Author
GOTO, S - KOBE UNIV., KOBE, JAPAN | |
TAKEDA, M - KOBE UNIV., KOBE, JAPAN | |
HAKIM, R. - HOWARD UNIV., WASH., DC | |
Loeb, Marcia |
Submitted to: In Vitro Biology
Publication Type: Abstract Only Publication Acceptance Date: 6/15/2000 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Insect midgut is not only the most important organ in the digestive system but also the entry point for Bacillus thuringiensis and other microorganisms. However, the physiology of the mechanisms that regulate midgut cell proliferation and differentiation is lacking. Methods for culturing lepidopteran midgut cells have been reported (Sadrud-Din, Hakim and Loeb, 1994), greatly stimulating this line of research. Midgut differentiation factor (MDF1) was purified from conditioned medium used for Manduca sexta midgut cell culture (Loeb et al., 1999). This polypeptide has homology to portions of bovine fetuin protein and stimulates cultured midgut stem cells of M. sexta or Heliothis virescens to differentiate.A polyclonal antiserum against MDF 1 was raised in a rabbit. MDF 1-like immunohistochemical reactivity was found in the cultured cells. Twenty four hours before molting from 4(th) instar to 5(th) instar (slipped head stage), a period when the stem cells in the larval midgut are undergoing rapid mitosis and differentiation in vivo, the number of cells stained by this serum increased. The only cell type that responded positively to the antibody was the mature columnar cell. |