The genome trilogy of Anopheles stephensi, an urban malaria vector, reveals structure of a locus associated with adaptation to environmental heterogeneity

Background: Anopheles stephensi is the most menacing malaria vector to watch for in newly urbanizing parts of the world. The fitness is reported to be a direct consequence of the vector adapting to laying eggs in over-head water tanks with street-side water puddles polluted by oil and sewage. Large frequent inversions of malaria vectors are implicated in adaptation. Results: We report the assembly of a strain of An. stephensi of the type-form, collected from a construction site from Chennai (IndCh) in 2016. The genome completes the trilogy with respect to a 16 Mbp inversion (2Rb) in An. stephensi associated with adaptation to environmental heterogeneity. Comparative genome analysis revealed breakpoint structure and allowed extraction of 22,650 segregating SNPs for typing this inversion. Using whole genome sequencing of 82 individual mosquitoes, we conclude that one third of both wild and laboratory populations maintain heterozygous genotype of 2Rb. The large number of SNPs are tailored to assign inversion genotype directly from 1740 exonic SNPs 80% of which are expressed in various developmental stages. Conclusions: The genome trilogy approach accelerates study of fine structure and typing of important inversions in malaria vectors putting the genome resources for the much understudied An. stephensi, on par with the extensively studied malaria vector, Anopheles gambiae. We argue that the IndCh genome is relevant for field translation work compared to those reported earlier by showing that individuals from diverse populations cluster with IndCh pointing to significant commerce between cities, perhaps, allowing for survival of the fittest strain.

Genetic Polymorphism and Intravenous Immunoglobulin Resistance Relationship in Kawasaki Disease

Objective Kawasaki disease (KD) is an acute febrile systemic vasculitis and the most common cause of coronary artery aneurysm (CAA) in children. Intravenous immunoglobulin (IVIG) therapy is used to prevent fever and systemic inflammation. However, IVIG resistance is the most important risk factor of morbidity and mortality. It has been identified several single nucleotide polymorphisms (SNPs) related to IVIG resistance and this research aims to analyze these polymorphisms in our study population. Methods Patients diagnosed with KD (n:259) were analyzed retrospectively. Blood samples were taken from a randomized subgroup (n:97). Previously reported IVIG resistance related exonic SNPs at five different gene loci (IL16, TNFSF14, NFATC2, DERL3, SAMD9L) were evaluated by whole exome sequencing (WES). Results Between 2010–2019, 259 patients (male/female: 1,67) with KD were submitted to our clinic. CAA and IVIG resistance rates were 11.6% and 21.6%, respectively. The risk of developing CAA was significantly increased in patients with IVIG resistance (p < 0.001). As a result, IVIG resistance frequency increased in the presence of three SNPs. These are "rs11556218"(p.Asn1147Lys), "rs344560"(p.Lys214Glu), "rs12479626"(p.His446Arg), and are located in IL16, TNFSF14, NFATC2 genes, respectively. Conclusions Until now, KD-related genetic data mostly obtained from studies involving large cohorts from Northeast Asian countries. In the analysis of this largest Turkish cohort in the literature, we found that, similar with previous studies, the IL16 gene may be plays important role in the IVIG resistance mechanism.

The CYP2R1 Enzyme: Structure, Function, Enzymatic Properties and Genetic Polymorphism

Since the discovery of its role in vitamin D metabolism, significant progress has been made in the understanding of gene organisation, protein structure, catalytic function, and genetic polymorphism of cytochrome P450 2R1 (CYP2R1). Located on chromosome 11p15.2, CYP2R1 possesses five exons, unlike most other CYP isoforms that carry nine exons. CYP2R1 crystal structure displays a fold pattern typical of a CYP protein, with 12 a-helices as its structural core, and b-sheets mostly arranged on one side, and the heme buried in the interior part of the protein. Overall, CYP2R1 structure adopts a closed conformation with the B′ helix serving as a gate covering the substrate access channel, with the substrate vitamin D3 occupying a position with the side chain pointing toward the heme group. In liver, CYP2R1 25-hydroxylates vitamin D and serves as an important determinant of 25(OH)D level in the tissue and in circulation. While substrate profile has been well studied, inhibitor specificity for CYP2R1 requires further investigation. Both exonic and non-exonic single nucleotide polymorphisms (SNPs) have been reported in CYP2R1, including the CYP2R1*2 carrying Leu99Pro exchange, and a number of non-exonic SNPs with variable functional consequences in gene regulation. A non-exonic SNP, rs10741657, has its causal relationship with diseases established, including that of rickets, ovarian cancer, and multiple sclerosis. The role of other CYP2R1 SNPs in vitamin D deficiency and their causal link to other traits however remain uncertain currently and more studies are warranted to help identify possible physiological mechanisms underlying those complex traits.

