ENVIRONMENTAL CONTAMINANTS AND SPERM Y:X CHROMOSOME RATIO. Impact of androgen- and dioxin-related effects in vivo and in vitro.
During the last decades, there has been concern that the environmental contaminants, such as POPs, may contribute to sex ratio changes in offspring of exposed populations. Accidental exposure to TCDD has been shown to be associated with fewer sons in men who were exposed in adolescence or earlier in...
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Department of Clinical Sciences, Lund University
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ftulundlup:oai:lup.lub.lu.se:6eeade58-932f-42f6-826e-9f71cd5a2efb 2023-05-15T16:30:35+02:00 ENVIRONMENTAL CONTAMINANTS AND SPERM Y:X CHROMOSOME RATIO. Impact of androgen- and dioxin-related effects in vivo and in vitro. Tiido, Tarmo 2007 https://lup.lub.lu.se/record/548542 eng eng Department of Clinical Sciences, Lund University https://lup.lub.lu.se/record/548542 urn:isbn:978-91-85559-51-0 Lund University Faculty of Medicine Doctoral Dissertation Series; 2007:73 (2007) ISSN: 1652-8220 Obstetrics Gynecology and Reproductive Medicine AR polymorphisms Sertoli cell endocrine disruption inhibitory cross-talk Biomedicinska vetenskaper Biomedical sciences AHR sperm Y:X chromosome ratio sex ratio POPs TCDD thesis/doccomp info:eu-repo/semantics/doctoralThesis text 2007 ftulundlup 2023-02-01T23:28:13Z During the last decades, there has been concern that the environmental contaminants, such as POPs, may contribute to sex ratio changes in offspring of exposed populations. Accidental exposure to TCDD has been shown to be associated with fewer sons in men who were exposed in adolescence or earlier in life. However, it is not known whether POPs could change the proportion of X- and Y-sperm. A variety of studies have indicated that POPs possess sex steroid-mimicking actions and/or AHR binding affinity. The aim of this thesis was to examine whether 1) the exposure to the POPs affects sperm Y:X ratio; 2) the endocrine disrupting action of POPs, in relation to observed changes in sperm sex chromosome ratio, may be modulated by genes involved in androgen and dioxin-mediated pathways; and 3) the functional interaction between AHR and the AR, which may play a part in regulation of sperm Y:X ratio, occurs in cultured Sertoli cells. The current study indicates that exposure to POPs may be involved in changing the proportion of Y-sperm. However, these findings were subject to modification, most likely due to varying exposure profiles and exposure levels, as indicated by diverging serum concentrations of CB-153 and p,p´-DDE in different cohorts (Sweden, Greenland, Warsaw and Kharkiv) studied. Moreover, our findings lend support to the notion that polymorphisms in genes involved in androgen and dioxin-related pathways may predispose to augmented effects of POPs in increasing the sperm Y:X ratio. Thus, p,p´-DDE levels were associated with Y-sperm proportion in Swedish fishermen carrying <22 CAG repeats in the AR and the AHRR P185A G-allele, but not in those missing one or both of these variants. We obtained, however, no evidence unambiguously demonstrating the mechanistic action of TCDD in interfering with androgen-dependent Pem reporter gene transcription in the SK11 Sertoli cells. A larger series of experiments or another study design may be required before any definitive conclusions can be drawn regarding the ... Doctoral or Postdoctoral Thesis Greenland Lund University Publications (LUP) Greenland |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Obstetrics Gynecology and Reproductive Medicine AR polymorphisms Sertoli cell endocrine disruption inhibitory cross-talk Biomedicinska vetenskaper Biomedical sciences AHR sperm Y:X chromosome ratio sex ratio POPs TCDD |
spellingShingle |
