Synthetic biology is a rapidly developing field aimed at engineering of biological systems with predictable properties. Synthetic biology accumulates the achievements of modern biological sciences, programming and computational model­ing as well as engineering technologies for creation of biologi­cal objects with user-defined properties. Evolution of synthetic biology has been marked by a number of technological developments in each of the mentioned fields. Thus, significant reduction in cost of DNA sequencing has provided an easy access to large amounts of data on the genetic sequences of various organisms, and decreased the price of the DNA sequence synthesis, which, analogous to Moore’s law, resulted in an opportunity to create a lot of potential genes without the time – consuming and labor – intensive traditional methods of molecular biology. Development of system biology has allowed forming a deeper understanding of the functions and relationship of natural biological models, as well as of the computational models describing processes at the cell and system levels. Combination of these factors has created an op­portunity for conscious changes of natural biological systems. In this review the modern approaches to oligonucleotide gene assembly synthesis are discussed, including such aspects as protocols for gene assembly, sequence verification, error cor­rection and further applications of synthesized genes.

Using chromosome C-banding and electrophoresis of grain storage proteins, gliadins, 17 Triticum aestivumAegilops columnaris lines with substitutions of chromosomes of homoeologous groups 1 and 6 were examined. Based on their high polymorphism, gliadins were used to identify alien genetic material. For all of the lines examined, electrophoretic analysis of gliadin spectra confirmed substitution of wheat chromosomes 6A, 6D or 1D for the homoeologous Aegilops chromosomes of genomes Uс or Xс. The substitution manifested in the disappearance of the products of gliadin-coding genes on chromosomes 6A, 6D or 1D with the simultaneous appearance of the products of genes localized on alien chromosomes of genomes Uс or Xс. Thus, Aegilops chromosomes were shown to be functionally active in the alien wheat genome. The absence of alien genes expression in the lines carrying a long arm deletion in chromosome 6X^c suggested that the gliadin-coding locus moved from the short chromosome arm (its characteristic position in all known wheat species) to the long one. This is probably associated with a large species-specific pericentric inversion. In spite of losing a part of its long arm and combination with a non-homologous chromosome of a different genome (4BL), chromosome 1D was fully functioning. For Aegilops, the block type of gliadin components inheritance was shown, indicating similarity in the structural organization of gliadin-coding loci in these genera. Based on determining genetic control of various polypeptides in the electrophoretic aegilops spectrum, markers to identify Ae. columnaris chromosomes 1Xс, 6Xс and 6Uс were constructed.

Diploid wheat Triticum boeoticum Boiss. (genome constitution AA) is a promising source of new valu­able alleles for improving cultivated wheat species. Therefore, the evaluation of the intraspecies diversity of T. boeoticum and DNA fingerprinting of accessions of this species are topical tasks. In this paper, the ge­netic diversity of over 60 T. boeoticum accessions was studied using 11 SSR markers. The analysis revealed 83 alleles, 7.5 alleles per locus on the average. The values of expected (HE) and observed (HO) heterozygosity varied within 0.00–0.74 and 0.17–0.89, respectively, the average indices being HO = 0.13 and HE = 0.52. The PIC value for each locus was within 0.17–0.88, 0.49 on the average. Unique alleles were found in all loci studied. Cluster analysis allowed the accessions studied to be combined into five major groups. The distances between the groups varied from 0 to 1, pointing to a high level of genetic differences in the collection under study. On the base of PCoA, five major groups were formed and some correspondence with the dendrogram was detected. Summarizing the data of PCoA and cluster analysis, we noted a weak genetic differentiation in the studied collection of T. boeoticum. A correlation between the genetic distance and geographic origin was revealed only for accessions of diploid wheat T. boeoticum from Iran. The analysis of the T. boeoticum accessions studied showed a wide diversity for SSR loci. The results expand our knowledge and pro­vide additional information on the genetic structure of the collection and on the genetic diversity of T. boeoti­cum accessions studied.

