The tRNA anticodon list for an extremely AT-rich bacterium, Mycoplasma capricolum, is unique and may be characterized by (1) removal of all the non-obligate CNN anticodons, (2) the presence of UNN (U, unmodified) anticodons in all family boxes, except arginine family box, (3) appearance of anticodon AGU for threonine colon ACU, (4) removal of GNN anticodons from family boxes, (5) occurrence of arginine anticodon ICG as in other bacteria and yet probable disappearance of anticodon CCG from arginine family box that would have resulted in CGG colon unassigned, and (6) development of anticodon *UCA that has led to the use of the universal stop colon UGA as a tryptophan colon. The above-mentioned deviation of the genetic code in Mycoplasma from the codes in other eubacteria, such as in E. coli and B. subtilis, may be explained by strong AT-directional mutation pressure that has been exerted to the Mycoplasma genome.
The results clearly show that there are two kinds of Hibuna, diploidy and triploidy, in the Harutori Lake. The diploid Hibuna, 2n=100, show the same chromosome constitution and C-band pattern as the gold-fish. The individuals with triploid chromosomes, 2n=154, are the same as those of the Ginbuna (C. a. langsdorfii) in the chromosome constitutions and C-band patterns.
Low concentrations (μg/ml level) of N-[N-(L-trans-3-carboxyoxirane- 2-carbonyl)-L-leucyl]-3-methyl-butylamine (E64C), a thiol-protease inhibitor, inhibited tyrosine release from skeletal muscle cells in which tyrosine release had been enhanced. Increase in cytoplasmic Ca2+ concentration seemed to be one of the factors that promoted the tyrosine release. These findings were discussed in relation to the mode of the protein degradation in the cells by thiolproteases including calcium-activated neutral protease.