Effect of the concentration of estradiol and vitellogenin in the blood serum of meat and egg breed chickens on egg productivity

The aim of the research is to determine the effect of changes in the concentration of estradiol-17β on the concentration of vitellogenin at the stage of egg shell formation and preparation of the body of meat and egg breed chickens (for example, the Pushkin breed) for ovulation.Materials and methods. The material for the study was the Pushkin breed chickens, in the amount of 28 heads. at the age of 48 weeks. Chickens were kept in individual cages. Light mode - 14C:10T. Drinking - nipple, temperature in the house and feeding - according to the standards adopted in the bioresource collection of RRIFAGB "Genetic collection of rare and endangered chicken breeds." Within 10 days prior to blood sampling, an ultrasound scan of the ovary and oviduct was performed from the studied group of chickens, which made it possible to determine the stage of egg formation. Blood from the studied chickens was taken in the morning on an empty stomach for the simultaneous determination of the concentration of estradiol and vitellogenin at the stage of egg shell formation. The concentration of estradiol and vitellogenin in the blood plasma of chickens was determined by ELISA. To clarify the effect of the concentration of estradiol (E2) on vitellogenin (VTG), the studied flock was divided into 2 groups according to the concentration of vitellogenin: 1st gr. – > Mav. (> 20 μg / ml) and 2nd gr. – < Mav. (<20 μg / ml). During the study period, eggs of chickens were evaluated according to the following morphometric parameters: the weight of the egg, yolk, protein and shell, elastic deformation, shape index, density of protein fractions, thickness of the shell and subshell, marbling. The number of eggs laid was determined in 10-day trial period.Results. It has been established that the duration of the ovulatory cycle in Pushkin breed chickens is 27-29 hours. As a result of such a long ovulatory cycle in the following days, laying of eggs occurs later with a progressive shift, as a result of which the laying cycle on average for the studied group of chickens is 3 days. The E2 level in the 1st group was 258,48 ± 30,60 pg/ml (p < 0,05), which significantly differed from the 2nd group – 181,45 ± 13,81 pg/ml. A positive correlation was found between VTG and E2, r = 0,5 (p < 0,001).Conclusion. The VTG level significantly increases in Pushkin chickens at the age of 48 weeks with an increase in the concentration of E2 in the blood. A positive correlation was noted between these features. According to the results of our research, the high content of estradiol and vitellogenin in the chickens blood serum did not have a significant effect on egg productivity.

phytanoyl-CoA dioxygenase domain-containing protein 1 plays an important role in egg shell formation of silkworm (Bombyx mori)

Yun7Ge is a giant egg mutant found in the silkworm variety Yun7. In comparison with the giant mutant Ge, the eggs of Yun7Ge are larger. The number of laid eggs and hatching rate of Yun7Ge are reduced, which is not conducive to reproduction. In this work, the target gene controlling giant egg trait is located on the Z chromosome and was determined through genetic analysis. Transcriptome results showed that phytanoyl-CoA dioxygenase domain-containing protein 1 (PHYHD1) on the Z chromosome was silenced, and the 25 chorion genes on chromosome 2 were remarkably downregulated. Sequence analysis showed that the 73.5 kb sequence including the PHYHD1 was replaced by a ~3.0 kb sequence. After knocking out the PHYHD1 by using CRISPR/Cas9, the chorion genes were significantly downregulated. Hence, the silencing of PHYHD1 leads to the downregulation of many chorion protein genes, thus directly causing giant eggs.

The Genome of the Zebra Mussel, Dreissena polymorpha: A Resource for Comparative Genomics, Invasion Genetics, and Biocontrol

The zebra mussel, Dreissena polymorpha, continues to spread from its native range in Eurasia to Europe and North America, causing billions of dollars in damage and dramatically altering invaded aquatic ecosystems. Despite these impacts, there are few genomic resources for Dreissena or related bivalves. Although the D. polymorpha genome is highly repetitive, we have used a combination of long-read sequencing and Hi-C-based scaffolding to generate a high-quality chromosome-scale genome assembly. Through comparative analysis and transcriptomics experiments we have gained insights into processes that likely control the invasive success of zebra mussels, including shell formation, synthesis of byssal threads, and thermal tolerance. We identified multiple intact Steamer-Like Elements, a retrotransposon that has been linked to transmissible cancer in marine clams. We also found that D. polymorpha have an unusual 67 kb mitochondrial genome containing numerous tandem repeats, making it the largest observed in Eumetazoa. Together these findings create a rich resource for invasive species research and control efforts.

