Abstract
We have established an assay system for sexual induction in an exclusively fissiparous strain (OH strain) of Dugesia ryukyuensis by feeding them with matured worms of Bdellocephala brunnea, an exclusively oviparous species. In this assay system, the asexual worms gradually differentiate the ovaries, testes, genital pore (copulatory apparatus) and yolk glands in this order, and eventually mate and lay cocoons. Almost all worms hatching from the cocoons become sexual. It was found that sexual induction has a point-of-no-return; the worms before reaching this point return to the asexual condition unless feeding on B. brunnea is maintained (reversible phase), while those beyond the point develop into fully sexual worms even if feeding on B. brunnea is discontinued (irreversible phase). Most worms just beyond the point-of-no-return still undergo fission for a few weeks, even though they have already been committed to become sexual. However, once they reach a certain stage, fission stops and they reproduce exclusively sexually. Therefore, it is likely that the process of switching from asexual to sexual reproduction in planarians consists of a series of crucial events.
| Original language | English |
|---|---|
| Pages (from-to) | 153-158 |
| Number of pages | 6 |
| Journal | Invertebrate Reproduction and Development |
| Volume | 36 |
| Issue number | 1-3 |
| Publication status | Published - 1999 Sep |
| Externally published | Yes |
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Keywords
- Asexual reproduction
- Freshwater planarians
- Reproductive strategies
- Sexual induction
- Sexual reproduction
ASJC Scopus subject areas
- Animal Science and Zoology
- Cell Biology
- Developmental Biology
Cite this
Switching from asexual to sexual reproduction in the planarian Dugesia ryukyuensis. / Kobayashi, Kazuya; Koyanagi, Ryo; Matsumoto, Midori; Hoshi, Motonori.
In: Invertebrate Reproduction and Development, Vol. 36, No. 1-3, 09.1999, p. 153-158.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Switching from asexual to sexual reproduction in the planarian Dugesia ryukyuensis
AU - Kobayashi, Kazuya
AU - Koyanagi, Ryo
AU - Matsumoto, Midori
AU - Hoshi, Motonori
PY - 1999/9
Y1 - 1999/9
N2 - We have established an assay system for sexual induction in an exclusively fissiparous strain (OH strain) of Dugesia ryukyuensis by feeding them with matured worms of Bdellocephala brunnea, an exclusively oviparous species. In this assay system, the asexual worms gradually differentiate the ovaries, testes, genital pore (copulatory apparatus) and yolk glands in this order, and eventually mate and lay cocoons. Almost all worms hatching from the cocoons become sexual. It was found that sexual induction has a point-of-no-return; the worms before reaching this point return to the asexual condition unless feeding on B. brunnea is maintained (reversible phase), while those beyond the point develop into fully sexual worms even if feeding on B. brunnea is discontinued (irreversible phase). Most worms just beyond the point-of-no-return still undergo fission for a few weeks, even though they have already been committed to become sexual. However, once they reach a certain stage, fission stops and they reproduce exclusively sexually. Therefore, it is likely that the process of switching from asexual to sexual reproduction in planarians consists of a series of crucial events.
AB - We have established an assay system for sexual induction in an exclusively fissiparous strain (OH strain) of Dugesia ryukyuensis by feeding them with matured worms of Bdellocephala brunnea, an exclusively oviparous species. In this assay system, the asexual worms gradually differentiate the ovaries, testes, genital pore (copulatory apparatus) and yolk glands in this order, and eventually mate and lay cocoons. Almost all worms hatching from the cocoons become sexual. It was found that sexual induction has a point-of-no-return; the worms before reaching this point return to the asexual condition unless feeding on B. brunnea is maintained (reversible phase), while those beyond the point develop into fully sexual worms even if feeding on B. brunnea is discontinued (irreversible phase). Most worms just beyond the point-of-no-return still undergo fission for a few weeks, even though they have already been committed to become sexual. However, once they reach a certain stage, fission stops and they reproduce exclusively sexually. Therefore, it is likely that the process of switching from asexual to sexual reproduction in planarians consists of a series of crucial events.
KW - Asexual reproduction
KW - Freshwater planarians
KW - Reproductive strategies
KW - Sexual induction
KW - Sexual reproduction
UR - http://www.scopus.com/inward/record.url?scp=0032818678&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032818678&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0032818678
VL - 36
SP - 153
EP - 158
JO - Invertebrate Reproduction and Development
JF - Invertebrate Reproduction and Development
SN - 0792-4259
IS - 1-3
ER -