Molecular characterization of cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH) associated with the erythrocyte antigens in dogs

Background N-glycolylneuraminic acid (Neu5Gc) is synthesized from its precursor N-acetylneuraminic acid (Neu5Ac) by cytidine-5′-monophospho-N acetylneuraminic acid hydroxylase (CMAH), which is encoded by the CMAH gene. Most mammals have both Neu5Gc and Neu5Ac, but humans and ferrets have only Neu5Ac because of loss-of-function mutations. Dogs and cats are polymorphic for Neu5Gc and Neu5Ac expression like cats, in which the CMAH gene is responsible for the AB Blood group system. Although the CMAH gene has been characterized in many species, not much is known about it in dogs. In this study, we cloned the dog CMAH cDNA, and performed mRNA expression analysis of this gene in several organs. We also identified single nucleotide polymorphisms (SNPs) in the CMAH gene. Results We cloned the 1737-bp open reading frame of the dog CMAH gene. This gene consists of at least 14 coding exons and codes for a polypeptide of 578 amino acids and is located on chromosome 35. The amino acid identities of dog CMAH with the corresponding sequences from cat, pig, chimpanzee, mouse, and rat were high (89 to 93%). RT-PCR analysis showed that the dog CMAH cDNA was expressed in various tissues. We identified four exonic SNPs (three synonymous and one non-synonymous), 11 intronic SNPs, and an indel in 11 dog breeds by analyzing the nucleotide sequences of the 14 exons, including the coding region of CMAH. In the genotype of the non-synonymous SNP, c.554 A > G (p.Lys185Arg), in a total of 285 dogs of seven different breeds, the allele G was widely distributed, and the allele A was the most frequent in the Shiba dogs. The dogs expressing Neu5Ac did not carry the loss-of-function deletion of CMAH found in humans and ferrets, and it remains unclear whether the point mutations influence the expression of Neu5Ac. Conclusions We characterized the canine CMAH gene at the molecular level for the first time. The results obtained in this study provide essential information that will help in understanding the molecular roles of the CMAH gene in canine erythrocyte antigens.

Whole genome analysis of Black Bengal goat from Savar Goat Farm, Bangladesh

Objectives Single nucleotide polymorphisms (SNPs) play critical roles in genetic diversity and disease. Many traits and diseases are linked with exonic SNPs that are significant for gene function, regulation or translation. This study focuses on SNPs that potentially act as the genetic basis for desirable traits in the Black Bengal Goat. This variety of goat is native to South Asia, and is identified as one of the most commercially important meat producing animals in the world. The aim of this study was to sequence the genome of Black Bengal Goats and identify SNPs that might play a significant role in determining meat quality in the organism. The study focuses on exonic SNPs for their greater likelihood of affecting the final translated protein product. Results Approximately 76,000 exonic variants were identified in the study. After filtration using a Wilcoxon test based score, the number came down to 49, 965 which were found to be distributed in 11,568 genes. The functional pathways affected by these variations included fatty acid metabolism and degradation, which are important processes that influence meat quality.

