A J Pask, J L Harry, M B Renfree, J A Marshall Graves
{"title":"Absence of SOX3 in the developing marsupial gonad is not consistent with a conserved role in mammalian sex determination.","authors":"A J Pask, J L Harry, M B Renfree, J A Marshall Graves","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Expression of Sox3 has been detected in the testes of humans and of developing and adult mice at the same time as Sox9 and Sry. The co-expression of these three related Sox genes in the mouse indifferent gonadal ridge led to the hypothesis that these three genes, encoding transcription factors with similar DNA target binding sites, may interact with each other in initiating testis differentiation. The location of SOX3 on the marsupial Dunnart X chromosome also makes it a candidate for the marsupial X-linked gene responsible for the SRY- and hormone-independent initiation of scrotum or mammary gland development. Here we show that although marsupial SOX3 is highly conserved at the genetic level and appears to have a conserved role in CNS development, its expression during sexual differentiation differs from that of mice and humans. SOX3 expression is absent from the developing marsupial genital ridge and from the scrotal and mammary primordia during the critical time of differentiation and throughout the time that SRY is expressed. The absence of expression in the developing gonad strongly suggests that SOX3 does not have a conserved role in mammalian sexual determination or differentiation.</p>","PeriodicalId":48923,"journal":{"name":"Genesis","volume":"27 4","pages":"145-52"},"PeriodicalIF":1.5,"publicationDate":"2000-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21827167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A subtractive gene expression screen suggests a role for vanin-1 in testis development in mice.","authors":"J Bowles, M Bullejos, P Koopman","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The molecular pathways leading from indifferent mammalian gonad to either testis or ovary are not well understood. A number of genes, including the Y-linked sex determining gene SRY, have been shown to play roles in sex determination or differentiation, but there are clearly many missing elements to be found. We used suppression-subtractive hybridization to construct normalized cDNA libraries enriched for male-specific or female-specific transcripts in mouse fetal gonads. We describe the strategy used to efficiently screen these libraries for candidate sex-determination and gonadogenesis genes. One gene arising from these screens is vanin-1, which encodes a protein implicated in the induction of cell migration into the thymus. We find that vanin-1 is expressed male-specifically in Sertoli cells of the developing testis and may be involved in inducing cell migration from the adjacent mesonephros, a process known to be critical for testis development. This screening approach is likely to be applicable to the isolation and study of genes involved in a variety of developmental systems.</p>","PeriodicalId":48923,"journal":{"name":"Genesis","volume":"27 3","pages":"124-35"},"PeriodicalIF":1.5,"publicationDate":"2000-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21788331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Rescue of embryonic lethality in hepatocyte growth factor/scatter factor knockout mice.","authors":"Y Uehara, C Mori, T Noda, K Shiota, N Kitamura","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>While the targeted disruption of a gene is a powerful tool for investigating the physiological functions of that gene, disruption of a gene essential for embryogenesis leads to embryonic death. Rescue of the defect(s) causing embryonic death should promote survival, thus permitting further evaluation of the roles that the gene plays later in the developmental process. Disruption of the gene for mouse hepatocyte growth factor/scatter factor (HGF/SF) leads to middle-stage embryonic lethality because of a defect in placental development. Here we report that a single injection of HGF/SF at embryonic day 9.5 (E9.5) into the amniotic cavity of HGF/SF(-/-) embryos rescued the placental defect and resulted in the survival of the embryos until term. Histological analysis suggested that HGF/SF is also required at the late stage of development for tissue organogenesis. Thus, injection of a secreted factor can be a useful method to rescue the defects causing embryonic lethality.