Zebrafish (Danio rerio) genetic screens allow isolation of a wide array of problems in vertebrate biology. The effects of base analogues 5-bromouracil and 6-aminopurine on the development of zebrafish embryos are repo...Zebrafish (Danio rerio) genetic screens allow isolation of a wide array of problems in vertebrate biology. The effects of base analogues 5-bromouracil and 6-aminopurine on the development of zebrafish embryos are reported for the first time in this study. The early development of the zebrafish embryos was little affected by 5-bromouracil and 6-aminopurine, while the late development (organogenesis) was significantly impaired. Embryos exposed to 5-bromouracil mainly showed curled tail, wavy body, golden pigmentation and the mouth with protruding lower jaw. 6-aminopurine-treated embryos had defective anterior structures, curled tails and wavy body. RAPD analysis showed that the majority of 5-bromouracil- and 6-aminopurine-treated larvae and fish shared banding patterns in common with the control, suggesting that most mutagenesis induced by these agents are point mutations. However, some fish derived from 5-bromouracil-treated embryos had golden (gol) pigmentation; and RAPD analysis revealed that their band patterns differed from those of the control. Possibly, 5-bromouracil can occasionally cause relatively extensive changes in the fish genome. The results of this study may provide valuable help for detailed studies of mutagenesis.展开更多
<i><span style="font-family:"">Annona</span></i><span style="font-family:""> <i>muricata</i> L. and <i>Annona</i> <i>squamosa&l...<i><span style="font-family:"">Annona</span></i><span style="font-family:""> <i>muricata</i> L. and <i>Annona</i> <i>squamosa</i> L. are tropical species whose</span><span style="font-family:""> fleshy fruit is edible. They offer real possibilities for socio-economic use, particularly in the fields of medicine, nutrition, ecosystem conservation and the poverty alleviation. This study was set up to evaluate different methods of micropropagation from juvenile material for the regeneration of these species. Thus, MS medium supplemented with [BAP 2 mg·L<sup>-1</sup>] <i>i.e.</i> M2 produced 2.87 newly <span>formed shoots from the cotyledonary nodes of <i>A.</i> <i>muricata</i>. For the terminal apices of <i>A.</i> <i>squamosa</i>, it was MMS medium supplemented with [BAP 2</span> mg·L<sup>-1</sup>] <i>i.e.</i> MM2 that was most conducive to new shoot formation (3.12). The addition of 0.1 and 0.2 mg·L<sup>-1</sup> of NAA in the M2 medium, made it possi<span>ble to have the best elongations and average number of nodes for the new shoots from cotyledonary nodes of <i>A.</i> <i>muricata</i> (9.11 cm for 5.62 nodes). With <i>A.</i> <i>squamosa</i>, MM7 medium [MMS + BAP 1 mg·L<sup>-1</sup></span></span><span style="font-family:""> </span><span style="font-family:"">+ KIN 1 mg·L<sup>-1</sup>]</span><span style="font-family:""> resulted in an average length of 9.05 cm with 5.62 nodes on average for the apical shoots. A 3-day rhizogenic induction period in the dark with [IBA 50 mg·L<sup>-1</sup>] and 2 g·L<sup>-1</sup> of activated charcoal gave a rooting rate of 66.67% for shoots originating from the cotyledonary nodes of <i>A.</i> <i>squamosa</i>;while with vitroplants from cotyledonary nodes of <i>A.</i> <i>muricata</i>, a better rooting rate (83.33%) was obtained following a 5-day rhizogenic induction. After 30 days of acclimatization, the survival rate reached 83.33% for plants from the tips of <i>A.</i> <i>muricata</i>, whereas for <i>A.</i> <i>squamosa,</i> it was plants grown from cotyledonary nodes that had the same survival rate.展开更多
基金This work was supported by Ministry of Science and Technology (MOST) of China (G 1999012005).
文摘Zebrafish (Danio rerio) genetic screens allow isolation of a wide array of problems in vertebrate biology. The effects of base analogues 5-bromouracil and 6-aminopurine on the development of zebrafish embryos are reported for the first time in this study. The early development of the zebrafish embryos was little affected by 5-bromouracil and 6-aminopurine, while the late development (organogenesis) was significantly impaired. Embryos exposed to 5-bromouracil mainly showed curled tail, wavy body, golden pigmentation and the mouth with protruding lower jaw. 6-aminopurine-treated embryos had defective anterior structures, curled tails and wavy body. RAPD analysis showed that the majority of 5-bromouracil- and 6-aminopurine-treated larvae and fish shared banding patterns in common with the control, suggesting that most mutagenesis induced by these agents are point mutations. However, some fish derived from 5-bromouracil-treated embryos had golden (gol) pigmentation; and RAPD analysis revealed that their band patterns differed from those of the control. Possibly, 5-bromouracil can occasionally cause relatively extensive changes in the fish genome. The results of this study may provide valuable help for detailed studies of mutagenesis.
文摘<i><span style="font-family:"">Annona</span></i><span style="font-family:""> <i>muricata</i> L. and <i>Annona</i> <i>squamosa</i> L. are tropical species whose</span><span style="font-family:""> fleshy fruit is edible. They offer real possibilities for socio-economic use, particularly in the fields of medicine, nutrition, ecosystem conservation and the poverty alleviation. This study was set up to evaluate different methods of micropropagation from juvenile material for the regeneration of these species. Thus, MS medium supplemented with [BAP 2 mg·L<sup>-1</sup>] <i>i.e.</i> M2 produced 2.87 newly <span>formed shoots from the cotyledonary nodes of <i>A.</i> <i>muricata</i>. For the terminal apices of <i>A.</i> <i>squamosa</i>, it was MMS medium supplemented with [BAP 2</span> mg·L<sup>-1</sup>] <i>i.e.</i> MM2 that was most conducive to new shoot formation (3.12). The addition of 0.1 and 0.2 mg·L<sup>-1</sup> of NAA in the M2 medium, made it possi<span>ble to have the best elongations and average number of nodes for the new shoots from cotyledonary nodes of <i>A.</i> <i>muricata</i> (9.11 cm for 5.62 nodes). With <i>A.</i> <i>squamosa</i>, MM7 medium [MMS + BAP 1 mg·L<sup>-1</sup></span></span><span style="font-family:""> </span><span style="font-family:"">+ KIN 1 mg·L<sup>-1</sup>]</span><span style="font-family:""> resulted in an average length of 9.05 cm with 5.62 nodes on average for the apical shoots. A 3-day rhizogenic induction period in the dark with [IBA 50 mg·L<sup>-1</sup>] and 2 g·L<sup>-1</sup> of activated charcoal gave a rooting rate of 66.67% for shoots originating from the cotyledonary nodes of <i>A.</i> <i>squamosa</i>;while with vitroplants from cotyledonary nodes of <i>A.</i> <i>muricata</i>, a better rooting rate (83.33%) was obtained following a 5-day rhizogenic induction. After 30 days of acclimatization, the survival rate reached 83.33% for plants from the tips of <i>A.</i> <i>muricata</i>, whereas for <i>A.</i> <i>squamosa,</i> it was plants grown from cotyledonary nodes that had the same survival rate.
