The differences between the localizations of MUC1, MUC5AC, MUC6 and osteopontin in quail proventriculus and gizzard may be a reflection of functional differences of stomach parts

Abstract

Mucins are high molecular weight glycoproteins which constitute the major component of the mucus layer and are produce by many epithelial tissues in vertebrates. Osteopontin (OPN) is an adhesive phosphorylated glycoprotein that is expressed by a broad range of tissues and cells. Although gastric mucins MUC1, MUC5AC, MUC6 and OPN have been widely used in histological studies and in diagnostic pathology in order to diagnose gastric carcinomas, their localizations in the stomach of quail have not yet been studied. In this study, the localizations of MUC1, MUC5AC, MUC6 and OPN in the proventriculus and gizzard of Japanese quail during the post-hatching period were compared at light microscope levels by applying immunohistochemical methods. In all ages studied, the immunoreactivity of MUC5AC was present in the lining epithelium of both folds and superficial proventricular glands in the proventriculus, whereas MUC1, MUC6 and OPN reactivity was found in the oxynticopeptic cells of profound proventricular glands. In addition, some cells in the fold epithelium of the proventriculus showed a positive reaction to OPN. The immunoreactivity of MUC1 in gizzard was different from that of MUC5AC. Although MUC5AC was expressed in the cells of both the surface epithelium and profound glands of the gizzard, MUC1 was only localized in the profound glands of the gizzard. However, MUC6 and OPN immunoreactivity was absent in the gizzard. The results indicated that the differences between the localizations of MUC1, MUC5AC, MUC6 and OPN in quail proventriculus and gizzard may be a reflection of functional differences of stomach parts. Although the biological significances of the expressions of MUC1, MUC5AC, MUC6 and OPN in the quail stomach remains unknown, these notable glycoproteins may be associated with barrier function, host defence, and ⁄ or secretion.

Histological Description of Morphogenesis of the Gastroesophageal Mucosa of Gallus gallus domesticus (Linnaeus, 1758)

“…In an anterior position, the proventriculus is responsible for peptic digestion. It is histologically characterized by being internally covered by mucus-secreting cylindrical cells and by containing several branched glands in the connective tissue, which are formed by oxyntic-peptic cells that secrete both hydrochloric acid and pepsinogen (Illanes et al, 2006;Askoy & Cinar, 2009;Liman et al). The gizzard is located posteriorly in the stomach.…”

“…The stomach of birds is composed of two histologically and physiologically distinct regions, a glandular portion or proventriculus, and a muscular portion or gizzard (Takiguchi et al, 1988;Liman et al, 2010). In an anterior position, the proventriculus is responsible for peptic digestion.…”

“…It is characterized by presenting a secretion plate on the inner surface and a well-developed muscle layer. Both characteristics represent an adaptation to grind grains (Catroxo et al, 1997;Askoy & Cinar;Liman et al).…”

Prenatal development and histochemical characteristics of gastrointestinal mucins in sheep fetuses

“…A mucus layer composed of ions, water, lipids, proteins, and glycoproteins covers the mucosal epithelium and provides protection against both mechanical, chemical and enzymatic damage and pathogenic microorganisms (Karakoç et al, ; Rose & Voynow, ). Gastric mucins are secreted by the luminal epithelial cells and gastric glands in some animal species and humans (Lacunza, Bara, Segal‐Eiras, & Croce, , b; Liman, Alan, and Küçük Bayram, ; Terada, ; Vernygorodskyi, ). In humans and the opossum, superficial cells of the gastric mucosa and glandula pylorica secrete only neutral mucins, while in the vole, rat, bison, rabbit, Japanese macaque, Rhesus monkey, raccoon dog, white‐tailed deer, guinea pig, and cat, they produce both acidic and neutral mucins (Karakoç et al, ; Schumacher et al, ).…”

Occurrence of a mosquito vector in bird houses: Developmental consequences and potential epidemiological implications

“…Digestion in birds involves many organs, each performing a specific function. In particular, birds have a well-developed crop that acts as a temporary food storage site and a two-part stomach consisting of a glandular portion (the proventriculus) and a muscular portion (the gizzard) where the food material is broken down, ground, and disassembled to facilitate enzymatic actions (Liman et al, 2010;Ventura et al, 2013). Birds possess a cloaca, which is the final holding area for waste products of digestion, where the output of the intestines is collected, and the liver, pancreatic tract, and the two ureters open (Vasiliu and Buruiana, 2010).…”