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Abstract Adverse early life experiences are well-established risk factors for neurological disorders later in life. However, the molecular mechanisms underlying the impact of adverse experiences on neurophysiological systems throughout life remain incompletely understood. Previous studies suggest that social attachment to parents in early development are indispensable for infants to grow into healthy adults. In situations where multiple offspring are born in a single birth in common marmosets, human hand-rearing is employed to ensure the survival of the offspring in captivity. However, hand-reared marmosets often exhibit behavioral abnormalities, including abnormal vocalizations, excessive attachment to the caretaker, and aggressive behavior. In this study, comprehensive transcriptome analyses were conducted on hippocampus tissues, a neuroanatomical region sensitive to social attachment, obtained from human hand-reared (N = 6) and parent-reared male marmosets (N = 5) at distinct developmental stages. Our analyses revealed consistent alterations in a subset of genes, including those related to neurodevelopmental diseases, across different developmental stages, indicating their continuous susceptibility to the effects of early parental deprivation. These findings highlight the dynamic nature of gene expression in response to early life experiences and suggest that the impact of early parental deprivation on gene expression may vary across different stages of development.

Hereditary methemoglobinemia associated with nicotinamide adenine dinucleotidecytochrome b5 reductase (b5R) deficiency is a rare autosomal recessive disorder in animals. Recently, nonsynonymous b5R gene (CYB5R3) variants have been reported to be associated with canine and feline hereditary methemoglobinemia. However, the underlying molecular mechanisms of canine and feline methemoglobinemia caused by these nonsynonymous variants have not yet been reported. Previously, we reported a Pomeranian dog family with hereditary methemoglobinemia, carrying CYB5R3 mutation of an A>C transition at codon 194 in exon 7, replacing an isoleucine residue with leucine (p.Ile194Leu). In this study, we investigated the enzymatic and structural properties of the soluble form of wild-type and Ile194Leu canine b5Rs to characterize the effects of this missense mutation. Our results showed that the kinetic properties of the mutant enzyme were not affected by this amino acid substitution. The secondary structure of the wild-type and Ile194Leu b5Rs detected by circular dichroism showed a similar pattern. However, the mutant enzyme exhibited decreased heat stability and increased susceptibility to trypsin hydrolysis. Moreover, the thermostability and unfolding measurements indicated that the mutant enzyme was more sensitive to temperature-dependent denaturation than the wild-type b5R. We concluded from these results that unstable mutant enzyme properties with normal enzymatic activity would be associated with hereditary methemoglobinemia in the Pomeranian dog family. [ABSTRACT FROM AUTHOR]

Malignant rhabdoid tumors (MRTs) are rare and highly aggressive pediatric cancers with no standard of care. MRTs are characterized by loss of SMARCB1, which results in upregulated expression of enhancer of zeste homolog 2 (EZH2), which is responsible for the methylation of lysine 27 of histone H3 (H3K27me3), leading to the repression of gene expression. Although previous reports suggest EZH2 as an effective therapeutic target, the functions of EZH1, the other homolog of EZH, in MRT remain unknown. Here, we show that EZH1, as well as EZH2, contributes to MRT cell growth and H3K27 methylation. Depletion or selective inhibition of EZH2 led to a compensatory increase in EZH1 expression, and depletion of EZH1 enhanced the effect of EZH2 inhibition. EZH1/2 dual inhibitors suppressed MRT cell growth markedly, reflecting the reduction of H3K27me3 accumulation at one of the EZH1/2 targets, the CDKN2A locus. Dual inhibition of EZH1/2 in vivo suppressed tumor growth completely, with no significant adverse effects. These findings indicate that both EZH1 and EZH2 are potential targets for MRT therapy, and that EZH1/2 dual inhibitors may be promising therapeutic strategies for MRT.

Pluripotent stem cells (PSCs), embryonic stem cells (ESCs), and induced PSCs (iPSCs) are excellent tools for studying embryonic development in organisms and classified into naïve and primed states. ESC-derived germline chimera individuals can be produced by injecting naïve ESCs/iPSCs into preimplantation embryos, and conversion of primed human ESCs/iPSCs into a naïve state provides insights into epiblast cell features. Non-human ESCs/iPSCs are alternatives to human naïve ESCs/iPSCs, which elicit ethical issues. In this study, we used the common marmoset (Callithrix jacchus) as an animal model. Since 1996, 16 marmoset ESC lines have been established. Because most of these ESC lines are female and were derived >10 years ago, new ESCs, particularly male marmoset ESC lines, are needed. Here, we successfully established 17 novel marmoset ESC lines, including six male ESC lines from in vitro-fertilized (IVF) embryos and 12 ESC lines under feeder-free conditions. This report is the first to establish ESC lines using feeder-free conditions and IVF preimplantation blastocysts in marmosets, and these novel ESC lines could potentially facilitate future non-human primate ESC studies.