Re-evaluating ‘Silkworm’ Cocoons in Early Medieval Poznań: A Critical Analysis

The aims of this article are introducing hand woven silk fabrics, a cultural heritage and woven in Harpoot to the world culture and informing about how silkworm breeding was carried out in villages through primitive methods. Silkworm breeding was a great source of revenue for people in Harpoot (Elazig-Harput) region and around between the years of 1870 and 1950. The silkworm breeding and cocoon production depend on the existence of mulberry trees. Harpoot, has both mulberry trees and available climate and soil structures. Therefore, the silkworm breeding became a family occupation carried out all along in Harpoot region. The study consists of two stages. At the first stage, negotiations were made with people who used to be engaged in silkworm breeding and obtained information from them about the silkworm breeding in that period. In the second stage, silk fabrics in the inventory of Elazig Archaeology and Ethnography Museum, were brought to light and examined. But youngsters’ lack of interest to silk production and weaving in the region caused this cultural heritage with important values disappear off the face of the earth.

Sericulture is one of the great inventions of the Chinese people and has become an important cultural feature of China. As China is the long-lasting center of silk production, genetic breeding of silkworm was highly developed historically, and has formed a comprehensive system for breeding and preservation of new varieties. However, silkworm breeding reached a bottleneck recently, because most of the traditional genetic resources have been utilized and silkworm strains have become homogeneous. Meanwhile, sericulture in China meets huge challenges in the 21st century. In recent years, with the development and rapid application of molecular biology, genomics, transgene and genome editing, silkworm genetic breeding has entered a new era. In this review, we summarize the development of silkworm genetic breeding, especially the progress and perspective of transgene and genome editing in genetic engineering of silkworms. We also discuss the future development of silkworm genetic breeding.

Coleus forskohlii (CF) is a well-known medicinally important plant and it has been part of Ayurveda for decades. Forskolin, a diterpene and active constituent of Coleus forskohlii root extract (CFRE). The CFRE has been used for treating various infections and chronic diseases. But the CFRE has never been used as a pesticide. Exorista bombycis (Uzi fly) is a common pest found to infest Bombyx mori (Silk worm) and cause severe loss to sericulture farmers or community. Uzi fly targets the fifth instar larvae of silk worm to lay its eggs and for the propagation of its species. CFRE and Forskolin were evaluated for its anti-Uzi fly properties and the Uzi fly maggots, Uzi fly pupae were treated with different concentrations of CFRE and Forskolin were used i.e. 0.5, 1.0, 1.5, 2.0 μg/μL. It was observed that the normal growth and development of Uzi fly were hindered at different stages of its life cycle. The fifth instar larvae of silkworm were treated with 0.5-2.0 μL of CFRE and Forskolin which resulted in oviposition deterrence, reduced egg hatching, aberrations and deformities in pupae and adult (i.e. molting process, ecdysial failure) and adult emergence from pupae. The observations from the present study clearly suggest that CFRE and Forskolin can be an alternative for commercially available pesticides for preventing the propagation of Uzi fly by influencing its growth, development, and metamorphosis of immature stages of Uzi fly. The efficacy of CFRE is slightly better than Forskolin in exerting its anti-Uzi fly properties.

The apparent variability of silkworm (Bombyx mori) silk and its relationship with degumming

Bombyx mori (B. mori) silk was modified with the nano-TiO2 and chitosan dispersion system by the crosslinking reactions of citric acid (CA) and maleic anhydride (MA). The average size of the nano-TiO2 particles in the aqueous dispersion system was 36.7 nm. The scanning electron microscopy (SEM) micrographs showed that the nano-TiO2 particles were spherical and homogeneously dispersed in the dispersion system, and the surface ofB. mori silk fiber treated with the nano-TiO2 and chitosan dispersion system was rougher than that of the untreated one. X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) Spectrometry indicated that the crystallinity of theB. mori silk fiber increased after treatment. It was also found that the nano-TiO2 and chitosan contributed to significantly enhance the mechanical properties including breaking strength, breaking elongation, initial modulus, rupture work, and elastic recovery property of theB. mori silk fiber. The wrinkle-resistant performance of the treatedB. mori silk fabrics was also greatly improved.

