Seyed Ehsan Mousavi , Frank Grützner , Jawahar G. Patil
{"title":"Enhanced mitotic arrest and chromosome resolution for cytogenetic analysis in the eastern mosquitofish, Gambusia holbrooki","authors":"Seyed Ehsan Mousavi , Frank Grützner , Jawahar G. Patil","doi":"10.1016/j.acthis.2023.152029","DOIUrl":null,"url":null,"abstract":"<div><p><span>Maximising the number of cells arrested at metaphase and their resolution is fundamentally important for molecular cytogenetic investigations, particularly in fish, which typically yield low mitotic index and have highly condensed chromosomes. To overcome these limitations, fish were injected with a mitotic stimulator (the yeast, </span><span><em>Saccharomyces cerevisiae</em></span><span><span>) to improve the mitotic index, and the intercalating agent<span> ethidium bromide<span> to produce elongated chromosomes. Specifically, adults were injected with activated yeast and then Colcemid (0.025 µg/µl solution, 10 µl per 1 g of body weight) at 24–96 h post yeast injections, followed by </span></span></span>chromosome preparations from multiple tissues. Results showed that gill tissue had the highest number of dividing cells at 72 h post yeast exposure with no significant (</span><em>p</em><span> > 0.05) differences between the sexes. Nonetheless, sex-specific differences in the mitotic index were observed in spleen, kidney, and liver, which may be attributed to sex-specific differences in immune responses. For elongation of mitotic chromosomes, individuals (both sexes) were first injected with activated yeast and after 48 h with ethidium bromide (2 or 4 µg/ml) and Colcemid (0.05 µg/µl solution, 10 µl per 1 g of body weight). Following which, animals were sampled at three time points (1, 4 and 8 h) for chromosome preparations. The results show that the optimum elongation of metaphase chromosomes<span> of males and females was achieved by using 2 µg/ml and 4 µg/ml, respectively, for 1 h. Interestingly, the average mitotic chromosome length (μm) of males and females post-ethidium bromide exposure was significantly different (</span></span><em>p</em><span> < 0.05) for both concentrations, except at 1 h exposure for 2 µg/ml EtBr. Such differences can be attributed to overall chromosomal condensation differences between sexes. Regardless, the increased mitotic index and chromosome resolution could benefit cytogenetic studies in other fish species.</span></p></div>","PeriodicalId":6961,"journal":{"name":"Acta histochemica","volume":null,"pages":null},"PeriodicalIF":2.3000,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta histochemica","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0065128123000351","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Maximising the number of cells arrested at metaphase and their resolution is fundamentally important for molecular cytogenetic investigations, particularly in fish, which typically yield low mitotic index and have highly condensed chromosomes. To overcome these limitations, fish were injected with a mitotic stimulator (the yeast, Saccharomyces cerevisiae) to improve the mitotic index, and the intercalating agent ethidium bromide to produce elongated chromosomes. Specifically, adults were injected with activated yeast and then Colcemid (0.025 µg/µl solution, 10 µl per 1 g of body weight) at 24–96 h post yeast injections, followed by chromosome preparations from multiple tissues. Results showed that gill tissue had the highest number of dividing cells at 72 h post yeast exposure with no significant (p > 0.05) differences between the sexes. Nonetheless, sex-specific differences in the mitotic index were observed in spleen, kidney, and liver, which may be attributed to sex-specific differences in immune responses. For elongation of mitotic chromosomes, individuals (both sexes) were first injected with activated yeast and after 48 h with ethidium bromide (2 or 4 µg/ml) and Colcemid (0.05 µg/µl solution, 10 µl per 1 g of body weight). Following which, animals were sampled at three time points (1, 4 and 8 h) for chromosome preparations. The results show that the optimum elongation of metaphase chromosomes of males and females was achieved by using 2 µg/ml and 4 µg/ml, respectively, for 1 h. Interestingly, the average mitotic chromosome length (μm) of males and females post-ethidium bromide exposure was significantly different (p < 0.05) for both concentrations, except at 1 h exposure for 2 µg/ml EtBr. Such differences can be attributed to overall chromosomal condensation differences between sexes. Regardless, the increased mitotic index and chromosome resolution could benefit cytogenetic studies in other fish species.
期刊介绍:
Acta histochemica, a journal of structural biochemistry of cells and tissues, publishes original research articles, short communications, reviews, letters to the editor, meeting reports and abstracts of meetings. The aim of the journal is to provide a forum for the cytochemical and histochemical research community in the life sciences, including cell biology, biotechnology, neurobiology, immunobiology, pathology, pharmacology, botany, zoology and environmental and toxicological research. The journal focuses on new developments in cytochemistry and histochemistry and their applications. Manuscripts reporting on studies of living cells and tissues are particularly welcome. Understanding the complexity of cells and tissues, i.e. their biocomplexity and biodiversity, is a major goal of the journal and reports on this topic are especially encouraged. Original research articles, short communications and reviews that report on new developments in cytochemistry and histochemistry are welcomed, especially when molecular biology is combined with the use of advanced microscopical techniques including image analysis and cytometry. Letters to the editor should comment or interpret previously published articles in the journal to trigger scientific discussions. Meeting reports are considered to be very important publications in the journal because they are excellent opportunities to present state-of-the-art overviews of fields in research where the developments are fast and hard to follow. Authors of meeting reports should consult the editors before writing a report. The editorial policy of the editors and the editorial board is rapid publication. Once a manuscript is received by one of the editors, an editorial decision about acceptance, revision or rejection will be taken within a month. It is the aim of the publishers to have a manuscript published within three months after the manuscript has been accepted