Programmed Cell Death in the Digestive Canal of Bombyx mori (Lepidoptera: Bombycidae) during Prepupal Period

Abstract

In silkworms, like other holometabolus insects, larval digestive canal degenerates via programmed
cell death (PCD) during larval-pupal metamorphosis. PCD plays a key role in developmental biology.
It generally occurs with two major mechanisms; apoptosis and autophagic cell death. In this study,
we aimed to determine the metamorphic events in the digestive canal of Bombyx mori during the
prepupal period. The general morphological changes were studied by using histological techniques; the
degenerative cells were determined using H&E (Hematoxylen&Eosin) and PAS (Periodic Acid Schiff)
staining. We have used TUNEL (terminal transferase-mediated dUTP nick end-labeling) assay for
determination of apoptotic cell nuclei. Also, the acid phosphatase activity was calculated to determine
the autophagic cell death. In conclusion; our observations indicated a co-occurrence of apoptosis and
autophagy observed during the cell death of the digestive canal.

Keywords

• Bombyx mori, apoptosis, digestive system, autophagy, TUNEL

Bombyx mori (Lepidoptera: Bombycidae)

Abstract

Tam metamorfoz geçiren ipek böceklerinde, larval-pupal gelişim sırasında sindirim kanalı programlanmış hücre ölümü yoluyla dejenere olmaktadır. Gelişim biyolojisinde programlanmış hücre ölümü anahtar rol oynamaktadır. Programlanmış hücre ölümü genel olarak, Apoptotik ve otofajik hücre ölümü olarak isimlendirilen iki ana mekanizma ile gerçekleşmektedir. Bu çalışmadaki amacımız, larvalpupal metamorfoz sırasında, Bombyx mori sindirim sisteminde meydana gelen metamorfik olayların gösterilmesidir. Histolojik teknikler kullanılarak morfolojik değişimler gösterilmiştir; H&E ve PAS boyama yöntemleri kullanılarak dejeneratif hücreler belirlenmiştir. Apoptotik hücre nukleuslarını belirlemek için TUNEL yöntemi uygulanmıştır. Otofajik hücre ölümünü göstermek amacıyla ise Asit Fosfataz aktivite hesaplamaları gerçekleştirilmiştir. Sonuç olarak; bulgularımız, sindirim kanalında meydana gelen ölümde apoptoz ve otofajinin birlikte rol oynadığını göstermiştir

Keywords

• Bombyx mori, apoptoz, sindirim sistemi, otofaji, TUNEL

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