMAN (1958), LENICQUE (1959), CLARKE und MCCALLION (1959a, KATOH (1961) wiesen nach, da13 solche homologe Hemmungen auch bei Huhnerembryonen m6glich sind.…”

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Beiträge Zum Problem Einer “Morphogene‐tischen Hemmung” an Hand Experimen‐teller Befunde Be1 Der Regeneration Von Planarien

Török¹,

Törö²

1962

Embryologia

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The effects of electrophoretically separated lens proteins on lens regeneration in Diemyctylus viridescens

Smith

1965

J. Exp. Zool.

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In the present study, lenses were removed from the eyes of adult anesthetized newts, macerated in 0.03 M borate buffer at pH 8.6, and separated by starch gel electrophoresis. Upon staining with amido black lO-B, seven distinct staining areas appeared in the blocks. Three bands moved toward the anode, and three toward the cathode. In addition, a seventh moiety represented by a smear of material moved toward the anode. One millimeter times five tenths millimeter plugs were removed from each of these areas and were placed into freshly lentectomized eyes.Plugs from most strongly positive and most weakly negative proteins inhibited lens regeneration. In addition, plugs from the area containing the weakly negative protein induced either lenses with aberrant polarity or double centered lenses with centers of opposed polarity. All other protein bands had no significant effect on regeneration.In addition to the above experiments, homogenates and proteinase-digested homogenates of lenses were injected into eyes following lentectomy. Three 5-pl samples were injected in each case over a six day period. Injection of the plain homogenate stimulated lens regeneration markedly, while the proteinase destroyed the stimulatory activity.Theoretical considerations of the above data are discussed.Since Colucci (1891) and Wolff (1894, 1895) described the phenomenon of lens regeneration in the salamander, an enormous amount of effort has been directed toward the elucidation of the mechanisms involved. Hans Spemann ('04) first suggested that the status quo within the eye is maintained by a balance of two primary influences, a factor which emanates from the lens and one derived from the neural retina. To the retinal factor he ascribed the function of stimulation of the regenerative process. To the lenticular influence, he ascribed the function of suppression of regeneration.There arose in time several hypotheses as to the mode of action of the lens in restricting regeneration, and these have been reviewed and discussed comprehensively by Reyer ('54, '62). The conclusion to which he is drawn, and which is most consistent with the data available, is that the lens does indeed produce a substance (or substances) which crosses the fluid gap between the lens and dorsal iris and prevents the dorsal iris cells from elaborating a new lens. The most convincing evidence of this J. EXP. ZOOL., 159: 149-166. inhibitory substance has been provided by Stone and Vultee ('49), who injected aqueous humor from normal eyes into lentectomized eyes and inhibited lens regeneration in Diemyctylus viridescens. Takano et al. ('57) could not confirm this finding in D. pyrrhogaster, but in recent experiments with viridescens, Stone ( ' 6 3 ) has demonstrated that if two parabiosed eyes possess a common anterior chamber, removal of the lens from one of the eyes does not, in some cases, lead to regeneration in that eye. The experiments presented in this paper also indicate that substances present in the lens can be isolated, introduced into a lensectomized e...

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The influence of neural retina and lens on the development of embryonic lens vesicles in Amblystoma punctatum and Triturus viridescens

Reyer

1966

J. Exp. Zool.

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Embryonic lens vesicles from both species of salamander self-diff erentiated into a small lens with fibers when implanted into either the dorsal f i n or anterior chamber of the larval eye. Growth of these lenses was very slow in Amblystoma and somewhat faster in Triturus. When implanted into the pupil in place of the extirpated host lens, the embryonic lens vesicles differentiated normally and had a normal rate of growth. Lens regeneration from the host iris in Triturus was frequently inhibited by the implanted lens. A statistical analysis by the method of covariance showed that, in both species, lenses from the implants were largest in the lentectomized eyes, smaller in the vitreous chamber of eyes with intact host lens and smallest in the anterior chamber, host lens present. In Amblystma, the growth rates, as indicated by the coefficients for linear regression, were significantly different between lenses developing in the absence of the host lens and those growing from implants into either the anterior or vitreous chambers of eyes containing the host lens. In Trituru.~, a significant difference was observed only between growth rates of lenses in the lentectomized eyes and in the anterior chambers, host lens present or in the dorsal fin. These results show that the neural retina stimulates growth and differentiation of embryonic lens vesicles and that the host lens retards their growth.The regeneration of a lost part in an older animal frequently repeats many of the events of morphogenesis and cytodifferentiation that characterized the development of this structure during embryonic Iife. However, this takes place in an environment which is quite different from that found in an embryo. Unlike the embryonic anlage, the regenerating part is subject to local influences from adjacent differentiated tissues and to systemic influences such as hormones. The interactions of these factors have been extensively investigated in the many studies on regeneration of the amphibian limb. The regeneration of a lens from the pigmented epithelium of the dorsal iris in certain urodeles also repeats the events of morphogenesis and histogenesis observed in the embryonic development of the lens from the surface ectoderm overlying the optic vesicle and cup. In the embryo, lens development is stimulated and modu- namely, the entoderm of the dorsal-antenor archenteron wall, the adjacent mesoderm and, finally, the optic vesicle and cup (Liedke, '51, '55; Reyer, '58a, b; Jacobson, '55, '58, '63a, b, c). In the larval and adult eye, the presence of the neural retina is essential for the initiation of lens regeneration from the iris (reviewed by Stone, '59, '65; Goss, '64; Reyer, '54, '62a). This is normally released by extirpation of the host lens. It was of interest, therefore, to test the response of the prospective lens-forming ectoderm and embryonic lens vesicle to the environment of the differentiated eye, especially to any influences emanating from the host neural retina or lens. Experiments have already been reported (Reyer...

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Polarized inhibitory control of differentiation in the early chick embryo, studied in Vitro

Cited by 12 publications

References 17 publications

Beiträge Zum Problem Einer “Morphogene‐tischen Hemmung” an Hand Experimen‐teller Befunde Be1 Der Regeneration Von Planarien

Beiträge Zum Problem Einer “Morphogene‐tischen Hemmung” an Hand Experimen‐teller Befunde Be1 Der Regeneration Von Planarien

The effects of electrophoretically separated lens proteins on lens regeneration in Diemyctylus viridescens

The influence of neural retina and lens on the development of embryonic lens vesicles in Amblystoma punctatum and Triturus viridescens

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