Defect control and Si/Ge core-shell heterojunction formation on silicon nanowire surfaces formed using the top-down method

Control of surface defects and impurity doping are important keys to realizing devices that use semiconductor nanowires (NWs). As a structure capable of suppressing impurity scattering, p-Si/i (intrinsic)-Ge core-shell NWs with radial heterojunctions inside the NWs were formed. When forming NWs using a top-down method, the positions of the NWs can be controlled, but their surface is damaged. When heat treatment for repairing surface damage is performed, the surface roughness of the NWs closely depends on the kind of atmospheric gas. Oxidation and chemical etching prior to shell formation removes the surface damaged layer on p-SiNWs and simultaneously achieves a reduction in the diameter of the NWs. Finally, hole gas accumulation, which is important for suppressing impurity scattering, can be observed in the i-Ge layers of p-Si/i-Ge core-shell NWs.

Improvement of monodispersity and shape symmetry of silica shell for PbS quantum dots by introducing surface silanization and adjusting reverse micelle size

Increasing the thickness of the quantum dot silica coating layer reduces monodispersity and shape symmetry. This paper reports three effective ways to solve this problem and achieve a large silica-coated QDs, i.e., proper silanization on the QD surface, control of reverse micelle size by adjusting the amount of QD solvent, and two-step formation of silica shell. Proper substitution of ligands on the QD surface in the early stages of silica shell formation was important for uniform coating reaction. An amount of toluene as QD solvent determined the size of reverse micelles during the silica shell formation. There was an optimum combination of inverse micelle size and silica shell size to obtain silica-coated QDs with good monodispersity and high shape symmetry. We succeeded in growing the thick silica shell with expanding reverse micelle size by additionally supplying toluene with the raw material using the optimum silica-coated QDs as growth nucleus

Gene recruitments and dismissals in argonaut octopus genome provide insights to pelagic lifestyle adaptation and shell-like eggcase reacquisition

The paper nautilus, Argonauta argo, also known as the greater argonaut, is a species of octopods distinctly characterized by its pelagic lifestyle and by the presence of a spiral-shaped shell-like eggcase in females. The eggcase functions by protecting the eggs laid inside it, and by building and keeping air intakes for buoyancy. To reveal the genomic background of the species′ adaptation to pelagic lifestyle and the acquisition of its shell-like eggcase, we sequenced the draft genome sequence of the species. The genome size was 1.1 Gb, which is the smallest among the cephalopods known to date, with the top 215 scaffolds (average length 5,064,479 bp) covering 81% (1.09 Gb) of the total assembly. A total of 26,433 protein-coding genes were predicted from 16,802 assembled scaffolds. From these, we identified nearly intact HOX, Parahox, Wnt clusters and some gene clusters probably related to the pelagic lifestyle, such as reflectin, tyrosinase, and opsin. For example, opsin might have undergone an extensive duplication in order to adapt to the pelagic lifestyle, as opposed to other octopuses, which are mostly the benthic. Our gene models also discovered several genes homologous to those related to calcified shell formation in Conchiferan Mollusks, such as Pif-like, SOD, and TRX. Interestingly, comparative genomics analysis revealed that the homologous genes for such genes were also found in the genome of the octopus, which does not have a shell, as well as the basal cephalopods Nautilus. Therefore, the draft genome sequence of A. argo we presented here had not only helped us to gain further insights into the genetic background of the dynamic recruitment and dismissal of genes for the formation of an important, converging extended phenotypic structure such as the shell and the shell-like eggcase, but also the evolution of lifestyles in Cephalopods and the octopods, from benthic to pelagic.