No abstract

Mitochondrial DNA (mtDNA) encodes vital proteins and RNAs for the normal functioning of the mitochondria. Mutations in mtDNA leading to mitochondrial dysfunction are relevant to a large spectrum of diseases, including fertility disorders. Since mtDNA undergoes rather complex processes during gametogenesis and fertilization, clarification of the changes and functions of mtDNA and its essential impact on gamete quality and fertility during this process is of great significance. Thanks to the emergence and rapid development of gene editing technology, breakthroughs have been made in mitochondrial genome editing (MGE), offering great potential for the treatment of mtDNA-related diseases. In this review, we summarize the features of mitochondria and their unique genome, emphasizing their inheritance patterns; illustrate the role of mtDNA in gametogenesis and fertilization; and discuss potential therapies based on MGE as well as the outlook in this field.

Parthenogenetic embryos derive their genomes entirely from the maternal genome and lack paternal imprint patterns. Many achievements have been made in the study of genomic imprinting using human parthenogenetic embryonic stem cells (hPg-ESCs). However, due to developmental defects and ethical limits, a comprehensive understanding of parthenogenetic embryonic development is still lacking. Here, we generated parthenogenetic blastoids (hPg-EPSCs blastoids) from hPg-ESC-derived extended pluripotent stem cells (hPg-EPSCs) using our previously published two-step induction protocol. Morphology, specific marker expression and single-cell transcriptome analysis showed that hPg-EPSCs blastoids contain crucial cell lineages similar to blastoids (hBp-EPSCs blastoids) generated from human biparental EPSCs (hBp-EPSCs). Single-cell RNA-seq compared the expression of genes related to imprinting and X chromosome inactivation in hPg-EPSCs blastoids and hBp-EPSCs blastoids. In conclusion, we generated parthenogenetic blastoids, which will potentially promote the study of genomic imprinting in embryonic development and uncover the influence of parental origin bias on human development and pathological mechanisms.

Premise Polymorphic nuclear simple sequence repeat (nSSR) markers were developed for Sanguinaria canadensis (Papaveraceae), a spring ephemeral native to eastern North America. Methods and Results Based on the genome skimming data of S. canadensis, a total of 240 nSSR primer pairs were designed for 80 loci from the assembled nuclear contigs. Of these primer pairs, 19 were selected for initial validation in four populations (80 individuals). All 19 loci produced heterologous amplification. The numbers of alleles per locus ranged from one to 21; the levels of observed and expected heterozygosity per locus ranged from 0.000 to 1.000 and from 0.000 to 0.847, respectively. Transferability of the loci was tested in the related species Eomecon chionantha. Conclusions The developed nSSR markers revealed polymorphism in the four studied populations and may contribute to investigations of the genetic diversity of S. canadensis and E. chionantha.