r. abdoli

Considering the production of new silkworm hybrids by prominent countries in the sericulture industry such as China and the import of these hybrids to the country in recent years, it is necessary to update these evaluations so that correct decisions can be made to choose the most suitable type of hybrid in terms of functional traits. Therefore, such comparisons are done annually and the results are sent to the Iran Sericultural Corporation- Silk Worm Research Center as an executive body for final decision. The present study aimed to investigate the performance of eight Chinese commercial silkworm hybrids, including Suju×Minghu (S×M), Minghu×Suju (M×S), Baiyue×Qiufeng (B×Q), Qiufeng×Baiyue (Q×B), BaiyueB×QiufengA (BB×QA), QiufengA×BaiyueB (QA×BB), 874×873, and 874×873. Hybrids 872×871 and 872×871 also were among the studied hybrids, but due to the decrease in the performance of cocoon-related traits compared to other hybrids that had a big difference in terms of the obtained values, they were removed and excluded from the final analysis. The desired hybrids for 14 traits including best cocoons weight produced per 26,000 larvae (BCW), total cocoons weight produced per 26,000 larvae (TCW), number of cocoons per liter (NCPL), weight of cocoons per liter (WCPL), percentage of pupa viability (PPV), mean weight of a cocoon (MWC), mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon (MWMC), mean weight of a male cocoon shell (MWMCS), mean of male cocoon shell percentage (MMCSP), mean weight of a female cocoon (MWFC), mean weight of a female cocoon shell (MWFCS), and mean of female cocoon shell percentage (MFCSP) were reared in the spring of 2022 after hatching and according to standard methods and under the same conditions in Iran Silk Research Center and their performance was recorded. Each silkworm hybrid was reared in three replications of 200 larvae (total number of observations including 600 records per hybrid for all traits) in a completely randomized design. The analysis of the obtained data was done by SAS software by using the procedure of generalized linear model (GLM), and the average performance of the traits was compared to each other using Tukey's range test at the probability level of P<0.05. The results of the analysis of variance for the studied traits showed that the effect of the hybrid type for most of the studied traits including best cocoons weight produced per 26,000 larvae (BCW), total cocoons weight produced per 26,000 larvae (TCW), number of cocoons per liter (NCPL), the weight of cocoons per liter (WCPL), mean weight of a cocoon (MWC), mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon (MWMC), mean weight of a male cocoon shell (MWMCS), mean of male cocoon shell percentage (MMCSP), mean weight of a female cocoon (MWFC), mean weight of a female cocoon shell (MWFCS) and mean of female cocoon shell percentage (MFCSP) was significant (P<0.05). In the meantime, only traits of the percentage of pupa viability (PPV) as the most important index related to survival and the mean of male cocoon shell percentage (MMCSP) were not affected by the hybrid type (P<0.05). The average performance of the hybrids showed a significant difference (P<0.05) for all the traits except for the percentage of pupa viability (PPV) and the mean of cocoon shell percentage (MCSP). The BB×QA hybrid showed a higher performance than other hybrids for six traits including the best cocoons weight produced per 26,000 larvae (BCW), the total cocoons weight produced per 26,000 larvae (TCW), the weight of cocoons per liter (WCPL), the mean weight of a cocoon (MWC), the mean weight of a male cocoon (MWMC), and the mean weight of a female cocoon (MWFC) (P<0.01). Also, the M×S hybrid showed a higher performance than other hybrids for the five traits of the mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon shell (MWMCS), mean weight of a female cocoon shell (MWFCS), and the mean of female cocoon shell percentage (MFCSP) (P<0.05). In addition, the M×S hybrid showed the lowest value compared to other hybrids for the number of cocoons per liter (NCPL), which the lower values of this trait are preferred (P<0.01).  