A study was conducted in an attempt to determine which functional regions of a particular conjugative transfer gene (tra1) are involved in the transfer of plasmid R27 in Salmonella enterica. The R27 plasmid is of significant clinical interest because it is capable of encoding multiple-antibiotic resistance to typhoid fever. To identify functional regions responsible for conjugal transfer, an analysis was conducted by Lawley et al. (2002). J. Bacteriol. 184:2173-2180 was conducted in which particular regions of the tra1 gene were mutated and tested for their impact on conjugation. Shown here is a map of the regions tested and believed to be involved in conjugative transfer of the plasmid. Similar coloring indicates related function. Numbers correspond to each functional region subjected to mutation analysis.

Accompanying the map is a table showing the effects of these mutations on R27 conjugation.
Effects of Mutations in Functional Regions of Transfer Region 1 (tra1) on R27 Conjugation



Given the data, do all functional regions appear to influence conjugative transfer?

Verified step by step guidance

1. Examine the color-coded map of the tra1 gene, noting that it is divided into 14 functional regions, each numbered from 1 to 14 and grouped by color to indicate related functions.
2. Understand that mutations were introduced into each of these regions to assess their impact on the conjugative transfer of the R27 plasmid in Salmonella enterica.
3. Recognize that if a mutation in a particular region significantly reduces or abolishes conjugative transfer, that region is likely important for the process.
4. Compare the transfer rates or functional outcomes associated with mutations in each region to determine which regions affect conjugation and which do not.
5. Conclude that not all regions may influence conjugative transfer equally; some regions might show no effect when mutated, indicating they are not essential for the transfer function.

Key Concepts

Conjugative Transfer and Plasmids

Conjugative transfer is a process where genetic material, typically plasmids, is transferred between bacteria through direct contact. Plasmids like R27 carry genes that can confer traits such as antibiotic resistance, making their transfer clinically significant. Understanding which gene regions control this transfer helps in combating the spread of resistance.

Functional Regions of Genes and Mutation Analysis

Genes often contain multiple functional regions, each responsible for specific activities or interactions. Mutation analysis involves altering these regions to observe changes in function, helping identify which parts are essential. In this study, mutating different regions of the tra1 gene reveals their role in plasmid conjugation.

Interpreting Color-Coded Genetic Maps

Color-coded maps visually group gene regions by related functions, aiding in understanding complex genetic structures. In the image, regions with similar colors share functional roles, and numbers indicate mutation sites tested. This helps correlate specific mutations with their impact on conjugative transfer efficiency.