Sequencing and comparative characterization of plant plastid genomes, or plastomes, is an important tool for modern phylogenetic and taxonomic studies, as well as for understanding the plastome evolution. The genus Allium L. (family Amaryllidaceae) incorporates more than 900 species, includes economically signifi­cant vegetable crops such as garlic A. sativum, onion A. cepa, leek A. porrum, etc. In this work, the plastome of garlic A. sativum has been completely sequenced. The A. sativum plastome is 153172 bp in size. It consists of a large unique (LSC, 82035 bp) and small unique (SSC, 18015 bp) copies, separated by inverted repeats (IRa and IRb) of 26561 bp each. In the garlic plastome, 134 genes have been annotated: 82 protein-coding genes, 38 tRNA genes, 8 rRNA genes, and 6 pseudogenes. Comparative analysis of A. sativum and A. cepa plastomes reveals differences in the sizes of structural elements and spacers at the inverted repeat bound­aries. The total numbers of genes in A. sativum and A. cepa are the same, but the gene composition is dif­ferent: the rpl22 gene is functional in A. sativum, being a pseudogene in A. cepa; conversely, the rps16 gene is a pseudogene in A. sativum and a protein-coding gene in A. cepa. In the A. sativum and A. cepa plastomes, 32 SSR sequences have been identified. More than half of them are dinucleotides, and the remaining are tetra-, penta-, and hexanucleotides at the same time, trinucleotides were absent. The compared plastomes differ in the numbers of certain SSRs, and some are present in only one of the species.

Poplars are widely used in landscaping of Moscow due to the ability to effectively purify the air from harmful impurities and to release a large amount of oxygen. The genus Populus is characterized by a high level of intraspecies polymorphism, as well as the presence of natural interspecies hybrids. The aim of our work was to evaluate the genetic diversity of poplars, which are growing on the territory of Moscow city by high-throughput sequencing of internal transcribed spacers of 45S rRNA genes (ITS sequences). Sequencing of ITS of 40 poplar plants was performed on Illumina platform (MiSeq) and about 3 000 reads were obtained for each sample in average. Bioinformatics analysis was performed using CLC Genomics Workbench tool. The involved set of poplars had a high level of genetic diversity – the number of single nucleotide polymorphisms (SNPs) detected in each genotype relative to the reference ITS1 and ITS2 sequences of P. trichocarpa varying from 4 to 44. We showed that even trees which had been planted on the same territory and, probably, at the same time had significant genetic differences. It can be speculated that highly polymorphic plant material was used for planting poplars in Moscow. For some sites with SNPs, several variants of nucleotides were found in the same individual and the ratio of SNPs was different. We assume that close to 50/50 ratio is observed in interspecific hybrids due to genetic differences in the ITS sequences between maternal and paternal genotypes. For SNPs with a predominance of one of the variants, the presence of paralogues among numerous genomic copies of ITS sequences is more likely. The results of our work can provide a framework for molecular genetic markers application with the purpose of Populus species and interspecific hybrids identification, determination the origin of a number of natural hybrids, and monitoring the diversity of genus Populus in the Moscow city.

Soybean (Glycine max (L.) Merr) is an essential food, feed, and technical culture. In Kazakhstan the area under soybean is increasing every year, helping to solve the problem of protein deficiency in human nutrition and animal feeding. One of the main problems of soybean production is fungal diseases causing yields losses of up to 30 %. Modern genomic studies can be applied to facilitate efficient breeding research for improvement of soybean fungal disease tolerance. Therefore, the objective of this genome-wide association study (GWAS) was analysis of a soybean collection consisting of 182 accessions in relation to fungal diseases in the conditions of South East and South Kazakh­stan. Field evaluation of the soybean collection suggested that Fusarium spp. and Cercospora sojina affected plants in the South region (RIBSP), and Septoria glycines – in the South East region (KRIAPP). The major objective of the study was identification of QTL associated with resistance to fusarium root rot (FUS), frogeye leaf spot (FLS), and brown spot (BS). GWAS using 4 442 SNP (single nucleotide polymorphism) markers of Illumina iSelect array allowed for identification of fifteen marker trait associations (MTA) resistant to the three diseases at two different stages of growth. Two QTL both for FUS (chromosomes 13 and 17) and BS (chromosomes 14 and 17) were genetically mapped, including one presumably novel QTL for BS (chromo­some 17). Also, five presumably novel QTL for FLS were genetically mapped on chromosomes 2, 7, and 15. The results can be used for improvement of the local breeding projects based on marker-assisted selection approach.          

