Total Proteolytic Activity on The Pupal Rectal Sac of Bombyx mori L. Lepidoptera: Bombycidae

Abstract

This study is aimed to demonstrate histologically secretory materials of the rectal sac and also determine total proteolytic enzyme activity of sac’s fluid of silkworm, Bombyx mori considered to be responsible for adult eclosion from its cocoon. The rectal sacs of pupae were fixed with Bouin’s solution. The sections taken from the sac were stained by Paraldehyde Fuchsin and Periodic acid-Schiff dyes. Total protein concentrations and proteolytic activities of sac contents were determined by Bradford method at 595nm and azocasein substrate at 420nm, respectively. The secretions -proteinic and lipoid- were determined by different stains. As the sac grew up gradually, these two secretory materials were separated into darker and lighter phases. Protein concentration existed in the darker phase of secretion was higher than that in the lighter one. The total proteolytic activity measurements of the lighter phase were higher than the darker one, in both sexes. It was found that the activity of lighter phase in male is higher than that of female on the 10th day. This result supports that male moths escape earlier from cocoon than the female moths. Consequently, proteinic secretion synthesized by some cells of rectal sac could play a role in emerging from their cocoons of moths.

Keywords

• Bombyx mori pupa,rectal sac,proteolytic activity,azocasein

Bombyx mori L. Lepidoptera: Bombycidae ‘ye Ait Pupa Rektal Kesesindeki Toplam Proteolitik Aktivite

Abstract

B u çalışmada ipekböceği, Bombyx mori ergininin kozasından çıkışında etkin olduğu düşünülen rektal kese salgısının hem histolojik olarak gösterilmesi hem de toplam proteolitik enzim aktivitesinin belirlenmesi amaçlanmıştır. Pupaya ait rektal keseler Bouin solüsyonu ile tespit edildi. Kesesinin bölümleri Paraldehit fuksin ve Periyodik asit-Schiff boyası ile boyandı. Kese içeriklerinin toplam protein derişimi ve proteolitik aktivitesi sırasıyla Bradford metodu ile 595 nm’de ve azokazein substratı ile 420 nm’de belirlendi. Sekresyonlar -proteinik ve lipoid- farklı suşlar kullanılarak belirlendi. Kese giderek büyürken, bu iki salgı malzemesi koyu ve açık fazlara ayrıldı. Salgının koyu fazı içerisindeki mevcut protein derişimi, açık fazın sahip olduğu miktardan daha yüksektir. Açık fazın toplam proteolitik aktivite ölçümleri her iki cinste de, koyu fazdakine gore bir daha yüksektir. 10. günde, erkekteki açık faz aktivitesinin dişidekine göre daha yüksek olduğu tespit edildi. Bu sonuç, erkek kelebeklerin dişi kelebeklerden daha once kozasından ayrıldığı bilgisini desteklemektedir. Sonuç olarak, rektal keseye ait bazı hücreler tarafından sentezlenen proteinik salgı kelebeklerin kendi kozasından çıkmasında önemli bir rol oynayabilmektedir

Keywords

• Bombyx mori pupa,rektal kese,proteolitik aktivite,azokazein

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