1996 Fiscal Year Final Research Report Summary
INDIVIDUAL VARIATIONS IN A POPULATION OF THE PARTHENOGENETIC SCORPION
| Project/Area Number |
06640893
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
系統・分類
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| Research Institution | UNIVERSITY OF TSUKUBA |
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Principal Investigator |
MAKIOKA Toshiki INSTITUTE OF BIOLOGICAL SCIENCES PROFESSOR, 生物科学系, 教授 (60015584)
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| Project Period (FY) |
1994 – 1996
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| Keywords | Liocheles australasiae / thelytoky / separate rearing through generations / individual variations / meiosis / conjugation of egg with polar body / homozygous and heterozygous genoms / population containing homo- and heterozygous genoms |
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| Research Abstract |
Adults of the viviparous scorpion, Liocheles australasiae, collected from Iriomote Isl., Japan, were all females with ovaries in pregnancy or interpregnancy. Juveniles of the first instar (Generation II) born from the females (Generation I) collected on July, 1994, were separately rared in the laboratory to grow into mature females about 15 months after the birth, through 6 moltings in some of the females or 5 in the remainder. These females of Generation II became pregnant partheno-genetically shortly after the final molting and gave birth to juveniles (Generation III) about 8 months later. Most of these juveniles are in the 4 or 5 instar on Mar., 1997.
Histological observations on the serial sections indicated evidence neither for the hermaphroditism nor for the asexual reproduction. It was therefore concluded that the egg matured through the meiosis came to develop after the conjugation possibly with the second polar body.
There were some variations in number of the pecten teeth and of the postembyonic molting even among sister juveniles. Although these variations have hardly clarified their genetic modes through the observations during only approximately 3 generations, they suggest that some individuals are heterozygous on some genetic characters and the others homozygous in the present parthenogenetic scorpion population. If the eggs are conjugated with the polar bodies, the rate of variations in this parthenogenetic population should resemble that in the self-fertilizing hermaphroditic population.
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