Download Break The Cocoon
Keva Magera
Wanting to help the butterfly, the boy snipped a slit in the cocoon with a pair of scissors. But the butterfly was small, weak, and its wings crumpled. The boy expected the insect to take flight, but instead it could only drag its undeveloped body along the ground. It was incapable of flying.
The boy, in his eagerness to help the butterfly, stunted its development. What he did not know was that the butterfly needed to go through the process of struggling against the cocoon to gain strength and fill its wings with blood. It was the struggle that made it stronger.
The phylogenetic tree was constructed using the Maximum Likelihood method, based on the Poisson correction model with 1,000 bootstrap replicates, and bootstrap support values more than 50% were shown in the tree. The 295 cocoonase homologs from 12 classes, identified with different colored fonts, are divided into 14 clades, showed in the outer ring. And 70 protein sequences from the Lepidoptera were aggregated with the clade containing silkworm cocoonase, shown in the orange curved area.
Syntenic analysis of cocoonase genes in lepidopteran species marked with purple clades and three outgroups with available linkage information. Orthologous genes are identified by a border with same color, and non-homologous genes and genes without functional annotation are indicated by ORFs and marked by a gray border. The green rectangles represent predicted transposons. The Arabic numerals in the figure showed the copy number of the cocoonase gene in each species. The two cocoonase genes of Plutella xylostella were located at different scaffold, and the IDs of the two enzymes were shown next to the gene on the scaffold diagram.
Based on the habits of cocooning or not and the characteristics of the cocoons, lepidopteran insects not spinning a cocoon, spinning a sealed cocoon, or having an unsealed cocoon were classified roughly and displayed on the right panels.
(A) Unpierced cocoon rate of BmCoc+/+ and BmCoc-/- individuals. One hundred individuals of wild type and BmCoc-/- homozygotes were randomly selected for analysis. (B) Morphological observations of BmCoc+/+ and BmCoc-/- cocoons. BmCoc+/+ cocoons with pierced holes caused by the moth escaping from the cocoon are shown on the top image. Intact cocoons of BmCoc-/- and split cocoons with a successfully metamorphosed moth inside are shown below. Bar = 1 cm. (C) Morphological observations of homozygotes naturally stored for more than six months. Inside the cocoons are dried moths that have died naturally. Bar = 2 cm.
Our investigation and analysis reveal that the cocoonase gene is specific to Lepidoptera. In the synteny analyses, Hyposmocoma kahamanoa, a kind of amphibious insect belonging to the genus Hyposmocoma (Cosmopterigidae) [40], was located at the base of the Lepidoptera lineage in the evolutionary tree of species. Although it does not construct cocoon, this species also has the cocoonase gene. Combined with the differentiation time of species and the cocooning behaviors of lepidopterans, it seemed that the cocoonase gene existed before the emergence of Lepidoptera insects spinning cocoons, which ensured that the adults could escape from their cocoons. With the increasing number of sequenced species, adding more basal lepidopteran insects is needed to strengthen the argument. In addition, insects spinning cocoons are distributed in multiple families that are not closely related, indicating that the cocooning behavior may have evolved convergently. Despite differences in cocooning behavior, the cocoonase gene is mainly affected by purifying selection in Lepidoptera and the selection is more intense in insects spinning sealed cocoons. The protease activities of Bombyx mori and Antheraea Pernyi were characterized by purified cocoonase through substrate degradation experiment [25, 32]. The results implied that the two enzymes have similar activities. In addition, there are other lepidopteran adults such as Dicranura vinula (Notodontidae), Saturnia carpini (Saturniidae), Limacodes testudo (Limacodidae) and Halias prasinana (Noctuide) were able to secrete vomiting fluid that could soften the cocoon assisting moth emergence [18, 19]. Combined with our research, we speculated that other cocoonase enzymes should have the conserved activities in dissolving cocoon. Further, genetic manipulation of cocoonase in the silkworm Bombyx mori forcefully illustrated its decisive role in adults escaping from sealed cocoons in lepidopteran insects. The gland producing silk and the cocoon silk proteins are very different among species [13, 14] and insects constructing sealed cocoons among other orders may have an additional factor (or other factors) for assisting adults in the escape from the cocoon.
The order of the species is based on the species tree displayed on the left panel and the number of cocoonase gene in each species was shown in the right histogram. Moths are marked in green and butterflies are marked in light purple.
