Sensitivity of Pipistrellus Nathusii Kidney Diploid Cell Strain to Viruses of Rhabdoviridae, Reoviridae, Bunyaviridae and Paramixoviridae Families

The discovery of a significant number of viral pathogens in bat tissue samples and excrement point to a potential prominent role of chiropters in the maintenance and spread of human and animal diseases. It also indicates the potential sensitivity of bat cells to a broad spectrum of viruses. The migratory pipistrelle bat, Pipistrellus nathusii, inhabits northeastern Europe and typically migrates to the southwest. Our study revealed the sensitivity (susceptibility) of a diploid cell line, derived from the kidney of P. nathusii to several transmissible animal disease causative agents such as Epizootic hemorrhagic disease, Akabane disease, Vesicular stomatitis virus and Peste des petit ruminants. High sensitivity of the P. nathusii kidney diploid cell line to viruses from various taxonomic groups allows them to be recommend for extensive use in virological studies.

Microbial Screening Based on the Mizoroki–Heck Reaction Permits Exploration of Hydroxyhexylitaconic-Acid-Producing Fungi in Soils

Recently, we developed a unique microbial screening method based on the Mizoroki–Heck reaction for itaconic acid (IA)-producing fungi. This method revealed that 37 out of 240 fungal strains isolated from soils produce vinyl compounds, including IA. In this study, we further characterized these compounds in order to verify that the screening method permits the isolation of fungi that produce other vinyl compounds, excluding IA. HPLC analysis showed that 11 out of 37 isolated strains produced IA, similar to Aspergillus terreus S12-1. Surprisingly, the other 8 isolated strains produced two vinyl compounds with HPLC retention times different from that of IA. From these strains, the vinyl compounds of Aspergillus niger S17-5 were characterized. Mass spectrometric and NMR analyses showed that they were identical to 8-hydroxyhexylitaconic acid (8-HHIA) and 9-HHIA. This finding showed that 8-HHIA- and 9-HHIA-producing fungi, as well as IA-producing fungi, are ubiquitously found in soils. Neither 8-HHIA nor 9-HHIA showed antibacterial or anti-inflammatory activities. Interestingly, 8-HHIA and 9-HHIA showed cytotoxicity against the human cervical cancer cell line (HeLa) and human diploid cell line (MRC-5), and MRC-5 only, respectively, compared to IA at the same concentration. This study indicates that the screening method could easily discover fungi producing 8-HHIA and 9-HHIA in soils.

Highly structured homolog pairing reflects functional organization of the Drosophila genome

Trans-homolog interactions have been studied extensively in Drosophila, where homologs are paired in somatic cells and transvection is prevalent. Nevertheless, the detailed structure of pairing and its functional impact have not been thoroughly investigated. Accordingly, we generated a diploid cell line from divergent parents and applied haplotype-resolved Hi-C, showing that homologs pair with varying precision genome-wide, in addition to establishing trans-homolog domains and compartments. We also elucidate the structure of pairing with unprecedented detail, observing significant variation across the genome and revealing at least two forms of pairing: tight pairing, spanning contiguous small domains, and loose pairing, consisting of single larger domains. Strikingly, active genomic regions (A-type compartments, active chromatin, expressed genes) correlated with tight pairing, suggesting that pairing has a functional implication genome-wide. Finally, using RNAi and haplotype-resolved Hi-C, we show that disruption of pairing-promoting factors results in global changes in pairing, including the disruption of some interaction peaks.

Highly structured homolog pairing reflects functional organization of the Drosophila genome

Trans-homolog interactions encompass potent regulatory functions, which have been studied extensively in Drosophila, where homologs are paired in somatic cells and pairing-dependent gene regulation, or transvection, is well-documented. Nevertheless, the structure of pairing and whether its functional impact is genome-wide have eluded analysis. Accordingly, we generated a diploid cell line from divergent parents and applied haplotype-resolved Hi-C, discovering that homologs pair relatively precisely genome-wide in addition to establishing trans-homolog domains and compartments. We also elucidated the structure of pairing with unprecedented detail, documenting significant variation across the genome. In particular, we characterized two forms: tight pairing, consisting of contiguous small domains, and loose pairing, consisting of single larger domains. Strikingly, active genomic regions (A-type compartments, active chromatin, expressed genes) correlated with tight pairing, suggesting that pairing has a functional role genome-wide. Finally, using RNAi and haplotype-resolved Hi-C, we show that disruption of pairing-promoting factors results in global changes in pairing.One Sentence SummaryHaplotype-resolved Hi-C reveals structures of homolog pairing and global implications for gene activity in hybrid PnM cells.

Alu Evolution in Human Populations: Using the Coalescent to Estimate Effective Population Size

There are estimated to be ~1000 members of the Ya5 Alu subfamily of retroposons in humans. This Subfamily has a distribution restricted to humans, with a few copies in gorillas and chimpanzees. Fifty-seven Ya5 elements were previously cloned from a HeLaderived randomly sheared total genomic library, sequenced, and screened for polymorphism in a panel of 120 unrelated humans. Forty-four of the 57 cloned Alu repeats were monomorphic in the sample and 13 Alu repeats were dimorphic for insertion presence/absence. The observed distribution of sample frequencies of the 13 dimorphic elements is consistent with the theoretical expectation for elements ascertained in a single diploid cell line. Coalescence theory is used to compute expected total pedigree branch lengths for monomorphic and dimorphic elements, leading to an estimate of human effective population size of ~18,000 during the last one to two million years.