共查询到19条相似文献,搜索用时 77 毫秒
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性别决定(sex determining)是生命科学的重要课题之一。性别决定包括初级性别决定(即性染色体决定性腺发育)和次级性别决定(随性腺分化,由其产生的激素诱导体细胞分化)。 相似文献
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虽然人们已经鉴定出了线虫、果蝇和哺乳动物的性别决定基因,但直到最近才首次在非哺乳类脊椎动物中发现了性别决定基因DMY.介绍了在青鳉中发现DMY基因的经过,发现DMY基因的意义和DMY基因在其他鱼类中的分布,最后对未来的研究进行了展望. 相似文献
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性别决定基因的研究进展 总被引:15,自引:4,他引:15
SRY基因在哺乳动物性别分化中起着关键作用,目前研究认为SRY仅是性别决
定过程的基因之一,其他基因如SOX基因家族、MIS、SF-1、DAX1、DSS等基因都参与了性腺分化与发育。性别决定研究取得很大进展并建立了一些假说,但仍有一些问题有待于进一步研究。
Abstract:In mammals the male sex determination switch is controlled by a single gene on the Y chromosome SRY.Apart from SRY,other genes,such as SOX gene family、MIS、SF-1、DAX1、DSS also take part in sex determination.Scientists have made great progress in research on sex determination and proposed some hypotheses.,but there are still many questions to be solved. 相似文献
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Most sexually reproducing animal species are characterized by two morphologically and behaviorally distinct sexes. The genetic, molecular and cellular processes that produce sexual dimorphisms are phylogenetically diverse, though in most cases they are thought to occur early in development. In some species, however, sexual dimorphisms are manifested after development is complete, suggesting the intriguing hypothesis that sex, more generally, might be considered a continuous trait that is influenced by both developmental and postdevelopmental processes. Here, we explore how biological sex is defined at the genetic, neuronal and behavioral levels, its effects on neuronal development and function, and how it might lead to sexually dimorphic behavioral traits in health and disease. We also propose a unifying framework for understanding neuronal and behavioral sexual dimorphisms in the context of both developmental and postdevelopmental, physiological timescales. Together, these two temporally separate processes might drive sex‐specific neuronal functions in sexually mature adults, particularly as it pertains to behavior in health and disease. 相似文献
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Lei Sheng Zengbei Feng Zhongping Hao Shumin Hou 《Current issues in molecular biology》2022,44(12):6385
Recently, it has been reported that a gene (PEN1) in Arabidopsis thaliana is highly resistant to Plutella xylostella. We screened all the homologous genes of PEN1 in Arabidopsis thaliana and found that the motif of these genes was very conserved. At present, few insect resistance genes have been identified and characterized in Brassica napus. Therefore, we screened all the homologous genes containing this motif in the Brassica napus genome and systematically analyzed the basic information, conserved domain, evolutionary relationship, chromosomal localization and expression analysis of these genes. In this study, 12 PEN1 homologous genes were identified in the Brassica napus genome, which is more than the number in Arabidopsis thaliana. These genes are unevenly distributed on the 12 chromosomes in Brassica napus. Furthermore, all the PEN1 homologous genes contained light responsiveness elements, and most of the genes contained gibberellin-responsive elements, meJA-responsive elements and abscisic-acid-responsive elements. The results will provide a theoretical basis for screening insect resistance genes from the genome of Brassica napus and analyzing the molecular mechanism of insect resistance in Brassica napus. 相似文献
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María Teresa Boquete Zulema Varela José Angel Fernández Juan Antonio Calleja Cristina Branquinho Antonina Chilà Nils Cronberg Ricardo Cruz de Carvalho Cristiana Aleixo Belén Estébanez‐Pérez Verónica Fernández‐González rés Baselga Carola Gómez‐Rodríguez Juana María González‐Mancebo Sebastien Leblond Javier Martínez‐Abaigar Nagore G. Medina Encarnación Núñez‐Olivera Jairo Patiño Rubén Retuerto Antón Vázquez‐Arias Alain Vanderpoorten Harald G. Zechmeister Jesús Ramón Aboal 《植物分类学报:英文版》2023,61(1):213-226
Unisexual bryophytes provide excellent models to study the mechanisms that regulate the frequency of sexual versusasexual reproduction in plants, and their ecological and evolutionary implications. Here, we determined sex expression, phenotypic sex ratio, and individual shoot traits in 242 populations of the cosmopolitan moss Pseudoscleropodium purum spanning its whole distributional range. We tested whether niche differentiation, sex-specific differences in shoot size, and biogeographical history explained the spatial variation of reproductive traits. We observed high levels of sex expression and predominantly female-biased populations, although both traits showed high intraspecific variation among populations. Sex expression and sex ratio were partly explained by current macroscale environmental variation, with male shoots being less frequent at the higher end of the environmental gradients defined by the current distribution of the species. Female bias in population sex ratio was significantly lower in areas recolonized after the last glacial maximum (recent populations) than in glacial refugia (long-term persistent populations). We demonstrated that reproductive trait variation in perennial unisexual mosses is partially driven by macroscale and historical environmental variation. Based on our results, we hypothesize that sexual dimorphism in environmental tolerance and vegetative growth contribute to sex ratio bias over time, constraining the chances of sexual reproduction, especially in long-term persistent populations. Further studies combining genetic analyses and population monitoring should improve our understanding of the implications of the intraspecific variation in the frequency of sexual versusasexual reproduction in bryophyte population fitness and eco-evolutionary dynamics. 相似文献
