Mating assay

Figure 5.2. High-throughput mating assay for two-hybrid protein interaction screening. Yeast strains containing individual bait and prey clones are combined in a well and allowed to mate. Diploids are then selected and scored for a protein-protein interaction using the selection provided by the transcriptional reporter gene.

Test-Mate Assay In addition to the laboratory-based methodologies, a field deployable unit is commercially available, the Test-mate ChE system (EQM Research Inc., Cincinnati, OH). This method is also based on the Ellman procedure and is supplied as a kit containing reagents to separately measure erythrocyte AChE and plasma-BChE with a battery-operated, photometric analyzer (Taylor et al., 2003). A specific serum BChE inhibitor (As 1397, or 10-(oi-diethylaminopropionyl)-phenothia-zone) is included in the kit and is required to measure AChE (after a period of incubation). Two capillary... 

As fewer cells will be able to grow on the selective plates than on the nonselective YEPD plates, the optimal dilution will likely be lower for the selective plates than for the YEPD plates. Similarly, as the presence of a-factor reduces the mating efficiency of wild-type cells, the optimal dilution for wild-type cells on selective plates will likely differ depending on whether or not pheromone was present during the mating assay. 

An alternative method to examine specificity is in a mating assay. Here, a strain of yeast of the opposite mating type, which harbors the individual unrelated bait constructs is crossed with the strain carrying the isolated library plasmid This is a more efficient method to rapidly screen large numbers of potential clones. 

Carmichael J, DeGraff WG, Gazdar AF et al. (1987) Evaluation of a tetrazolium-based semiauto-mated colorimetric assay assessment of chemosensitivity testing. Cancer Res. 47 936-942. 

Dominant lethal assays in mice were performed using o- and p-cresols. Male mice were given a single dose of o-cresol (0, 75, 250, or 750 mg/kg) or p- cresol (0, 100, 275, or 550 mg/kg) by gavage in corn oil and mated to untreated females in order to assess dominant lethal effects. The matings were continued for 6 weeks so that all stages of male germ cell development were tested. 

Non-Jewish. Because Ashkenazi Jews tend to partner with others from their ethnic group, the mutation spectrum for common hereditary disease is often confined within that population. Mating tendencies cause certain alleles to become more prevalent within the inbred population than in the country as a whole. Therefore, mutation coverage and risk-reduction statistics are specific for a particular ethnicity. As a consequence, an Ashkenazi Jewish individual with a negative CF test by DNA and no family history has a significantly diminished risk of being a carrier (1/801) compared with a Caucasian non-Jew (1/241) with the same assay result. 

Many factors influence the outcomes of these studies, including the exact time of mating, species/strain used and local husbandry conditions. It is important to obtain sufficient numbers of offspring for analysis in these studies thus, the number of deaths caused by lethal mutation should be optimized to allow detection of both lethal and non-lethal effects. As with any toxicological model, careful control of parameters is required. However, this assay system is a useful model to examine inherited congenital malformations and tumours in the progeny of exposed males, and this kind of data could be useful for predicting effects in humans. 

Laboratory observations remain essential because they can delineate the timing of mate finding and mating in relation to other activities, and observations can provide important information about interactions between the sexes and the role of sex pheromones. The identification of sex pheromones also requires standard laboratory behavioral assays. We urge students of cockroach behavior and chemical ecology to develop more realistic behavioral assays that will facilitate the identification of sex pheromones as well as a better understanding of their role in cockroach mating systems. 

In a dominant lethal assay, male CD rats were exposed to 55 ppm [220 ing/ni ] vinylidene chloride for 6 h per day on five days per week (Short et al., 1977). On week 11 of exposure, males were mated with untreated females. There was no evidence of pre-or post-implantation loss in the pregnant females. Male CD-I mice exposed to 10, 30 or 50 ppm [40, 120 or 200 mg/m ] vinylidene chloride for 6 h per day for five days and subsequently mated with untreated females exhibited no pre- or post-implantation loss (Anderson et al., 1977), indicating an absence of adverse effects on male reproduction. 

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