Alloplasmic lines are formed when the cytoplasm of one species is replaced by the cytoplasm of another as a result of repeated recurrent crosses of wide hybrids with the paternal genotype. Since the cytoplasm replacement results in new intergenomic interactions between a nucleus and cytoplasm leading to variability of plant characteristics, alloplasmic lines with restored fertility can be an additional source of biodiversity of cultivated plants. Earlier, recombinant alloplasmic lines (H. vulgare)-T. aestivum designated as L-17(1)–L-17(37) were formed from a plant with partially restored fertility of the BC3 generation of barley-wheat hybrid H. vulgare (cv. Nepolegayushchii) × T. aestivum (cv. Saratovskaya 29). This male-sterile hybrid was consistently backcrossed with wheat varieties Mironovskaya 808 (twice) and Saratovskaya 29, and Mironovskaya 808 had a positive impact on the restoration of fertility. This paper presents the results of investigation into a group of recombinant alloplasmic lines (L-17F4), as well as into doubled haploids (DH) lines – alloplasmic DH-17-lines obtained from anther culture of alloplasmic lines (L-17F2). The most productive of these lines were used as initial breeding genotypes. Hybrid form Lutescens 311/00-22 developed from the crossing of the alloplasmic DH(1)-17 line (as maternal genotype) with euplasmic line Com37 (CIMMYT), the source of the 1RS.1BL wheat-rye translocation, proved to be successful for breeding. The presence of the 1RS.1BL translocation in the genome of the Lutescens 311/00-22 form and the L-311(1)–L-311(6) alloplasmic lines isolated from it did not lead to a decrease of fertility or sterility in the plants. This indicates that the chromosome of the 1BS wheat does not carry the gene(s) that determine the restoration of fertility in the studied (H. vulgare)-T. aestivum alloplasmic lines. Alloplasmic lines L-311(1)–L-311(6) showed their advantage in comparison with the standard varieties for resistance to leaf and stem rust, yield, and grain quality. The breeding tests performed at Omsk Agricultural Scientific Center, Agrocomplex “Kurgansemena”, Federal State Unitary Enterprise “Ishimskoe” (Tyumen Region), using alloplasmic lines L-311(5), L-311(4) and L-311(6) resulted in varieties of spring common wheat Sigma, Uralosibirskaya 2 and Ishimskaya 11, respectively.              

In the meantime, search for environmentally friendly renewable energy sources alternative to fossil fuel has been driven by energy security challenges including limited availability of fuel and energy price fluctuations. Therefore herbal perennial grasses with their rapid growth and prominent biomass yield increasingly make it a favorite choice as a valuable agricultural crop usable for cellulosic ethanol production. As an example, the genus Miscanthus Anderss. (silvergrass) comprises ca. 14–20 species including M. sacchariflorus (Maxim.) Hack., M. sinensis Anderss., M. purpurascens Anderss, and M. × giganteus, which appear to be an almost inexhaustible source of sustainable raw material, and several Miscanthus species were investigated as a potential biofuel energy crop with commercially viable way of its producing. Introduction and investigation of Miscanthus species were initiated in the Central Siberian Botanical Garden of the Siberian Branch of the Russian Academy of Sciences (CSBG SB RAS, Novosibirsk, Russia) based on the grass and ornamental plant collection in the late 1990s. The paper objective is studying the biological traits of three Miscanthus species introduced into the CSBG SB RAS, selection and genetic identification of cultivars and varieties as the most perspective agricultural crop. To evaluate the potential crop yield and selection prospects of Miscanthus species being competitive as a valuable biofuel energy crop, the authors have estimated seasonal rhythms of model species development in the continental climate conditions of West Siberia. The article characterizes different Miscanthus varieties obtained either by the ex situ or in situ methods; presents the biochemical analysis of plant material and molecular identification of three Miscanthus species introduced into the CSBG SB RAS. The seasonal development analysis of three selected varieties of Miscanthus (M. sacchariflorus, M. sinensis, and M. purpurascens) proved the hydrometeorological conditions to be advantageous for prominent biomass yield, e. g. contributory to use Miscanthus in West Siberia as an easy to grow cellulose-rich grass. Molecular markers applicable in DNA-identification and genetic passportization of Miscanthus varieties have been established, which are perspective as such an economically available plant material as alternative non-woody source of cellulose.

