Are Spiders a Good Source of Protein?
WouterSpider silks are produced by a number of arthropod species, including herbivorous moth larvae and spiders. Silks are highly expressed proteins that include chains of amino acids. As a result, the silks are extremely resilient. They can stretch about 30% longer than their original length.
The silks of spiders are characterized by a variety of crystalline and amorphous fractions. These fractions have different amino acid compositions and may represent a historical record of the resources available to the spider.
Several studies have examined the effects of protein on spider silk. Some researchers have found that supplementation of amino acids increases the strength of spider silks. Others have shown that individual insects produce different types of silk through nongenomic mechanisms.
However, there is a lack of information about the molecular genetics of silk proteins, particularly silks from other arthropods. Molecular genetics has also not considered silks from different ecological contexts. Consequently, it is not clear whether different species of silk are produced through combinatorial association or through posttranscriptional editing.
In laboratory experiments, scientists found that the protein content of spider silk was influenced by the prey the spiders fed. They were fed crickets, bees, and blowflies. Those fed high-prey diets gained the most weight, but spiders on a low-prey diet gained significantly less.
A matched pair, signed-rank test was used to analyze the results. All samples were collected before and after treatments. For the control group, the food was soaked in solution made of rice bran and maltodextrin. Each group received one meal every three days. Afterwards, the silks were collected by hand.
