单套染色体组在泽蛙雌核单倍体发育中的作用

本文比较了泽蛙(Rana limnocharis Boie)单倍体和二倍体的胚胎发育。结果表明:泽蛙单倍体的生活力低下,器官发生异常,自原肠胚起发育速度减慢。据此,作者讨论了单套染色体组在个体发育中的作用。

THE ROLE OF A SINGLE GENOME IN THE DEVELOPMENT OF THE GYNOGENETIC HAPLOID OF RANA LIMNOCHARIS

The development of embryos of gynogenetic haploids of the frog Rana limnocharis was observed and compared with that of the diploids of Eana limnocharis on the basis of Shumway's stages. It was found by our experiments that the development of the haploids, like other frog's haploids, had been retarded since gastrulation and their mortality was greater than that of the control diploids in all stages. All the haploids developed into abnormal embryos and died before they were able to feed.At the stage of operculum completion, the embryos of the haploids and those of the diploids were fixed with Smith's fixative and were cut into serial sections by paraffin method, which were stained with HE. We had also made comparative studies on the morphogenesis of the internal organs of the haploids and those of the diploids. The results showed that the organs of the haploids were imperfect, the retina lacking the normal arrangement of structure, the semicircular canals of the internal ear being not yet differentiated, the internal gills underdeveloped, the myocardia hypertrophied, the intestinal villi not yet formed, the hepatic sinusoids of the liver enlarged, the development of bile-cyst and bile-duct retarded, the pronephric capsules oedematous, the urini-ferous tubules of pronephros becoming shortened and their lumens expanded. Besides, the ratio between the size of the organs of the haploids was found to be abnormal as compared with the corresponding organs of the diploids. The eyes of the haploids were only 57% of those of the diploids in volume while the intestine only 48.8% of that of the diploids in length. But the pronephros was 120.5% larger in size than that of the diploids. The size of the internal ear, the heart and the liver also showed statistical differences, when compared with the corresponding organs of the diploids. Based on these results, we have discussed the role of the genome in development.