Whole genome analysis of Black Bengal goat from Savar Goat Farm, Bangladesh

Objectives: Single Nucleotide Polymorphisms (SNPs) play critical roles in genetic diversity and disease. Many traits and diseases are linked with exonic SNPs that are significant for gene function, regulation or translation. This study focuses on SNPs that potentially act as the genetic basis for desirable traits in the Black Bengal Goat. This variety of goat is native to South Asia, and is identified as one of the most commercially important meat producing animals in the world. The aim of this study was to sequence the genome of Black Bengal Goats and identify SNPs that might play a significant role in determining meat quality in the organism. The study focuses on exonic SNPs for their greater likelihood of affecting the final translated protein product. Results: Approximately 76,000 exonic variants were identified in the study. After filtration using a Wilcoxon test based score, the number came down to 49, 965 which were found to be distributed in 11,568 genes. The functional pathways affected by these variations included fatty acid metabolism and degradation, which are important processes that influence meat quality.

Whole genome analysis of Black Bengal goat from Savar Goat Farm, Bangladesh

Objectives: Single Nucleotide Polymorphisms (SNPs) play critical roles in genetic diversity and disease. Many traits and diseases are linked with exonic SNPs that are significant for gene function, regulation or translation. This study focuses on SNPs that potentially act as the genetic basis for desirable traits in the Black Bengal Goat. This variety of goat is native to South Asia, and is identified as one of the most commercially important meat producing animals in the world. The aim of this study was to sequence the genome of Black Bengal Goats and identify SNPs that might play a significant role in determining meat quality in the organism. The study focuses on exonic SNPs for their greater likelihood of affecting the final translated protein product. Results: Approximately 76,000 exonic variants were identified in the study. After filtration using a Wilcoxon test based score, the number came down to 49, 965 which were found to be distributed in 11,568 genes. The functional pathways affected by these variations included fatty acid metabolism and degradation, which are important processes that influence meat quality.

Whole genome analysis of Black Bengal goat from Savar Goat Farm, Bangladesh

Objectives Single Nucleotide Polymorphisms (SNPs) play critical roles in genetic diversity and disease. Many traits and diseases are linked with exonic SNPs that are significant for gene function, regulation or translation. This study focuses on SNPs that potentially act as the genetic basis for desirable traits in the Black Bengal Goat. This variety of goat native to South Asia, and is identified as one of the most commercially important meat producing animals in the world. The aim of this study was to sequence the genome of Black Bengal Goats and identify SNPs that might play a significant role in determining meat quality in the organism. The study focuses on exonic SNPs for their greater likelihood of affecting the final translated protein product. The genes were also filtered according to their functional relevance to meat quality. The study is based on a single observation. Results Approximately 76,000 exonic variants were identified in the study. After filtration using a Wilcoxon test based score, the number came down to 49, 965 which were found to be distributed in 11,568 genes. The functional pathways affected by these variations included fatty acid metabolism and degradation, which are important processes that influence meat quality.

Complete RHD next-generation sequencing: establishment of reference RHD alleles

The Rh blood group system (ISBT004) is the second most important blood group after ABO and is the most polymorphic one, with 55 antigens encoded by 2 genes, RHD and RHCE. This research uses next-generation sequencing (NGS) to sequence the complete RHD gene by amplifying the whole gene using overlapping long-range polymerase chain reaction (LR-PCR) amplicons. The aim was to study different RHD alleles present in the population to establish reference RHD allele sequences by using the analysis of intronic single-nucleotide polymorphisms (SNPs) and their correlation to a specific Rh haplotype. Genomic DNA samples (n = 69) from blood donors of different serologically predicted genotypes including R1R1 (DCe/DCe), R2R2 (DcE/DcE), R1R2 (DCe/DcE), R2RZ (DcE/DCE), R1r (DCe/dce), R2r (DcE/dce), and R0r (Dce/dce) were sequenced and data were then mapped to the human genome reference sequence hg38. We focused on the analysis of hemizygous samples, as these by definition will only have a single copy of RHD. For the 69 samples sequenced, different exonic SNPs were detected that correlate with known variants. Multiple intronic SNPs were found in all samples: 21 intronic SNPs were present in all samples indicating their specificity to the RHD*DAU0 (RHD*10.00) haplotype which the hg38 reference sequence encodes. Twenty-three intronic SNPs were found to be R2 haplotype specific, and 15 were linked to R1, R0, and RZ haplotypes. In conclusion, intronic SNPs may represent a novel diagnostic approach to investigate known and novel variants of the RHD and RHCE genes, while being a useful approach to establish reference RHD allele sequences.