Desenvolvimento pós-embrionário do intestino médio de Dermatobia hominis (Linnaeus Jr.) (Diptera, Cuterebridae)

Abstract

ABSTRACT. Post-embryonic developrnent of Dermatobia "olllinis (Linnaeus Jr.) (Diptera, Cuterebridae) midgut. Dermatobia "omillis (Linnaeus, 1781) midgul is internally lined by an epithelium 01' polylenic cells, some low others prismatic with well developed brush bordel'. Their apical portion are enlarged by secretOlY vesicles, forming butlon-Iike SlruClures lhal are pinched off lo lhe lumen, some accompained by lhe nucleus characterizing apocrine and holocrine secrelions. This epithelium is gradually renewed by small, non polylenic regenerative cells, found scattered aI ils basal portion. AI lhe end 01' lhe lhird inslar lhe metamorphosis begins. The epithelial cells present signs 01' degeneralion and aI lhe firsl day 01' pupation the regeneralive cells increase in num bel'. By lhe 5 th day 01' pupation these regenerative cells, besides being increased in number, differentiale lhemselves inlo lwo layers: one similar lO lhe dense coneclive tissue that suslainning lhe larva I epithelium is pinched off to lhe midgul lumen forming lhe "yellow bodies"; lhe olheI', develops righl under il as lhe imaginai epilelium. The disorganized muscles bundles 01' lhe midgut wall, are invaded by phagocytes. AI lhe end ofpupalion lhe midgut has a low prismalic epilhelium wilh brush-border. In the adult, the torax portion oI' lhe midgut has prismatic homogeneously basophilic epilhelium while in lhe abdominal portion lhe epithelium is made 01' high prismalic cells full oI' small vacuoles. The larval midgul epilhelium suffers programmed cell dealh non compalible with apoptose. During lhe metamorphosis lhe midgut lenght diminishes from 3 I111m in the larva lo 14111111 in lhe adult. K.EY WüROS. Diplera, Dermatobia hominis, l11idgul, metamorphosis, hislology, posl-embryonic developmenl Trabalhos sobre a morfologia interna do beme são encontrados, em LELLü ef aI. (1984, 1985, 1987); GREGÓRIO et aI. 1981GREGÓRIO et aI. , 1990aGREGÓRIO et aI. ,b, 1992.VIEIRA & LELLO (1996) desecreveram o desenvolvimento anatômico do tubo digestivo de D. hominis e observaram que de maneira geral ele é similar aos de outros dípteros muscóides, não apresentando entretanto, papo e cecos intestinais, em qualquer estágio do desenvolvimento e nem glândulas salivares na fase adulta. O tubo digestivo de D. hominis consta de três porções anatômicas distintas: o intestino anterior, o qual inclui como regiões diferenciadas, a faringe, o esôfago e o cárdia; o intestino médio e o intestino posterior.Este trabalho tem como objetivo mostrar as modificações histológicas do intestino médio (IM) de D. hominis durante o período pós embrionário.

Morphological regional differences of epithelial cells along the midgut in Diatraea saccharalis Fabricius (Lepidoptera: Crambidae) larvae

“…This large quantity of PAS-positive material in the cytoplasm of columnar cells also was observed in the midgut of Dermatobia hominis L. (Diptera: Cuterebridae) (Lello & Vieira 2001) and in Triatoma infestans Klug (Heteroptera: Reduviidae) (Burgos & Gutiérrez 1976).…”

“…Few studies describe the morphology of these projections under a light microscope (Caetano & Zara 2001, Lello & Vieira 2001, Levy et al 2004, Ferreira & Cruz-Landim 2005; and although the authors did not emphasize variability in the number of cytoplasmic protrusions dependent on the localization of columnar cells in the midgut, the morphological aspects described are similar to those observed in D. saccharalis. Our ultrastructural observations show that the scarce cytoplasmic protrusions of the anterior region exhibit microvilli on part of its surface and that these are absent in those of the posterior region, where its surface becomes smooth.…”