Weighted gene Co-expression network analysis (WGCNA) reveals a set of hub genes related to chlorophyll metabolism process in chlorella (Chlorella vulgaris) response androstenedione

Androstenedione (ADSD) was the main androgen detected in wastewaters. Chlorella was the most widely used plant in biological wastewater treatment process. In order to understand the toxicological response of chlorella to ADSD contamination, we used the weighted gene co-expression network analysis (WGCNA) method to systematically analyze the gene regulatory networks of chlorella after ADSD treatments. Total of 25 modules was identified from gene co-expression networks, and the turquoise module were selected for GO and KEGG enrichment analysis. Results showed that most hub genes were associated with chloroplast organizations or photosystems processes. Among them, the expressions profiles of hcar, nol, pao and sgr genes were highly correlated to the content fluctuations of chlorophylls after different ADSD treatments. All these results demonstrated that chlorophylls play a key role in preventing cell damage of chlorella caused by ADSD contamination. Besides, we proposed a possible chlorophyll metabolism pathway in chlorella response to ADSD contamination.