Induction of cleft lip in cultured rat embryos by localized administration of tunicamycin

Development ◽  
1981 ◽  
Vol 64 (1) ◽  
pp. 1-9
Author(s):  
Kazuhiro Eto ◽  
Alvaro Figueroa ◽  
Gakuzo Tamura ◽  
Robert M. Pratt

Whole-embryo culture techniques have advanced to the point where the study of normal and abnormal primary palate development in vitro is possible. The purpose of this study was to ascertain whether localized administration of tunicamycin (TM) an inhibitor of protein glycosylation, into the region of the developing primary palate would induce cleft lip in culture. Rat embryos were explanted on late day 11 of gestation and cultured with open yolk sacs for 40 h. TM was administered by implanting a sterile eyelash soaked in TM into the nasal placode region. The contralateral placode was used as the control by implanting an eyelash lacking TM. Under these conditions, TM-treated placodes were found to develop cleft lip in 14 out of 15 embryos compared to 0 for the controls. These experiments demonstrate that localized administration of TM results in cleft lip formation in whole embryo culture. The technique of localized administration of drugs and teratogens in whole embryo culture should prove useful for similar studies on embryonic development.

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1050A-1050
Author(s):  
Natalie Anderson ◽  
David H. Byrne ◽  
Maria B. Raseira

A major obstacle faced by programs that breed early-ripening peach cultivars [Prunus persica (L.) Batsch] is the low viability of the embryos from the early-ripening parents that are used as females. Embryo culture techniques have been developed to allow embryos to mature in vitro, thus increasing the chances of germination and survivability. Several media types exist for Prunus embryo culture. Two types, Woody Plant Medium (WPM) and Smith, Bailey, and Hough (SBH) were investigated for this report. The WPM type was studied in two forms, one made from scratch and the other in a prepackaged form. The SBH type was studied with the addition of vitamins and without vitamins. Eight peach genotypes with embryo lengths ranging from 9.6 to 12.7 mm were used. Surprisingly enough, it was found that WPM from scratch performed better than WPM from a prepackaged mix. For all eight genotypes studied, WPM from scratch resulted in as good as or better germination than SBH with or without vitamins. A large media by genotype effect was found, which is partially attributed to the embryo size. The genotypes with larger embryos (>11 mm) tended to perform equally on all media tested whereas the embryos <10.5 mm germinated better on WPM as compared to SBH.


Author(s):  
Katharine V. Jackson ◽  
Catherine Racowsky

2022 ◽  
Vol 53 (5) ◽  
Author(s):  
Ivana Kmetič ◽  
Monika Roller ◽  
Marina Miletić ◽  
Teuta Murati

U toksikološkim istraživanjima uz uporabu klasičnih (in vivo) istraživanja, primjenjuju se alternativni test sustavi. Korištenje laboratorijskih životinja, embrija, humanog i animalnog tkiva, kultura stanica i fetalnog seruma u istraživanjima smatra se etički problematičnim te se ograničava zakonima, pravilnicima i praksom. Razmatranjem načina kojima bi se neetičnost mogla izbjeći, došlo je do razvoja “3R” načela (akronim za tri pristupa koja bi se trebala provoditi pri istraživanjima na laboratorijskim životinjama), a to su: smanjenje/racionalizacija uporabe laboratorijskih životinja (engl. Reduction), načelo njihove zamjene (engl. Replacement) i poboljšanje uvjeta uzgoja, smještaja i skrbi za životinje (engl. Refinement). Većina je alternativnih testova toksičnosti još uvijek u postupku validacije. Pojedini in vitro testovi za istraživanja embriotoksičnosti (etički posebno osjetljivo područje) koja su priznala nadležna regulatorna tijela, su EST (engl. Embryonic Stem cell Test), WEC (engl. Whole- Embryo Culture) i MM (engl. MicroMass) test. Standardizacija protokola i uvođenje novih in vitro modela predstavlja važan segment napretka u toksikološkim istraživanjima. Znanstvena budućnost tu vidi mogućnost razvoja i implementacije načela etičnosti u istraživanja primjenjujući sustave koji će promišljeno i bez korištenja živih organizama dijelom nadomjestiti metode u biomedicini, veterinarskoj medicini, biotehnologiji i užem smislu - toksikologiji i farmakologiji.


Development ◽  
1979 ◽  
Vol 50 (1) ◽  
pp. 145-154
Author(s):  
Alvaro A. Figueroa ◽  
Robert M. Pratt

The facial processes involved in primary palate formation undergo epithelial fusion in a manner morphologically analogous to that observed during secondary palate formation. We have used whole embryo culture to analyze the synthesis of macromolecules (DNA, protein, glycoprotein) in the primary palate, based on the incorporation of various labeled precursors. The results of this study demonstrate that changes in the synthesis of macromolecules occur during the fusion of the facial processes, which resemble those previously reported to occur during secondary palate development. These changes include cessation of DNA synthesis in cells in a restricted zone of the epithelium, concomitant with maintenance of glycoprotein synthesis. These findings indicate that the molecular events underlying the development of the primary and secondary palate may be similar.


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