Fi Translocation Test

TABLE 4. Genetic Radiosensitivity of Male Germ Cells 

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Chemical Spermatocyte test on treated males Reference Fi translocation test Reference... 

The results of Cattanach et a/. 83) vv ith the Fi translocation test have already been discussed. As shown in Table 9, this compound induces a very high frequency of Fi translocated male and female offspring the incidence of translocation heterozygotes was 7-9% for the animals sired the first 3 days, 15-16% for the animals sired on the fourth to the fifth days, 28-38% for the animals sired on the eighth to the tenth days, and up to 50% for the animals sired on the sixth to the seventh days. Comparison of the EMS 83) and TEM experiments 8) demonstrates that at equimolar doses TEM is by far the more effective agent. 83)... 

The characteristic meiotic configurations of spermatocyte I chromosomes at the diakinesis first metaphase stage thus provide a reliable technique for the detection of rearrangements or other chromosome aberrations induced in spermatogonia of the treated males spermatocyte test on treated males). Cytological analysis of dividing spermatocytes can also be used to confirm in Fi males the presence of translocations indicated by semisterility, the Fi females being indirectly tested by examination of sons F translocation test) (Table 1). 

The subunit domain a b2 Ci2 in Fq is considered to be the site for proton translocation, but the details of the mechanism remain to be explored. It is generally agreed, however, that the a- and c-subunits mediate proton translocation, while the b-subunit only acts as a structural element to link F, (a3 p3) with Fq (the a-subunit). It is also known from the study of Schneider and Altendorf that all three subunits, a, b and c, are required for an active proton channel reconstituted in E. coli ATP synthase. In their experiment, these authors first dissociated, separated and purified the individual subunits and then integrated the subunits in all possible combinations into phospholipid vesicles. Each assembly was then tested for proton-translocation activity as well as its ability to bind to Fi, and it was found that functional activity could only be achieved by the combination a b2 Cio, the same combination that exists in native Fq. 

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