Based on the results of the present research, the priority of importing and rearing silkworm eggs in 2023 is suggested for BB×QA and M×S hybrids. Although the performance of these two hybrids with other hybrids, except for the 874×873 and 874×873 hybrids, is not significant in most of the examined traits, they can still be considered as next-import priorities. The desired hybrids for 14 traits including: best cocoons weight produced per 26,000 larvae (BCW), total cocoons weight produced per 26,000 larvae (TCW), number of cocoons per liter (NCPL), weight of cocoons per liter (WCPL), percentage of pupa viability (PPV), mean weight of a cocoon (MWC), mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon (MWMC), mean weight of a male cocoon shell (MWMCS), mean of male cocoon shell percentage (MMCSP), mean weight of a female cocoon (MWFC), mean weight of a female cocoon shell (MWFCS) and mean of female cocoon shell percentage (MFCSP) were reared in the spring of 2022 after hatching and according to standard methods and under the same conditions in Iran Silk Research Center and their performance was recorded. Each silkworm hybrid was reared in 3 replications of 200 larvae (total number of observations including 600 records per hybrid for all traits) in a completely randomized design. The analysis of the obtained data was done by SAS software (version 9.4) by using the procedure of generalized linear models (GLM) and the average performance of the traits was compared to each other using Tukey's range test at the probability level of P<0.05. The results of the analysis of variance for the studied traits show that the effect of the hybrid type for most of the studied traits including best cocoons weight produced per 26,000 larvae (BCW), total cocoons weight produced per 26,000 larvae (TCW), number of cocoons per liter (NCPL), the weight of cocoons per liter (WCPL), mean weight of a cocoon (MWC), mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon (MWMC), mean weight of a male cocoon shell (MWMCS), mean of male cocoon shell percentage (MMCSP), mean weight of a female cocoon (MWFC), mean weight of a female cocoon shell (MWFCS) and mean of female cocoon shell percentage (MFCSP) is significant (P<0.05). In the meantime, only traits of the percentage of pupa viability (PPV) as the most important index related to survival and the mean of male cocoon shell percentage (MMCSP) were not affected by the hybrid type (P<0.05). The average performance of the hybrids showed a significant difference (P<0.05) for all the traits except for percentage of pupa viability (PPV) and the mean of cocoon shell percentage (MCSP). The hybrid BB*QA showed a higher performance than other hybrids for six traits including the best cocoons weight produced per 26,000 larvae (BCW), the total cocoons weight produced per 26,000 larvae (TCW), the weight of cocoons per liter (WCPL), the mean weight of a cocoon (MWC), the mean weight of a male cocoon (MWMC) and the mean weight of a female cocoon (MWFC) (P<0.01). Also, the M*S hybrid showed a higher performance than other hybrids for the five traits of mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon shell (MWMCS), mean weight of a female cocoon shell (MWFCS), and the mean of female cocoon shell percentage (MFCSP) (P< 0.05). Also, the M*S hybrid showed the lowest value compared to other hybrids for the number of cocoons per liter (NCPL); the lower values of which are preferred (P<0.01). Based on the results of the present research, the priority of importing and rearing silkworm eggs in 2023 is suggested for BB*QA and M*S hybrids. Although the performance of these two hybrids with other hybrids, except for the 874×873 and 874×873 hybrids, is not significant in most of the examined traits, and they can still be considered as next import priorities.

