Bleomycin is a powerful chemotherapeutic drug used to treat a variety of cancers. However, individual patients vary in their responses to bleomycin. The identification of genetic differences that underlie this response variation could improve treatment outcomes by tailoring bleomycin dosages to each patient. We used the model organism Caenorhabditis elegans to identify genetic determinants of bleomycin-response differences by performing linkage mapping on recombinants derived from a cross between the laboratory strain (N2) and a wild strain (CB4856). This approach identified a small genomic region on chromosome V that underlies bleomycin-response variation. Using near-isogenic lines, and strains with CRISPR-Cas9 mediated deletions and allele replacements, we discovered that a novel nematode-specific gene (scb-1) is required for bleomycin resistance. Although the mechanism by which this gene causes variation in bleomycin responses is unknown, we suggest that a rare variant present in the CB4856 strain might cause differences in the potential stress-response function of scb-1 between the N2 and CB4856 strains, thereby leading to differences in bleomycin resistance.

The polymorphism of microphthalmia-associated transcription factor (MITF) and tyrosinase (TYR) genes have been proposed to play a vital role in coat colour genesis in mammals, but their role remains ambiguous in geese at best. Here, we cloned and sequenced 1,397 bp coding region of MITF gene and a 588 bp fragment of TYR exon 1 for polymorphism analysis among 157 domestic geese showing three types of plumage colour. We detected a total of three SNPs (c.280T>C, c.345G>A, and c.369G>A) in TYR and six haplotypes (H1-H6). Among them, haplotypes H1, H2, H3, and H5 were significantly associated with white plumage trait of Zhedong White Geese. However, only diplotype H1H1 and H3H5 were significantly associated with white plumage trait of Zhedong White Geese (pT) for MITF gene and found that genotype CT and TT were significantly associated with white plumage trait of Zhedong White Geese. Briefly, our study suggested an association between polymorphisms of TYR and MITF genes and the plumage colour trait in domestic geese.

Short tandem repeats (STRs) represent an important class of genetic variation that can contribute to phenotypic differences. Although millions of single nucleotide variants (SNVs) and short indels have been identified among wildCaenorhabditis elegansstrains, the natural diversity in STRs remains unknown. Here, we characterized the distribution of 31,991 STRs with motif lengths of 1–6 bp in the reference genome ofC. elegans. Of these STRs, 27,667 harbored polymorphisms across 540 wild strains and only 9691 polymorphic STRs (pSTRs) had complete genotype data for more than 90% of the strains. Compared with the reference genome, the pSTRs showed more contraction than expansion. We found that STRs with different motif lengths were enriched in different genomic features, among which coding regions showed the lowest STR diversity and constrained STR mutations. STR diversity also showed similar genetic divergence and selection signatures among wild strains as in previous studies using SNVs. We further identified STR variation in two mutation accumulation line panels that were derived from two wild strains and found background-dependent and fitness-dependent STR mutations. We also performed the first genome-wide association analyses between natural variation in STRs and organismal phenotypic variation among wildC. elegansstrains. Overall, our results delineate the first large-scale characterization of STR variation in wildC. elegansstrains and highlight the effects of selection on STR mutations.

The polymorphisms ofMC1Rgene play a crucial role in coat color variation in mammals; however, the relationship is still unclear in pigeons. In this study, we sequenced 741 bp fragment of theMC1Rfor 39 individuals with five plumage color patterns (gray plumage,n=12; black plumage,n=9; white plumage,n=3; spotted plumage,n=12; red plumage,n=3). A total of three single nucleotide polymorphisms (SNPs) were detected, including G199A, G225A, and A466G, which subsequently determined four haplotypes (H1–H4). Among them, H1 is the predominant haplotype. Association analysis revealed that H1 and H3 were significantly associated with the black plumage trait (P<0.05), while the H4 was significantly associated with gray plumage trait (P<0.05). Furthermore, only diplotype H1H1 was significantly associated with black and gray traits of pigeons. Collectively, our study suggested an association between genetic variation ofMC1Rand plumage color in pigeon.

Innate immunity is an essential line of defense against pathogen invasion which is gained at birth, and the mechanism involved is mainly to identify pathogen-associated molecular patterns through pattern recognition receptors. STING (stimulator of interferon genes) is a signal junction molecule that hosts the perception of viral nucleic acids and produces type I interferon response, which plays a crucial role in innate immunity. However, relatively few studies have investigated the molecular characterization, tissue distribution, and potential function of STING in chickens. In this study, we cloned the full-length cDNA of chicken STING that is composed of 1341 bp. Sequence analyses revealed that STING contains a 1140-bp open-reading frame that probably encodes a 379-amino acid protein. Multiple sequence alignments showed that the similarity of the chicken STING gene to other birds is higher than that of mammals. Real-time polymerase chain reaction (PCR) assays revealed that STING is highly expressed in the spleen, thymus and bursa of fabricious in chickens. Furthermore, we observed that STING expression was significantly upregulated both in vitro and in vivo following infection with Newcastle disease virus (NDV). STING expression was also significantly upregulated in chicken embryo fibroblasts upon stimulation with poly(I:C) or poly(dA:dT). Taken together, these findings suggest that STING plays an important role in antiviral signaling pathways in chickens.