【摘要】 在爪蟾受精卵第一次有丝分裂中期进行静液压处理,抑制细胞质分裂从而得到四倍体。实验中获得三只存活了三年以上的四倍体雌性爪蟾。其中一只雌性与二倍体雄性爪蟾作人工催青得到受精卵。现已产卵三批,发育的胚胎400余,经检查子代染色体为三倍体。更多还原

【Abstract】 Tetraploid embryos can be produced by supressing the first cleavage division of eggs through the application of hydrostatic pressure. Eggs were pressurized at 530kg/cm2 for 6 minutes. Of the 5165 eggs treated 1067 developed to neurulae, of which 3.1% were tetraploids and 1.2% diplotetraploids. Three tetraploids, all females, survived more than 3 years. Two of them had abnormal arms. One was normal. The size of tetraploid adults was the same as that of diploids, but the size of tetraploid nuclei, as well as cells, wewe twice as that of dip-loids. The reproductive capacity of tetraploid adults is an important question. After the femal tetraploid were injected with gonadotropic hormone, nearly 2000 eggs were spawned. These eggs were fertilized with sperms of normal diploid male, and only one fertilized egg developed. It developed to stage 40, then died. Four monthes later, spawning was induced by injection of gonadolropic hormone again, and 1153 eggs were spawned, 539 of them were fertilized of which 76 (14.1%) developed to blastulas and 20 (3.7%) developed to stage 40. Chromosomal counts were made from tail-tip at stage. 40. Eighteen of them were triploids and 2 hypertriploids. Four monthes later, the experiment was repeated again, and 1038 eggs were spawned. Of which 382 (36.8%) developed to blastulas and 170 (16.4%) developed to stage 40, and 95% tadpoles were triploids. At present, most of them have developed to metamorphosis.The eggs of tetraploid were larger than that of normal diploid Xenopus The average volume of eggs from tetraploid was 1.98±0.01mm3 and that from normal diploid was 0.98± 0.01mm3, nearly one-half of the former.It can be clearly seen that the ovary and oviduct of the tetraploid developed well. Oo-genesis was normal or nearly normal in tetraploid Xenopus, which could reproduce progeny.更多还原