Transcriptome analysis elucidates key changes of pleon in the process of carcinization

When megalopa molting to the first juvenile crab stage,the crabs undergo carcinization morphogenesis.To study the key physiological and morphological processes in carcinization,we performed a comparative transcriptomic analysis between the cephalothoraxes and the pleons of megalopa and the first juvenile crab stage in Chinese mitten crab.The results reveal that the major physiological and morphological changes in the pleon were related to energy metabolism(oxidative phosphorylation and AMPK pathways),ventral nerve cord fusion(apoptosis-related pathways),and metamorphosis(transcription factors,Hedgehog and Hippo pathways).We also discovered that the key Hox genes abdominal-B and abdominal-A might regulate morphological changes,especially in the degeneration of the fifth pair of pleopods,and ganglion fusion,respectively.Studying the regulatory mechanisms of carcinization may help us better understand the developmental biology of the juvenile crabs.