Mitochondrial DNA (mitogenome) is a small and extra-chromosomal DNA, located in the cytoplasm and presents an ideal model to study evolution and genetic similarity. Classical phylogenetics is based on the morphological characteristics of the organisms, while in modern approaches, the phylogenetic distance and its related comparative methods are estimated based on observed genetic diversity in the studied genetic sequences. The aim of the present study was to investigate the divergence and percentage of genetic similarity along with the phylogenetic analysis of the seven main known species of wild and domestic sheep based on the complete sequence of the mitochondrial genome and the separate sequences of 13 protein-coding genes for each genome.
In the present study, complete mitochondrial genome sequences along with separate sequences of 13 protein-coding genes (including NADH ubiquinone oxidoreductase (ND1, ND2, ND3, ND4, ND5, and ND6), cytochrome c oxidase (COX1, COX2, and COX3), ATP synthase (ATP6 and ATP8), NADH dehydrogenase 4 L (ND4L), and cytochrome b (CYTB))  per each genome from six wild species of sheep including Asian Mouflon (Ovis orientalis), Bighorn (Ovis canadensis), Argali (Ovis ammon), Urial (Ovis vignei), Snow (Ovis nivicola), Dall (Ovis dalli), and domesticated species of sheep (Ovis aries) were retrieved from NCBI database and compared to each other. Mitochondrial genomes and genes’ alignment were accomplished by the MegAlign module of DNASTAR software and compared by the Clustal W method. The Sequence Distances sub-section of the MegAlign module of DNASTAR also was used for the analysis of complete genome and gene sequences divergence and similarity percentage. For phylogenetic analysis, complete mitochondrial genomes and protein-coding genes’ sequences were aligned using MEGA7 software. Based on the alignment, phylogenetic tree was constructed using the maximum likelihood method. The percentage of replicate trees of 1000 replicates of bootstrap test was used to represent the evolutionary history for the studied sheep species.
The results obtained from sequence distance analysis showed high genetic similarity (99.8 %) between Ovis orientalis and Ovis aries. Also, the lowest similarity (95 %) was observed between Ovis aries and Ovis dalli. In phylogenetic analysis, two main clusters, each with different sub-clusters were identified. Domesticated species of sheep (Ovis aries) along with Ovis orientalis, Ovis vignei, and Ovis ammon wild species of sheep formed distinct cluster, and Ovis nivicola, Ovis dalli, and Ovis Canadensis fell in a same cluster. In terms of all 13 protein-coding genes (including NADH ubiquinone oxidoreductase (ND1, ND2, ND3, ND4, ND5, and ND6), cytochrome c oxidase (COX1, COX2, and COX3), ATP synthase (ATP6 and ATP8), NADH dehydrogenase 4 L (ND4L) and cytochrome b (CYTB)), the results obtained from sequence distance similarity analysis and phylogenetic trees were similar to the sequences of the complete mitochondrial genomes. More than 99% of the genetic similarity for ND1, ND2, ND5, ND6, COX1, COX2, COX3, and ATP6 genes and 100% of the genetic similarity for ND3, ND4, ND4L, ATP8, and CYTB genes between domestic sheep (Ovis aries) and Mouflon (Ovis orientalis) sheep species were found. Also, similar to the results obtained from the comparison of the complete mitochondrial genome, the domestic sheep species (Ovis aries) showed the least genetic similarity with the Dall (Ovis dalli) and Bighorn (Ovis canadensis) wild sheep species in all 13 protein-coding genes. Similar to the results of phylogenetic analysis of complete mitochondrial genomes, domestic sheep species (Ovis aries) together with Ovies orientalis wild sheep were placed in the same sub-cluster and Ovis vignei and Ovis ammon species were placed in other distinct sub-clusters. In addition, the Ovis nivicola, Ovis dalli, and Ovis canadensis wild species fell in another main cluster, and in this cluster, Ovis dalli and Ovis canadensis were placed in a similar sub-cluster and Ovis nivicola in another distinct sub-cluster.
In previous studies, small parts of the mitochondrial genome (such as a part of the control region or cytochrome b gene) have been considered to show the genetic differences and phylogenetic relationships between different species and breeds of sheep. In the present study, the complete sequences of the mitochondrial genome along with the complete sequences of 13 protein-encoding genes per each genome in seven main species of wild and domestic sheep have been considered for examining genetic similarity and divergence and phylogenetic analysis for the first time. Based on the results obtained from the present study, mitochondrial genome sequences could be used for accurate phylogenetic analysis and clustering of different species of sheep.

