Mammals oocyte

In mammals, at least six somatic H1/H5 variants have been identified (see Fig. 3 Table 1). These are Hl.l to HI.5, and Hl°. In addition, an oocyte-specific linker, Hloo/Hlfoo, and two testis-specific forms. Hit and HILSl, were described (reviewed in Khochbin et al. 2001 Woodcock et al. 2006). 

In this example, D is some observed end point in the mammal—specific-locus mutation rate, skeletal anomalies, cataracts, or heritable chromosomal damage. The values for D and E are assumed to be the same, although our confidence in the extrapolation would be increased if the observations in D involved several strains of several mammals. There is some possibility of direct dosimetry in man. With molecular dosimetry, the ENA damage in A and B can be measured in the same way. This corrects for differences in mutagen metabolism and mutation processes in the two organisms. B is measured directly in the spermatogonia or oocytes. The mutational end point, C, is whatever is most appropriate for the particular test organism. 

Tsafriri A, (1978). Oocyte maturation in mammals. In The Vertebrate Ovary. (Jones, R.E., Ed.), pp. 409-442. Plenum Press, New York. 

In Chapter 4, Olson discusses ovarian nitric oxide, a local regulator of ovulation, oocyte maturation, and luteal function in mammals. Although this is a relatively new area of investigation, there is compelling evidence that nitric oxide is a local regulator of all of these key ovarian processes in mammals. The author provides an experimental basis for this conclusion and for future studies. 

Kdn-gp appeared to be synthesized during relatively later stages of oogenesis, since it was undetectable in the oocyte 3 months prior to ovulation. Although the cell types that synthesize Kdn-gp have not been identified, it is most likely synthesized under hormonal control in some extraoocj e cells (i.e. follicle cells), secreted and partly incorporated into the second outermost layer of the vitelline envelope just before ovulation. Kdn-gp may thus be a molecule homologous to the oviduct glycoproteins of mammals that are reported to be secreted and partly incorporated into the egg surface [58-60]. 

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