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احمد علي احمد علام

Assistant Professor

أستاذ مساعد

كلية العلوم
King Saud University, College of Science, Department of Zoology, Riyadh11451, Saudi Arabia
المنشورات
مقال فى مجلة
2011

Comparative morphology of the skin of Natrix tessellata (family: Colubridae) and Cerastes vipera (family: Viperidae).

AA., Abo-Eleneen RE, Allam . 2011

We studied beneficial difference of the skin of two snakes. Two snakes were chosen from two different habitats and two families: Colubridae (Natrix tessellata) and Viperidae (Cerastes vipera). The investigations were performed by light and electron microscopy. Histologically, the skin of the studied species show pronounced modifications that correlated with functional demands. The scales in Natrix tessellata overlapped slightly, while in Cerastes vipera they were highly overlapped. SEM shows that scales of Natrix tessellata had bidentate tips while the scales of Cerastes vipera were keeled. Histochemically, in both studied species, melanocytes and collagenous fibres were distributed throughout the dermis. Polysaccharides were highly concentrated in the epidermis and dermis of both species while proteins were highly concentrated only in the epidermis. Transmission electron microscopy (TEM) showed that the skin of both snakes consisted of keratins located in the epidermis. Some lipids and mucus were incorporated into the outer scale surfaces such that lipids were part of the fully keratinised hard layer of the snakes' skins. Lipids are probably responsible for limiting water loss and ion movements across the skin. Melanosomes from epidermal melanocytes were present only in Cerastes vipera. In aggregate, these results indicate that snakeskin may provide an ecological indicator whereby epidermal and integumentary specializations may be ecologically correlated.

نوع عمل المنشور
paper
مجلة/صحيفة
Zoolog Sci. 2011 Oct;28(10):743-8. doi: 10.2108/zsj.28.743.
مزيد من المنشورات
publications

Nicotine exposure during pregnancy induces oxidative stress and leads to behavioral alterations in early childhood and young adulthood. The current study aimed to investigate the possible…

بواسطة 1) Jamaan S. Ajarem, Gadh Al-Basher, Ahmed A. Allam and Ayman M. Mahmoud
2017
publications

In the present study, it was hypothesized that micromorphology of the surface of many lizard scales appears to mimic the topography of the habitat in which they live. Many authors have suggested…

بواسطة 5) Allam AA, Abo-Eleneen R, ALOthman S.
2017
publications

The power of tumorigenesis, chemo-resistance and metastasis in malignant ovarian
tumors resides in a tiny population of cancer cells known as ovarian cancer stem cells (OCSCs).

بواسطة Amoura Abou-ElNaga, Ghada Mutawa, Ibrahim M. El-Sherbiny, Hassan Abd-ElGhaffar, Ahmed A. Allam, Jamaan Ajarem and Shaker A. Mousa
2017