Background
The immediate early gene ZENK (acronym zif268, Egr-1, NGFI-A, krox24) has been used extensively in songbird research (Mello et al., 1992; Jarvis and Nottebohm, 1997), as well as other research areas. ZENK has been used in assessing learning and memory, measuring neural activation, and identifying the cellular and molecular substrates involved in the first stages of memory formation (Watson and Clements, 1980). Previous songbird research has found that neurons located within the areas involved in auditory perception, namely the caudomedial nidopallium and caudomedial mesopallium, exhibit high levels of ZENK protein expression in response to conspecific songs and calls (Mello and Ribeiro, 1998; Avey et al., 2011). New method: In large part due to its neuronal-specific labeling of ZENK protein, Santa Cruz Egr-1 sc-189 has been widely accepted as the standard primary antibody in songbird research. However, Santa Cruz Biotechnology Egr-1 no longer specifically labels and has also discontinued production of Egr-1 sc-189. Thus, the current study is focused on analyzing the effectiveness of alternative primary antibodies: Abcam polyclonal c-Fos, Abcam monoclonal ab133695 Egr-1, and Proteintech polyclonal Egr-1.
Conclusions
Abcam monoclonal Egr-1 effectively labels ZENK in the songbird auditory nuclei, making it a suitable primary antibody replacement for Santa Cruz polyclonal Egr-1.
Methods
Abcam monoclonal Egr-1 ab133695 was found to produce differential and specific labeling in the targeted auditory nuclei similar to previous studies successfully using Santa Cruz polyclonal Egr-1 (i.e. Mello and Ribeiro, 1998). Conclusions: Abcam monoclonal Egr-1 effectively labels ZENK in the songbird auditory nuclei, making it a suitable primary antibody replacement for Santa Cruz polyclonal Egr-1.
Results
Abcam monoclonal Egr-1 was successful in specifically labeling ZENK positive cells in the songbird auditory nuclei. Abcam polyclonal c-Fos and Proteintech polyclonal Egr-1 were found to have non-specific labeling. Comparison with existing methods: Abcam monoclonal Egr-1 ab133695 was found to produce differential and specific labeling in the targeted auditory nuclei similar to previous studies successfully using Santa Cruz polyclonal Egr-1 (i.e. Mello and Ribeiro, 1998). Conclusions: Abcam monoclonal Egr-1 effectively labels ZENK in the songbird auditory nuclei, making it a suitable primary antibody replacement for Santa Cruz polyclonal Egr-1.