Generally, genetic markers, associated with metabolic pathways, might be used in marker-assisted selection to improve production and reproduction traits in farm animals. Especially, some traits with low heritabilities, such as reproduction and health traits could not be easily improved by classic selection strategies. However, the use of genetic markers and marker-assisted selection are considered powerful tools for the genetic improvement of low-heritable traits. Thus, detection of genetic markers associated with production and reproduction traits is an effective way to save endangered indigenous breeds, such as the Markhoz goat, a mohair-producing breed in Iran. The thyroid hormone-responsive (THRSP) gene is a candidate gene involved in thyroid hormone functions and the lipogenesis process. This gene is a protein-coding gene, with two exons, located on chromosome 29 in goats. There are some reports on the association of THRSP with production traits in farm animals. There are limited studies on metabolic pathways of THRSP and its associations with important economic traits in small ruminants and no study on the association of THRSP and reproduction traits was found in the literature. The aim of the present study was the investigation of the THRSP gene polymorphism and its association with body weight and litter size traits in Markhoz goats.

A total of 140 blood samples of Markhoz goats were randomly collected from the Research and Breeding Station in Kurdistan province in western Iran. Genomic DNA was extracted from whole blood samples. A pair of primers were designed using the Primer 3 online software to amplify a 486 bp fragment in THRSP gene exon 1. The designed primers were as follows:Forward: 5’-AGTCTGCGGGACTCCATATG-3’ Reverse: 5’-AAAATGGGACAGGCCATGT-3’ Polymorphism of the amplified fragment was investigated using the single-strand conformational polymorphism (SSCP) method and sequencing of three random samples for each SSCP pattern. The observed sequences were aligned to the GenBank reference sequence using the MegAlign module of DNAStar software and compared based on the Clustal W method. The sequences were translated by the Translate section of the ExPASy website (us.expasy.org/translatetool). Associations of body weight traits, including birth weight, three-month, six-month, nine-month, and 12-month body weights, with the observed genotypes were investigated using a general linear model, fitting genotype, birth year, birth type, and dam age as the fixed factors. The association of the observed genotypes with litter size was investigated using a two-way Chi-squared test. The SAS 9.4 program was employed for the association analyses.

In the studied samples, two different SSCP patterns and two single-nucleotide polymorphisms (SNPs) were detected in 148 and 173 bp locations of the studied fragment, as g.148G>A (resulting in Arginine to Glutamine amino acids exchange) and g.173A>G (a synonymous mutation), both as heterozygous loci. In the studied population, the frequency of the double-homozygous genotype, GG/AA (0.743), was noticeably higher than the double-heterozygous genotype, which is GA/AG (0.257). The alleles G and A had high frequencies, both equal to 0.871 in the 148 and 173 bp loci, respectively. Both loci had a significant deviation from Hardy-Weinburg equilibrium (P<0.0001). Polymorphism of the studied fragment did not have any significant effect on body weight traits. A significant association was observed between the detected genotypes and litter size. Whereby, litter size in double-heterozygous does (1.21) was significantly higher than the double-homozygous individuals (1.04), (P = 0.015). The present study is probably the first report on the association of the THRSP gene with litter size in goats. The THRSP is a protein which involves in thyroid hormone function and therefore might affect many metabolic pathways. However, a significant association of the observed genotypes with prolificacy is probably due to the role of THRSP in lipids metabolism and the association of lipids metabolism with reproduction performance.

The THRSP exon 1 is polymorphic in Markhoz goats. The studied fragment did not have any significant associations with body weight traits, but it had a significant effect on litter size. Based on the results of this study, the THRSP gene could be considered a candidate gene for litter size, and the detected SNPs at 148 and 173 bp of the studied fragment, could be used for marker-assisted selection in Markhoz goats. However, more studies on possible associations between THRSP polymorphism and production and reproduction traits are still needed in other goat breeds.

Using scaffold microstructure for bone tissue graft has been widely considered. Among the several properties of a scaffold, permeability plays a prominent role in the transport of nutrients, oxygen, and minerals. It is a key parameter which comprises various geometrical features such as pore shape, pore size and interconnectivity, porosity, and specific surface area. The main aim of this research is to characterize the permeability of the scaffold microstructure in terms of different pore sizes and porosity. To this end, cylindrical geometries for pores were modeled and the permeability coefficient was calculated using velocity and pressure drop and employing Darcy’s law. The validation process of the numerical results was done by comparing with experimental data. In this regard, a simple experiment setup was presented based on the constant head method. Additionally, the scaffolds were built using Solid Freeform Fabrication (SFF) techniques. The results showed that increasing porosity leads to an increase in permeability. Moreover, the permeability increases as the pore size increases. Eventually, the reducing pore diameters have a significant effect on the flow and hence permeability (e.g., a 20% decrease in diameter yields a 76% decrease in permeability).