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Eva Holá Tarja Vesalainen Jakub Těšitel Sanna Laaka‐Lindberg 《Botanical journal of the Linnean Society. Linnean Society of London》2014,175(2):229-241
Scapania undulata is an aquatic dioicous liverwort growing in shallow streams in boreal to subtropical zones. We studied the expressed sex ratio, sex‐specific differences in shoot architecture and possible trade‐off between sexual and asexual reproduction in ten populations of S. undulata by surveying 100 plots in ten streams in southern Finland. The expressed sex ratio was male biased, in contrast with the sex ratio in most dioicous bryophytes. It was also highly variable between the streams, but individual plots frequently comprised shoots from only one sex. The overproduction of males might be a strategy to overcome sperm dilution and ensure fertilization over longer distances in water. No size differences between females and males were detected, but they differed in branching patterns. Evidence for a higher cost of sexual reproduction in females than males can be seen from the following: the male‐biased sex ratio; low number of sex‐expressing female shoots in female‐only plots; no co‐occurrence of gemmae and female sex organs on a single branch, and no more than one sexual branch per female shoot. In contrast, high gemma production of male and female sex‐expressing shoots indicates a minimal trade‐off between sexual and asexual reproduction. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 229–241. 相似文献
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Lu Barbalho de Macêdo Marcela dos Santos Magalhes Lucas Castanhola Dias Khelven Klay de Azevedo Lemos Ryshely Sonaly de Moura Borges Mrcia Viviane Alves Saraiva Moacir Franco de Oliveira Antnio Chaves de Assis Neto Carlos Eduardo Bezerra de Moura 《Animal Reproduction》2022,19(3)
Sex steroid hormones are critical in gonadal differentiation in turtles. The gonads are not the only organs responsible for producing these hormones during this phase. Mesonephros play an important role in steroidogenesis. The present study aimed to investigate the presence of steroidogenic cells in mesonephros of Podocnemis expansa during gonadal differentiation and to evaluate their morphology and ultrastructure. Ten embryos of P. expansa were collected from 5 nests on day 36 of incubation, during spawning period on an artificial beach. Embryos were extracted from eggs by slicing the shell and euthanized. They were dissected under a stereoscopic microscope to collect the gonad-mesonephro complex, in which were fixed and subsequently processed for light microscopy, immunohistochemistry and transmission electron microscopy analysis. During histological analysis was observed mesonephros has typical morphological structure. Immunohistochemistry showed immunoreaction to aromatase in cells of intertubular space. Confirming these findings, it was possible to observe a type of intertubular cell in several regions of mesonephro, being more predominant in region close to blood vessels, distal and proximal tubules. In ultrastructural analysis these cells were characterized by having a clear, large, and rounded nucleus with evident nucleolus and cytoplasm rich in electron-dense droplets. This study demonstrated for the first time the presence of cells with morphological, immunohistochemical and ultrastructural characteristics similar to steroid-producing cells in P. expansa mesonephrons, suggesting that this organ may contribute to gonadal differentiation in this species. 相似文献
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Gempe T Beye M 《BioEssays : news and reviews in molecular, cellular and developmental biology》2011,33(1):52-60
Animals have evolved a bewildering diversity of mechanisms to determine the two sexes. Studies of sex determination genes--their history and function--in non-model insects and Drosophila have allowed us to begin to understand the generation of sex determination diversity. One common theme from these studies is that evolved mechanisms produce activities in either males or females to control a shared gene switch that regulates sexual development. Only a few small-scale changes in existing and duplicated genes are sufficient to generate large differences in sex determination systems. This review summarises recent findings in insects, surveys evidence of how and why sex determination mechanisms can change rapidly and suggests fruitful areas of future research. 相似文献