Leaf rust, caused by the fungus Puccinia triticina Erikss., inflicts serious crop loss of common wheat Triticum aesti­vum L. The species Aegilops speltoides Tausch (2n = 14, SS) is considered a promising issue of genes to protect bread wheat from diseases. The objective of this study was the monitoring of resistance to leaf rust of Ae. speltoides ac­cessions and introgressive lines and cultivars with genetic material of this species to the Western Siberian popula­tion of fungus. The estimation of specimens in the field conditions on natural infectious background showed that the Ae. speltoides accessions were immune to leaf rust, however, а tendency towards increasing susceptibility of the introgressive lines and varieties was detected. The protective effect of the known genes Lr28, Lr36 and Lr35 decreased, but Lr47 remained efficient in West Siberia, as confirmed by the results of testing of the Omsk population of P. triticina for virulence to the mentioned genes. During the study (2003-2017) the resistance has been overcome of lines Od 26/89, 156/90, analogs of cv. Novosibirskaya 67 – ANK-39 (B, C), and L-500 from the “Arsenal” сollection. High resistance to leaf rust was preserved of lines Od (35/1, 35/89, 210/90, 278/89); ANK39 (A, D, E); L-501 and cvs. Chelyaba 75 and Mit. Analysis of DNA markers and phytopathological tests showed that the studied variet­ies and lines lacked the known genes Lr28, Lr36, and Lr47 from Ae. speltoides (except for the lines of cvs. Thatcher and Pavon). On the base of analysis of DNA markers, it was assumed that Chelyaba 75 and seven resistant lines from the Odand ANK-39-series have translocations bearing the LrSp gene. Presumably, the rest of samples possess additional not yet identified genes of Ae. speltoides. The trend of overcoming of resistance to leaf rust of introgres­sive lines and varieties with Ae. speltoides genes should be taken into consideration in common wheat breeding in Western Siberia.

Wolbachia is a genus of bacteria causing intracellular infection in the natural populations of Drosophila melanogaster on all continents. In D. melanogaster, Wolbachia affects various life history traits, behaviour, sensitivity to stress and viral infection. The phenotypic effects of Wolbachia might evolve to promote its further spreading, increasing the interest in exploring the spread of Wolbachia, in particular, at the boundar­ies of the D. melanogaster habitat, in association with the effects on vital traits of host species. In this paper, we present data on the level of Wolbachia infection in two D. melanogaster populations from the northern regions of European Russia: Alexandrov (56.41° N, 38.72° E) and Valday (58.02° N, 33.24° E). The flies were collected in private apple gardens located in two small hamlets without supermarkets or fruit markets, from 2010 to 2015. The both populations demonstrated the same level of infection: in average, 69.7 % of the inbred lines (ILs) obtained from single females of the Alexan­drov population and 68.4 % of ILs obtained from single females of the Valday population. The infection rate varied from year to year showing a tendency to reduc­tion, its overall level being within the range previously observed in other habitats. Life spans were compared in sub-lines of the same IL, one infected with Wolbachia and the other treated with tetracycline healing this infection. In four out of five ILs, the lifespan of both males and females was severely affected by Wolbachia; in different ILs, the mean life spans reduced from 1.8 to 5.4 times and from 1.4 to 2.4 times, respectively. Our results confirm that, despite D. melanogaster widespread distribution, the Wolbachia effect on their life span has been mostly negative.                                     

The area of invasive species Aedes albopictus and Aedes aegypti is expanding. Precise identification and understanding of the genetic diversity of invasive mosquito populations allows us to develop appropriate control methods. Endosymbiotic bacterium Wolbachia pipientis has different effects on their arthropod hosts and can influence the transmission and spread of the pathogens. The objective of the presented study was molecular-genetic identification of the Aedes mosquitoes collected in sampling sites on the Black Sea coast from 2007 to 2017; determination of genetic variability of Ae. aegypti, Ae. albopictus and their symbiotic bacteria Wolbachia; assessment of mosquitoes ability to be infected and to spread parasitic Dirofilaria. Another objective was obtaining the genetic characteristic of laboratory strain Ae. aegypti IMPITM. We investigated two markers of nuclear and mitochondrial DNA from Ae. albopictus and Ae. aegypti and compared them to DNA from Ae. cretinus and Ae. koreiсus sympatrically inhabiting the territory, as well as to one of Ae. aegypti from a laboratory line. The study of nuclear and mitochondrial DNA revealed a low level of variability in the invasive mosquitoes Ae. albopictus and Ae. aegypti collected at different collection sites and in different years. More than a half of Ae. albopictus were infected with Wolbachia, two strains of bacteria, wAlbA and wAlbB, occur in the Ae. albopictus population on the Black Sea coast. Total infection of Ae. aegypti and Ae. albopictus with dirofilariae was 1.8 %. Dirofilaria immitis was found only in mosquito abdomen, larvae of infective stage L3 were not found. D. repens larvae developed to the infective stage in the mosquitoes of both species.                                         