The phylogenetic tree were constructed for phylogenetic analysis using maximum likelihood method based on the alignment of cocoonase coding sequences. The maximum likelihood tree was inferred using Kimura 2-parameter model with 1,000 bootstrap replicates. The numbers at the nodes indicated bootstrapping values. Insects not spinning a cocoon, spinning a sealed cocoon or having an unsealed cocoon were marked with rings, black circles and black triangles, respectively.
The multiple alignment was produced using Muscle and amino acids were further analyzed within three groups, insects spinning sealed or unsealed cocoon and insects do not spin a cocoon. The aligned amino acids with more than 50% conservation among different insects were colored. The diverse colors indicated the different types of amino acids. And the functional sites relevant to serine protease are shown above the sequences. The arrow implied the signal cleavage site; blue asterisk marked the three catalytic active sites of serine protease (histidine, aspartic acid and serine); the purple asterisk represented the substrate binding sites; the letter C stood for the cysteine that forms the disulfide bond.
Beyond your cocoon is a Universe ripe with abundance and opportunity for expansion, love and peace. The cocoon is simply the illusion of all of the above, because in comfort there is no real peace, only the stagnant shadow of what could be.
Overcoming your own habits and the cultural obsession with always being comfortable and fitting in is not an easy task, but it is a natural one. The stagnant air of the cocoon is hard to breathe. The dark sleepy energy of comfort gets old and the drive to wake up and expand takes over if you let it.
Imagine for a moment a pile of leaves and soil. In the middle of this pile is a precious diamond. The diamond is the core of your being. It is within you at all times. The leaves and soil are your cocoon (your ego trying to cover up the amazing truth of who you really are). Clearing away the detritus is simple, and the detritus itself has a purpose.
As the jet slams into the cocoon, it causes it to glow, a phenomenon that astronomers call the afterglow. However, it had been unclear whether the jet is able to penetrate through the cocoon and emerge on the other side.
Babei Group, a private silk necktie-producing enterprise, announced on Sunday that its first batch of mass-produced silkworm cocoons had rolled off production line, marking the success of a seven-year-long research on factory-raised silkworms.
With a total investment of 350 million yuan (51.5 million U. S. dollars), the company's silkworm workshop is able to churn out 10,000 tonnes of high-quality cocoons annually, about the total yield of 100,000 households of farmers, using less than 200 workers.
Many insects spin cocoons to protect the pupae from unfavorable environments and predators. After emerging from the pupa, the moths must escape from the sealed cocoons. Previous works identified cocoonase as the active enzyme loosening the cocoon to form an escape-hatch. Here, using bioinformatics tools, we show that cocoonase is specific to Lepidoptera and that it probably existed before the occurrence of lepidopteran insects spinning cocoons. Despite differences in cocooning behavior, we further show that cocoonase evolved by purification selection in Lepidoptera and that the selection is more intense in lepidopteran insects spinning sealed cocoons. Experimentally, we applied gene editing techniques to the silkworm Bombyx mori, which spins a dense and sealed cocoon, as a model of lepidopteran insects spinning sealed cocoons. We knocked out cocoonase using the CRISPR/Cas9 system. The adults of homozygous knock-out mutants were completely formed and viable but stayed trapped and died naturally in the cocoon. This is the first experimental and phenotypic evidence that cocoonase is the determining factor for breaking the cocoon. This work led to a novel silkworm strain yielding permanently intact cocoons and provides a new strategy for controlling the pests that form cocoons.
Spinning and cocooning are the instincts of many insects, providing a shelter to the residing pupae to resist adverse factors. After the metamorphosis of pupa into adult, the adult must break open the cocoon to emerge, which is called decocooning. We have bioinformatically identified that cocoonase is specific to Lepidoptera, and demonstrated that it is the determining factor for breaking the sealed cocoon experimentally for the first time. This work led to a novel silkworm strain yielding permanently intact cocoons and provides a new strategy for controlling the pests that form cocoons and for breeding.
It is particularly noteworthy that, a recent study identified 29 proteins in the silkmoth-vomiting fluid through LC-MS/MS assay [36]. The result implied that some other proteins besides cocoonase in the vomiting fluid may also participate in the cocoon digesting process. To explore whether cocoonase is the unique component enough to dissolve cocoon or other proteins in the silkmoth-vomiting fluid have the same hydrolytic ability, and investigate the origin and evolution of cocoonase, we identified the cocoonase genes in a wide range of species and performed evolutionary analysis. Further, we knocked out the cocoonase (BmCoc) gene in the domesticated silkworms which spin sealed and dense cocoons by CRISPR/Cas9 system to explore its role in the decocooning process.
760c119bf3