The preferential location of the human Y chromosome in somatic metaphase. I. Influence of Y polymorphism

Abstract

The location of the V chromosome in metaphase figures was studied, with respect to its polymorphism, on 700 micrographs from blood lymphocyte cultures from 70 normal male members of seven Candian family lines whose polymorphic Y chromosomes were inherited in a patrilinear fashion from seventeenth-century French ancestors. Three of these family lines were carriers of a long Y chromosome, two a small one, one had an average length Y and a seventh one had a satellited V marker. The V chromosome was peripheral in 75 to 90 per cent of the metaphase plates from each individual investigated. The long V markers were more peripheral than the small ones while the average length V chromosome had an intermediate position, whereas the satellited V chromosome was located within the small group. The difference between the location of the long and the small V chromosomes was highly significant. It is hypothesised that a heteromorphic V might affect the nonrandom orientation of metaphasic chromosomes and favour meiotic nondisjunction and aneuploidy. DU CTI ONWhile the relative position of chromosomes in metaphase spreads should tend to be nonrandom, there is some disagreement about the actual metaphysic location of the Y chromsome. These conflicting views may be due to differences in methodology, variability in the definition of by the method and peripheral definition of Kowaiski et al., (1978), directly on enlarged micrographs (x2,800) of 10 lymphocyte 46-chromosome metaphases of each of 10 normal males from each of the seven (7) family lines. Cells were randomly chosen providing that they were euploid and the Y chromosome could be identified easily on chromosome preparations stained by the conventional Giemsa technique in order to have we1l-defined centromeres. To evaluate the position of the Y chromosome a reference line was drawn connecting the centromere of chromosomes 1.These were chosen because they were easily identified. Lines parallel and perpendicular to the reference line were then drawn through the centromeres of the most peripheral chromosomes with respect to the starting point. A rectangle (or square) was then formed in which all the chromosomes in the spread were included. The centre of the metaphase was therefore at the intersection of two diagonals

A busca de si-mesmo e da identidade nas transformações corporais

“…Há um monte de pessoas que conheço e que não entendo, mas não há realmente nada para entender. Eu sou realista, sensato e inteligente" (Genest, 2012); Dennis Avner, o "Homem-Tigre", também já falecido, que mudou seu rosto, fez implante de bigodes, mudou seus lábios, dentre outras transformações similares, procurando se aproximar ao máximo da aparência de um tigre, descrevia um dos aspectos de seu modo de viver: "Eu como carne todos os dias, assim como um tigre faria. Deve ser o mais próximo possível do cru, ou na temperatura de um animal que tivesse acabado de ser morto.…”