Chromosomes in Osmunda

Orientation and Locus of Tropic Photoreceptor Molecules in Spores of Botrytis and Osmunda

Study of the tropic responses of Botrytis cinerea and Osmunda cinnamomea spores to blue light shows the photoreceptor molecules to be highly dichroic and oriented: in Botrytis their axes of maximum absorption lie perpendicular to the nearby cell surface; in Osmunda, parallel. The chief evidence lies in a comparison of their responses to plane polarized light-both germinate parallel to the vibra...

I-18: The Role of Sex Chromosomes in Female Germ Cell Differentiation

Background When gonadal sex reversal occurs in mammalian species, the resultant XX males and XY females become infertile or subfertile, suggesting critical roles of sex chromosomes in germ cell differentiation. The objective of our study is to clarify the mechanism of infertility in the B6.YTIR (XY) sex-reversed female mouse, which can be attributed to a failure in the second meiotic division i...

Chromosomes in paediatrics.

Mammalian Chromosomes in Vitro

The complete DNA replication sequence of the entire complement of chromosomes in the Chinese hamster may be studied by using the method of continuous H(3)-thymidine labeling and the method of 5-fluorodeoxyuridine block with H(3)-thymidine pulse labeling as relief. Many chromosomes start DNA synthesis simultaneously at multiple sites, but the sex chromosomes (the Y and the long arm of the X) beg...

Chromosomes in the ‘hood

omites, the precursors of vertebrae, striated muscle, and dermis, are laid down in a timed sequence from anterior to posterior. Now, Alexander Aulehla, Bernhard Herrmann (Max-PlanckInstitut für Immunbiologie, Freiburg, Germany), and colleagues report that a gradient and two dueling molecular clocks, all driven directly or indirectly by Wnt3a, combine to create the striped pattern of somites. Th...