Kinetics of gametogenesis

Cell and Tissue Research - In the rat (Wistar-WU) sexual differentiation of the gonads occurs between days 14 and 15 post conception (p.c.). At this time the oogonia and their parallel population...     

The nucleoside triphosphate–ribonucleic acid nucleotidyltransferase (EC 2.7.7.6) of Agrobacterium tumefaciens (Smith and Townsend) Conn. Purification and properties of the enzyme from the tumorigenic strain B6806

The RNA nucleotidyltransferase (RNA polymerase) of the plant-tumorigenic bacterium Agrobacterium tumefaciens was purified. The method involves the disruption of the bacterial cells with glass beads in a Waring Blendor, treatment with DEAE-cellulose, fractionation with (NH(4))(2)SO(4), protamine sulphate precipitation, DEAE-cellulose column chromatography and either glycerol-gradient centrifugation or phosphocellulose chromatography. The subunit structure of the highly purified enzyme is similar to, although not identical with, the RNA nucleotidyltransferase of Escherichia coli. It can be described as beta', beta, chi(1) and alpha (mol.wts. 160000, 150000, 98000, and 41000+/-10% respectively). chi(1) is the temporary designation for a protein subunit, which might have the same functions as the sigma subunit in E. coli. The enzyme of A. tumefaciens is rifampicin-sensitive, has a temperature optimum in vitro of 41+/-1 degrees C and a pH optimum of 8.2+/-0.1. Mg(2+) and Mn(2+) are activators. The enzyme transcribes with different efficiencies artificial, viral, bacterial, plant and animal templates.     

The expected changes in the frequency of alleles affecting the sex ratio

An equation is derived giving the changes per generation in the frequency of alleles affecting the sex ratio. The alleles considered are assumed to be those of an autosomal locus and to act only in one sex. The results indicate that alleles determining the production of more males should always be more common in males than in females.