Flygut: an atlas of the Drosophila adult midgut

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Home Overview of gut regions Anatomy Histology Transgene expression mapping Gene expression

Overview of gut regions

1- A 2D map of the Drosophila midgut regions

The Drosophila digestive tract is divided into three major parts of different developmental origins:
  1. The foregut, which consists of tissues of ectodermic origin including the pharynx, the esophagus, the crop (a storage food bag), and the proventriculus (the central part of the cardia, which forms a valve at the midgut entrance).
  2. The midgut forms the central and endodermal part of the gut starting with the outer epithelium layer of the cardia and ending at the midgut-Malpighian tubules junctions.
  3. The hindgut forms the posterior part of the gut and is also of ectodermal origin.
To increase our knowledge about the Drosophila midgut, we established a map of midgut regions using three distinct approaches:
  1. A morphometric analysis allowed us to define 6 regions within the midgut (including R0, the endodermic portion of the cardia). See Anatomy
  2. A histological analysis confirmed the existence of the 6 regions described above and allowed the identification of additional sub-regions: R1a & R1b, R3ab & R3c, and R4a & R4bc. See Histology
  3. A gene expression pattern analysis including those of 92 reporter transgenes expressed in enterocytes allowed the identification of additional sub-regions in the midgut. The expression pattern of the transgenes used in this study is described in the section Gene expression patterning.

Overview scheme
Figure 1: The schematic representation of the Drosophila midgut is based on anatomical, histological and reporter gene expression mapping. Note that the midgut region R0 was not analyzed for subregional details in our study.

A 3D model of the Drosophila midgut

We generated a 3D reconstruction of the gut based both on a morphometric analysis of the midgut and on measurements performed on histological sections. Shown is a 3D view of the midgut revealing its folding within the body cavity. The distinct midgut regions are colored as indicated in the table; major boundaries are depicted in blue. The table presents the average region coordinates expressed as a percentage of midgut length (0 corresponds to the start and 100 to the end of the midgut).
(Click on the picture to activate the 3D view):

Color Name Position Anatomical region Histological region Start (% of midgut) Stop (% of midgut)
Crop 1 Crop Crop
cardia (proventriculus) 2 Cardia Cardia
cardia (midgut part) 3 Cardia Cardia 0.0 2.3
Boundary P-1 4 Boundary P-1 Boundary P-1 2.3 4.0
R1a 5 R1 R1a 4.0 9.0
R1b 6 R1 R1b 9.0 13.0
R2a 7 R2 R2 13.0 27.0
R2b 8 R2 R2 27.0 35.0
R2c 9 R2 R2 35.0 45.0
Boundary 2-3 10 Boundary 2-3 Boundary 2-3 45.0 48.0
R3a 11 R3 R3ab 48.0 52.0
R3b 12 R3 R3ab 52.0 54.0
R3c 13 R3 R3c 54.0 59.0
Boundary 3-4 14 Boundary 3-4 Boundary 3-4 59.0 62.0
R4a 15 R4 R4a 62.0 69.0
R4b 16 R4 R4bc 69.0 77.0
R4c 17 R4 R4bc 77.0 89.0
R5a 18 R5 R5 89.0 93.0
R5b 19 R5 R5 93.0 100.0
Hindgut 20 Hindgut Hindgut