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Pattern development in palleal buds of the polystyelid ascidian,Polyandrocarpa misakiensis: Bud grafting induces bilateral asymmetry conversion through polarity reversal

✍ Scribed by Kawamura, Kazuo ;Watanabe, Hiroshi


Publisher
John Wiley and Sons
Year
1982
Tongue
English
Weight
939 KB
Volume
224
Category
Article
ISSN
0022-104X

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✦ Synopsis


Abstract

Previous work has shown that the anteroposterior axis and the transverse axis of the palleal buds of some botryllid and polystyelid ascidians develop in a predictable manner, depending on the position of the buds on the parental lateral wall. In the present study, three kinds of homopleural and heteropleural bud grafts were performed to invert the presumptive bud axes. The results show that the polarity of the bud A‐P axis can be inverted with relative ease, depending on the duration of the connection of the bud with a host adult zooid. Concurrently with the reversal of this axis, the normal pattern of body asymmetry is reversed. When both the presumptive anteroposterior and transverse axes are inverted, the future zooid develops the same body asymmetry pattern as its parent. Body asymmetry conversion was induced most efficiently (22.8%) when buds were amputated and grafted with reversed proximodistal axis on the host mantle wall. The polarities of zooid body patterns are transmitted through subsequent (asexual) blastogenic generations. This work shows that the future body pattern of a bud depends on the two axial polarities of its parent.