Sandra Correa-Garhwal

• Doctor of Philosophy
• PostDoc Position at American Museum of Natural History

Net-casting spiders (Deinopidae) are cribellate spiders that spin a rectangular, sticky net that is held stretched between the claws of their first two pairs of legs. Deinopids produce eight distinct silk types, but knowledge of the silk-producing morphologies is mostly limited to the spigots associated with different fibers. As there have been no...

Introduction Orb web and cobweb weaving spiders in the superfamily Araneoidea are distinguished by their ability to make a chemically sticky aqueous glue in specialized aggregate silk glands. Aggregate glue is an environmentally responsive material that has evolved to perform optimally around the humidity at which a spider forages. Protein componen...

Background Spiders have evolved two types of sticky capture threads: one with wet adhesive spun by ecribellate orb-weavers and another with dry adhesive spun by cribellate spiders. The evolutionary history of cribellate capture threads is especially poorly understood. Here, we use genomic approaches to catalog the spider-specific silk gene family (...

The origin of aggregate silk glands and their production of wet adhesive silks is considered a key innovation of the Araneoidea, a superfamily of spiders that build orb-webs and cobwebs. Orb-web weavers place aggregate glue on an extensible capture spiral, whereas cobweb weavers add it to the ends of strong, stiff fibers, called gumfoot lines. Here...

Spider silks are renowned for their high-performance mechanical properties. Contributing to these properties are proteins encoded by the spidroin (spider fibroin) gene family. Spidroins have been discovered mostly through cDNA studies of females based on the presence of conserved terminal regions and a repetitive central region. Recently, genome se...

The semicrystalline protein structure and impressive mechanical properties of major ampullate (MA) spider silk make it a promising natural alternative to polyacrylonitrile (PAN) fibers for carbon fiber manufacture. When annealed using a similar procedure to carbon fiber production, PAN fibers strengthen and stiffen while MA silk fibers weaken consi...

Spiders are commonly found in terrestrial environments and many rely heavily on their silks for fitness related tasks such as reproduction and dispersal. Although rare, a few species occupy aquatic or semi-aquatic habitats and for them, silk-related specializations are also essential to survive in aquatic environments. Most spider silks studied to...

Most spiders spin multiple types of silk, including silks for reproduction, prey capture, and draglines. Spiders are a megadiverse group and the majority of spider silks remain uncharacterized. For example, nothing is known about the silk molecules of Tengella perfuga, a spider that spins sheet webs lined with cribellar silk. Cribellar silk is a ty...

Maximum likelihood tree of spidroin N-terminal regions. Shaded boxes indicate spidroin types as in Fig 1. Tree rooted with California trapdoor spider Bothriocyrtum californicum fibroin 1 (not shown). Bootstrap percentages ≥ 50% are shown. Scale bar represents substitutions per site. (PDF)

Tengella perfuga spidroins. (PDF)

Spidroin repetitive sequences of Tengella perfuga. (A) Repetitive sequence adjacent to N-terminal region. (B) Repetitive sequence adjacent to C-terminal region. Spidroin names abbreviated as in S2 Table. Amino acids abundant in silks are highlighted: alanine (red), serine (blue), and glycine (green). Pyriform amino acid motifs indicated in boxes. T...

Summary of Tengella perfuga de novo transcriptome assembly. (PDF)

Spidroin sequences from GenBank used in phylogenetic analyses. (PDF)

Background Orb-web weaving spiders and their relatives use multiple types of task-specific silks. The majority of spider silk studies have focused on the ultra-tough dragline silk synthesized in major ampullate glands, but other silk types have impressive material properties. For instance, minor ampullate silks of orb-web weaving spiders are as tou...

Spider silks are the toughest known biological materials, yet are lightweight and virtually invisible to the human immune system, and they thus have revolutionary potential for medicine and industry. Spider silks are largely composed of spidroins, a unique family of structural proteins. To investigate spidroin genes systematically, we constructed t...

Spiders (order Araneae) rely on their silks for essential tasks, such as dispersal, prey capture, and reproduction. Spider silks are largely composed of spidroins, members of a protein family that are synthesized in silk glands. As needed, silk stored in silk glands is extruded through spigots on the spinnerets. Nearly all studies of spider silks h...

Spider silk research has largely focused on spidroins, proteins that are the primary components of spider silk fibers. Although a number of spidroins have been characterized, other types of proteins associated with silk synthesis are virtually unknown. Previous analyses of tissue-specific RNAseq libraries identified 647 predicted genes that were di...

Spider silks have outstanding mechanical properties. Most research has focused on dragline silk proteins (major ampullate spidroins - MaSps) from orb-weaving spiders. Using silk gland expression libraries from the haplogyne spider Scytodes thoracica, we discovered two novel spidroins (S. thoracica fibroin 1 and 2). The amino acid composition of S....

Spiders from the family Scytodidae have a unique prey capturing technique - they spit a zig-zagged silken glue to tether prey to a surface. Effectiveness of this sticky mixture is based on a combination of contraction and adhesion trapping prey until the spider immobilizes it by envenomation and then feeds. We identify components expressed in Scyto...