The mechanical behavior and microstructure of minor ampullate gland silk (miS) of two orb-web spinning species, Argiope trifasciata and Nephila inaurata, were extensively characterized, enabling detailed comparison with other silks. The similarities and differences exhibited by miS when compared with the intensively studied major ampullate gland silk (MAS) and silkworm (Bombyx mori) silk offer a genuine opportunity for testing some of the hypotheses proposed to correlate microstructure and tensile properties in silk. In this work, we show that miSs of different species show similar properties, even when fibers spun by spiders that diverged over 100 million years are compared. The tensile properties of miS are comparable to those of MAS when tested in air, significantly in terms of work to fracture, but differ considerably when tested in water. In particular, miS does not show a supercontraction effect and an associated ground state. In this regard, the behavior of miS in water is similar to that of B. mori silk, and it is shown that the initial elastic modulus of both fibers can be explained using a common model. Intriguingly, the microstructural parameters measured in miS are comparable to those of MAS and considerably different from those found in B. mori. This fact suggests that some critical microstructural information is still missing in our description of silks, and our results suggest that the hydrophilicity of the lateral groups or the large scale organization of the sequences might be routes worth exploring.

Genetic hybridization of highly active exogenous functional proteins into silk-based materials using “light-clothing” strategy

Development of novel electrospun nanofibrous scaffold from P. Ricini And A. Mylitta silk fibroin blend with improved surface and biological properties.

Microsporidiosis of silkworm, Bombyx mori L. is one of the deadliest diseases caused by intracellular obligatory parasite. Infections of the disease range from chronic to highly virulent and can result in complete loss to the sericulture industry. The disease has become increasingly more and more complex as more number of microsporidian strains / species infecting silkworms are being identified from India and other sericulture practicing countries of the world. These microsporidians differ in pathogenicity, rate of spread, transmission and multiplication. Therefore, an attempt has been made to review the literature on microsporodiosis of the silkworm B. mori L. Key words: Bombyx mori L, microsporidia, Nosema bombycis, ultra structure.

Degummed Bombyx mori (B. mori) silk fabrics modified by cold oxygen plasma (COP) and/or titania sols (TSs) were investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction, field emission scan electronic microscopy (FE-SEM), thermo-gravimetric and differential thermal analysis, and ultraviolet (UV) transmittance methods in this study. FT-IR analysis demonstrated that titania particles were associated with B. mori silk fibers by forming organic–inorganic hybrid blends. Processing sequences of COP and TSs, and curing conditions showed significant impacts on the crystalline, thermal, micro-morphological, and UV resistant characteristics of silk fabrics. Crystallinity index by both area and height methods, and crystallite sizes of silk fabrics were calculated as well. Results showed that crystallinity index of finished samples approximate to that of degummed silk fabric could be obtained by applying TSs and curing at 160 °C for 2 min prior to COP treatment, or vice versa with lower temperature of 140 °C for 3 min, whereas the crystallite sizes of treated samples increased slightly. The initial decomposition temperatures of finished samples were elevated by 23–35 °C with increased char residues at 600 °C, while the transmittance of UVA and UVB of finished samples decreased by 11.7, 17.7%, respectively. FE-SEM analysis revealed that titania particles were associated on the fiber surfaces with different smoothness.

Silks: Properties and uses of natural and designed variants

Fabrication of the FGF1-functionalized sericin hydrogels with cell proliferation activity for biomedical application using genetically engineered Bombyx mori (B. mori) silk

