1) A transcriptional fusion of regulatory sequences of a particular gene with a reporter gene results in relatively uniform expression of the reporter gene in all cells of an organism, whereas a translational fusion with the same gene shows reporter gene expression only in the nucleus of a specific cell type.

Choose the correct possible biological causes for the difference in expression patterns of the two transgenes. Select the three correct answers.

a) Expression of the gene is controlled transcriptionally.
b) Expression of the gene is controlled translationally.
c) Expression of the gene is controlled post-translationally.
d) Expression of the gene is controlled post-transcriptionally.
e) Expression of the gene is controlled by modification of DNA.

2) The CBF genes of Arabidopsis are induced by exposure of the plants to low temperature.

How would you examine the temporal and spatial patterns of expression after induction by low temperature?
Select the two correct answers.
transcriptional fusion with GFP gene
translational fusion with GFP gene
translational fusion with lacZ gene
transcriptional fusion with lacZ gene

3) Can you design a method that would indicate these changes in gene expression in a way that a farmer could recognize them by observing plants growing in the field?

a) fusion with GFP gene
b) enhancer trapping
c) fusion with lacZ gene

d) in situ hybridization

1) a), b), and d)
2) transcriptional fusion with GFP gene and translational fusion with GFP gene
3) b) enhancer trapping

1) The correct possible biological causes for the difference in expression patterns of the two transgenes are:

a) Expression of the gene is controlled transcriptionally.
b) Expression of the gene is controlled translationally.
d) Expression of the gene is controlled post-transcriptionally.

2) To examine the temporal and spatial patterns of expression after induction by low temperature, the correct methods would be:

transcriptional fusion with GFP gene
translational fusion with lacZ gene

3) To indicate changes in gene expression in a way that a farmer could recognize them by observing plants growing in the field, the correct method would be:

b) enhancer trapping

1) The correct possible biological causes for the difference in expression patterns of the two transgenes are:

a) Expression of the gene is controlled transcriptionally.
d) Expression of the gene is controlled post-transcriptionally.
e) Expression of the gene is controlled by modification of DNA.

To determine the possible causes, one can analyze the experimental results and consider the different levels at which gene expression can be regulated. Transcriptional control refers to the regulation of gene expression at the level of transcription, where the regulatory sequences of the gene control the initiation of transcription. Post-transcriptional control refers to the regulation of gene expression after transcription has occurred, such as mRNA stability, processing, or transport. DNA modifications, such as DNA methylation or histone modifications, can also affect gene expression by regulating the accessibility of DNA to the transcriptional machinery.

2) To examine the temporal and spatial patterns of expression after induction by low temperature, the two correct approaches are:
transcriptional fusion with GFP gene
translational fusion with GFP gene

Transcriptional fusion with a reporter gene like GFP involves fusing the regulatory sequences of the CBF gene to the GFP gene. This allows the visualization of GFP expression under the control of the CBF gene's regulatory elements. By observing the fluorescence of GFP, one can track the temporal and spatial patterns of gene expression after exposure to low temperature.

Similarly, translational fusion with GFP gene involves fusing the coding sequence of GFP to the CBF gene. This allows the GFP protein to be produced under the control of the CBF gene's regulatory elements. After exposure to low temperature, the localization of GFP fluorescence can be observed to determine the spatial pattern of gene expression.

3) To indicate changes in gene expression that a farmer could recognize by observing plants growing in the field, the possible method would be:
b) enhancer trapping

Enhancer trapping is a technique where a reporter gene, such as lacZ, is randomly integrated into the genome, often in close proximity to regulatory sequences. If the reporter gene is positioned near an enhancer element of a specific gene, its expression will reflect the activity of that gene. In this case, the farmer could observe changes in gene expression by observing the expression of the reporter gene, such as lacZ, through a visible color change or other detectable signal in the field.