In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

 The coding region of nifA was determined using a translational lacZ fusion and by site - directed mutagenesis to identify which of four in frame AUG codons was used .
lacZ fusion

 A V1 mutant generated in vivo with 11 of the 14 N - terminal amino acids altered , was viable and produced symptoms typical of a wild - type infection .
V1 mutant

 Symptoms , skin - prick tests ( SPT ) with environmental allergens and Pt salt , total serum IgE , lung function , and bronchial hyperresponsiveness were assessed by standard procedures .

serum IgE