BackgroundAntennae are multi-segmented appendages and main odor-sensing organs in insects. In Lepidoptera (moths and butterflies), antennal morphologies have diversified according to their ecological requirements. While diurnal butterflies have simple, rod-shaped antennae, nocturnal moths have antennae with protrusions or lateral branches on each antennal segment for high-sensitive pheromone detection. A previous study on the Bombyx mori (silk moth) antenna, forming two lateral branches per segment, during metamorphosis has revealed the dramatic change in expression of antennal patterning genes to segmentally reiterated, branch-associated pattern and abundant proliferation of cells contributing almost all the dorsal half of the lateral branch. Thus, localized cell proliferation possibly controlled by the branch-associated expression of antennal patterning genes is implicated in lateral branch formation. Yet, actual gene function in lateral branch formation in Bombyx mori and evolutionary mechanism of various antennal morphologies in Lepidoptera remain elusive.ResultsWe investigated the function of several genes and signaling specifically in lateral branch formation in Bombyx mori by the electroporation-mediated incorporation of siRNAs or morpholino oligomers. Knock down of aristaless, a homeobox gene expressed specifically in the region of abundant cell proliferation within each antennal segment, during metamorphosis resulted in missing or substantial shortening of lateral branches, indicating its importance for lateral branch formation. aristaless expression during metamorphosis was lost by knock down of Distal-less and WNT signaling but derepressed by knock down of Notch signaling, suggesting the strict determination of the aristaless expression domain within each antennal segment by the combinatorial action of them. In addition, analyses of pupal aristaless expression in antennae with various morphologies of several lepidopteran species revealed that the aristaless expression pattern has a striking correlation with antennal shapes, whereas the segmentally reiterated expression pattern was observed irrespective of antennal morphologies.ConclusionsOur results presented here indicate the significance of aristaless function in lateral branch formation in B. mori and imply that the diversification in the aristaless expression pattern within each antennal segment during metamorphosis is one of the significant determinants of antennal morphologies. According to these findings, we propose a mechanism underlying development and evolution of lepidopteran antennae with various morphologies.

Biomaterials that stimulate cell attachment and proliferation without any surface modification (e.g. RGD coating) provide potent and cost effective scaffold for regenerative medicine. This study assessed the physico-chemical properties and cell supportive potential of a silk fibroin blend scaffold derived from eri (Philosamia ricini) and tasar (Antheraea mylitta) silk (ET) respectively by electrospinning process. The scanning electron microscopy and transmission electron microscopy study found that the fiber diameters are in 200 to 800 nm range with flat morphology. The porosity of ET scaffold is found to be 79 ± 5% with majority of pore diameter between 2.5 to 5 nm. Similarly, Bombyx mori (BM) silk fibroin and gelatin nanofibrous scaffolds were prepared and taken as control. The ultimate tensile strength of the ET and BM scaffold are found to be 1.83 ± 0.13 MPa and 1.47 ± 0.10 MPa respectively. The measured contact angle (a measure of hydrophilicity) for ET (54.7° ± 1.8°) is found to be lower than BM (62° ± 2.3°). The ability to deposit apatite over ET is comparable to that of BM nanofibers. All the scaffolds were seeded with cord blood derived mesenchymal stem cells (hMSCs) and cultured for 14 days in vitro. The immunofluorescence study reveals enhanced cell attachment with higher metabolic activity for MSCs grown over ET than BM and gelatin. The ET scaffold also demonstrated expression of higher amount cell adhesion molecules (CD29/CD44) and higher proliferation rate than BM and gelatin as confirmed by MTT assay, DNA content estimation assay, flow cytometry study and SEM study. Overall, it may be concluded that ET scaffold may have potential in developing bone tissue grafts for clinical applications in the future.

India, contributing over 18% to global silk production, has made significant strides in sericulture through advancements in silkworm breeding. This review evaluates the performance of recently developed single and double hybrids of bivoltine silkworms (Bombyx mori) in India. These hybrids are essential for enhancing silk productivity and quality, addressing the challenges of environmental stress. This assessment reveals that these new hybrids exhibit improved growth rates, silk yields, and thermotolerance. However, limitations such as genetic stability and environmental sensitivity persist, which could impact long-term sustainability. The novelty of this work lies in its comprehensive analysis of these hybrids’ performance under varied conditions, providing insights into their potential and areas needing further improvement. Continued research, advanced breeding techniques, integrated pest and disease management, large scale evaluation at farmer’s field and supportive policies are crucial for the sustainable growth of India’s sericulture industry. By adopting these hybrids and modern rearing practices, the industry can achieve higher yields, better quality silk and substantial contributions to the rural economy and global silk market.