著者

Hirokatsu Saito Kentaro Tanemura Yusuke Furukawa Takahiro Sasaki Jun Kanno Satoshi Kitajima

出版者

The Japanese Society of Toxicology

雑誌

The Journal of Toxicological Sciences (ISSN:03881350)

巻号頁・発行日

vol.48, no.4, pp.203-210, 2023 (Released:2023-04-03)

参考文献数

32

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Acetamiprid (ACE), a neonicotinoid chemical, is widely used as a pesticide due to its rapid insecticidal activity. Although neonicotinoids exert very low toxicity in mammals, the effects of early exposure to neonicotinoids on the adult central nervous system are poorly understood. This study investigated the effects of ACE exposure in early life on brain function in adult mice. We exposed male C57BL/6N mice to ACE (10 mg/kg) orally when they were two (postnatal lactation) or 11 weeks old (adult). We examined the effects of ACE on the central nervous system using the mouse behavioral test battery, consisting of the open field test, light/dark transition test, elevated plus-maze test, contextual/cued fear conditioning test, and pre-pulse inhibition test at 12–13 weeks old. In the mouse behavioral test battery, learning memory abnormalities were detected in the mature treatment group. In addition, learning memory and emotional abnormalities were detected in the postnatal lactation treatment group. These results suggest that the behavioral effects of postnatal lactation treatment with ACE were qualitatively different from the behavioral abnormalities in the mature treatment group.

著者

Shiro YAMASHITA Yuhei KOGASAKA Yuuki HIRADATE Kentaro TANEMURA Yutaka SENDAI

出版者

THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2019-088, (Released:2019-11-24)

被引用文献数

9

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Gene-modified animals, including pigs, can be generated efficiently by introducing CRISPR associated protein 9 (CRISPR/Cas9) into zygotes. However, in many cases, these zygotes tend to become mosaic mutants with various different mutant cell types, making it difficult to analyze the phenotype of gene-modified founder animals. To reduce the mosaic mutations, we introduced three-prime repair exonuclease 2 (Trex2), an exonuclease that improves gene editing efficiency, into porcine zygotes along with CRISPR/Cas9 via electroporation. Although the rate of porcine blastocyst formation decreased due to electroporation (25.9 ± 4.6% vs. 41.2 ± 2.0%), co-delivery of murine Trex2 (mTrex2) mRNA with CRISPR/Cas9 did not affect it any further (25.9 ± 4.6% vs. 31.0 ± 4.6%). In addition, there was no significant difference in the diameter of blastocysts carrying CRISPR/Cas9 (164.7 ± 10.2 μm), and those with CRISPR/Cas9 + mTrex2 (151.9 ± 5.1 μm) as compared to those from the control group (178.9 ± 9.0 μm). These results revealed that mTrex2 did not affect the development of pre-implantation embryo. We also found bi-allelic, as well as mono-allelic, non-mosaic homozygous mutations in the blastocysts. Most importantly, co-delivery of mTrex2 with CRISPR/Cas9 increased non-mosaic mutant blastocysts (29.3 ± 4.5%) and reduced mosaic mutant blastocysts (70.7 ± 4.5%) as compared to CRISPR/Cas9 alone (5.6 ± 6.4% and92.6 ± 8.6%, respectively). These data suggest that the co-delivery of CRISPR/Cas9 and mTrex2 is a useful method to suppress mosaic mutation.

著者

Kosuke OTAKA Yuuki HIRADATE Norio KOBAYASHI Yoshiki SHIRAKATA Kentaro TANEMURA

出版者

日本繁殖生物学会

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2015-013, (Released:2015-06-14)

被引用文献数

3

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During mammalian spermatogenesis, spermatogenic cells undergo mitotic division and are subsequently divided into haploid spermatids by meiotic division, but the dynamics of sex chromosomes during spermatogenesis are unclear in vivo. To gain insight into the distribution of sex chromosomes in the testis, we examined the localization of sex chromosomes before and after meiosis in mouse testis sections. Here, we developed a method of fluorescence in situ hybridization (FISH) using specific probes for the X and Y chromosomes to obtain their positional information in histological testis sections. FISH analysis revealed the sex chromosomal position during spermatogenesis in each stage of seminiferous epithelia and in each spermatogenic cell. In the spermatogonia and leptotene spermatocytes, sex chromosomes were distantly positioned in the cell. In the zygotene and pachytene spermatocytes at prophase I, X and Y chromosomes had a random distribution. After meiosis, the X and Y spermatids were random in every seminiferous epithelium. We also detected aneuploidy of sex chromosomes in spermatogenic cells using our developed FISH analysis. Our results provide further insight into the distribution of sex chromosomes during spermatogenesis, which could help to elucidate a specific difference between X and Y spermatids and sex chromosome-specific behavior.

著者

Ayano Hasegawa Takahiro Sasaki Jahidul Islam Takashi Tominaga Tomonori Nochi Kenshiro Hara Kentaro Tanemura

出版者

The Japanese Society of Toxicology

雑誌

The Journal of Toxicological Sciences (ISSN:03881350)

巻号頁・発行日

vol.48, no.3, pp.149-159, 2023 (Released:2023-03-01)

参考文献数

32

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Reportedly, antibiotics, which are frequently prescribed in children, have long-term effects owing to gut microbiota dysregulation. Tosufloxacin tosilate hydrate (TFLX) is the first orally administered new quinolone with high efficacy and broad-spectrum action approved as an antibacterial agent for pediatric use in Japan. However, studies on the effects of its early-stage administration are limited. Therefore, we aimed to analyze the later effects of its developmental administration by monitoring growth rate, neurobehavior, and gut microbiota in mice. The TFLX was administered via drinking water at a dose of up to 300 mg/kg for two consecutive weeks during the developmental period (4–6 weeks of age) or adulthood (8–10 weeks of age). Thereafter, the body weights of the mice were measured weekly to monitor growth rate. Behavioral tests were also conducted on 11–12-week-old mice to examine the neurobehavioral effects of the treatment. Further, to examine the effects of the treatment on microbiota, fecal samples were collected from the rectum of mice dissected at 12 weeks of age, and 16s rRNA analysis was conducted. Our results showed increased body weights after TFLX administration, without any long-term effects. Behavioral analysis suggested alterations in anxiety-like behaviors and memory recall dysregulation, and gut microbiota analysis revealed significant differences in bacterial composition. These findings indicated that TFLX administration during the developmental period affects mice growth rate, neurobehavior, and gut microbiota structure. This is the first study to report that TFLX is potentially associated with the risk of long effects.