Biology subjects

Demireva, E. Y.

Publications and source records attributed to Demireva, E. Y..

3 recordsLinked to original sources

bioRxiv2023

PNLDC1 catalysis and postnatal germline function are required for piRNA trimming, LINE1 silencing, and spermatogenesis in mice

PIWI-interacting RNAs (piRNAs) play critical and conserved roles in transposon silencing and gene regulation in the animal germline. Two distinct piRNA populations are present during mouse spermatogenesis: pre-pachytene piRNAs in fetal/neonatal testes and pachytene piRNAs in adult testes. PNLDC1 is required for both pre-pachytene piRNA and pachytene piRNA 3 end maturation in multiple species. However, whether PNLDC1 is the bona fide piRNA trimmer and the physiological role of 3 trimming of two distinct piRNA populations in spermatogenesis remain unclear. Here, by inactivating Pnldc1 exonuclease activity in vitro and in mice, we reveal that PNLDC1 trimmer activity is required for both pre-pachytene piRNA and pachytene piRNA 3 end trimming and male fertility. Furthermore, conditional inactivation of Pnldc1 in postnatal germ cells causes LINE1 transposon de-repression and spermatogenic arrest in mice. This indicates that pachytene piRNA trimming, but not pre-pachytene piRNA trimming, is essential for mouse germ cell development and transposon silencing. Our findings highlight the potential of inhibiting germline piRNA trimmer activity as a potential means for male contraception.

developmental biology↗

bioRxiv2023

CRISPR-based Genome Editing of a Diurnal Rodent, Nile Grass Rat (Arvicanthis niloticus)

Diurnal and nocturnal mammals have evolved distinct pathways to optimize survival for their chronotype-specific lifestyles. Conventional rodent models, being nocturnal, may not sufficiently recapitulate the biology of diurnal humans in health and disease. Although diurnal rodents are potentially advantageous for translational research, until recently, they have not been genetically tractable. Here, we address this major limitation by demonstrating the first successful CRISPR genome editing of the Nile grass rat (Arvicanthis niloticus), a valuable diurnal rodent. We establish methods for superovulation; embryo development, manipulation, and culture; and pregnancy maintenance to guide future genome editing of this and other diurnal rodent species.

genomics↗

bioRxiv2019

Mice with GNAO1 R209H Movement Disorder Variant Display Hyperlocomotion Alleviated by Risperidone

Neurodevelopmental disorder with involuntary movements (NEDIM, OMIM: 617493) is a severe, early onset neurological condition characterized by a delay in psychomotor development, hypotonia, and hyperkinetic involuntary movements. Heterozygous de novo mutations in the GNAO1 gene cause NEDIM. Go, the gene product of GNAO1, is the alpha subunit of Go, a member of the heterotrimeric Gi/o family of G-proteins. Go is found abundantly throughout the brain but the pathophysiological mechanisms linking Go functions to clinical manifestations of GNAO1-related disorders are still poorly understood. One of the most common mutant alleles among the GNAO1 encephalopathies is the c.626G>A or p.Arg209His (R209H) mutation. We developed heterozygous knock-in Gnao1+/R209H mutant mice using CRISPR/Cas9 methodology to assess whether a mouse model could replicate aspects of the NEDIM clinical pattern. Mice carrying the R209H mutation exhibited increased locomotor activity and a modest gait abnormality at 8-12 weeks. In contrast to mice carrying other mutations in Gnao1, the Gnao1+/R209H mice did not show enhanced seizure susceptibility. Levels of protein expression in multiple brain regions were unchanged from WT mice but the nucleotide exchange rate of mutant R209H Go was 9 times faster than WT. The atypical neuroleptic risperidone has shown efficacy in a patient with the R209H mutation. It also alleviated the hyperlocomotion phenotype observed in our mouse model but suppressed locomotion in WT mice as well. In this study, we show that Gnao1+/R209H mice mirror elements of the patient phenotype and respond to an approved pharmacological agent.

neuroscience↗