Chapter 1, The Reptilian Spectacle - UWSpace - University of ...

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Figure 4-7. ß keratin immunoblot of snake spectacle
scale proteins. 1: Southern Pacific rattlesnake
(Crotalus oreganus helleri, Viperidae); 2: boa constrictor
(Boa constrictor, Boidae); 3: green anaconda (Eunectes
murinus, Boidae); 4: Mexican west coast rattlesnake
(Crotalus basiliscus, Viperidae); 5: western
diamondback rattlesnake (Crotalus atrox, Viperidae); 6:
Louisiana pine snake (Pituophis ruthveni, Colubridae);
7: hognose snake (Heterodon platirhinos, Colubridae,
subfamily Colubrinae).
4.3.2 Keratins of Gecko Spectacle, Labial and Head scales.
Comparisons of the proteins of gecko scales are shown in Figure 4-8 (Gekko grossmanni, next page)
and Figure 4-9 (Phelsuma madagascariensis grandis, next page). Gecko spectacle scales contain no ß
keratin. G. grossmanni expresses two forms of α keratin in the range of 54-65 kDa and P. m. grandis
expresses a single form of 55-60 kDa. The labial and head scales however are largely composed of ß
keratin with a single tight α keratin band in P. m. grandis and no detectable α keratin in G. grossmanni.
In both species, the diversity of ß keratins in these scales is greater than in the snake scales and their
sizes are larger on average, clustering around 17-18 kDa and ranging from ~12-22 kDa. The univ-ß
antibody reacted with most of the putative ß keratins, but also exhibited non-specific binding to the α
keratin of P. m. grandis, a problem noted by previous authors with other anti-ß keratin antibodies
(Alibardi & Toni 2005b). To determine if other proteins were present in quantities too small to detect
with the standard methodology, a sample of P. m. grandis labial scale was overloaded in one gel and
the image heavily processed (Figure 4-9C). This demonstrated the presence of several other proteins
present in minute quantities, including two proteins slightly larger than 24 kDa, a diffuse band of 38
kDa, and two proteins between this and the single α keratin. The larger proteins of 38 to ~50 kDa may
correspond with loricrin, filaggrin-like protein, sciellin and/or transglutaminase, all accessory
cornification proteins shown by Alibardi & Toni (2005b) to occur in the gecko integument.
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