摘要Insect midgut plays a central role in food digestion and nutrition absorption.Larval silkworm midgut could be divided into 3 distinct regions based on their morpholog-ical colors.However,it remains rudimentary of regional gene expression and physiological function in larval silkworm midgut.Through transcriptome sequencing of 3 midgut com-partments,a comprehensive analysis of gene expression atlas along the anterior-posterior axis was conducted.Posterior midgut was found transcriptionally divergent from anterior and middle midgut.Differentially expressed gene analysis revealed the regional special-ization of digestive enzyme production,transmembrane transport,chitin metabolism,and hormone regulation in different midgut regions.In addition,gene subsets of pan-midgut and region-specific transcription factors(TFs)along the length of midgut were also iden-tified.The results suggested that homeobox TFs might play an essential role in transcrip-tional variations across the midgut.Altogether,our study provided the first fundamental resource to investigate physiological function and regulation mechanism in larval midgut compartmentalization.