</p>","PeriodicalId":48923,"journal":{"name":"Genesis","volume":"27 3","pages":"99-103"},"PeriodicalIF":1.5,"publicationDate":"2000-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21788408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Micro-capillary tube in situ hybridisation: a novel method for processing small individual samples.","authors":"A A Avilion, D M Bell, R Lovell-Badge","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>We have developed a strategy to individually analyse large numbers of small tissue samples by RNA in situ hybridisation. Samples of approximately 0.4 mm x 0.5 mm are processed in rectangular capillary tubes fitted with nylon mesh and glass beads using standard protocols. Eighteen samples can be assayed simultaneously without loss, and background is low. Specifically, mouse Sox2 RNA expression is examined in the chorion of extraembryonic tissue of 7.5 days post-coitum embryos. This technique works equally well for double RNA labelling and could potentially be used for antibody staining of proteins.</p>","PeriodicalId":48923,"journal":{"name":"Genesis","volume":"27 2","pages":"76-80"},"PeriodicalIF":1.5,"publicationDate":"2000-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21733074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A Yamamoto, C Kemp, D Bachiller, D Geissert, E M De Robertis
{"title":"Mouse paraxial protocadherin is expressed in trunk mesoderm and is not essential for mouse development.","authors":"A Yamamoto, C Kemp, D Bachiller, D Geissert, E M De Robertis","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Paraxial protocadherin (PAPC) is a cell adhesion molecule that marks cells undergoing convergence-extension cell movements in Xenopus and zebrafish gastrulating embryos. Here a mouse homologue (mpapc) was identified and characterized. During early- to mid-gastrulation, mpapc is expressed in the primitive streak as the trunk mesoderm undergoes morphogenetic cell movements. At head-fold stage mpapc expression becomes localized to paraxial regions in which somites are formed in the segmental plate. At later stages, mpapc displays a complex expression pattern in cerebral cortex, olfactory bulb, inferior colliculus, and in longitudinal stripes in hindbrain. To analyze the effect of the loss of PAPC function during mouse development, a null allele of the mouse papc gene was generated. Homozygous animals show no defects in their skeleton and are viable and fertile.</p>","PeriodicalId":48923,"journal":{"name":"Genesis","volume":"27 2","pages":"49-57"},"PeriodicalIF":1.5,"publicationDate":"2000-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21733165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J L Brewster, S L Martin, J Toms, D Goss, K Wang, K Zachrone, A Davis, G Carlson, L Hood, J D Coffin
{"title":"Deletion of Dad1 in mice induces an apoptosis-associated embryonic death.","authors":"J L Brewster, S L Martin, J Toms, D Goss, K Wang, K Zachrone, A Davis, G Carlson, L Hood, J D Coffin","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Dad1 is a putative anti-apoptosis gene identified in several distantly related organisms. Expression of Dad1 in transfected cells inhibits apoptosis in vitro. To determine whether Dad1 has a similar function in vivo, we used gene targeting to delete Dad1. Heterozygous adult mice (+/-) show no obvious phenotype or abnormalities, but genotype analysis of over 100 offspring from heterozygous matings detected no weanling, homozygous Dad1 null (-/-) mice. Subsequent analysis of embryos from heterozygous matings detected Dad1 null (-/-) embryos at E3.5 but no later, suggesting Dad1 is required for development beyond the late blastocyst stage. Increased levels of apoptosis were observed in cultured embryos lacking a functional copy of the gene, consistent with an anti-apoptotic role for Dad1.</p>","PeriodicalId":48923,"journal":{"name":"Genesis","volume":"26 4","pages":"271-8"},"PeriodicalIF":1.5,"publicationDate":"2000-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21599907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optimal N-ethyl-N-nitrosourea (ENU) doses for inbred mouse strains.","authors":"J S Weber, A Salinger, M J Justice","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>ENU is a powerful germline mutagen in the mouse, providing the opportunity to analyze the functions of large numbers of genes in the mammalian genome. In many mutagenesis experiments, it would be beneficial to exploit the advantages of inbred mouse strains. To perform an effective ENU mutagenesis screen using inbred mice, a dosage regimen is required to determine the optimal dose of ENU for that inbred strain, a time-consuming preliminary process. We have carried out dosage regimens for mutagenizing doses of ENU in ten inbred strains of mouse: 129X1/SvJ, 129S6/SvEv, A/J, BALB/cJ, BTBR/N, C3He/J, C3HeB/FeJ, C57BL/6J, C57BR/cdJ, and CBA/CaJ, and determined an optimal dose for each strain, defined by length of sterile period and number of males to survive treatment. Three strains: A/J, BALB/cJ and C57BL/6J, are able to tolerate high doses, up to 300 mg/kg body weight, and are highly recommended for mutagenesis studies.</p>","PeriodicalId":48923,"journal":{"name":"Genesis","volume":"26 4","pages":"230-3"},"PeriodicalIF":1.5,"publicationDate":"2000-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21599431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J A Belo, D Bachiller, E Agius, C Kemp, A C Borges, S Marques, S Piccolo, E M De Robertis
