187 research outputs found
High Temperature Corrosion of Nickel Based Heat Resistant Alloys and their Diffusion Brazed Parts(Materials, Metallurgy & Weldability)
Музыка ДНК человека и исполинской саламандры
The DNA genetic code, which is common to all organisms on the earth, and music, a product of human intellect, share the same composition principle of repetitious recurrence. Thus, DNA sequences can be transformed into musical scores. In this article, I introduce one example of music generated from transforming the genome sequences of humans and the giant salamander, a unique creature inhabiting the Japanese islands.Генетический код ДНК, который является общим для всех организмов на Земле, и музыка, продукт человеческого интеллекта, имеют один и тот же композиционный принцип повторяющейся последовательности. Таким образом, последовательности ДНК могут быть преобразованы в музыкальные партитуры. В этой статье я представляю один пример музыки, созданной в результате трансформации геномных последовательностей людей и исполинской саламандры, уникального существа, обитающего на Японских островах.Ekaterinburg, 2013-201
Sex Chromosomes of Rana rugosa with Special Reference to Local Differences in Sex-determining Mechanism
The karyotypes of the two populations, Kumano and Hirosaki, of Rana rugosa were compared with each other by the methods of conventional Giemsa staining, C-banding and LR (late replication)-banding. It was found that in the Kumano population, the 13 pairs of chromosomes are completely homozygous and there are no chromosome pairs which have any sexual differences, while chromosome pair No.7 of the females in the Hirosaki population are heteromorphic and constructed of a subtelocentric Z and a metacentric W chromosome. The W chromosome also distinctly differs from the Z chromosome in both C-band and LR-band patterns. It is probable that the W chromosome was induced from the Z chromosome by two inversions on the basis of the LR-band pattern. In the Kumano population, nearly all of the females are changed into males by injection of testosterone propionate at the tadpole stage. The offspring of the sex-reversed genetic females mated with normal females are almost females. This seems to show that the Kumano population of Rana rugosa is of the XX-XY type. In the Hirosaki population, it has been confirmed by the methods of conventional Giemsa staining, C-banding and LR-banding that this is of the ZW-ZZ type and there are no frogs whose sex is reversed by injection of testosterone propionate. Sex ratios were examined in the offspring of reciprocal crosses between the Kumano and Hirosaki populations. It was found that the offspring (XZ) between the females (XX) of the Kumano population and the males (ZZ) of the Hirosaki population are almost all males, while the offspring (WX, WY, ZX, ZY) between the females (ZW) of the Hirosaki population and the males (XY) of the Kumano population include nearly the same number of females and males. It was quite evident that almost all the frogs having the W chromosomes were females, while all the frogs having the Z chromosomes were males, regardless of the existence of the X or Y chromosome
Evidence for True Fall-mating in Japanese Newt Cynops pyrrhogaster
The mating season of Japanese newt Cynops pyrrhogaster is generally thought to occur once a year in spring to early summer, during the months of April to June, as in many other Japanese amphibians. However, in fall, from September to October, we often observed breeding colored males demonstrating a mating behavior with females in the field. In this study, in order to identify their true mating season, we anatomically and histologically investigated the annual maturation cycle of gonads and reproductive organs, including cloacal spermathecae in females, and, using a molecular marker, identified the seasonal origins of sperm, which are released in spring to perform insemination. We found that, in fall, ovaries are somewhat immature, while the testes were mature and the sperm already stored in the deferent ducts. Females stored a significant amount of sperm in around 80% of the spermatechae examined in October and 100% in December. When artificially ovulated in March before contact with male partners after hibernation, the females spawned fertilized eggs and these developed normally. Finally, we identified heterozygous genotypes of the visual pigment gene for the two different population types in the embryos, which were derived from a female who established contact with males of the same population in fall and then switched to males from another population until oviposition in spring. We therefore, conclude that the true mating season of this species occurs from fall to early summer, interrupted only by winter, and lasts six months longer (from October to June) than generally believed
Four Kinds of Sex Chromosomes in Rana rugosa
The sex chromosomes of Rana rugosa distributed widely in Japan were analyzed by the methods of conventional staining, C-banding and late replication (LR)-banding on 196 frogs consisting of 105 females and 91 males belonging to 24 populations of one group and three subgroups. The chromosome numbers of these frogs were all of 2n=26. The 12 pairs other than chromosome pair No. 7 had no sex differences in all the populations. In chromosome pair No. 7,sex-specific changes were found among some local populations. Seven populations belonging to the northern subgroup of the eastern group, including the Asahikawa and Sapporo populations in Hokkaido region, the Hirosaki, Akita and Inawashiro populations in Tohoku region, the Murakami and Kanazawa populations in Hokuriku region and the Katata population in Kinki region of the southern subgroup, had chromosome pair No. 7 which was the sex chromosomes of the ZW type. The Z chromosome was subtelo- or submetacentric, while the W chromosome was metacentric. By the C-banding and LR-banding patterns, the Z chromosome was divided into five types, Z^A, Z^B, Z^C, Z^D and Z^O, while the W chromosome was divided into two types, W^1 and W^2. Five populations of the southern subgroup of the eastern group, including the Toba population in Kinki region, and the Oigawa, Hamakita, Miyakoda and Yonezu populations in Chubu region,..
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