ISSN:
1573-6857
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Mosaicism in silkworms is easily inducible by applying a cold shock to the hybrid eggs between two strains with different markers at the early developmental stage. When BF1 eggs from the cross between a tetraploid female (which had been induced from the cross between a red egg and a white egg strain) and a male of the red egg strain were exposed to a cold shock, hexaploid eggs and two types of mosaic eggs were obtained: black-black (BB-) mosaic eggs, which possessed two kinds of black serosa cells with different-sized nuclei, and black-red (BR-) mosaic eggs. Cytological studies on the embryos from these mosaic eggs revealed that the BB-mosaic type was a 3n/6n mixoploid, while the BR-mosaic type was mixoploid with n/2n/3n, n/3n, or 2n/6n constitution. The hatchability of BB- and BR-mosaic eggs was considerably lower than that of either n/2n or 2n/4n mixoploid eggs obtained by a cold treatment of diploid eggs. Since abnormal development was observed at a high frequency in the embryos from BB- and BR-mosaic eggs at the blastokinesis stage, it is speculated that the coexistence of hexaploid or triploid cells may be a factor in the induction of such abnormality in early embryogenesis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00122373
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