{"title":"Cerberus-like is a secreted BMP and nodal antagonist not essential for mouse development.","authors":"J A Belo, D Bachiller, E Agius, C Kemp, A C Borges, S Marques, S Piccolo, E M De Robertis","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Mouse cerberus-like (cer-l) is a member of the Cerberus/Dan family of secreted factors. As other members of this family of proteins, Cer-l functions in the extracellular space, inhibiting signaling molecules. Here we show that the neural-inducing and mesoderm-inhibiting activities of Cer-l result from specific binding to BMP and Nodal molecules, respectively. These properties resemble the ones from the related factor Xenopus Cerberus. However, Xenopus Cerberus in addition to BMP4 and Nodal also binds to and inhibits Wnt proteins. We show that Cer-l does not directly inhibit Wnt signals. A null allele of the mouse Cer-l gene was generated by targeted inactivation in ES cells. Homozygous embryos show no anterior patterning defects, are born alive, and are fertile. Since mouse Cer-l and Xenopus Cerberus differ in biochemical activities, we propose the existence of additional members of this family of inhibitors, which may compensate for the loss of cer-l.</p>","PeriodicalId":48923,"journal":{"name":"Genesis","volume":"26 4","pages":"265-70"},"PeriodicalIF":1.5,"publicationDate":"2000-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21599906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Identification of a prx1 limb enhancer.","authors":"J F Martin, E N Olson","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Mice with a loss of function of prx1, a paired-related homeobox gene formerly called Mhox, showed craniofacial defects, limb shortening, and incompletely penetrant spina bifida. To investigate the mechanisms that regulate prx1 expression, we analyzed a 2.4-kb prx1 genomic flanking region in transgenic mice. This region of the prx1 gene contains an enhancer element that directs expression of a LacZ reporter gene in limb bud mesenchyme and a subset of craniofacial mesenchyme. Deletional analysis in transgenic founders identified a necessary 530-bp core element. Comparison of this core element with human Prx1 sequence showed two highly conserved cassettes that also contained a prx recognition element. Moreover, transgene expression was diminished in posterior handplate of prx1; prx2 double mutant mice. Our data reveal that the prx1 limb enhancer is proximally located within the prx1 gene and suggest that prx1 may have an autoregulatory function in limb mesenchyme.</p>","PeriodicalId":48923,"journal":{"name":"Genesis","volume":"26 4","pages":"225-9"},"PeriodicalIF":1.5,"publicationDate":"2000-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21599430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The cerberus-related gene, Cerr1, is not essential for mouse head formation.","authors":"W Shawlot, J Min Deng, M Wakamiya, R R Behringer","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The Xenopus cerberus gene encodes a secreted factor expressed in the Spemann organizer that can cause ectopic head formation when its mRNA is injected into Xenopus embryos. In mouse, the cerberus-related gene, Cerr1, is expressed in the anterior mesendoderm that underlies the presumptive anterior neural plate and its expression is downregulated in Lim1 headless embryos. To determine whether Cerr1 is required for head formation we generated a null mutation in Cerr1 by gene targeting in mouse embryonic stem cells. We found that head formation is normal in Cerr1(-/-) embryos and we detected no obvious phenotypic defects in adult Cerr1(-/-) mice. However, in embryonic tissue layer recombination assays, Cerr1(-/-) presomitic/somitic mesoderm, unlike Cerr1-expressing wild-type presomitic/somitic mesoderm, was unable to maintain expression of the anterior neural marker gene Otx2 in ectoderm explants. These findings suggest that establishment of anterior identity in the mouse may involve the action of multiple functionally redundant factors.</p>","PeriodicalId":48923,"journal":{"name":"Genesis","volume":"26 4","pages":"253-8"},"PeriodicalIF":1.5,"publicationDate":"2000-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21599435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}