The Demoiselle crane (Anthropoides virgo Linneaus, 1758) is a widespread crane species of Eurasia distributed in the steppe and semi-desert zones from southeast Ukraine eastward to Northern China. The Demoiselle crane uses two wintering grounds in Africa and India corresponding to the European and Asian breeding parts of the range subdivided into several spatially separated breeding flocks. The first estimates of the genetic diversity and differentiation have been obtained from five of them: 1) Azov & Black Sea, 2) Caspian, 3) Volga & Ural, 4) South Siberian and 5) Eastern Asian sampled across the total breeding range in Russia using data from 10 microsatellite loci and the 1 003-bp control region of mitochondrial DNA. In total, the Demoiselle crane demonstrates high level of observed (HO = 0.638 ± 0.032) and expected (HE = 0.657 ± 0.023) hete-rozygosity and haplotype diversity (h = 0.960). Genetic dif­ferentiation among populations has shown to be weak for both the microsatellite loci (Wright’s FST = 0.052 or AMOVA estimate 0.016) and mtDNA (FST = 0.040). No evidence of significant population structuring of the Demoiselle crane has been found using the STRUCTURE analysis of multilo­cus microsatellite genotypes and the NETWORK grouping of control region haplotypes. Despite the haplotype diversity was high, the nucleotide diversity of the species was low (0.0033 ± 0.0003). Negative but non-significant Tajima’s and Fu’s tests did not suggest the recent population expansion in the Demoiselle crane evolutionary history which contrasts to other cranes of the Palearctic (the Eurasian crane Grus grus, and the Hooded crane G. monacha). These data indicate more stable conditions for the Demoiselle crane breeding groups in the steppe zone in Pleistocene as compared to boreal and subarctic breeding grounds of other crane species.

Most G-coupled receptors undergo posttranslational modifications. Among these modifications is S-palmitoylation, carried out by specialized enzymes palmitoyl transferases. Palmitoylation is the covalent attachment of a long-chain fatty acid, palmitate, to cysteine residues. It can influence receptor stability, transportation, and function. Obviously, malfunction of G-protein coupled receptors can cause various psychic disor­ders, including depression. However, no association between palmitoyl transferases and depressive-like behavior has been found hitherto. There is no informa­tion on brain structure specific features of palmitoyl transferase expression either. Here we investigate the expression of ZDHHC5, ZDHHC9, and ZDHHC21 palmi­toyl transferases in brain structures of ASC mice with genetic predisposition to depressive-like behavior in comparison with “nondepressive” CBA mice. Several brain region-specific features were detected in the immunodetection of palmitoyl transferase proteins. Western blot of the ZDHHC5 protein in the midbrain revealed two bands at 75 kDa and 55 kDa. Immuno­detection of ZDHHC21 palmitoyl transferase revealed two bands. One of them was visualized at 27 kDa in the frontal cortex and midbrain. The other, at 32 kDa in the hippocampus. Probing for ZDHHC9 also showed two bands in each of the midbrain and hippocampus, at 46 and 41 kDa. However, the expression of all investigated palmitoyl transferases in ASC mice with depressive-like behavior was almost identical to those in CBA mice. Thus, it was the first detection of brain region-specific features of the expression of investigated palmitoyl transferases. However, the study demonstrates that the genetic predisposition to depression-like behavior in ASC mice is not associated with changes in ZDHHC5, ZDHHC9, or ZDHHC21 palmitoyl transferase expression.

The significant increase in the number of people diagnosed with diabetes mellitus in recent years makes studies of this problem topical. The persistent hyperglycemia accompanying the development and course of type 1 diabetes mellitus (T1DM) can affect the func-tional and structural levels of the organization of the central nervous system. These changes may be medi­ated by metabolic aberrations. Magnetic resonance spectroscopy (MRS) is a common method of intravital detection of metabolic reactions. In this study, MRS of the hippocampus of NOD.CB17-Prkdcscid/NcrCrl mice (NODSCID) was performed 4 days after the administration of streptozotocin (STZ) to assess the effect of STZ itself, and 60 days after the administration of STZ to another group of animals to assess the effect of chronic hyperglycemia caused by the delayed ef­fect of STZ, involving the death of pancreatic β-cells. The simulation of T1DM by STZ administration is used worldwide. Nevertheless, the question remains whether there is a short-term effect of the introduc­tion of STZ at the level of hippocampal metabolites recorded by MRS. The comparison of experimental and control animal groups revealed no effect of STZ on metabolites in the hippocampus of NODSCID mice on day 4 after its administration. In contrast, another comparison of the experimental and control animals on day 60 after STZ administration showed elevated contents of alanine and taurine, and a reduced lactate content. Thus, the introduction of STZ itself does not affect the metabolism of the hippocampus, and MRS is a promising method for assessing the effect of T1DM on brain metabolism in animals.

