Apocrine secretion of amylase and exocytosis of trypsin along the midgut of Tenebrio molitor larvae.

نویسندگان

  • Cristofoletti
  • Ribeiro
  • Terra
چکیده

Amylase and trypsin were purified from Tenebrio molitor midgut larvae and used to raise antibodies in a rabbit. A Western blot of T. molitor midgut homogenates, after sodium dodecyl sulfate-polyacrylamide gel electrophoresis using amylase and trypsin antisera, showed only bands co-migrating with the purified enzymes. The antisera were used to localize the enzymes by immunofluorescence and immunogold labeling. Amylase occurs in a few regularly disposed anterior midgut cells. Non-amylase-secreting anterior midgut cells are proposed to be water-absorbing cells based on morphology and dye movements. Amylase is found inside vesicles originating from Golgi areas that seem to fuse together before their release along with the now disorganized apical cytoplasm (apocrine secretion). Trypsin precursors are observed inside small vesicles near the apical plasma membrane of posterior midgut cells, suggesting an exocytic mechanism of secretion, followed by putative trypsin activation. Apocrine secretion is thought to be an adaptation to enhance the dispersion of secretory vesicle contents released from a water-absorbing epithelium, whereas exocytosis is an efficient secretory mechanism in a water-secreting epithelium.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Digestion of Starch Granules from Maize, Potato and Wheat by Larvae of the the Yellow Mealworm, Tenebrio molitor and the Mexican Bean Weevil, Zabrotes subfasciatus

Scanning electron microscopy images were taken of starch granules from different sources following exposure in vivo and in vitro to gut alpha-amylases isolated from Tenebrio molitor L. (Coleoptera: Tenebrionidae) and Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae). One alpha-amylase was isolated from whole larval midguts of T. molitor using non-denaturing SDS-PAGE, while two other alpha-a...

متن کامل

Effects of dietary replacement of fishmeal by yellow mealworm (Tenebrio molitor) larvae meal on growth performance, hematological indices and some of non-specific immune responses of juvenile rainbow trout (Oncorhynchus mykiss)

8-week feeding trial was conducted for juvenile rainbow trout (Oncorhynchus mykiss) to determine the optimal amount of Tenebrio molitor meal (TM) that could replace fishmeal in feeds without reducing growth performance, hematological indices and non-specific immune responses. Five isonitrogenous and isolipidic diets were formulated with TM replacing 0% (Control), 25% (TM25), 50% (TM50), 75% (TM...

متن کامل

Diversity of digestive proteinases in Tenebrio molitor (Coleoptera: Tenebrionidae) larvae.

The spectrum of Tenebrio molitor larval digestive proteinases was studied in the context of the spatial organization of protein digestion in the midgut. The pH of midgut contents increased from 5.2-5.6 to 7.8-8.2 from the anterior to the posterior. This pH gradient was reflected in the pH optima of the total proteolytic activity, 5.2 in the anterior and 9.0 in the posterior midgut. When measure...

متن کامل

Investigation of pancreatic digestive enzymes changes from egg to larvae phase of Schizothorax zarudnyi

In order to identify trends and provide suitable diet for Schizothorax zarudnyi, the activity of alpha-amylase, trypsin, and lipase in five treatment groups including: fertilized egg, newly-hatched larvae, the larvae a day, larvae absorbed in the bag 2/ 3 yolk and absorption of yolk sac larvae, in 20 embryonated eggs and 80 larvae at the end of 53 days were studied. Analysis of the data showed ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Journal of insect physiology

دوره 47 2  شماره 

صفحات  -

تاریخ انتشار 2001