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PubMed1985

Preparation and characterization of bovine aortic actin.

A functional vascular smooth-muscle actin from bovine aorta was purified to homogeneity by an original method and was able to polymerize. Aortic actin is composed of two major isoforms and at least two minor ones. This actin was not phosphorylated by either cyclic AMP-dependent protein kinase or C kinase. The physical properties of aortic actin were found to be very similar to those of skeletal-muscle actin, except for amino acid composition (three tryptophan residues instead of four). The aortic actin and skeletal-muscle actin differ in the extent of activation of the Mg-dependent ATPase of skeletal-muscle myosin.

Actins↗

PubMedDate not supplied

Genetic evidence that ZFY is not the testis-determining factor.

In mammals, the testis determining gene (TDF), present on the Y chromosome, induces the undifferentiated gonads to form testes. The position of TDF on the human Y chromosome has been defined by analysing the genomes of XX males and XY females, generated by abnormal genetic exchange between the X and Y chromosomes in male meiosis. In this way TDF has been localized close to the pseudoautosomal region shared by the sex chromosomes, in the distal Y-specific region. A recently cloned human gene, ZFY, has many features indicating that it is TDF. For example, ZFY encodes a protein with many features of a transcription factor including a domain with multiple 'zinc-finger' motifs. Less consistent with ZFY being TDF, however, is the presence of a very similar gene, ZFX, on the X chromosome, and the presence of a sequence related to ZFY on autosomes in marsupials. We now report on analysis of XX males lacking ZFY. In these individuals, the male phenotype could be explained by a mutation in a gene 'downstream' of ZFY in the sex-determining hierarchy; but in that case there should be no exchange of material between the X and Y chromosomes. We find on the contrary that in 4 XX males lacking ZFY, there is exchange of Y-specific sequences next to the pseudoautosomal boundary, redefining the region in which TDF must lie.

Blotting, Southern↗