Epigenetic mechanisms are commonly known to underlie memory formation. Presently, scientists’ attention is focused on changes in the levels of histone modifications (mainly acetylation and methylation) in the chromatin of CNS cells tested in various experimental models. Owing to their relatively simple CNSs, mollusks are among the most popular models. Our experiments were con-ducted with the mollusk Helix lucorum because its CNS had been investigated in detail and most of its neurons had been proven to participate in the formation of different behavior patterns, including the prolonged response to various stimuli. This work concerns the influence of various effectors (serotonin and FMRFamide, associated with CNS activator and inhibitory pathways, respectively) on the acetylation of H4 histone in the subesopha­geal ganglion complex and in defensive behavior command neurons of the right and left parietal ganglia (RPa3/2 and LPa3/2) in the snail. Western blot analysis showed that FMRFamide inhibited histone H4 acetylation induced by serotonin in the subesophageal complex of CNS ganglia. How­ever, serotonin and FMRFamide cooperatively enhanced the induction of histone H4 acetylation in RPa3/2 defensive behavior command neurons. No changes were found in the counterpart LPa3/2. It is a new piece of evidence for functional asym­metry in Helix. The inhibitory pathways mediated by FMRFamide not only inhibit the activatory in­tracellular processes in the entire CNS but can also enhance them, as in RPa3/2 defensive behavior command neurons.

With a view to trace the Mongol expansion in Tuvinian gene pool we studied two largest Tuvinian clans – those in which, according to data of humanities, one could expect the highest Central Asian ancestry, connected with the Mongol expansion. Thus, the results of Central Asian ancestry in these two clans component may be used as upper limit of the Mongol influence upon the Tuvinian gene pool in a whole. According to the data of 59 Y-chromosomal SNP markers, the haplogroup spectra in these Tuvinian tribal groups (Mongush, N = 64, and Oorzhak, N = 27) were similar. On average, two-thirds of their gene pools (63 %) are composed by North Eurasian haplogroups (N*, N1a2, N3a, Q) connected with autochtonous populations of modern area of Tuvans. The Central Asian haplogroups (C2, O2) composed less then fifth part (17 %) of gene pools of the clans studied. The opposite ratio was revealed in Mongols: there were 10 % North Eurasian haplogroups and 75 % Central Asian haplogroups in their gene pool. All the results derived – “genetic portraits”, the matrix of genetic distances, the dendrogram and the multidimensional scaling plot, which mirror the genetic connections between Tuvinian clans and populations of South Siberia and East Asia, demonstrated the prominent similarity of the Tuvinian gene pools with populations from and Khakassia and Altai. It could be therefore assumed that Tuvinian clans Mongush and Oorzhak originated from autochtonous people (supposedly, from the local Samoyed and Kets substrata). The minor component of Central Asian haplogroups in the gene pool of these clans allowed to suppose that Mongol expansion did not have a significant influence upon the Tuvinan gene pool at a whole.

The human primary immunodeficiency diseases (PIDs) refer to a rare heterogeneous group of single-gene inherited disorders causing malfunctions in the immune system, and thus the affected patients have a predisposition to severe life-threatening infections. The heterogeneous nature of PIDs, which involves at list 300 different genes, makes diagnosis of the disease a complex issue. Although studies revealed that six million people have a kind of PID, but due to a complex diagnosis procedure many affected individuals have not gotten a correct diagnosis. However, thanks to advancing in the DNA sequencing method and availability of sophisticated sequencers molecular characterization of genetic disorders have been revolutionized. The whole exome sequencing (WES) method can help clinicians detect Mendelian disease and other complex genetic disorders. The presented study used WES to investigate two infants with symptoms of primary immunodeficiency including hemophagocytic lymphohistio­cytosis (HLH) and severe combined immunodeficiency (SCID). It has been shown that the HLH patient had a mutation in the UNC13D gene (NM_199242.2:c.627delT), and the SCID patient had a mutation in the RAG1 gene (NM_000448.2:c.322C>G). It has been demonstrated that WES is a fast and cost-effective method facilitating genetic diagnosis in PID sufferers.