Obstetrics Gynecology and Reproductive Medicine AR polymorphisms Sertoli cell endocrine disruption inhibitory cross-talk Biomedicinska vetenskaper Biomedical sciences AHR sperm Y:X chromosome ratio sex ratio POPs TCDD Tiido, Tarmo ENVIRONMENTAL CONTAMINANTS AND SPERM Y:X CHROMOSOME RATIO. Impact of androgen- and dioxin-related effects in vivo and in vitro. |
topic_facet |
Obstetrics Gynecology and Reproductive Medicine AR polymorphisms Sertoli cell endocrine disruption inhibitory cross-talk Biomedicinska vetenskaper Biomedical sciences AHR sperm Y:X chromosome ratio sex ratio POPs TCDD |
description |
During the last decades, there has been concern that the environmental contaminants, such as POPs, may contribute to sex ratio changes in offspring of exposed populations. Accidental exposure to TCDD has been shown to be associated with fewer sons in men who were exposed in adolescence or earlier in life. However, it is not known whether POPs could change the proportion of X- and Y-sperm. A variety of studies have indicated that POPs possess sex steroid-mimicking actions and/or AHR binding affinity. The aim of this thesis was to examine whether 1) the exposure to the POPs affects sperm Y:X ratio; 2) the endocrine disrupting action of POPs, in relation to observed changes in sperm sex chromosome ratio, may be modulated by genes involved in androgen and dioxin-mediated pathways; and 3) the functional interaction between AHR and the AR, which may play a part in regulation of sperm Y:X ratio, occurs in cultured Sertoli cells. The current study indicates that exposure to POPs may be involved in changing the proportion of Y-sperm. However, these findings were subject to modification, most likely due to varying exposure profiles and exposure levels, as indicated by diverging serum concentrations of CB-153 and p,p´-DDE in different cohorts (Sweden, Greenland, Warsaw and Kharkiv) studied. Moreover, our findings lend support to the notion that polymorphisms in genes involved in androgen and dioxin-related pathways may predispose to augmented effects of POPs in increasing the sperm Y:X ratio. Thus, p,p´-DDE levels were associated with Y-sperm proportion in Swedish fishermen carrying <22 CAG repeats in the AR and the AHRR P185A G-allele, but not in those missing one or both of these variants. We obtained, however, no evidence unambiguously demonstrating the mechanistic action of TCDD in interfering with androgen-dependent Pem reporter gene transcription in the SK11 Sertoli cells. A larger series of experiments or another study design may be required before any definitive conclusions can be drawn regarding the ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Tiido, Tarmo |
author_facet |
Tiido, Tarmo |
author_sort |
Tiido, Tarmo |
title |
ENVIRONMENTAL CONTAMINANTS AND SPERM Y:X CHROMOSOME RATIO. Impact of androgen- and dioxin-related effects in vivo and in vitro. |
title_short |
ENVIRONMENTAL CONTAMINANTS AND SPERM Y:X CHROMOSOME RATIO. Impact of androgen- and dioxin-related effects in vivo and in vitro. |
title_full |
ENVIRONMENTAL CONTAMINANTS AND SPERM Y:X CHROMOSOME RATIO. Impact of androgen- and dioxin-related effects in vivo and in vitro. |
title_fullStr |
ENVIRONMENTAL CONTAMINANTS AND SPERM Y:X CHROMOSOME RATIO. Impact of androgen- and dioxin-related effects in vivo and in vitro. |
title_full_unstemmed |
ENVIRONMENTAL CONTAMINANTS AND SPERM Y:X CHROMOSOME RATIO. Impact of androgen- and dioxin-related effects in vivo and in vitro. |
title_sort |
environmental contaminants and sperm y:x chromosome ratio. impact of androgen- and dioxin-related effects in vivo and in vitro. |
publisher |
Department of Clinical Sciences, Lund University |
publishDate |
2007 |
url |
https://lup.lub.lu.se/record/548542 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Lund University Faculty of Medicine Doctoral Dissertation Series; 2007:73 (2007) ISSN: 1652-8220 |
op_relation |
https://lup.lub.lu.se/record/548542 urn:isbn:978-91-85559-51-0 |
_version_ |
1766020324171710464 |